阅读说明：本技术 变流器的水冷系统及其控制方法 (Water cooling system of converter and control method thereof ) 是由 王幸智 王雄 李彦涌 黄南 范伟 陈明翊 杨林 彭凯 廖军 丁云 于 2018-09-07 设计创作，主要内容包括：本发明属于热管理技术领域,具体公开了一种用于变流器的水冷系统及其控制方法。其中,水冷系统包括：膨胀箱、泵、热交换器和散热器以构成冷却回路；以及控制器,耦接至泵和热交换器,控制器配置为：确定功率器件的实时热损耗功率,基于实时热损耗功率确定散热器热阻和热交换器热阻,基于散热器热阻确定冷却液流量,基于热交换器热阻和冷却液流量确定散热器的风机的空气流量,基于冷却液流量确定泵的工作频率,基于空气流量确定风机的工作频率,以及控制泵和风机分别以所确定的工作频率运行。本发明可以使变流器的功率器件稳定地保持在所希望的目标温度,从而提高牵引变流器特别是电力电子器件的可靠性和寿命,并降低水冷系统能耗。(The invention belongs to the technical field of heat management, and particularly discloses a water cooling system for a converter and a control method thereof. Wherein, water cooling system includes: the expansion tank, the pump, the heat exchanger and the radiator form a cooling loop; and a controller coupled to the pump and the heat exchanger, the controller configured to: the method comprises the steps of determining real-time heat loss power of a power device, determining heat radiator resistance and heat exchanger resistance based on the real-time heat loss power, determining cooling liquid flow based on the heat radiator resistance, determining air flow of a fan of a heat radiator based on the heat exchanger resistance and the cooling liquid flow, determining working frequency of a pump based on the cooling liquid flow, determining working frequency of the fan based on the air flow, and controlling the pump and the fan to operate at the determined working frequencies respectively. The invention can stably keep the power device of the converter at the expected target temperature, thereby improving the reliability and the service life of the traction converter, particularly a power electronic device, and reducing the energy consumption of a water cooling system.)

1. A water cooling system for a converter for cooling power devices performing electric power conversion in the converter, the water cooling system comprising:

the expansion tank, the pump, the heat exchanger and the radiator form a cooling loop; and

a controller coupled to the pump and the heat exchanger, the controller configured to:

determining real-time heat dissipation power Q of the power device,

determining a heat sink thermal resistance R based on the real-time heat loss power Q_s-wAnd heat exchanger thermal resistance R_w-a，

Based on the heat resistance R of the radiator_s-wDetermining coolant flow V_w，

Based on the heat exchanger thermal resistance R_w-aAnd the flow rate V of the cooling liquid_wDetermining the air flow V of the fan of the heat exchanger_a，

Based on the coolant flow V_wDetermining the operating frequency f of the pump_w，

Based on the air flow V_aDetermining the operating frequency f of the fan_aAnd an

And controlling the pump and the fan to respectively operate at the determined working frequency.

2. The water cooling system of claim 1, wherein the controller is further configured to determine the real-time heat rejection power Q based on real-time operating conditions of the converter.

3. Water cooling system according to claim 1, characterised in that a temperature sensor is provided in the cooling circuit for detecting the water temperature T_wThe heat exchanger is provided with a temperature sensor for acquiring real-time air temperature T of the air inlet of the fan_a，

The controller is further coupled to each temperature sensor, the controller further configured to:

based on the real-time heat loss power Q and the water temperature T_wAnd the temperature T of the table top of the radiator_sCalculating the heat sink thermal resistance R_s-wWherein R is_s-w＝(T_s-T_w)/Q，

Based on the real-time heat loss power Q and the water temperature T_wAnd said real-time air temperature T_aCalculating the heat exchanger thermal resistance R_w-aWherein R is_w-a＝(T_w-T_a)/Q，

Based on the heat resistance R of the radiator_s-wCalculating the coolant flow V_wWherein R is_s-w＝a·V_w ^bA, b are empirical constants, and

based on the heat exchanger thermal resistance R_w-aAnd the flow rate V of the cooling liquid_wDetermining the air flow V of the fan of the heat exchanger_aWherein R is_w-a＝k·V_w ^x·V_a ^yK, x, y are empirical constants.

4. The water cooling system of claim 3, wherein the controller is further configured to:

a target temperature T based on the power device_jAnd calculating the table temperature T of the radiator by the real-time heat loss power Q_sWherein T is_s＝T_j–Q·(R_j-c+R_TLM)，R_j-cIs the device junction thermal resistance, R_TIMIs the interface thermal resistance.

5. The water cooling system of claim 1, wherein the controller is further configured to base the coolant flow rate V on_wLooking up a pump operating frequency-flow correspondence table to determine the operating frequency f_w。

6. The water cooling system of claim 1, wherein the controller is further configured to determine the air flow rate V based on_aSearching a fan working frequency-flow correspondence table to determine the working frequency f_a。

7. The water cooling system of claim 1, wherein the pump comprises a stepless variable frequency speed regulating water pump and the fan is a stepless variable frequency speed regulating fan.

8. A control method for a water cooling system of a converter is used for cooling power devices which perform electric power conversion in the converter, and the water cooling system comprises an expansion tank, a pump, a heat exchanger and a radiator to form a cooling loop; the control method comprises the following steps:

determining real-time heat loss power Q of the power device;

determining a heat sink thermal resistance R based on the real-time heat loss power Q_s-wAnd heat exchanger thermal resistance R_w-a；

Based on the heat resistance R of the radiator_s-wDetermining coolant flow V_w；

Based on the heat exchanger thermal resistance R_w-aAnd the flow rate V of the cooling liquid_wDetermining the air flow V of the fan of the heat exchanger_a；

Based on the coolant flow V_wDetermining the operating frequency f of the pump_w；

Based on the air flow V_aDetermining the operating frequency f of the fan_a(ii) a And

and controlling the pump and the fan to respectively operate at the determined working frequency.

9. The control method of claim 8, wherein said determining the real-time heat loss power Q comprises:

and determining the real-time heat loss power Q based on the real-time operation condition of the converter.

10. The control method according to claim 8,

the determined heat sink thermal resistance R_s-wIncluding based on said real-time heat loss power Q, said water temperature T_wAnd the temperature T of the table top of the radiator_sCalculating the heat sink thermal resistance R_s-wWherein R is_s-w＝(T_s-T_w)/Q，

The determined heat exchanger thermal resistance R_w-aIncluding based on said real-time heat loss power Q, said water temperature T_wAnd said real-time air temperature T_aCalculating the heat exchanger thermal resistance R_w-aWherein R is_w-a＝(T_w-T_a)/Q，

Said determined coolant flow rate V_wIncluding based on the heat sink thermal resistance R_s-wCalculating the coolant flow V_wWherein R is_s-w＝a·V_w ^bA, b are empirical constants, and

the determined air flow V_aIncluding based on the heat exchanger thermal resistance R_w-aAnd the flow rate V of the cooling liquid_wDetermining the air flow V of the fan of the heat exchanger_aWherein R is_w-a＝k·V_w ^x·V_a ^yK, x, y are empirical constants.

11. The control method according to claim 10, further comprising:

a target temperature T based on the power device_jAnd calculating the table temperature T of the radiator by the real-time heat loss power Q_sWherein T is_s＝T_j–Q·(R_j-c+R_TLM)，R_j-cIs the device junction thermal resistance, R_TIMIs the interface thermal resistance.

12. Control method according to claim 8, characterized in that said determined operating frequency f_wBased on the coolant flow V_wLooking up a pump operating frequency-flow correspondence table to determine the operating frequency f_w。

13. Control method according to claim 8, characterized in that said determined operating frequency f_aIncluding based on said air flow V_aSearching a fan working frequency-flow correspondence table to determine the working frequency f_a。

14. A computer arrangement comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the steps of the method according to any of claims 8-13 are implemented when the computer program is executed by the processor.

15. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 8-13.

Technical Field

The invention relates to the technical field of heat management, in particular to a water cooling system for a converter and a control method thereof.

Background

The traction converter is an important component of an electric system of a high-power alternating-current transmission locomotive. The electric power conversion of the traction converter is carried out by adopting power electronic devices. With the development of the locomotive traction converter towards miniaturization and light weight, the power loss of the whole device is also increased sharply, and the problem of heat dissipation is increasingly prominent. The cooling technology applied to the locomotive traction converter mainly comprises the following steps: air cooling technology, oil cooling technology, heat pipe cooling technology and water cooling technology. Since water has a heat capacity several thousand times that of air, water cooling technology is considered to be a more efficient cooling means than air cooling.

Fig. 1 shows a schematic diagram of a conventional water cooling system. As shown in the figure, the pump body sends the cooling medium in the expansion tank into the heat exchanger outside the converter cabinet body, the cooling medium is cooled by the heat exchanger and then is communicated to the liquid cooling device to take away the heat generated by the power devices of the main converter, such as the pulse rectification unit and the inversion unit, when working, so as to achieve the purpose of cooling, and then the cooling medium flows back into the expansion tank, so that the cooling medium flows circularly.

Generally, the pump and the fan are both fixed-frequency and always work in a rated state, so that the cooling air quantity generated by the fan is always fixed, and the flow in the water cooling circulation is also fixed and unchanged. However, the external working condition of the traction converter is changed drastically all the time, the corresponding operating power is not changed continuously, and the generated heat loss power is changed all the time.

In this way, on the one hand, as the ambient temperature and the power of the traction converter vary drastically, the temperature of the liquid in the water-cooling circulation system and the temperature of the radiator surface also vary drastically, reducing the reliability and lifetime of the traction converter, in particular of the power electronics. On the other hand, in order to operate the traction converter at a safe temperature as much as possible, the pump and the fan are often operated at a high frequency, which consumes a lot of energy.

Accordingly, there is a need in the art for an improved water cooling system and method for controlling the same to stably maintain the power devices of the inverter at a desired target temperature.

Disclosure of Invention

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

In order to stably maintain a desired target temperature of power devices of a converter, the present invention provides a water cooling system for a converter for cooling power devices performing electric power conversion in the converter, the water cooling system may include:

the expansion tank, the pump, the heat exchanger and the radiator form a cooling loop; and

a controller coupled to the pump and the heat exchanger, the controller configured to:

determining real-time heat loss power Q of the power device,

determining heat sink thermal resistance R based on real-time heat loss power Q_s-wAnd heat exchanger thermal resistance R_w-a，

Based on heat resistance R of radiator_s-wDetermining coolant flow V_w，

Based on heat exchanger thermal resistance R_w-aAnd coolant flow rate V_wDetermining the air flow V of a fan of a heat exchanger_a，

Based on coolant flow V_wDetermining the operating frequency f of a pump_w，

Based on air flow V_aDetermining the operating frequency f of a fan_aAnd an

And controlling the pump and the fan to respectively operate at the determined working frequency.

Preferably, in the water cooling system for the converter provided by the invention, the controller may be further configured to determine the real-time heat loss power Q based on the real-time operation condition of the converter.

Optionally, in the water cooling system for the converter provided by the invention, a temperature sensor may also be arranged in the cooling loop for collecting the water temperature T_wThe heat exchanger is provided with a temperature sensor for acquiring the real-time air temperature T of the air inlet of the fan_a，

The controller is further coupled to each temperature sensor, and the controller may also be further configured to:

based on real-time heat loss power Q and water temperature T_wAnd the temperature T of the table top of the radiator_sCalculating heat radiator thermal resistance R_s-wWherein R is_s-w＝(T_s-T_w)/Q，

Based on real-time heat loss power Q and water temperature T_wAnd real time air temperature T_aCalculating Heat exchanger thermal resistance R_w-aWherein R is_w-a＝(T_w-T_a)/Q，

Based on heat resistance R of radiator_s-wCalculating the flow rate V of the cooling liquid_wWherein R is_s-w＝a·V_w ^bA, b are empirical constants, and

based on heat exchanger thermal resistance R_w-aAnd coolant flow rate V_wDetermining the air flow V of a fan of a heat exchanger_aWherein R is_w-a＝k·V_w ^x·V_a ^yK, x, y are empirical constants.

Preferably, in the water cooling system for the converter provided by the present invention, the controller may be further configured to:

target temperature T based on power device_jCalculating the table temperature T of the radiator with real-time heat loss power Q_sWherein T is_s＝T_j–Q·(R_j-c+R_TLM)，R_j-cIs the device junction thermal resistance, R_TIMIs the interface thermal resistance.

Optionally, in the water cooling system for the converter provided by the invention, the controller may be further configured to control the flow rate V of the cooling liquid based on the measured flow rate V_wSearching the water pump working frequency-flow corresponding table to determine the working frequency f_w。

Optionally, in the water cooling system for the converter provided by the invention, the controller may be further configured to control the flow rate V based on the air flow_aSearching fan working frequency-flow corresponding table to determine working frequency f_a。

Optionally, in the water cooling system for the converter provided by the invention, the pump may include a stepless variable frequency speed control water pump, and the fan may be a stepless variable frequency speed control fan.

According to another aspect of the present invention, there is also provided a control method for a water cooling system of a converter for cooling power devices performing electric power conversion in the converter, wherein the water cooling system may include an expansion tank, a pump, a heat exchanger, and a radiator to constitute a cooling circuit; the control method may include:

determining real-time heat loss power Q of the power device;

determining heat sink thermal resistance R based on real-time heat loss power Q_s-wAnd heat exchanger thermal resistance R_w-a；

Based on heat resistance R of radiator_s-wDetermining coolant flow V_w；

Based on heat exchanger thermal resistance R_w-aAnd coolant flow rate V_wDetermining the air flow V of a fan of a heat exchanger_a；

Based on coolant flow V_wDetermining the operating frequency f of a pump_w；

Based on air flow V_aDetermining the operating frequency f of a fan_a(ii) a And

and controlling the pump and the fan to respectively operate at the determined working frequency.

Preferably, in the control method for the water cooling system of the converter provided by the present invention, determining the real-time heat loss power Q may further include:

and determining real-time heat loss power Q based on the real-time operation condition of the converter.

Optionally, in the control method for the water cooling system of the converter provided by the present invention, the method may further include:

determining heat sink resistance R_s-wThe method can comprise the following steps: based on real-time heat loss power Q and water temperature T_wAnd the temperature T of the table top of the radiator_sCalculating heat radiator thermal resistance R_s-wWherein R is_s-w＝(T_s-T_w)/Q，

Determining heat exchanger thermal resistance R_w-aThe method can comprise the following steps: based on real-time heat loss power Q and water temperature T_wAnd real time air temperature T_aCalculating Heat exchanger thermal resistance R_w-aWherein R is_w-a＝(T_w-T_a)/Q，

Determining coolant flow V_wThe method can comprise the following steps: based on heat resistance R of radiator_s-wCalculating the flow rate V of the cooling liquid_wWherein R is_s-w＝a·V_w ^bA, b are empirical constants, and

determining the air flow V_aThe method can comprise the following steps: based on heat exchanger thermal resistance R_w-aAnd coolant flow rate V_wDetermining the air flow V of a fan of a heat exchanger_aWherein R is_w-a＝k·V_w ^x·V_a ^yK, x, y are empirical constants.

Preferably, in the control method for the water cooling system of the converter provided by the present invention, the method may further include:

target temperature T based on power device_jCalculating the table temperature T of the radiator with real-time heat loss power Q_sWherein T is_s＝T_j–Q·(R_j-c+R_TLM)，R_j-cIs the device junction thermal resistance, R_TIMIs the interface thermal resistance.

Optionally, in the control method for the water cooling system of the converter provided by the invention, the operating frequency f is determined_wMay also include a flow rate V based on the cooling fluid_wSearching the water pump working frequency-flow corresponding table to determine the working frequency f_w。

Optionally, in the control method for the water cooling system of the converter provided by the invention, the operating frequency f is determined_aMay also include basing the air flow V_aSearching fan working frequency-flow corresponding table to determine working frequency f_a。

According to another aspect of the present invention, there is also provided a computer device, which may include a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, may implement any one of the above steps of the control method for the water cooling system of the converter.

According to another aspect of the present invention, there is also provided a computer readable storage medium, on which a computer program is stored, wherein the computer program, when executed by a processor, may implement the steps of any one of the above-mentioned control methods for a water cooling system of a converter.

Drawings

The above features and advantages of the present disclosure will be better understood upon reading the detailed description of embodiments of the disclosure in conjunction with the following drawings. In the drawings, components are not necessarily drawn to scale, and components having similar relative characteristics or features may have the same or similar reference numerals.

FIG. 1 is a schematic diagram of a conventional water cooling system;

fig. 2 is a schematic diagram of a water cooling system for a converter according to an embodiment of the disclosure;

fig. 3 is a flowchart illustrating a control method for a water cooling system of a converter according to an embodiment of the present invention;

fig. 4 is a flowchart illustrating a control method for a water cooling system of a converter according to another embodiment of the present invention.

The labels in the figure are:

11 is an expansion tank; 12 is a pump; 13 is a deionization device; 14 is a heat exchanger; 15 is a fan; 16 is a liquid cooling device; 17 is an electronic device;

21 is an expansion tank; 22 is a pump; 23 is a valve; 24 is a heat exchanger; 25 is a fan; 26 is a radiator; 27 is a power electronic device; 28 is a cooling circuit; 29 is a controller; 210 is a water temperature sensor; 211 is an air temperature sensor;

S301-S307 are steps of a control method of the water cooling system;

s3011, determining real-time heat loss power Q of the power device;

s3021 determining Heat sink resistance R_s-wA step (2);

s3022 determining Heat exchanger thermal resistance R_w-aA step (2);

s3031 determining coolant flow V_wA step (2);

s3041 determining air flow V of fan of heat exchanger_aThe step (2).

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. It is noted that the aspects described below in connection with the figures and the specific embodiments are only exemplary and should not be construed as imposing any limitation on the scope of the present invention.

As shown in fig. 2, in order to stably maintain the power devices of the converter at a desired target temperature and reduce the energy consumption of the water cooling system, the present invention provides an embodiment of a water cooling system for a converter, for cooling the power devices performing electric power conversion in the converter, the water cooling system may include:

the expansion tank 21, the pump 22, the heat exchanger 24, and the radiator 26 to constitute a cooling circuit 28; and

a controller 29 coupled to the pump 22 and the heat exchanger 24.

In the water cooling system for the inverter provided in the present embodiment, the expansion tank 21, the pump 22, the heat exchanger 24, and the radiator 26 are connected by a coolant conduit, and together constitute a cooling circuit 28.

The expansion tank 21 is used for storing the coolant, and has functions of compensating for thermal expansion of the fluid due to temperature rise of the coolant, removing air mixed in the coolant, and reducing pressure shock in the water cooling system.

Operating frequency f of the pump 22_wAlternatively, the coolant is driven to flow in the coolant conduit so that the coolant flows through the expansion tank 21, the pump 22, the heat exchanger 24, and the radiator 26, respectively. The cooling fluid is at different flow rates V in response to different operating frequencies of the pump 22_wFlows in the coolant conduit.

A fan 25 is arranged in the heat exchanger 24, and the working frequency f of the fan 25_aAnd may be adapted to blow cooling air to remove heat from the cooling fluid flowing through the heat exchanger 24 out of the water cooling system. The flow rate V of cooling air generated by the fan 25 in response to different operating frequencies of the fan 25_aDifferent.

The heat sink 26 may be provided with a heat sink table for accommodating the power electronics 27 to be cooled, for conducting heat from the power electronics 27 to the cooling liquid flowing through the heat sink 26.

The power electronics 27 may comprise any power device, such as an IGBT, for performing the conversion function of the electrical power in the traction converter.

The controller 29 is coupled to the pump 22 and the heat exchanger 24, respectively, and may include a signal transmission module, an I/O module, a driving device, and a PLC. The signal transmission module is used for realizing communication between the water cooling system and the outside, the driving device is used for driving the pump 22 and the fan 25 in the heat exchanger 24, and the PLC is used for calculating and controlling the working frequency f of the pump 22_wAnd the operating frequency f of the fan 25_aThe power electronics 27 of the converter are stably maintained at the desired target temperature T_j。

In the water cooling system for the converter provided in the present embodiment, the controller 29 may be configured to:

the real-time heat loss power Q of the power electronics 27 is determined from real-time data acquired by the controller 29 during operation of the traction converter,

based on real-time heat loss power Q and water temperature T_wAnd the temperature T of the table top of the radiator_sDetermining heat sink resistance R_s-wWherein R is_s-w＝(T_s-T_w)/Q，

Based on real-time heat loss power Q and water temperature T_wAnd real time air temperature T_aDetermining heat exchanger thermal resistance R_w-aWherein R is_w-a＝(T_w-T_a)/Q，

Based on heat resistance R of radiator_s-wDetermining the flow rate V of the cooling liquid according to the corresponding relation obtained by experiment_w，

Based on heat exchanger thermal resistance R_w-aAnd coolant flow rate V_wDetermining the air flow V of the fan 25 of the heat exchanger 24 from the experimentally obtained correspondence_a，

Based on coolant flow V_wDetermining the operating frequency f of the pump 22 from the experimentally obtained correspondence_w，

Based on air flow V_aDetermining the working frequency f of the fan 25 according to the corresponding relationship obtained by the experiment_a，

The pump 22 and the fan 25 are controlled to operate at the determined operating frequencies, respectively.

It will be appreciated that in order to maintain the power electronics 27 of the converter stably at the desired target temperature T_jTemperature T of table top of radiator_sShould remain unchanged. To facilitate quantitative calculation and control by the controller 29, the water temperature T is measured during actual operation of the water cooling system_wAnd the cooling air temperature T_aNor will it be significantly altered. Thus, the heat sink mesa temperature T involved in the water cooling system_sWater temperature T_wAnd the cooling air temperature T_aThe temperature sensor is not necessarily required to be used for acquisition, and the acquisition can be realized through presetting, pre-measurement and other modes.

Based on the water cooling system for the converter provided in this embodiment, in its cooling circuit 28, the power electronic device 27 may be disposed on the radiator table of the radiator 26 with real-time temperature T_jAnd generates heat with real-time heat loss power Q. Due to the fact thatThe heat sink 26 itself has a heat sink thermal resistance R_s-wAfter the cooling liquid flowing through the heat sink 26 sufficiently absorbs the heat emitted from the power electronic device 27, the temperature T of the cooling liquid_wWill still be slightly less than the temperature T of the power electronics 27_jAt a certain temperature difference T_j＝T_w+ΔT_j-w(ii) a Similarly, at the heat exchanger 24 side, the temperature T of the cooling liquid_wAnd the temperature T of the cooling air_aThe heat resistance R of the heat exchanger_w-aIs present to generate a certain temperature difference deltat_w-a。

In order to maintain the power electronics 27 of the converter stably at the desired target temperature T_jI.e. satisfy T_j＝T_a+ΔT_j-w+ΔT_w-a＝T_a+Q·(R_s-w+R_w-a) The controller 29 needs to quantitatively control the operating frequency f of the pump 22_wAnd/or the operating frequency f of the fan 25_aTo control the flow rate V of the cooling liquid_wAnd/or cooling air flow V_aThereby controlling the heat radiator thermal resistance R_s-wAnd/or heat exchanger thermal resistance R_w-aSo as to adjust the technical effect of the temperature difference of all the parts in the water cooling system. For example: if the real-time heat loss power Q increases, the operating frequency f of the pump 22 needs to be increased accordingly_wAnd/or the operating frequency f of the fan 25_aTo increase the flow rate V of the cooling liquid_wAnd/or cooling air flow V_aThereby reducing the heat sink thermal resistance R_s-wAnd/or heat exchanger thermal resistance R_w-aTo maintain the target temperature T of the power electronics 27_jThe technical effect is unchanged; in the same way, if the temperature T of the cooling air is_aIncreasing, then Δ T_j-w+ΔT_w-aShould be reduced accordingly, the controller 29 should correspondingly raise the operating frequency f of the pump 22_wAnd/or the operating frequency f of the fan 25_aIncreasing the coolant flow rate V_wAnd/or cooling air flow V_aThereby reducing the heat sink thermal resistance R_s-wAnd/or heat exchanger thermal resistance R_w-aTo maintain the target temperature T of the power electronics 27_jThe technical effect is unchanged.

It is understood that, in the water cooling system for the converter provided in this embodiment, the cooling liquid is mainly used for absorbing and transferring heat, so that any fluid medium with heat absorbing and transferring capacity, such as water, oil, ethanol, etc., can be used as the cooling liquid; correspondingly, the expansion tank 21, the pump 22, the heat exchanger 24, the water passing end of the radiator 26, and the coolant conduit should be made of a material that is sufficiently strong to carry the coolant without being corroded by the coolant.

In the water cooling system provided in this embodiment, the real-time heat loss power Q of the traction converter may be obtained by the controller 29 in real time during the operation of the traction converter, or may be an average summarized according to the daily operation condition of the traction converter.

In most cases, the external working condition of the traction converter is always in drastic change, so that the real-time heat loss power Q generated by the traction converter is changed all the time, and the change of the real-time heat loss power Q can cause large-range fluctuation of the temperature of the power electronic device, so that the reliability and the service life of the power electronic device are influenced. Therefore, in order to further improve the reliability and the service life of the power electronic device in the traction converter and reduce the energy consumption of the water cooling system, in a preferred embodiment of this embodiment, the heat loss power Q may also be obtained in real time, and the operating frequency f of the pump may be adjusted in real time according to the obtained real-time heat loss power Q_wAnd/or the operating frequency f of the fan_aChanging the coolant flow rate V_wAnd/or cooling air flow V_aThe temperature of the power electronics in the traction converter is more stably maintained at the desired target temperature with minimal energy consumption.

According to different practical situations, in this embodiment, the water cooling system can be disposed in a closed converter cabinet, and the expansion tank 21, the pump 22, the heat exchanger 24, the radiator 26, and the coolant conduit should have certain heat insulation capability to ensure that the heat in the water cooling system is discharged out of the converter cabinet only through the heat exchanger 24. In other embodiments, if the water cooling system can be installed in an open environment, the expansion tank 21, the pump 22, the heat exchanger 24, the radiator 26, and the coolant conduit can also be made of heat conductive material to increase the heat dissipation area and improve the heat dissipation capability.

Optionally, as shown in fig. 2, in a preferred embodiment of the present embodiment, a temperature sensor 210 may also be disposed in the cooling circuit 28 of the water cooling system for collecting the temperature T of the cooling liquid_wThe heat exchanger 24 may also be provided with a temperature sensor 211 for detecting the real-time cooling air temperature T at the inlet of the fan 25_a，

The controller 29 may be further coupled to the temperature sensor 210 and the temperature sensor 211, and the controller 29 may be further configured to:

based on heat resistance R of radiator_s-wCalculating the flow rate V of the cooling liquid_wWherein R is_s-w＝a·V_w ^bA, b are empirical constants, and

based on heat exchanger thermal resistance R_w-aAnd coolant flow rate V_wDetermining the air flow V of the fan 25 of the heat exchanger 24_aWherein R is_w-a＝k·V_w ^x·V_a ^yK, x, y are empirical constants.

In the present embodiment, the temperature sensor 210 and the temperature sensor 211 are adopted to respectively obtain the real-time temperature T of the cooling liquid_wAnd the real-time temperature T of the cooling air at the inlet of the fan 25 of the heat exchanger 24_aAnd calculating the heat sink thermal resistance R based on the calculated heat sink thermal resistance R_s-wAnd heat exchanger thermal resistance R_w-a. In other embodiments, the cooling air with a specific temperature may be blown into the heat exchanger by the fan, a temperature of the cooling liquid greater than the temperature of the cooling air and less than the target temperature of the power electronic device may be determined, and the required thermal resistance values of the heat sink and the heat exchanger may be calculated based on the determined temperature of the cooling air and the determined temperature of the cooling liquid.

In the present embodiment, the heat resistance R is based on the heat sink_s-wCalculating the flow rate V of the cooling liquid_wIs given by the formula R_s-w＝a·V_w ^bThe empirical constants a and b in (1) are the heat resistance R of the radiator obtained by counting a plurality of experiments_s-wAnd coolant flow rate V_wAfter the numerical relationship between the two is substituted into a power function formula, fitting the obtained proportionality constant a and exponential constant b. Similarly, the empirical constants k, x andy is the heat exchanger thermal resistance R obtained after counting a plurality of experiments_w-aCoolant flow rate V_wAnd cooling air flow V_aAfter the numerical relation between the two is substituted into a power function formula, a proportional constant k and the flow rate V of the cooling liquid are obtained through fitting_wAnd the cooling air flow V_aIs constant y. In other embodiments, based on the same concept, other function formulas can be adopted to apply the heat resistance R of the heat sink_s-wCoolant flow rate V_wHeat exchanger thermal resistance R_w-aAnd cooling air flow V_aCarrying out curve fitting on the numerical relationship; or establishing a statistical table of the correlation, adopting a mode of interpolation of the comparison statistical table, and determining the heat resistance R of the radiator_s-wAnd heat exchanger thermal resistance R_w-aEstimating the required coolant flow V_wAnd cooling air flow V_a。

Preferably, in a preferred aspect of this embodiment, the controller of the water cooling system may be further configured to:

target temperature T based on power device_jCalculating the table temperature T of the radiator with real-time heat loss power Q_sWherein T is_s＝T_j–Q·(R_j-c+R_TLM)，R_j-cIs the device junction thermal resistance, R_TIMIs the interface thermal resistance.

Under the actual working condition of the converter, device junction-shell thermal resistance R often exists between a PN junction of a power device and a shell_j-cInterface thermal resistance R also exists between the power electronic device and the heat sink table_TIMThe operating temperature noted in the specification of the power device generally refers to the junction temperature T of the power device_jTemperature T of the table top of the radiator_sThere is a certain temperature difference between them. In a preferred embodiment of this embodiment, the controller of the water cooling system can further adjust the temperature T of the top of the radiator_sTarget temperature T of PN junction of power device_jTemperature difference Δ T therebetween_j-s＝Q·(R_j-c+R_TLM) And also included in the calculation range, thereby further improving the reliability and the service life of the power electronic device.

Due to T under steady state conditions_j＝T_a+Q·(R_j-c+R_TLM+R_s-w+R_w-a) And in the actual working process of the converter, the device junction thermal resistance R of the power device_j-cAnd interfacial thermal resistance R_TIMUsually no significant change will occur, so to save computation, the controller may not have to consider the device junction resistance R_j-cAnd interfacial thermal resistance R_TIMSpecific variations of (2). In the embodiment, when the real-time heat loss power of the power device is changed from Q to Q + delta Q, only by adjusting R_s-wValue and R_w-aValue, ream (R'_s-w+R’_w-a)＝(T_j-T_a)/(Q+ΔQ)–(R_j-c+R_TLM) So that the junction temperature of the power device is kept constant; based on the same concept, when the air temperature is from T_aIs changed into T_aIn case of this, it is also possible to use only the regulation of R_s-wValue and R_w-aValue, (R)'_s-w+R’_w-a)＝(T_j-T’_a)/Q–(R_j-c+R_TLM) So that the junction temperature of the power device remains unchanged. In other embodiments, in order to improve the control accuracy, the controller can also make the device crust thermal resistance R based on the same concept_j-cAnd interfacial thermal resistance R_TIMAlso incorporates the thermal resistance R of the radiator_s-wAnd heat exchanger thermal resistance R_w-aIn the calculation range of (c).

Optionally, in a preferred aspect of this embodiment, the controller of the water cooling system may be further configured to control the flow rate V of the cooling liquid based on the temperature of the cooling liquid_wChecking the working frequency-flow corresponding table of the water pump to determine the working frequency f of the water pump_w。

As shown in table 1, in this embodiment, the working frequency-flow rate correspondence table of the water pump may be first counted according to experimental data or a parameter specification of the pump. Wherein, the higher the working frequency of the water pump is, the larger the flow rate of the cooling liquid is.

Table 1 water pump working frequency-flow corresponding table

5Hz

10Hz

15Hz

20Hz

25Hz

30Hz

35Hz

40Hz

45Hz

50Hz

Vw1

Vw2

Vw3

Vw4

Vw5

Vw6

Vw7

Vw8

Vw9

Vw10

The controller determines the cooling liquid flow rate V_wIs carried out with a water pump working frequency-flow corresponding tableAnd comparing, and obtaining the required working frequency of the water pump by adopting an interpolation mode. For example, when

V_w5<V_w<V_w6

The required operating frequency f of the water pump at that time is determined_wIs composed of

f_w＝25Hz·(V_w6-V_w)/(V_w6-V_w5)+30Hz·(V_w-V_w5)/(V_w6-V_w5)。

It will be appreciated that the flow rate V is based on the coolant_wThe way of looking up the working frequency-flow correspondence table of the water pump is not to determine the working frequency f of the water pump_wThe only way of doing so. In other embodiments, the curve fitting may be performed on the numerical relationship between the operating frequency and the flow rate of the water pump by means of statistical experimental data, so as to determine the flow rate V of the cooling liquid_wTo determine the required operating frequency f of the water pump_w。

Optionally, in a preferred embodiment of the present embodiment, the controller of the water cooling system may be further configured to control the flow rate of the air flow V_aSearching the fan working frequency-flow corresponding table to determine the working frequency f of the fan_a。

Based on the same concept as the water pump operating frequency-flow correspondence table, in this embodiment, the fan operating frequency-flow correspondence table may also be counted according to experimental data or a parameter specification of the fan. Wherein, the higher the operating frequency of the fan, the larger the flow of the cooling air. The controller may also determine the flow rate V of the cooling air_aAnd comparing the frequency with a fan working frequency-flow corresponding table, and obtaining the required water pump working frequency by adopting an interpolation mode.

Similarly, based on the flow V of the cooling air_aThe way of searching the working frequency-flow corresponding table of the fan is not to determine the working frequency f of the fan_aThe only way of doing so. In other embodiments, the curve fitting may be performed on the numerical relationship between the operating frequency and the flow rate of the fan by means of statistical experimental data, so as to determine the flow rate V of the cooling air_aTo determine the required fanOperating frequency f_a。

Optionally, in the water cooling system for the converter provided by the invention, the pump may include a stepless variable frequency speed control water pump, and the fan may be a stepless variable frequency speed control fan.

It is understood that, in the water cooling system for the inverter provided in the present embodiment, as long as the flow rate V of the cooling liquid can be changed by changing the operating frequency thereof_wAnd cooling air flow V_aThe water pump and the fan can meet the requirements of the invention. In the preferred scheme, the stepless variable-frequency speed-regulating water pump and the stepless variable-frequency speed-regulating fan are adopted, so that the flow regulation of the pump and the fan is smoother, and the accurate control of the controller on the temperature of a power device is facilitated.

According to another aspect of the present invention, there is also provided an embodiment of a control method for a water cooling system of a converter for cooling power devices performing electric power conversion in the converter.

As shown in fig. 2 and 3, the water cooling system may include an expansion tank 21, a pump 22, a heat exchanger 24, and a radiator 26 to constitute a cooling circuit 28. The control method may include:

s301: determining real-time heat loss power Q of the power device 27;

s302: determining heat sink thermal resistance R based on real-time heat loss power Q_s-wAnd heat exchanger thermal resistance R_w-a；

S303: based on heat resistance R of radiator_s-wDetermining coolant flow V_w；

S304: based on heat exchanger thermal resistance R_w-aAnd coolant flow rate V_wDetermining the air flow V of the fan 25 of the heat exchanger 24_a；

S305: based on coolant flow V_wDetermining the operating frequency f of the pump 22_w；

S306: based on air flow V_aDetermining the operating frequency f of the fan 25_a(ii) a And

s307: the pump 22 and the fan 25 are controlled to operate at the determined operating frequencies, respectively.

In the control method for the water cooling system of the converter provided in this embodiment, the real-time heat loss power Q of the traction converter may be obtained in real time during the operation of the traction converter, or may be an average number summarized according to the daily operation condition of the traction converter. That is, in the preferred embodiment of the present invention, step S301 may be adopted, or step S3011: and determining real-time heat loss power Q based on the real-time operation condition of the converter.

In most cases, the external working condition of the traction converter is always in drastic change, so that the real-time heat loss power Q generated by the traction converter is changed all the time, and the change of the real-time heat loss power Q can cause large-range fluctuation of the temperature of the power electronic device, so that the reliability and the service life of the power electronic device are influenced. Therefore, in order to further improve the reliability and the service life of the power electronic device in the traction converter and reduce the energy consumption of the water cooling system, in a preferred embodiment of this embodiment, the heat loss power Q may also be obtained in real time, and the operating frequency f of the pump may be adjusted in real time according to the obtained real-time heat loss power Q_wAnd/or the operating frequency f of the fan_aChanging the coolant flow rate V_wAnd/or cooling air flow V_aThe temperature of the power electronics in the traction converter is more stably maintained at the desired target temperature with minimal energy consumption.

In the control method for the water cooling system of the converter provided by the embodiment, the heat radiator thermal resistance R_s-wCan be based on real-time heat loss power Q and water temperature T_wAnd the temperature T of the table top of the radiator_sIs defined in which R is_s-w＝(T_s-T_w)/Q，

Heat exchanger thermal resistance R_w-aCan be based on real-time heat loss power Q and water temperature T_wAnd real time air temperature T_aIs defined in which R is_w-a＝(T_w-T_a)/Q，

Flow rate V of cooling liquid_wMay be the experimentally obtained coolant flow V_wThermal resistance R of radiator_s-wThe corresponding relationship of (a) to (b) is determined,

air flow V of fan 25 of heat exchanger 24_aCan beHeat exchanger thermal resistance R obtained according to experiment_w-aAnd coolant flow rate V_wThe corresponding relationship of (a) to (b) is determined,

operating frequency f of the pump 22_wMay be based on the coolant flow V_wDetermined according to the corresponding relationship obtained by experiments,

operating frequency f of the fan 25_aMay be based on the air flow V_aAnd the corresponding relation obtained by experiments is determined.

It will be appreciated that in order to maintain the power electronics 27 of the converter stably at the desired target temperature T_jTemperature T of table top of radiator_sShould remain unchanged. To facilitate quantitative calculation and control by the controller 29, the water temperature T is measured during actual operation of the water cooling system_wAnd the cooling air temperature T_aNor will it be significantly altered. Thus, the heat sink mesa temperature T involved in the water cooling system_sWater temperature T_wAnd the cooling air temperature T_aThe temperature sensor is not necessarily required to be used for acquisition, and the acquisition can be realized through presetting, pre-measurement and other modes.

In the control method of the water cooling system for the converter provided in the present embodiment, the power electronic device 27 in the cooling circuit 28 may be disposed on the radiator table of the radiator 26, and its real-time temperature is T_jAnd generates heat with real-time heat loss power Q. Due to the existence of the heat sink 26 itself, the heat sink thermal resistance R_s-wAfter the cooling liquid flowing through the heat sink 26 sufficiently absorbs the heat emitted from the power electronic device 27, the temperature T of the cooling liquid_wWill still be slightly less than the temperature T of the power electronics 27_jAt a certain temperature difference T_j＝T_w+ΔT_j-w(ii) a Similarly, at the heat exchanger 24 side, the temperature T of the cooling liquid_wAnd the temperature T of the cooling air_aThe heat resistance R of the heat exchanger_w-aIs present to generate a certain temperature difference deltat_w-a。

In order to maintain the power electronics 27 of the converter stably at the desired target temperature T_jI.e. satisfy T_j＝T_a+ΔT_j-w+ΔT_w-a＝T_a+Q·(R_s-w+R_w-a) The operating frequency f of the pump 22 needs to be quantitatively controlled_wAnd/or the operating frequency f of the fan 25_aTo control the flow rate V of the cooling liquid_wAnd/or cooling air flow V_aThereby controlling the heat radiator thermal resistance R_s-wAnd/or heat exchanger thermal resistance R_w-aSo as to adjust the technical effect of the temperature difference of all the parts in the water cooling system. If the real-time heat loss power Q increases, the operating frequency f of the pump 22 needs to be increased accordingly_wAnd/or the operating frequency f of the fan 25_aIncreasing the coolant flow rate V_wAnd/or cooling air flow V_aThereby reducing the heat sink thermal resistance R_s-wAnd/or heat exchanger thermal resistance R_w-aTo maintain the target temperature T of the power electronics 27_jThe technical effect is unchanged; in the same way, if the temperature T of the cooling air is_aIncreasing, then Δ T_j-w+ΔT_w-aShould be reduced accordingly, the controller 29 should correspondingly raise the operating frequency f of the pump 22_wAnd/or the operating frequency f of the fan 25_aIncreasing the coolant flow rate V_wAnd/or cooling air flow V_aThereby reducing the heat sink thermal resistance R_s-wAnd/or heat exchanger thermal resistance R_w-aTo maintain the target temperature T of the power electronics 27_jConstant technical effect

It can be understood that, in the control method of the water cooling system provided in this embodiment, the cooling liquid is mainly used for absorbing and transferring heat, so that any fluid medium with heat absorbing and transferring capabilities, such as water, oil, ethanol, and the like, can be used as the cooling liquid; correspondingly, the expansion tank 21, the pump 22, the heat exchanger 24, the water passing end of the radiator 26, and the coolant conduit should be made of a material that is sufficiently strong to carry the coolant without being corroded by the coolant.

According to different practical use conditions, in the present embodiment, the water cooling system can be disposed in a closed converter cabinet, so that the expansion tank 21, the pump 22, the heat exchanger 24, the radiator 26, and the coolant conduit all have certain heat insulation capability, and the heat in the water cooling system is ensured to be exhausted from the converter cabinet only through the heat exchanger 24; in other embodiments, if the water cooling system can be installed in an open environment, the expansion tank 21, the pump 22, the heat exchanger 24, the radiator 26, and the coolant conduit can also be made of heat conductive material to increase the heat dissipation area and improve the heat dissipation capability.

Optionally, as shown in fig. 2 and 4, in the control method for the water cooling system of the converter provided by the present invention, the method may also include:

s3011: determining real-time heat loss power Q based on the real-time operation condition of the converter;

s3021: based on real-time heat loss power Q and water temperature T_wAnd the temperature T of the table top of the radiator_sCalculating heat radiator thermal resistance R_s-wWherein R is_s-w＝(T_s-T_w)/Q，

S3022: based on real-time heat loss power Q and water temperature T_wAnd real time air temperature T_aCalculating Heat exchanger thermal resistance R_w-aWherein R is_w-a＝(T_w-T_a)/Q；

S3031: based on heat resistance R of radiator_s-wCalculating the flow rate V of the cooling liquid_wWherein R is_s-w＝a·V_w ^bA, b are empirical constants, and

s3041: based on heat exchanger thermal resistance R_w-aAnd coolant flow rate V_wDetermining the air flow V of the fan 25 of the heat exchanger 24_aWherein R is_w-a＝k·V_w ^x·V_a ^yK, x, y are empirical constants;

s305: based on coolant flow V_wDetermining the operating frequency f of a pump_w；

S306: based on air flow V_aDetermining the operating frequency f of a fan_a；

S307: and controlling the pump and the fan to respectively operate at the determined working frequency.

In the present embodiment, the temperature sensor 210 and the temperature sensor 211 are adopted to respectively obtain the real-time temperature T of the cooling liquid_wAnd the real-time temperature T of the cooling air at the inlet of the fan 25 of the heat exchanger 24_aAnd calculating the heat dissipation according to the calculated heat dissipationThermal resistance R_s-wAnd heat exchanger thermal resistance R_w-a. In other embodiments, the cooling air with a specific temperature may be blown into the heat exchanger by the fan, a temperature of the cooling liquid greater than the temperature of the cooling air and less than the target temperature of the power electronic device may be determined, and the required thermal resistance values of the heat sink and the heat exchanger may be calculated based on the determined temperature of the cooling air and the determined temperature of the cooling liquid.

In the present embodiment, the heat resistance R is based on the heat sink_s-wCalculating the flow rate V of the cooling liquid_wIs given by the formula R_s-w＝a·V_w ^bThe empirical constants a and b in (1) are the heat resistance R of the radiator obtained by counting a plurality of experiments_s-wAnd coolant flow rate V_wAfter the numerical relationship between the two is substituted into a power function formula, fitting the obtained proportionality constant a and exponential constant b. Similarly, the empirical constants k, x and y are the heat exchanger thermal resistances R obtained after counting multiple experiments_w-aCoolant flow rate V_wAnd cooling air flow V_aAfter the numerical relation between the two is substituted into a power function formula, a proportional constant k and the flow rate V of the cooling liquid are obtained through fitting_wAnd the cooling air flow V_aIs constant y. In other embodiments, based on the same concept, other function formulas can be adopted to apply the heat resistance R of the heat sink_s-wCoolant flow rate V_wHeat exchanger thermal resistance R_w-aAnd cooling air flow V_aCarrying out curve fitting on the numerical relationship; or establishing a statistical table of the correlation, adopting a mode of interpolation of the comparison statistical table, and determining the heat resistance R of the radiator_s-wAnd heat exchanger thermal resistance R_w-aEstimating the required coolant flow V_wAnd cooling air flow V_a。

Preferably, in a preferred aspect of this embodiment, the method for controlling the water cooling system may further include:

s308: target temperature T based on power device_jCalculating the table temperature T of the radiator with real-time heat loss power Q_sWherein T is_s＝T_j–Q·(R_j-c+R_TLM)，R_j-cIs the device junction thermal resistance, R_TIMIs the interface thermal resistance.

Under the actual working condition of the converter, device junction-shell thermal resistance R often exists between a PN junction of a power device and a shell_j-cInterface thermal resistance R also exists between the power electronic device and the heat sink table_TIMThe operating temperature noted in the specification of the power device generally refers to the junction temperature T of the power device_jTemperature T of the table top of the radiator_sThere is a certain temperature difference between them. In a preferred embodiment of this embodiment, the controller of the water cooling system can further adjust the temperature T of the top of the radiator_sTarget temperature T of PN junction of power device_jTemperature difference Δ T therebetween_j-s＝Q·(R_j-c+R_TLM) And also included in the calculation range, thereby further improving the reliability and the service life of the power electronic device.

Due to T under steady state conditions_j＝T_a+Q·(R_j-c+R_TLM+R_s-w+R_w-a) And in the actual working process of the converter, the device junction thermal resistance R of the power device_j-cAnd interfacial thermal resistance R_TIMUsually no significant change occurs, so the controller can save the amount of calculation without considering the device junction thermal resistance R_j-cAnd interfacial thermal resistance R_TIMSpecific variations of (2). In the embodiment, when the real-time heat loss power of the power device is changed from Q to Q + delta Q, only by adjusting R_s-wValue and R_w-aValue, ream (R'_s-w+R’_w-a)＝(T_j-T_a)/(Q+ΔQ)–(R_j-c+R_TLM) So that the junction temperature of the power device is kept constant; based on the same concept, when the air temperature is from T_aIs changed into T_aIn case of this, it is also possible to use only the regulation of R_s-wValue and R_w-aValue, (R)'_s-w+R’_w-a)＝(T_j-T’_a)/Q–(R_j-c+R_TLM) So that the junction temperature of the power device remains unchanged. In other embodiments, the device crusting thermal resistance R can be improved based on the same concept in order to improve the control precision of the water cooling system_j-cAnd interfacial thermal resistance R_TIMSpecific variations of (2)Also incorporates the heat sink thermal resistance R_s-wAnd heat exchanger thermal resistance R_w-aIn the calculation range of (c).

Optionally, in the control method of the water cooling system provided in a preferred aspect of this embodiment, the operating frequency f of the water pump is determined_wMay also include S3051: based on coolant flow V_wSearching water pump working frequency-flow corresponding table to determine working frequency f of water pump_w。

As shown in table 1, in this embodiment, the working frequency-flow rate correspondence table of the water pump may be first counted according to experimental data or a parameter specification of the pump. Wherein, the higher the working frequency of the water pump is, the larger the flow rate of the cooling liquid is.

Table 1 water pump working frequency-flow corresponding table

5Hz

10Hz

15Hz

20Hz

25Hz

30Hz

35Hz

40Hz

45Hz

50Hz

Vw1

Vw2

Vw3

Vw4

Vw5

Vw6

Vw7

Vw8

Vw9

Vw10

The determined cooling liquid flow rate V_wAnd comparing the frequency with a water pump working frequency-flow corresponding table, and obtaining the required water pump working frequency by adopting an interpolation mode. For example, when

V_w5<V_w<V_w6

The required operating frequency f of the water pump at that time is determined_wIs composed of

f_w＝25Hz·(V_w6-V_w)/(V_w6-V_w5)+30Hz·(V_w-V_w5)/(V_w6-V_w5)。

It will be appreciated that the flow rate V is based on the coolant_wThe way of looking up the working frequency-flow correspondence table of the water pump is not to determine the working frequency f of the water pump_wThe only way of doing so. In other embodiments, the curve fitting may be performed on the numerical relationship between the operating frequency and the flow rate of the water pump by means of statistical experimental data, so as to determine the flow rate V of the cooling liquid_wTo determine the required operating frequency f of the water pump_w。

Optionally, in the control method of the water cooling system provided in a preferred embodiment of this embodiment, the operating frequency f of the fan is determined_aMay also include S3061: based on air flow V_aSearching fan working frequency-flow corresponding table to determine working frequency f_a。

Based on the same concept as the water pump operating frequency-flow correspondence table, in this embodiment, the fan operating frequency-flow correspondence table may also be counted according to experimental data or a parameter specification of the fan. Wherein, the higher the operating frequency of the fan, the larger the flow of the cooling air. Can be determined by the determined flow rate V of the cooling air_aAnd comparing the frequency with a fan working frequency-flow corresponding table, and obtaining the required water pump working frequency by adopting an interpolation mode.

Similarly, based on the flow V of the cooling air_aThe way of searching the working frequency-flow corresponding table of the fan is not to determine the working frequency f of the fan_aThe only way of doing so. In other embodiments, the curve fitting may be performed on the numerical relationship between the operating frequency and the flow rate of the fan by means of statistical experimental data, so as to determine the flow rate V of the cooling air_aTo determine the required fan operating frequency f_a。

According to another aspect of the present invention, there is also provided an embodiment of a computer device, which may include a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of any one of the above-mentioned control methods for the water cooling system of the converter can be implemented, so as to stably maintain the power device of the converter at a desired target temperature and reduce the energy consumption of the water cooling system.

According to another aspect of the invention, there is also provided an embodiment of a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by the processor, the steps of any one of the above-mentioned control methods for the water cooling system of the converter can be realized, so that the power device of the converter is stably maintained at a desired target temperature, and the energy consumption of the water cooling system is reduced.

While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more embodiments, occur in different orders and/or concurrently with other acts from that shown and described herein or not shown and described herein, as would be understood by one skilled in the art.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.