阅读说明：本技术 一种直流电源单元控制检测系统与方法 (Control detection system and method for direct-current power supply unit ) 是由 刘洋 康智斌 任青云 于 2019-11-01 设计创作，主要内容包括：本发明涉及一种直流电源单元控制检测系统与方法,与直流电源单元连接,所述直流电源单元的输入端与电网连接,输出端连接有负载,包括依次连接的开关频次陷波器、六脉波陷波器、PI调节器、最小值选取单元、PWM驱动单元,所述直流电源单元包括IGBT逆变桥,所述开关频次陷波器的输入端连接直流电源单元的母线输出端,所述PWM驱动单元的输出端与IGBT逆变桥连接。使用陷波器对高频次开关纹波和六脉波纹波进行滤除,不会影响直流电源单元母线输出端的反馈信号的快速响应。当电网发生突变或负载发生突变时,能够快速调节控制IGBT逆变桥的PWM占空比,迅速降低直流电源单元的输出,不会导致过流、过载等停机故障,避免给用户端的负载带来损失和不便。(The invention relates to a control detection system and a control detection method for a direct-current power supply unit, wherein the control detection system is connected with the direct-current power supply unit, the input end of the direct-current power supply unit is connected with a power grid, the output end of the direct-current power supply unit is connected with a load, the control detection system comprises a switching frequency wave trap, a six-pulse wave trap, a PI regulator, a minimum value selection unit and a PWM (pulse width modulation) driving unit which are sequentially connected, the direct-current power supply unit comprises an IGBT (insulated gate bipolar transistor) inverter bridge, the input end of the switching frequency wave trap is connected with the bus output end. The wave trap is used for filtering the high-frequency secondary switching ripple waves and the six-pulse ripple waves, and the quick response of the feedback signals at the bus output end of the direct-current power supply unit cannot be influenced. When the power grid or the load suddenly changes, the PWM duty ratio of the IGBT inverter bridge can be quickly adjusted and controlled, the output of the direct-current power supply unit is quickly reduced, the shutdown faults such as overcurrent and overload can not be caused, and the loss and inconvenience brought to the load of a user side are avoided.)

1. The utility model provides a DC power supply unit control detecting system, is connected with DC power supply unit, DC power supply unit input is connected with the electric wire netting, and DC power supply unit's bus output end is connected with load, its characterized in that: the direct-current power supply unit comprises a switching frequency wave trap, a six-pulse wave trap, a PI regulator, a minimum value selecting unit and a PWM driving unit which are sequentially connected, wherein the direct-current power supply unit comprises an IGBT inverter bridge, the input end of the switching frequency wave trap is connected with the bus output end of the direct-current power supply unit, and the output end of the PWM driving unit is connected with the IGBT inverter bridge.

2. The dc power supply unit control detection system of claim 1, wherein: the switching frequency wave trap comprises a switching voltage frequency wave trap and a switching current frequency wave trap, and the input end of the switching voltage frequency wave trap and the input end of the switching current frequency wave trap are respectively connected with the bus output end of the direct-current power supply unit.

3. The dc power supply unit control detection system of claim 2, wherein: the six-pulse wave trap comprises a voltage six-pulse wave trap and a current six-pulse wave trap, wherein the input end of the voltage six-pulse wave trap is connected with the output end of the switching voltage frequency trap, and the input end of the current six-pulse wave trap is connected with the output end of the switching current frequency trap.

4. A dc power supply unit control detection system according to claim 3, wherein: the PI regulator comprises a PI voltage regulator and a PI current regulator, wherein the input end of the PI voltage regulator is connected with the output end of the voltage six-pulse wave trap, and the input end of the PI current regulator is connected with the output end of the current six-pulse wave trap; and the output end of the PI voltage regulator and the output end of the PI current regulator are respectively connected with the minimum value selection unit.

5. The DC power supply unit control detection system of claim 4, wherein: the direct current power supply unit further comprises a first rectifier bridge, a high-frequency transformer and a second rectifier bridge, wherein the input end of the first rectifier bridge is connected with a power grid, the output end of the first rectifier bridge is connected with the input end of an IGBT inverter bridge, the output end of the IGBT inverter bridge is connected with the input end of the high-frequency transformer, the output end of the high-frequency transformer is connected with the input end of the second rectifier bridge, and the output end of the second rectifier bridge is connected with a switching voltage frequency trap and a switching current frequency trap respectively.

6. The method according to claim 1, wherein the method comprises the steps of: the method comprises the following steps:

step S1: extracting a feedback signal at a bus output end of the direct-current power supply unit;

step S2: connecting the feedback signal to a switching frequency wave trap and a six-pulse wave trap for filtering;

step S3: respectively comparing the processed voltage Udc and current Idc with a reference voltage V_refReference current I_refAdjusting the difference by a PI adjuster;

step S4: the PI regulator respectively sends the regulating values obtained by the difference of the voltage and the current to a minimum value selection unit;

step S5: the minimum value selection unit selects the minimum regulating value as a PID _ out signal and outputs the PID _ out signal to the PWM driving unit;

step S6: and the PWM driving unit converts the PID _ out signal into a PWM duty ratio and outputs the PWM duty ratio to the IGBT inverter bridge to control the IGBT inverter bridge.

7. The method according to claim 6, wherein the method comprises the steps of: the step S1 specifically includes the following steps: extracting feedback voltage V at two ends of bus output end capacitor C2 of direct current power supply unit_fAnd a feedback current I at the bus bar output_f。

8. The method according to claim 7, wherein the method comprises the steps of: the step S2 specifically includes the following steps: will feedback the voltage V_fThe input switching voltage frequency wave trap is used for carrying out high-frequency switching ripple wave filtering processing and then sending the processed signal to the voltage six-pulse wave trap; will feed back the current I_fThe current is input to a switching current frequency wave trap for high-frequency switching ripple wave filtering processing, and the processed current is transmitted to a current six-pulse wave trap;

the voltage six-pulse wave trap receives the feedback voltage processed by the switching voltage frequency trap and carries out filtering processing on the feedback voltage by a 300Hz six-pulse ripple wave to obtain a voltage Udc; and the current six-pulse wave trap receives the feedback current processed by the switching current frequency trap and carries out filtering processing on the feedback current by a 300Hz six-pulse ripple wave to obtain a current Idc.

9. The method according to claim 8, wherein the method comprises the steps of: the step S3 specifically includes the following steps: the voltage Udc obtained after the processing of the voltage six-pulse wave trap and the reference voltage V given by the system_refPerforming difference to obtain a voltage difference value, and sending the voltage difference value to the PI voltage regulator; the current Idc obtained after the processing of the current six-pulse wave trap and the reference current I given by the system_refAnd performing difference to obtain a current difference value, and sending the current difference value to the PI current regulator.

10. The dc power supply unit control detecting method according to claim 9, wherein: the step S4 specifically includes the following steps: the PI voltage regulator regulates the voltage difference value after the difference is made, the obtained voltage regulating value is sent to the minimum value selecting unit, the PI current regulator regulates the current difference value after the difference is made, and the obtained current regulating value is sent to the minimum value selecting unit.

Technical Field

The invention relates to the technical field of direct-current power supply control, in particular to a system and a method for controlling and detecting a direct-current power supply unit.

Background

Many industrial sites require heating of loads, and the control of power output and hence load temperature is required in relation to heating. The traditional silicon controlled rectifier power supply controls a silicon controlled rectifier switch, then the voltage is reduced through a power frequency transformer, and a large current is output to heat a load, so that the power transformer is large in size and is gradually replaced by a high-frequency IGBT power supply. For heating loads, temperature inertia is large, the load temperature can be stable only by long-time average power stabilization, and therefore, the requirement on output ripple waves of a power supply is basically eliminated. For this reason, in order to save costs, the rectified filter parameters of such power supplies are small or almost none. For a three-phase power grid with the power frequency of 50Hz, 300Hz alternating-current voltage ripples exist in a rectification input bus, and 300Hz alternating-current voltage ripples exist in output. For such a direct current power supply with output fluctuation, a tracking static error exists in the traditional PI control tracking method. In order to quickly track changes of the load and the power grid, the fluctuation of the PID output is large, and further the bus fluctuation is caused. Especially when the power grid is weak, the fluctuation of the bus causes the input current to change, and the serious condition can cause the unbalance of the three-phase input current, which is unfavorable for the power grid. Feedback is also filtered, and a low-pass filter is designed to filter out 300Hz alternating current components, but the feedback is delayed, and quick tracking cannot be realized when the load or the power grid suddenly changes.

Disclosure of Invention

The present invention is directed to overcoming the deficiencies of the prior art and providing a system and a method for controlling and detecting a dc power unit.

In order to achieve the above object, the embodiments of the present invention provide the following technical solutions:

the utility model provides a DC power supply unit control detecting system, is connected with DC power supply unit, DC power supply unit input is connected with the electric wire netting, and DC power supply unit's generating line output is connected with the load, selects unit, PWM drive unit including the switching frequency trapper, six pulse wave trappers, PI regulator, minimum that connect gradually, DC power supply unit includes IGBT inverter bridge, the generating line output of DC power supply unit is connected to the input of switching frequency trapper, PWM drive unit's output and IGBT inverter bridge are connected.

The invention realizes the high-frequency heating power supply with stable power, has extremely small input and output filter component parameters in the direct-current power supply unit for saving cost, carries out trap processing on the feedback signal of the bus output end of the direct-current power supply unit, filters the signal which is not required to be adjusted by a system, can complete no-difference tracking by adopting a conventional PI regulator, and does not influence the normal work of the direct-current power supply unit. The lag generated by using a conventional low-pass filter for feedback regulation is avoided, the regulation error and regulation fluctuation generated when the conventional feedback does not process 300Hz are avoided, and the large fluctuation change and imbalance of the three-phase incoming line current generated under the condition of weak power grid caused by tracking static error existing after regulation are avoided.

Furthermore, in order to better implement the present invention, the switching frequency trap includes a switching voltage frequency trap and a switching current frequency trap, and an input end of the switching voltage frequency trap and an input end of the switching current frequency trap are respectively connected to a bus output end of the dc power supply unit.

Furthermore, in order to better implement the present invention, the six-pulse wave trap includes a voltage six-pulse wave trap and a current six-pulse wave trap, an input end of the voltage six-pulse wave trap is connected to an output end of the switching voltage frequency trap, and an input end of the current six-pulse wave trap is connected to an output end of the switching current frequency trap.

Furthermore, in order to better implement the present invention, the PI regulator includes a PI voltage regulator, a PI current regulator, an input end of the PI voltage regulator is connected with an output end of the voltage six-pulse wave trap, and an input end of the PI current regulator is connected with an output end of the current six-pulse wave trap; and the output end of the PI voltage regulator and the output end of the PI current regulator are respectively connected with the minimum value selection unit.

Furthermore, in order to better implement the present invention, the dc power supply unit further includes a first rectifier bridge, a high frequency transformer, and a second rectifier bridge, wherein an input end of the first rectifier bridge is connected to the power grid, an output end of the first rectifier bridge is connected to an input end of the IGBT inverter bridge, an output end of the IGBT inverter bridge is connected to an input end of the high frequency transformer, an output end of the high frequency transformer is connected to an input end of the second rectifier bridge, and an output end of the second rectifier bridge is connected to the switching voltage frequency trap and the switching current frequency trap, respectively.

A control detection method for a direct current power supply unit comprises the following steps:

step S1: extracting a feedback signal at a bus output end of the direct-current power supply unit;

step S2: connecting the feedback signal to a switching frequency wave trap and a six-pulse wave trap for filtering;

step S3: respectively comparing the processed voltage Udc and current Idc with a reference voltage V_refReference current I_refAdjusting the difference by a PI adjuster;

step S4: the PI regulator respectively sends the regulating values obtained by the difference of the voltage and the current to a minimum value selection unit;

step S5: the minimum value selection unit selects the minimum regulating value as a PID _ out signal and outputs the PID _ out signal to the PWM driving unit;

step S6: and the PWM driving unit converts the PID _ out signal into a PWM duty ratio and outputs the PWM duty ratio to the IGBT inverter bridge to control the IGBT inverter bridge.

Further, in order to better implement the present invention, the step S1 specifically includes the following steps: extracting feedback voltage V at two ends of bus output end capacitor C2 of direct current power supply unit_fAnd a feedback current I at the bus bar output_f。

Further, in order to better implement the present invention, the step S2 specifically includes the following steps: will feedback the voltage V_fThe input switching voltage frequency wave trap is used for carrying out high-frequency switching ripple wave filtering processing and then sending the processed signal to the voltage six-pulse wave trap; will feed back the current I_fThe current is input to a switching current frequency wave trap for high-frequency switching ripple wave filtering processing, and the processed current is transmitted to a current six-pulse wave trap;

the voltage six-pulse wave trap receives the feedback voltage processed by the switching voltage frequency trap and carries out filtering processing on the feedback voltage by a 300Hz six-pulse ripple wave to obtain a voltage Udc; and the current six-pulse wave trap receives the feedback current processed by the switching current frequency trap and carries out filtering processing on the feedback current by a 300Hz six-pulse ripple wave to obtain a current Idc.

Further, in order to better implement the present invention, the step S3 specifically includes the following steps: the voltage Udc obtained after the processing of the voltage six-pulse wave trap and the reference voltage V given by the system_refPerforming difference to obtain a voltage difference value, and sending the voltage difference value to the PI voltage regulator; the current Idc obtained after the processing of the current six-pulse wave trap and the reference current I given by the system_refAnd performing difference to obtain a current difference value, and sending the current difference value to the PI current regulator.

Further, in order to better implement the present invention, the step S4 specifically includes the following steps: the PI voltage regulator regulates the voltage difference value after the difference is made, the obtained voltage regulating value is sent to the minimum value selecting unit, the PI current regulator regulates the current difference value after the difference is made, and the obtained current regulating value is sent to the minimum value selecting unit.

Compared with the prior art, the invention has the beneficial effects that:

the filtering parameters of the bus input end and the bus output end of the direct current unit are extremely small, even if the filtering parameters are not small, the bus output end has larger alternating current ripples which comprise high-frequency secondary switching ripples and six-pulse ripple voltage, and the high-frequency secondary switching ripples and the six-pulse ripple voltage are filtered by using the wave trap, so that the quick response of a feedback signal of the bus output end of the direct current power supply unit cannot be influenced. When the power grid or the load suddenly changes, the PWM duty ratio of the IGBT inverter bridge can be quickly adjusted and controlled, the output of the direct-current power supply unit is quickly reduced, the shutdown faults such as overcurrent and overload can not be caused, and the loss and inconvenience brought to the load of a user side are avoided. After the wave trap of the invention is used for filtering fixed frequency, the output is direct current quantity, the voltage on a bus of a direct current power supply unit can not be influenced, and the large fluctuation change of three-phase incoming line current in weak network caused by adjusting and tracking a feedback signal can not occur.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a block diagram of the modules of the present invention;

FIG. 2 is a waveform of various parameters after passing through a trap processor according to the present invention;

FIG. 3 is a waveform of various parameters without being processed by the wave trap of the present invention;

fig. 4 is a block diagram of a conventional dc power supply unit.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Also, in the description of the present invention, the terms "first", "second", and the like are used for distinguishing between descriptions and not necessarily for describing a relative importance or implying any actual relationship or order between such entities or operations.