阅读说明：本技术 一种电压控制型半导体器件串联均压方法及均压电路 (Voltage-control type semiconductor device series voltage-sharing method and voltage-sharing circuit ) 是由 陈宇 童炉鹏 康勇 于 2020-06-23 设计创作，主要内容包括：本发明涉及电力电子技术领域,具体涉及一种电压控制型半导体器件串联均压方法及均压电路,其中方法包括：采集串联的每个半导体器件的第一极和第二极之间的电压信号,根据多个半导体器件的电压信号计算一个参考电压信号,分别计算多个电压信号与参考电压信号之间的误差补偿信号；根据误差补偿信号反馈控制对应的可控驱动电源输出的电压控制信号,以使得多个半导体器件同时导通或关断,从而达到均压的效果。该方法减少了杂散参数的引入,也降低了成本,同时功率损耗小、效率高、均压效果好。(The invention relates to the technical field of power electronics, in particular to a voltage-controlled semiconductor device series voltage-sharing method and a voltage-sharing circuit, wherein the method comprises the following steps: collecting voltage signals between a first pole and a second pole of each semiconductor device connected in series, calculating a reference voltage signal according to the voltage signals of the plurality of semiconductor devices, and respectively calculating error compensation signals between the plurality of voltage signals and the reference voltage signal; and controlling the voltage control signal output by the corresponding controllable driving power supply according to the error compensation signal feedback so as to simultaneously switch on or off the plurality of semiconductor devices, thereby achieving the effect of voltage sharing. The method reduces the introduction of stray parameters, reduces the cost, and has the advantages of low power loss, high efficiency and good voltage-sharing effect.)

1. A voltage-sharing method for series connection of voltage-controlled semiconductor devices, each semiconductor device comprising a first electrode, a second electrode and a control electrode, the control electrode of each semiconductor device being connected to an output terminal of a driving circuit, an input terminal of the driving circuit being connected to a controllable driving power supply, the method comprising:

collecting voltage signals between a first pole and a second pole of each semiconductor device connected in series to obtain a plurality of voltage signals;

calculating a reference voltage signal according to the voltage signals, and calculating error compensation signals between the voltage signals and the reference voltage signal respectively;

and according to the error compensation signal, carrying out feedback control on a voltage control signal output by the corresponding controllable driving power supply so as to simultaneously switch on or off the plurality of semiconductor devices.

2. A method for equalizing voltage in series of semiconductor devices according to claim 1, wherein said calculating a reference voltage information based on voltage signals of said plurality of semiconductor devices, respectively calculating error compensation signals between a plurality of voltage signals and said reference voltage information comprises:

and taking the voltage signal of one semiconductor device as the reference voltage signal or taking the average value of the voltage signals of all the semiconductor devices as the reference voltage signal, respectively calculating the difference value of the voltage signal of each semiconductor device and the reference voltage signal, and accumulating the difference values to obtain the error compensation signal.

3. A series voltage equalizing method for semiconductor devices according to claim 1, wherein said voltage control signal comprises a positive voltage signal and/or a negative voltage signal outputted from a controllable driving power supply;

the feedback control of the voltage control signal output by the corresponding controllable driving power supply according to the error compensation signal so as to enable the plurality of semiconductor devices to be simultaneously switched on or switched off comprises the following steps:

and controlling the positive voltage signal and/or the negative voltage signal output by the corresponding controllable driving power supply according to the error compensation signal in a feedback manner so as to change the voltage change rate input by the control electrode of the corresponding semiconductor device when the corresponding semiconductor device is switched on and/or switched off.

4. A method for grading a series voltage of semiconductor devices as recited in claim 3, further comprising: acquiring a current output voltage control signal of each controllable driving power supply, calculating a corresponding feedback control signal according to the error compensation signal and the current output voltage control signal, and performing feedback control on the corresponding voltage control signal output by the controllable driving power supply according to the feedback control signal so as to simultaneously switch on or switch off a plurality of semiconductor devices;

wherein, the obtaining of the current output voltage control signal of each controllable driving power supply, and the calculating of the corresponding feedback control signal according to the error compensation signal and the current output voltage control signal comprise:

and the feedback control signal is obtained after the error compensation signal and the voltage control signal are subjected to differential operation and feedback regulation operation in sequence, and the positive voltage signal and/or the negative voltage signal output by the corresponding controllable driving power supply are subjected to feedback control through the feedback control signal so as to change the voltage change rate input by the control electrode of the corresponding semiconductor device when the corresponding semiconductor device is switched on and/or switched off, so that all the semiconductor devices connected in series are switched on or switched off simultaneously.

5. A semiconductor device series voltage-sharing method as claimed in claim 4, wherein said feedback controlling the positive voltage signal and/or the negative voltage signal currently output by the corresponding controllable driving power source through the feedback control signal to change the voltage change rate of the gate input of the corresponding semiconductor device when the corresponding semiconductor device is turned on and/or off comprises:

the controllable driving power supply is controlled to output the positive pressure signal and/or the negative pressure signal through the feedback control signal; controlling a control electrode of the semiconductor device to switch on the positive voltage signal and the negative voltage signal so as to realize switching between the on state and the off state of the semiconductor device;

and the controllable driving power supply is subjected to feedback control to change the magnitude of the positive voltage signal and/or the negative voltage signal output by the controllable driving power supply so as to change the voltage change rate on the control electrode when the semiconductor devices are switched between the on state and the off state, so that all the semiconductor devices connected in series are switched on or off at the same time.

6. A series voltage-sharing circuit of a semiconductor device is characterized by comprising a plurality of controllable driving power supplies, a plurality of voltage measuring circuits, a plurality of driving circuits and at least one voltage-sharing adjusting module;

wherein the plurality of voltage measurement circuits are respectively for measuring voltage signals between first and second poles of the plurality of semiconductor devices;

the voltage-sharing adjusting module is used for calculating a reference voltage signal according to the voltage signals of the plurality of semiconductor devices and respectively calculating error compensation signals between the plurality of voltage signals and the reference voltage signal;

the plurality of controllable driving power supplies are used for outputting different voltage control signals and calculating corresponding feedback control signals according to the error compensation signals and the current output voltage control signals; and controlling a voltage control signal output at the next moment according to the feedback control signal;

the driving circuit is used for controlling the plurality of semiconductor devices to be simultaneously switched on or switched off according to the voltage control signal.

7. A semiconductor device series voltage grading circuit according to claim 6, characterized in that said voltage measuring circuit comprises a current sensor arranged in the static voltage grading circuit of the corresponding semiconductor device for measuring the current in the static voltage grading circuit of the corresponding semiconductor device, from which current the voltage signal between the first and second poles of the semiconductor device is calculated.

8. The semiconductor device series voltage-sharing circuit according to claim 6, wherein the controllable driving power supply comprises a control module, and the control module is configured to calculate a corresponding feedback control signal according to the error compensation signal and the current output voltage control signal, and control a voltage control signal output at a next time according to the feedback control signal.

9. The semiconductor device series voltage equalizing circuit of claim 8, wherein said controllable driving power supply further comprises a voltage output circuit for varying a voltage control signal output therefrom in accordance with a feedback control signal output from said control module.

10. The semiconductor device series voltage equalizing circuit according to claim 8, wherein the voltage control signal includes a positive voltage signal and/or a negative voltage signal output by the controllable driving power supply; the control module is used for controlling the magnitude of the positive pressure signal and/or the negative pressure signal output by the controllable driving power supply;

the driving circuit comprises a signal input end, wherein the signal input end is used for receiving a driving signal to control the driving circuit to switch on the positive voltage signal or the negative voltage signal so as to realize the switching of the semiconductor device between a conducting state and a switching-off state;

the control module is used for controlling the voltage output circuit in a feedback mode to change the magnitude of the positive voltage signal and/or the negative voltage signal output by the voltage output circuit so as to change the voltage change rate input by the control electrode of the corresponding semiconductor device when the corresponding semiconductor device is switched on and/or switched off, and therefore all the semiconductor devices connected in series can be switched on or switched off simultaneously.

Technical Field

The invention relates to the technical field of power electronics, in particular to a voltage-control type semiconductor device series connection voltage-sharing method and a voltage-sharing circuit.

Background

With the development of semiconductor technology, voltage control type power semiconductor devices represented by IGBTs and MOSFETs are widely used in high-power situations such as flexible dc power transmission, large renewable energy grid connection, medium-high voltage ac transmission, and the like. However, the voltage that a single power semiconductor device can bear is limited, and for the application occasions of high voltage class, the power semiconductor devices need to be connected in series to form a basic unit with higher voltage-resistant class. In addition, the switch unit formed by connecting the power semiconductor devices in series can bear high voltage, and the problems of low turn-off speed, large loss and the like caused by the increase of the thickness of a drift region of a single high-voltage switch tube can be solved.

The key of whether the series application of the power semiconductor devices can be realized is whether the voltage balance of each device under the switching transient state and the static state can be ensured, otherwise, the local overvoltage caused by the voltage unbalance can cause the overvoltage switch tube to be broken down, and the safety of all the series switch tubes is threatened. The main reasons for the voltage imbalance of the series power semiconductor devices include the dispersion of the parameters of the switching tubes and the asynchronization of the driving signals. The voltage distribution of the switching tube in a static state (in an off state) is unbalanced due to the inconsistency of parameters such as parasitic capacitance, off-state resistance and the like of the series power semiconductor device, and the problem can be better solved by connecting voltage-sharing resistors in parallel at two ends of the switching tube. However, there is no simple and easy solution to the problem of dynamic voltage imbalance of the power semiconductor device in the on/off transient state caused by different internal parameters and asynchronous driving signals among the devices, so that it is also a hot spot of current research.

Aiming at the problem of dynamic voltage sharing of direct series connection of power semiconductor devices, related researches provide solutions, and two methods, namely passive buffering and voltage clamping, are mainly adopted. The passive buffering method is mainly characterized in that RC or RCD buffers are connected in parallel at two ends of each series-connected switch tube, the change rate of the voltage of the collector and emitter of the switch tube is slowed down in the buffers, and instantaneous overvoltage is absorbed, so that the dynamic voltage difference between different switch tubes is reduced. In addition, the buffer circuit can greatly slow down the switching speed of the device, and simultaneously, the extra power loss can be increased, so that the efficiency is low in medium-power and high-power occasions. In addition, high power applications often require large buffer capacitors, which results in a bulky series switching cell. The voltage clamping method is that clamping circuits composed of Zener diodes, capacitors and other devices are connected between the collector and emitter of each switching device, when the voltage of the collector and emitter of a certain switching tube exceeds a certain value, the clamping circuits are triggered to clamp the voltage at two ends of the switching tube within a safe voltage. Compared with a passive buffering method, the method has small influence on the switching speed of the device, but can only avoid overvoltage at two ends of the device, but cannot control the voltage to keep balance in a dynamic process, and in addition, a clamping circuit can flow larger current when being triggered, so that higher power loss is caused. Active voltage clamping circuits are connected between the series-connected switch tubes, so that the switch tubes are mutually influenced, a voltage-sharing effect is achieved, the circuits are complex and not easy to realize, and the influence on the switching speed is increased.

Therefore, the dynamic voltage equalizing method for the direct series connection of the power semiconductor devices in the prior art has certain defects and needs to be improved.

Disclosure of Invention

In order to overcome the defects of the dynamic voltage-equalizing method for directly connecting power semiconductor devices in series in the prior art, the application provides a voltage-control type serial voltage-equalizing method for semiconductor devices and a voltage-equalizing circuit.

A series voltage-sharing method for voltage-controlled semiconductor devices, each semiconductor device comprising a first electrode, a second electrode and a control electrode, the control electrode of each semiconductor device being connected to an output terminal of a driving circuit, an input terminal of the driving circuit being connected to a controllable driving power supply, the method comprising:

collecting voltage signals between a first pole and a second pole of each semiconductor device connected in series to obtain a plurality of voltage signals;

calculating a reference voltage signal according to the voltage signals, and calculating error compensation signals between the voltage signals and the reference voltage signal respectively;

and according to the error compensation signal, carrying out feedback control on a voltage control signal output by the corresponding controllable driving power supply so as to simultaneously switch on or off the plurality of semiconductor devices.

In one embodiment, the calculating one reference voltage information from the voltage signals of the plurality of semiconductor devices, the calculating error compensation signals between the plurality of voltage signals and the reference voltage signal respectively includes:

and taking the voltage signal of one semiconductor device as the reference voltage signal or taking the average value of the voltage signals of all the semiconductor devices as the reference voltage signal, respectively calculating the difference value of the voltage signal of each semiconductor device and the reference voltage signal, and accumulating the difference values to obtain the error compensation signal.

In one embodiment, the voltage control signal comprises a positive voltage signal and/or a negative voltage signal output by the controllable driving power supply;

the feedback control of the voltage control signal output by the corresponding controllable driving power supply according to the error compensation signal so as to enable the plurality of semiconductor devices to be simultaneously switched on or switched off comprises the following steps:

and controlling the positive voltage signal and/or the negative voltage signal output by the corresponding controllable driving power supply according to the error compensation signal in a feedback manner so as to change the voltage change rate input by the control electrode of the corresponding semiconductor device when the corresponding semiconductor device is switched on and/or switched off.

In one embodiment, further comprising: acquiring a current output voltage control signal of each controllable driving power supply, calculating a corresponding feedback control signal according to the error compensation signal and the current output voltage control signal, and performing feedback control on the corresponding voltage control signal output by the controllable driving power supply according to the feedback control signal so as to simultaneously switch on or switch off a plurality of semiconductor devices;

the obtaining of the current output voltage control signal of each controllable driving power supply, and the calculating of the corresponding feedback control signal according to the error compensation signal and the current output voltage control signal include:

and the feedback control signal is obtained after the error compensation signal and the voltage control signal are subjected to differential operation and feedback regulation operation in sequence, and the positive voltage signal and/or the negative voltage signal output by the corresponding controllable driving power supply are subjected to feedback control through the feedback control signal so as to change the voltage change rate input by the control electrode of the corresponding semiconductor device when the corresponding semiconductor device is switched on and/or switched off, so that all the semiconductor devices connected in series are switched on or switched off simultaneously.

In one embodiment, the feedback controlling, by the feedback control signal, the positive voltage signal and/or the negative voltage signal currently output by the corresponding controllable driving power source to change the voltage change rate of the gate input of the corresponding semiconductor device when the corresponding semiconductor device is turned on and/or turned off includes:

the controllable driving power supply is controlled to output the positive pressure signal and/or the negative pressure signal through the feedback control signal; controlling a control electrode of the semiconductor device to switch on the positive voltage signal and the negative voltage signal so as to realize switching between the on state and the off state of the semiconductor device;

and the controllable driving power supply is subjected to feedback control to change the magnitude of the positive voltage signal and/or the negative voltage signal output by the controllable driving power supply so as to change the voltage change rate on the control electrode when the semiconductor devices are switched between the on state and the off state, so that all the semiconductor devices connected in series are switched on or off at the same time.

A series voltage-sharing circuit of a semiconductor device comprises a plurality of controllable driving power supplies, a plurality of voltage measuring circuits, a plurality of driving circuits and at least one voltage-sharing adjusting module;

wherein the plurality of voltage measurement circuits are respectively for measuring voltage signals between first and second poles of the plurality of semiconductor devices;

the voltage-sharing adjusting module is used for calculating a reference voltage signal according to the voltage signals of the plurality of semiconductor devices and respectively calculating error compensation signals between the plurality of voltage signals and the reference voltage signal;

the plurality of controllable driving power supplies are used for outputting different voltage control signals and calculating corresponding feedback control signals according to the error compensation signals and the current output voltage control signals; and controlling a voltage control signal output at the next moment according to the feedback control signal;

the driving circuit is used for controlling the plurality of semiconductor devices to be simultaneously switched on or switched off according to the voltage control signal.

In one embodiment, the voltage measuring circuit comprises a current sensor, the current sensor is arranged in the static voltage-sharing circuit of the corresponding semiconductor device and is used for measuring the current on the static voltage-sharing circuit of the corresponding semiconductor device, and the voltage signal between the first pole and the second pole of the semiconductor device is calculated through the current.

In an embodiment, the controllable driving power supply includes a control module, and the control module is configured to calculate a corresponding feedback control signal according to the error compensation signal and the current output voltage control signal, and control a voltage control signal output at a next time according to the feedback control signal.

In one embodiment, the controllable driving power supply further comprises a voltage output circuit, and the voltage output circuit is used for changing the output voltage control signal according to the feedback control signal output by the control module.

In one embodiment, the voltage control signal comprises a positive voltage signal and/or a negative voltage signal output by the controllable driving power supply; the control module is used for controlling the magnitude of the positive pressure signal and/or the negative pressure signal output by the controllable driving power supply;

the driving circuit comprises a signal input end, wherein the signal input end is used for receiving a driving signal to control the driving circuit to switch on the positive voltage signal or the negative voltage signal so as to realize the switching of the semiconductor device between a conducting state and a switching-off state;

the control module is used for controlling the voltage output circuit in a feedback mode to change the magnitude of the positive voltage signal and/or the negative voltage signal output by the voltage output circuit so as to change the voltage change rate input by the control electrode of the corresponding semiconductor device when the corresponding semiconductor device is switched on and/or switched off, and therefore all the semiconductor devices connected in series can be switched on or switched off simultaneously.

The semiconductor device series voltage equalizing method according to the above embodiment includes: collecting voltage signals between a first pole and a second pole of each semiconductor device connected in series to obtain a plurality of voltage signals; calculating a reference voltage signal according to the voltage signals, and calculating error compensation signals between the voltage signals and the reference voltage signal respectively; and controlling the voltage control signal output by the corresponding controllable driving power supply according to the error compensation signal feedback so as to simultaneously switch on or off the plurality of semiconductor devices, thereby achieving the effect of voltage sharing. Compared with the existing method, the method avoids the series connection of an additional auxiliary circuit between the control electrode and the first electrode or the second electrode of the semiconductor device, reduces the introduction of stray parameters, reduces the cost, and has small power loss, high efficiency and good voltage-sharing effect.

Drawings

Fig. 1 is a flowchart of a method for equalizing voltage of series connection of semiconductor devices according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a series voltage-sharing circuit of a semiconductor device according to an embodiment of the present application;

FIG. 3 is a circuit diagram of a voltage output circuit according to an embodiment of the present application;

FIG. 4 is a schematic structural diagram of a voltage measurement circuit and a voltage-sharing regulation module according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a control module according to an embodiment of the present disclosure;

fig. 6 is a schematic structural diagram of a controllable driving power supply according to an embodiment of the present application.

Detailed Description

The present invention will be described in further detail with reference to the following detailed description and accompanying drawings. Wherein like elements in different embodiments are numbered with like associated elements. In the following description, numerous details are set forth in order to provide a better understanding of the present application. However, those skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in detail in order to avoid obscuring the core of the present application from excessive description, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.

Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. Also, the various steps or actions in the method descriptions may be transposed or transposed in order, as will be apparent to one of ordinary skill in the art. Thus, the various sequences in the specification and drawings are for the purpose of describing certain embodiments only and are not intended to imply a required sequence unless otherwise indicated where such sequence must be followed.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning.

The semiconductor device in this application is a three-terminal transistor, the three terminals of which are a control electrode, a first electrode and a second electrode. The transistors may be Insulated Gate Bipolar Transistors (IGBTs), metal-oxide semiconductor field effect transistors (MOSFETs), or the like. For example, when the transistor is an IGBT, the control electrode refers to a gate electrode of the IGBT, the first electrode may be a collector or an emitter of the IGBT, and the corresponding second electrode may be an emitter or a collector of the IGBT; when the transistor is a MOSFET, the control electrode refers to the gate of the MOSFET, the first electrode may be the drain or source of the MOSFET, and the corresponding second electrode may be the source or drain of the MOSFET.