CN-121689763-B - Driving circuit for three-phase system power switching device

CN121689763BCN 121689763 BCN121689763 BCN 121689763BCN-121689763-B

Abstract

The invention provides a driving circuit for a power switch device of a three-phase system, the three-phase system comprises power switch groups corresponding to each phase one by one, the power switch groups comprise an upper bridge arm power switch and a lower bridge arm power switch, the driving circuit corresponds to the upper bridge arm power switch, the driving circuit comprises a capacitive voltage division circuit, a voltage stabilizing circuit and a push-pull driving circuit, the capacitive voltage division circuit is respectively connected with two phases except the corresponding phase, and the output end of the capacitive voltage division circuit is connected with the upper bridge arm power switch of the corresponding phase sequentially through the corresponding voltage stabilizing circuit and the push-pull driving circuit, so that direct electricity taking from a three-phase power supply and stable direct current voltage generation are realized. The invention realizes the efficient and reliable driving of the power switch device and overcomes the limitation of relying on a heavy isolation transformer or a complex switching power supply in the traditional driving circuit.

Inventors

TAN YOUQI
ZHOU DONGQING
LI JUAN
XIAO XIANGCHEN
TAN XULIN
ZHANG YI
ZHOU KEHUI
TANG HAIGUO
WANG YANQING
TAN SHENGQI
ZHENG SHUAI

Assignees

国网湖南省电力有限公司
国网湖南省电力有限公司永州供电分公司
国网湖南省电力有限公司电力科学研究院
国家电网有限公司

Dates

Publication Date: 20260508
Application Date: 20260210

Claims (6)

1. The driving circuit for the three-phase system power switch device is characterized in that the three-phase system comprises a power switch group corresponding to each phase one by one, the power switch group comprises an upper bridge arm power switch and a lower bridge arm power switch, the driving circuit corresponds to the upper bridge arm power switch, the driving circuit comprises a capacitance voltage dividing circuit, a voltage stabilizing circuit and a push-pull driving circuit, two phases except the corresponding phases are respectively connected, the output end of the capacitance voltage dividing circuit is sequentially connected with the upper bridge arm power switch of the corresponding phase through the corresponding voltage stabilizing circuit and the push-pull driving circuit, direct electricity taking from a three-phase power supply and stable direct voltage generation are realized, the capacitance voltage dividing circuit comprises a first isolation capacitor, a second isolation capacitor, a first diode, a second diode and a filter capacitor, the anode of the first diode is connected with one phase of the two phases except the corresponding phase through the first isolation capacitor, the anode of the second diode is connected with the other phase of the corresponding phase through the second isolation capacitor, and the cathode of the first diode is connected with the cathode of the corresponding voltage dividing circuit and the cathode of the corresponding filter capacitor is connected with the anode of the voltage dividing circuit and the cathode of the corresponding bridge arm power switch circuit as the positive electrode of the reference capacitor.
2. The driving circuit for a three-phase system power switch device according to claim 1, wherein the upper bridge arm power switch adopts a MOSFET switch or a pair of anti-parallel IGBTs, when the upper bridge arm power switch adopts a MOSFET switch, the cathode of the first diode and the cathode of the second diode are both connected with the source of the corresponding phase MOSFET switch through a filter capacitor, and when the upper bridge arm power switch adopts a pair of anti-parallel IGBTs, the driving circuit is in one-to-one correspondence with the IGBTs, and the cathode of the first diode and the cathode of the second diode are both connected with the emitter of the corresponding IGBT through the filter capacitor.
3. The driving circuit for the three-phase system power switching device according to claim 1, wherein the voltage stabilizing circuit comprises a first current limiting resistor, a second current limiting resistor, a triode, a voltage stabilizing diode, a compensation capacitor and an output capacitor, wherein the positive electrode of the output end of the capacitance voltage dividing circuit is connected with the collector electrode of the triode through the first current limiting resistor, the positive electrode of the output end of the capacitance voltage dividing circuit is connected with the base electrode of the triode through the second current limiting resistor, the emitting electrode of the triode is connected with the positive electrode of the output capacitor, the base electrode of the triode is also connected with the cathode of the voltage stabilizing diode, the compensation capacitor is connected between the base electrode of the triode and the positive electrode of the output capacitor, the anode of the voltage stabilizing diode is connected with the driving reference ground of the upper bridge arm power switch of the corresponding phase, and the positive electrode and the negative electrode of the output capacitor are respectively connected with the corresponding driving circuit as the positive electrode and the negative electrode of the output end of the voltage stabilizing circuit.
4. The driving circuit for a three-phase system power switching device according to claim 3, wherein the upper bridge arm power switch adopts a MOSFET switch or a pair of anti-parallel IGBTs, when the upper bridge arm power switch adopts a MOSFET switch, the anode of the zener diode is connected to the source of the corresponding phase MOSFET switch, and when the upper bridge arm power switch adopts a pair of anti-parallel IGBTs, the driving circuit is in one-to-one correspondence with the IGBTs, and the anode of the zener diode is connected to the emitter of the corresponding phase IGBT.
5. The driving circuit for a three-phase system power switching device according to claim 1, wherein the push-pull driving circuit comprises a first triode and a second triode, and further comprises a base current limiting resistor and an accelerating capacitor which are connected in parallel, wherein bases of the first triode and the second triode are connected with external driving control signals through the base current limiting resistor and the accelerating capacitor which are connected in parallel, a collector of the first triode is connected with an output positive electrode of the voltage stabilizing circuit, a collector of the second triode is connected with a driving reference ground of an upper bridge arm power switch of a corresponding phase, and an emitter of the first triode and an emitter of the second triode form a push-pull output end which is connected to a controlled end of the upper bridge arm power switch of the corresponding phase.
6. The driving circuit for a three-phase system power switching device according to claim 5, wherein the upper bridge arm power switch adopts a MOSFET switch or a pair of anti-parallel IGBTs, when the upper bridge arm power switch adopts a MOSFET switch, a collector of the second triode is connected with a source of the corresponding phase MOSFET switch, emitters of the first triode and the second triode form push-pull output ends to be connected with gates of the corresponding phase MOSFET switch, when the upper bridge arm power switch adopts a pair of anti-parallel IGBTs, the driving circuit is in one-to-one correspondence with the IGBTs, a collector of the second triode is connected with an emitter of the corresponding phase IGBT, and emitters of the first triode and the second triode form push-pull output ends to be connected with gates of the corresponding phase IGBT.

Description

Driving circuit for three-phase system power switching device Technical Field The invention relates to the technical field of power electronics, in particular to a driving circuit for a three-phase system power switching device. Background Insulated Gate Bipolar Transistors (IGBTs) and Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) are used as core power switching devices in modern power electronics, and their reliable, efficient operating state is highly dependent on the performance of the gate drive circuit. An excellent driving circuit needs to provide pulse voltage with enough amplitude, steep rising edge and falling edge for the grid electrode of the power device, and has necessary functions of isolation, protection and voltage stabilization. In the application of three-phase alternating current systems (such as three-phase motor variable frequency drive, three-phase uninterruptible power supply, photovoltaic/wind power inverter, etc.), it is a great technical challenge to provide a driving power supply for the IGBT or MOSFET of the upper bridge arm. Because the reference ground (emitter or source) of the upper bridge arm power device is suspended on a high potential, the traditional single direct current bus power supply driving scheme cannot be directly applied. Currently, the main technical solutions for solving this problem mainly include the following two types: An isolation transformer is used, which is a classical solution. The low voltage power supply energy at the control board is coupled to each floating drive point through a multi-path isolation transformer. The advantage of this solution is that the technology is mature and reliable electrical isolation can be provided. However, the disadvantages are also significant in that isolation transformers are often bulky, heavy, and disadvantageous for the miniaturised and lightweight design of power electronics, and in that the core material and non-ideal properties of the transformer may limit its operation at high frequencies and introduce significant electromagnetic interference (EMI). This is a more modern solution, using a dedicated switching power supply, such as a switched capacitor charge pump or an isolated DC-DC module. Independent isolated power is provided for each upper leg drive circuit by either designing a complex switching power circuit (e.g., an ASIC-based charge pump) or directly using a finished isolated DC-DC power module. This approach, while excellent in performance, introduces significant complexity and cost. The special chip or module has higher price, and the peripheral circuit has complex design, thus increasing the number of components, the PCB area and the whole cost of the whole system. In summary, there is a common contradiction between the conventional driving power scheme, that is, the requirement of high performance isolation driving (such as a transformer scheme) is difficult to meet if a simple structure and low cost are pursued, and that is, complicated circuit, high cost and large volume are often accompanied if high performance and high reliability are pursued (such as a switching power scheme). This contradiction is particularly pronounced in situations such as three-phase systems where multiple isolated drive power sources are required. Disclosure of Invention The invention aims to solve the technical problems in the prior art, and provides a driving circuit for a three-phase system power switching device, which can safely and efficiently obtain energy from a main power loop directly on the premise of not depending on a heavy transformer and a complex switching power supply, and provide stable and reliable driving voltage for IGBT/MOSFET of an upper bridge arm, thereby realizing good balance of cost, volume and performance, and particularly optimizing driving stability and anti-interference capability under a high dv/dt environment. In order to solve the technical problems, the invention adopts the following technical scheme: The driving circuit comprises a capacitance voltage division circuit, a voltage stabilizing circuit and a push-pull driving circuit, wherein the capacitance voltage division circuit is respectively connected with two phases except the corresponding phase, and the output end of the capacitance voltage division circuit is connected with the upper bridge arm power switch of the corresponding phase sequentially through the corresponding voltage stabilizing circuit and the push-pull driving circuit, so that direct electricity taking from a three-phase power supply and stable direct voltage generation are realized. Further, the capacitive voltage divider circuit comprises a first isolation capacitor, a second isolation capacitor, a first diode, a second diode and a filter capacitor, wherein the anode of the first diode is connected with one of two phases except the corresponding phase through the first isolation capacitor, the anode of the second diode is connected with the oth