Topological fault-tolerant reconstruction circuit and switching method for three-phase series-winding AC motor drive

Abstract

The present invention provides a three-phase series-winding AC motor drive topology fault-tolerant reconstruction circuit and switching method, including a first bridge arm, a second bridge arm, a third bridge arm, a fourth bridge arm, a first bidirectional thyristor, a second bidirectional thyristor, a third bidirectional thyristor, a fourth bidirectional thyristor, a fifth bidirectional thyristor, a sixth bidirectional thyristor, a first uncontrolled three-phase rectifier bridge and a ninth power switch device; each bridge arm includes an upper bridge arm power switch device and a lower bridge arm power switch device. The application of this technical solution can ensure that the three-phase series-winding AC motor drive topology can continue to operate fault-tolerantly when various types of faults such as open circuit and short circuit of the AC motor stator winding and the motor driver bridge arm occur, thereby improving the reliability of the motor drive system.

Description

Technical Field

[0001] The present invention relates to the field of AC motor and drive control technology, in particular to a three-phase series winding AC motor drive topology fault-tolerant reconstruction circuit and a switching method. Background Art

[0002] The rapid development of motor drive systems in electric vehicles, drones, industrial robots, and other applications places increasing demands on the performance of these systems. Currently, the most popular AC motor drive topologies include conventional three-phase inverters connected to Y-type motors, dual-inverter open-winding motor topologies, and three-phase series winding topologies. The traditional single inverter connected to the Y-type motor drive system, a single inverter connected to the Y-type load, includes three bridge arms, its topology is simple, and has no fault-tolerant operation capability; the dual inverter open winding motor topology opens the neutral point of the Y-type connected motor stator winding, and the two ends of the winding are powered by two inverters respectively. The inverter utilization rate is high and can output multiple levels. The topology structure is redundant and has fault-tolerant operation capability, but the number of switches is large, the cost is high, and the control is complex; the three-phase series winding topology opens the neutral point of the motor's three-phase stator winding and connects the three-phase winding in series. At the same time, a bridge arm is added to the traditional three-phase inverter to form a three-phase four-bridge arm structure. It is a new type of motor controller topology. Without weakening the magnetic field, the speed range of the three-phase series winding topology is increased, the fault tolerance performance is improved, and the switching device demand is less. It has good driving performance and prospects for industrial application.

[0003] The introduction of power electronic controllers increases the likelihood of motor drive system failures. However, reliability is a key indicator for evaluating motor drive system performance. Therefore, it is increasingly important for three-phase motor systems to be able to operate fault-tolerantly after a fault occurs. There are seven typical fault conditions in the three-phase series winding topology, including four-bridge arm faults and three-winding faults. When a phase winding or two side bridge arms of the controller are open-circuited, the motor can achieve fault-tolerant operation in two-phase mode when driven by four bridge arms, but the output capacity will be reduced. When the two middle bridge arms of the controller are open-circuited, the same current flows through the two windings, and the motor cannot generate smooth torque. Additional circuits are required to obtain the same structure as the previous type of fault in order to achieve fault-tolerant operation.

[0004] Therefore, the current topological fault-tolerant control strategy for three-phase series-winding AC motor drives is difficult to cover all possible fault types such as open circuit and short circuit that may occur in the driver bridge arm and motor stator winding. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a three-phase series winding type AC motor drive topology fault-tolerant reconstruction circuit and switching method to ensure that the three-phase series winding type AC motor drive topology can continue to operate fault-tolerantly when various types of faults such as AC motor stator winding and motor driver bridge arm open circuit and short circuit occur, thereby improving the reliability of the motor drive system.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a three-phase series winding type AC motor drive topology fault-tolerant reconstruction circuit and switching method, including a first bridge arm, a second bridge arm, a third bridge arm, a fourth bridge arm, a first bidirectional thyristor, a second bidirectional thyristor, a third bidirectional thyristor, a fourth bidirectional thyristor, a fifth bidirectional thyristor, a sixth bidirectional thyristor, a first uncontrolled three-phase rectifier bridge and a ninth power switch device; the first bridge arm includes a first upper bridge arm power switch device and a first lower bridge arm power switch device, the second bridge arm includes a second upper bridge arm power switch device and a second lower bridge arm power switch device, the third bridge arm includes a third upper bridge arm power switch device and a third lower bridge arm power switch device, the fourth bridge arm includes a fourth upper bridge arm power switch device and a fourth lower bridge arm power switch device; the first upper bridge arm power switch device, the second upper arm power switch device, and the second lower bridge arm power switch device are connected. The upper nodes of the first upper arm power switch device, the third upper arm power switch device and the fourth upper arm power switch device are respectively connected to the DC bus voltage; the lower nodes of the first lower arm power switch device, the second lower arm power switch device, the third lower arm power switch device and the fourth lower arm power switch device are respectively connected to the power ground; the lower node of the first upper arm power switch device is connected to the upper node of the first lower arm power switch device as the output node of the first bridge arm; the lower node of the second upper arm power switch device is connected to the upper node of the second lower arm power switch device as the output node of the second bridge arm; the lower node of the third upper arm power switch device is connected to the upper node of the third lower arm power switch device as the output node of the third bridge arm; the lower node of the fourth upper arm power switch device is connected to the upper node of the fourth lower arm power switch device as the output node of the fourth bridge arm;

[0007] The left node of the first bidirectional thyristor is connected to the output node of the first bridge arm, the left node of the third bidirectional thyristor is connected to the output node of the second bridge arm, the left node of the fifth bidirectional thyristor is connected to the output node of the third bridge arm, the right node of the second bidirectional thyristor is connected to the output node of the second bridge arm, the right node of the fourth bidirectional thyristor is connected to the output node of the third bridge arm, and the right node of the sixth bidirectional thyristor is connected to the output node of the fourth bridge arm;

[0008] The left node of the A-phase winding is connected to the right node of the first bidirectional thyristor, the middle node of the A-phase winding is connected to the first input node of the first uncontrolled three-phase rectifier bridge, and the right node of the A-phase winding is connected to the left node of the second bidirectional thyristor;

[0009] The left node of the B-phase winding is connected to the right node of the third bidirectional thyristor, the middle node of the B-phase winding is connected to the second input node of the first uncontrolled three-phase rectifier bridge, and the right node of the B-phase winding is connected to the left node of the fourth bidirectional thyristor;

[0010] The left node of the C-phase winding is connected to the right node of the fifth bidirectional thyristor, the middle node of the C-phase winding is connected to the third input node of the first uncontrolled three-phase rectifier bridge, and the right node of the C-phase winding is connected to the left node of the sixth bidirectional thyristor;

[0011] The upper node of the ninth power switch device is connected to the positive output node of the first uncontrolled three-phase rectifier bridge, and the lower node of the ninth power switch device is connected to the negative output node of the first uncontrolled three-phase rectifier bridge.

[0012] In a preferred embodiment, the first bidirectional thyristor, the second bidirectional thyristor, the third bidirectional thyristor, the fourth bidirectional thyristor, the fifth bidirectional thyristor, the sixth bidirectional thyristor and the ninth power switch device are used to switch the topology of the AC motor drive system.

[0013] In a preferred embodiment, when the AC motor drive system is operating normally, the ninth power switch is turned off, the first bidirectional thyristor is turned on, the second bidirectional thyristor is turned on, the third bidirectional thyristor is turned on, the fourth bidirectional thyristor is turned on, the fifth bidirectional thyristor is turned on, and the sixth bidirectional thyristor is turned on. The AC motor is driven by the first bridge arm, the second bridge arm, the third bridge arm, and the fourth bridge arm. This is a three-phase series winding type AC motor drive topology in normal operating mode, which is suitable for normal operation of the motor within the full speed range.

[0014] In a preferred embodiment, when the system detects a fault in the power switching device of the second bridge arm, a fault between the middle node and the right node of the A-phase winding, a fault between the left node and the middle node of the B-phase winding, or a fault between the left node and the middle node of the C-phase winding, the power switching device of the second bridge arm is turned off, the second bidirectional thyristor is turned off, the third bidirectional thyristor is turned off, the fifth bidirectional thyristor is turned off, the first bidirectional thyristor is turned on, the fourth bidirectional thyristor is turned on, the sixth bidirectional thyristor is turned on, and the ninth power switching device is turned on. The AC motor is driven by the first bridge arm, the third bridge arm, and the fourth bridge arm. This is a three-phase series winding AC motor drive topology in the first fault-tolerant operation mode. Due to the winding current limitation, the output torque needs to be reduced.

[0015] In a preferred embodiment, when the system detects a fault in the power switching device of the third bridge arm, a fault between the middle node and the right node of the A-phase winding, a fault between the middle node and the right node of the B-phase winding, or a fault between the left node and the middle node of the C-phase winding, the power switching device of the third bridge arm is turned off, the second bidirectional thyristor is turned off, the fourth bidirectional thyristor is turned off, the fifth bidirectional thyristor is turned off, the first bidirectional thyristor is turned on, the third bidirectional thyristor is turned on, the sixth bidirectional thyristor is turned on, and the ninth power switching device is turned on. The AC motor is driven by the first bridge arm, the second bridge arm, and the fourth bridge arm. This is a three-phase series winding AC motor drive topology in the second fault-tolerant operation mode, which is suitable for the motor to operate within the full speed range. Due to the winding current limit, the output torque needs to be reduced.

[0016] In a preferred embodiment, when the system detects a fault in the power switching device of the first bridge arm, a fault between the left node and the middle node of the A-phase winding, a fault between the left node and the middle node of the B-phase winding, or a fault between the left node and the middle node of the C-phase winding, the power switching device of the first bridge arm is turned off, the first bidirectional thyristor is turned off, the third bidirectional thyristor is turned off, the fifth bidirectional thyristor is turned off, the second bidirectional thyristor is turned on, the fourth bidirectional thyristor is turned on, the sixth bidirectional thyristor is turned on, and the ninth power switching device is turned on. The AC motor is driven by the second bridge arm, the third bridge arm, and the fourth bridge arm. This is a three-phase series winding AC motor drive topology in the third fault-tolerant operation mode, which is suitable for the motor to operate within the full speed range. Due to the winding current limit, the output torque needs to be reduced.

[0017] In a preferred embodiment, when the system detects a fault in the power switching device of the fourth bridge arm, a fault between the middle node and the right node of the A-phase winding, a fault between the middle node and the right node of the B-phase winding, and a fault between the middle node and the right node of the C-phase winding, the power switching device of the fourth bridge arm is turned off, the second bidirectional thyristor is turned off, the fourth bidirectional thyristor is turned off, the sixth bidirectional thyristor is turned off, the first bidirectional thyristor is turned on, the third bidirectional thyristor is turned on, the fifth bidirectional thyristor is turned on, and the ninth power switching device is turned on. The AC motor is driven by the first bridge arm, the second bridge arm, and the third bridge arm. This is a three-phase series winding AC motor drive topology in the fourth fault-tolerant operation mode, which is suitable for the motor to operate within the full speed range. Due to the winding current limit, the output torque needs to be reduced.

[0018] In a preferred embodiment, when the system detects a fault in the power switching device of the fourth bridge arm or a fault between the left node and the right node of the C-phase winding, the power switching device of the fourth bridge arm is turned off, the fifth bidirectional thyristor is turned off, the sixth bidirectional thyristor is turned off, the first bidirectional thyristor is turned on, the second bidirectional thyristor is turned on, the third bidirectional thyristor is turned on, the fourth bidirectional thyristor is turned on, and the ninth power switching device is turned off. The AC motor is driven by the first bridge arm, the second bridge arm, and the third bridge arm. This is a three-phase series winding AC motor drive topology in the fifth fault-tolerant operation mode, which is suitable for the motor to operate fault-tolerantly within the full speed range. The motor operates in a two-phase operation mode, and the output torque needs to be reduced.

[0019] In a preferred embodiment, when the system detects a fault between the left node and the right node of the B-phase winding, the third bidirectional thyristor is turned off, the fourth bidirectional thyristor is turned off, the ninth power switch device is turned off, the first bidirectional thyristor is turned on, the second bidirectional thyristor is turned on, the fifth bidirectional thyristor is turned on, and the sixth bidirectional thyristor is turned on. The AC motor is driven by the first bridge arm, the second bridge arm, the third bridge arm, and the fourth bridge arm. This is a three-phase series winding AC motor drive topology in the sixth fault-tolerant operation mode, which is suitable for the motor to operate fault-tolerantly within the full speed range. The motor works in a two-phase operation mode, and the output torque needs to be reduced.

[0020] In a preferred embodiment, when the system detects a fault in the power switching device of the first bridge arm or a fault between the left node and the right node of the A-phase winding, the power switching device of the first bridge arm is turned off, the first bidirectional thyristor is turned off, the second bidirectional thyristor is turned off, the third bidirectional thyristor is turned on, the fourth bidirectional thyristor is turned on, the fifth bidirectional thyristor is turned on, the sixth bidirectional thyristor is turned on, and the ninth power switching device is turned off. The AC motor is driven by the second bridge arm, the third bridge arm, and the fourth bridge arm. This is a three-phase series winding AC motor drive topology in the seventh fault-tolerant operation mode, which is suitable for the motor to operate fault-tolerantly within the full speed range. The motor operates in a two-phase operation mode, and the output torque needs to be reduced.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The three-phase series winding AC motor drive topology fault-tolerant reconstruction circuit and switching method proposed in the present invention can operate fault-tolerantly in the event of various faults such as open circuit and short circuit in the AC motor stator winding and the motor controller bridge arm;

[0023] 2. Compared with the three-phase series winding topology, the three-phase series winding AC motor drive topology fault-tolerant reconstruction circuit proposed in this invention only needs to add six thyristors, a three-phase rectifier bridge and an insulated gate bipolar transistor. The additional device operating frequency and hardware cost are low, which can significantly improve the operating reliability of the three-phase series winding motor drive system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a fault-tolerant reconfiguration topology of a three-phase series-winding AC motor according to a preferred embodiment of the present invention;

[0025] Figure 2 This is a three-phase series winding AC motor drive topology during normal operation of a preferred embodiment of the present invention;

[0026] Figure 3 A three-phase series winding type AC motor drive topology during the first fault-tolerant operation of a preferred embodiment of the present invention;

[0027] Figure 4 The third embodiment of the present invention is a three-phase series winding type AC motor drive topology during the second fault-tolerant operation.

[0028] Figure 5 This is a three-phase series winding type AC motor drive topology during the third fault-tolerant operation of the preferred embodiment of the present invention;

[0029] Figure 6 This is a third-phase series winding AC motor drive topology during fault-tolerant operation according to a preferred embodiment of the present invention;

[0030] Figure 7 This is a fifth fault-tolerant operation three-phase series winding type AC motor drive topology according to a preferred embodiment of the present invention;

[0031] Figure 8 The third embodiment of the present invention is a three-phase series winding type AC motor drive topology during the sixth fault-tolerant operation.

[0032] Figure 9 This is the seventh fault-tolerant operation three-phase series winding type AC motor drive topology of the preferred embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0035] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application; as used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form, and it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations.

[0036] A three-phase series winding AC motor drive topology fault-tolerant reconstruction circuit, reference Figure 1 , including a first bridge arm, a second bridge arm, a third bridge arm, a fourth bridge arm, a first bidirectional thyristor Tr1, a second bidirectional thyristor Tr2, a third bidirectional thyristor Tr3, a fourth bidirectional thyristor Tr4, a fifth bidirectional thyristor Tr5, a sixth bidirectional thyristor Tr6, a first uncontrolled three-phase rectifier bridge and a ninth power switch device T9. The first bridge arm includes a first upper bridge arm power switch device T1 and a first lower bridge arm power switch device T2, the second bridge arm includes a second upper bridge arm power switch device T3 and a second lower bridge arm power switch device T4, the third bridge arm includes a third upper bridge arm power switch device T5 and a third lower bridge arm power switch device T6, and the fourth bridge arm includes a fourth upper bridge arm power switch device T7 and a fourth lower bridge arm power switch device T8;

[0037] The upper nodes of the first upper bridge arm power switch device T1, the second upper bridge arm power switch device T3, the third upper bridge arm power switch device T5 and the fourth upper bridge arm power switch device T7 are respectively connected to the DC bus voltage; the lower nodes of the first lower bridge arm power switch device T2, the second lower bridge arm power switch device T4, the third lower bridge arm power switch device T6 and the fourth lower bridge arm power switch device T8 are respectively connected to the power ground; the lower node of the first upper bridge arm power switch device T1 is connected to the upper node of the first lower bridge arm power switch device T2 as the output node of the first bridge arm; the lower node of the second upper bridge arm power switch device T3 is connected to the upper node of the second lower bridge arm power switch device T4 as the output node of the second bridge arm; the lower node of the third upper bridge arm power switch device T5 is connected to the upper node of the third lower bridge arm power switch device T6 as the output node of the third bridge arm; the lower node of the fourth upper bridge arm power switch device T7 is connected to the upper node of the fourth lower bridge arm power switch device T8 as the output node of the fourth bridge arm.

[0038] The left node of the first bidirectional thyristor Tr1 is connected to the output node of the first bridge arm, the left node of the third bidirectional thyristor Tr3 is connected to the output node of the second bridge arm, the left node of the fifth bidirectional thyristor Tr5 is connected to the output node of the third bridge arm, the right node of the second bidirectional thyristor Tr2 is connected to the output node of the second bridge arm, the right node of the fourth bidirectional thyristor Tr4 is connected to the output node of the third bridge arm, and the right node of the sixth bidirectional thyristor Tr6 is connected to the output node of the fourth bridge arm.

[0039] The left node of the A-phase winding is connected to the right node of the first bidirectional thyristor Tr1, the middle node of the A-phase winding is connected to the first input node of the first uncontrolled three-phase rectifier bridge, and the right node of the A-phase winding is connected to the left node of the second bidirectional thyristor Tr2;

[0040] The left node of the B-phase winding is connected to the right node of the third bidirectional thyristor Tr3, the middle node of the B-phase winding is connected to the second input node of the first uncontrolled three-phase rectifier bridge, and the right node of the B-phase winding is connected to the left node of the fourth bidirectional thyristor Tr4;

[0041] The left node of the C-phase winding is connected to the right node of the fifth bidirectional thyristor Tr5, the middle node of the C-phase winding is connected to the third input node of the first uncontrolled three-phase rectifier bridge, and the right node of the C-phase winding is connected to the left node of the sixth bidirectional thyristor Tr6;

[0042] The upper node of the ninth power switch device T9 is connected to the positive output node of the first uncontrolled three-phase rectifier bridge, and the lower node of the ninth power switch device T9 is connected to the negative output node of the first uncontrolled three-phase rectifier bridge;

[0043] The first bidirectional thyristor Tr1, the second bidirectional thyristor Tr2, the third bidirectional thyristor Tr3, the fourth bidirectional thyristor Tr4, the fifth bidirectional thyristor Tr5, the sixth bidirectional thyristor Tr6 and the ninth power switch device T9 are used to switch the topology of the AC motor drive system:

[0044] When the AC motor drive system operates normally, the ninth power switch device T9 is turned off, the first bidirectional thyristor Tr1 is turned on, the second bidirectional thyristor Tr2 is turned on, the third bidirectional thyristor Tr3 is turned on, the fourth bidirectional thyristor Tr4 is turned on, the fifth bidirectional thyristor Tr5 is turned on, and the sixth bidirectional thyristor Tr6 is turned on. The AC motor is driven by the first bridge arm, the second bridge arm, the third bridge arm, and the fourth bridge arm. This is a three-phase series winding type AC motor drive topology in normal operating mode, such as Figure 2 As shown, it is applicable to the normal operation of the motor in the full speed range;

[0045] When the system detects a fault in the second upper bridge arm power switch device T3 and the second lower bridge arm power switch device T4 of the second bridge arm, a fault between the middle node and the right node of the A phase winding, a fault between the left node and the middle node of the B phase winding, or a fault between the left node and the middle node of the C phase winding, the system turns off the second upper bridge arm power switch device T3 and the second lower bridge arm power switch device T4 of the second bridge arm, turns off the second bidirectional thyristor Tr2, turns off the third bidirectional thyristor Tr3, turns off the fifth bidirectional thyristor Tr5, turns on the first bidirectional thyristor Tr1, turns on the fourth bidirectional thyristor Tr4, turns on the sixth bidirectional thyristor Tr6, and turns on the ninth power switch device T9. The AC motor is driven by the first bridge arm, the third bridge arm, and the fourth bridge arm, which is a three-phase series winding AC motor drive topology in the first fault-tolerant operation mode, such as Figure 3 As shown, due to the limitation of winding current, the output torque needs to be derated;

[0046] When the system detects a fault in the third upper bridge arm power switch device T5 and the third lower bridge arm power switch device T6 of the third bridge arm, a fault between the middle node and the right node of the A phase winding, a fault between the middle node and the right node of the B phase winding, or a fault between the left node and the middle node of the C phase winding, the system turns off the third upper bridge arm power switch device T5 and the third lower bridge arm power switch device T6 of the third bridge arm, turns off the second bidirectional thyristor Tr2, turns off the fourth bidirectional thyristor Tr4, turns off the fifth bidirectional thyristor Tr5, turns on the first bidirectional thyristor Tr1, turns on the third bidirectional thyristor Tr3, turns on the sixth bidirectional thyristor Tr6, and turns on the ninth power switch device T9. The AC motor is driven by the first bridge arm, the second bridge arm, and the fourth bridge arm, which is a three-phase series winding AC motor drive topology in the second fault-tolerant operation mode, such as Figure 4 As shown, it is applicable to the situation where the motor is running incorrectly within the full speed range and the output torque needs to be derated due to the winding current limitation.

[0047] When the system detects a fault in the first upper bridge arm power switch device T1 and the first lower bridge arm power switch device T2 of the first bridge arm, a fault between the left node and the middle node of the A-phase winding, a fault between the left node and the middle node of the B-phase winding, or a fault between the left node and the middle node of the C-phase winding, the system turns off the first upper bridge arm power switch device T1 and the first lower bridge arm power switch device T2 of the first bridge arm, turns off the first bidirectional thyristor Tr1, turns off the third bidirectional thyristor Tr3, turns off the fifth bidirectional thyristor Tr5, turns on the second bidirectional thyristor Tr2, turns on the fourth bidirectional thyristor Tr4, turns on the sixth bidirectional thyristor Tr6, and turns on the ninth power switch device T9. The AC motor is driven by the second bridge arm, the third bridge arm, and the fourth bridge arm, which is a three-phase series winding AC motor drive topology in the third fault-tolerant operation mode, such as Figure 5 As shown, it is applicable to the situation where the motor is running incorrectly within the full speed range and the output torque needs to be derated due to the winding current limitation.

[0048] When the system detects a fault in the fourth upper bridge arm power switch device T7 and the fourth lower bridge arm power switch device T8 of the fourth bridge arm, a fault between the middle node and the right node of the A phase winding, a fault between the middle node and the right node of the B phase winding, and a fault between the middle node and the right node of the C phase winding, the fourth upper bridge arm power switch device T7 and the fourth lower bridge arm power switch device T8 of the fourth bridge arm are turned off, the second bidirectional thyristor Tr2, the fourth bidirectional thyristor Tr4, the sixth bidirectional thyristor Tr6 are turned off, the first bidirectional thyristor Tr1, the third bidirectional thyristor Tr3, the fifth bidirectional thyristor Tr5, and the ninth power switch device T9 are turned on, and the AC motor is driven by the first bridge arm, the second bridge arm, and the third bridge arm, which is a three-phase series winding AC motor drive topology in the fourth fault-tolerant operation mode, as shown in FIG. Figure 6As shown, it is applicable to the situation where the motor is running incorrectly within the full speed range and the output torque needs to be derated due to the winding current limitation.

[0049] When the system detects a fault in the fourth upper bridge arm power switch device T7 and the fourth lower bridge arm power switch device T8 of the fourth bridge arm, or a fault between the left node and the right node of the C-phase winding, the fourth upper bridge arm power switch device T7 and the fourth lower bridge arm power switch device T8 of the fourth bridge arm are turned off, the fifth bidirectional thyristor Tr5 and the sixth bidirectional thyristor Tr6 are turned off, the first bidirectional thyristor Tr1 is turned on, the second bidirectional thyristor Tr2 is turned on, the third bidirectional thyristor Tr3 is turned on, the fourth bidirectional thyristor Tr4 is turned on, and the ninth power switch device T9 is turned off. The AC motor is driven by the first bridge arm, the second bridge arm, and the third bridge arm, which is a three-phase series winding AC motor drive topology in the fifth fault-tolerant operation mode, as shown in FIG. Figure 7 As shown, it is applicable to the motor running in the full speed range, the motor works in two-phase operation mode, and the output torque needs to be reduced;

[0050] When the system detects a fault between the left node and the right node of the B-phase winding, the third bidirectional thyristor Tr3, the fourth bidirectional thyristor Tr4, and the ninth power switch device T9 are turned off, the first bidirectional thyristor Tr1, the second bidirectional thyristor Tr2, the fifth bidirectional thyristor Tr5, and the sixth bidirectional thyristor Tr6 are turned on, and the AC motor is driven by the first bridge arm, the second bridge arm, the third bridge arm, and the fourth bridge arm. This is the three-phase series winding AC motor drive topology in the sixth fault-tolerant operation mode, as shown in FIG. Figure 8 As shown, it is applicable to the motor running in the full speed range, the motor works in two-phase operation mode, and the output torque needs to be reduced;

[0051] When the system detects a power switch failure in the first bridge arm or a failure between the left node and the right node of the A-phase winding, the first upper bridge arm power switch T1 and the first lower bridge arm power switch T2 of the first bridge arm are turned off, the first bidirectional thyristor Tr1 is turned off, the second bidirectional thyristor Tr2 is turned off, the third bidirectional thyristor Tr3 is turned on, the fourth bidirectional thyristor Tr4 is turned on, the fifth bidirectional thyristor Tr5 is turned on, the sixth bidirectional thyristor Tr6 is turned on, and the ninth power switch T9 is turned off. The AC motor is driven by the second bridge arm, the third bridge arm, and the fourth bridge arm, which is a three-phase series winding AC motor drive topology in the seventh fault-tolerant operation mode, as shown in FIG. Figure 9 As shown, it is applicable to the motor running in the full speed range, the motor works in two-phase operation mode, and the output torque needs to be reduced;

[0052] Preferably, the first upper arm power switch device T1, the first lower arm power switch device T2, the second upper arm power switch device T3, the second lower arm power switch device T4, the third upper arm power switch device T5, the third lower arm power switch device T6, the fourth upper arm power switch device T7, the fourth lower arm power switch device T8 and the ninth power switch device T9 are all current-controlled power semiconductor switches, such as MOSFET or IGBT, and the bidirectional thyristor can be replaced by a contactor contact with a certain arc extinguishing capability or a switch formed by two groups of diodes in series and IGBTs in anti-parallel.

[0053] It should be noted that the light-colored part in the figure is the circuit of the faulty part.

[0054] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A three-phase series winding AC motor drive topology fault-tolerant reconstruction circuit, characterized in that: The invention comprises a first bridge arm, a second bridge arm, a third bridge arm, a fourth bridge arm, a first bidirectional thyristor, a second bidirectional thyristor, a third bidirectional thyristor, a fourth bidirectional thyristor, a fifth bidirectional thyristor, a sixth bidirectional thyristor, a first uncontrolled three-phase rectifier bridge and a ninth power switch device; the first bridge arm comprises a first upper bridge arm power switch device and a first lower bridge arm power switch device, the second bridge arm comprises a second upper bridge arm power switch device and a second lower bridge arm power switch device, the third bridge arm comprises a third upper bridge arm power switch device and a third lower bridge arm power switch device, the fourth bridge arm comprises a fourth upper bridge arm power switch device and a fourth lower bridge arm power switch device; the first upper bridge arm power switch device, the second upper bridge arm power switch device, the third upper bridge arm power switch device and the fourth upper bridge arm power switch device The upper nodes of the switching devices are respectively connected to the DC bus voltage; the lower nodes of the first lower bridge arm power switching device, the second lower bridge arm power switching device, the third lower bridge arm power switching device and the fourth lower bridge arm power switching device are respectively connected to the power ground; the lower node of the first upper bridge arm power switching device is connected to the upper node of the first lower bridge arm power switching device, serving as the output node of the first bridge arm; the lower node of the second upper bridge arm power switching device is connected to the upper node of the second lower bridge arm power switching device, serving as the output node of the second bridge arm; the lower node of the third upper bridge arm power switching device is connected to the upper node of the third lower bridge arm power switching device, serving as the output node of the third bridge arm; the lower node of the fourth upper bridge arm power switching device is connected to the upper node of the fourth lower bridge arm power switching device, serving as the output node of the fourth bridge arm; The left node of the first bidirectional thyristor is connected to the output node of the first bridge arm, the left node of the third bidirectional thyristor is connected to the output node of the second bridge arm, the left node of the fifth bidirectional thyristor is connected to the output node of the third bridge arm, the right node of the second bidirectional thyristor is connected to the output node of the second bridge arm, the right node of the fourth bidirectional thyristor is connected to the output node of the third bridge arm, and the right node of the sixth bidirectional thyristor is connected to the output node of the fourth bridge arm; The left node of the A-phase winding is connected to the right node of the first bidirectional thyristor, the middle node of the A-phase winding is connected to the first input node of the first uncontrolled three-phase rectifier bridge, and the right node of the A-phase winding is connected to the left node of the second bidirectional thyristor; The left node of the B-phase winding is connected to the right node of the third bidirectional thyristor, the middle node of the B-phase winding is connected to the second input node of the first uncontrolled three-phase rectifier bridge, and the right node of the B-phase winding is connected to the left node of the fourth bidirectional thyristor; The left node of the C-phase winding is connected to the right node of the fifth bidirectional thyristor, the middle node of the C-phase winding is connected to the third input node of the first uncontrolled three-phase rectifier bridge, and the right node of the C-phase winding is connected to the left node of the sixth bidirectional thyristor; The upper node of the ninth power switch device is connected to the positive output node of the first uncontrolled three-phase rectifier bridge, and the lower node of the ninth power switch device is connected to the negative output node of the first uncontrolled three-phase rectifier bridge.

2. The three-phase series winding AC motor drive topology fault-tolerant reconstruction circuit according to claim 1, characterized in that: The first bidirectional thyristor, the second bidirectional thyristor, the third bidirectional thyristor, the fourth bidirectional thyristor, the fifth bidirectional thyristor, the sixth bidirectional thyristor and the ninth power switch device are used for switching the topology structure of the AC motor drive system.

3. A switching method for a three-phase series winding AC motor drive topology fault-tolerant reconstruction circuit, characterized in that: The three-phase series winding type AC motor drive topology fault-tolerant reconstruction circuit described in claim 2 is adopted. When the AC motor drive system is operating normally, the ninth power switch device is turned off, the first bidirectional thyristor is turned on, the second bidirectional thyristor is turned on, the third bidirectional thyristor is turned on, the fourth bidirectional thyristor is turned on, the fifth bidirectional thyristor is turned on and the sixth bidirectional thyristor is turned on. The AC motor is driven by the first bridge arm, the second bridge arm, the third bridge arm and the fourth bridge arm. This is the three-phase series winding type AC motor drive topology in normal operating mode, which is suitable for normal operation of the motor within the full speed range.

4. The switching method for a three-phase series winding AC motor drive topology fault-tolerant reconstruction circuit according to claim 3, characterized in that: When the system detects a fault in the power switching device of the second bridge arm, a fault between the middle node and the right node of the A-phase winding, a fault between the left node and the middle node of the B-phase winding, or a fault between the left node and the middle node of the C-phase winding, the power switching device of the second bridge arm is turned off, the second bidirectional thyristor is turned off, the third bidirectional thyristor is turned off, the fifth bidirectional thyristor is turned off, the first bidirectional thyristor is turned on, the fourth bidirectional thyristor is turned on, the sixth bidirectional thyristor is turned on, and the ninth power switching device is turned on. The AC motor is driven by the first bridge arm, the third bridge arm, and the fourth bridge arm. This is a three-phase series winding AC motor drive topology in the first fault-tolerant operation mode. Due to the winding current limitation, the output torque needs to be reduced.

5. The switching method for a three-phase series winding AC motor drive topology fault-tolerant reconstruction circuit according to claim 3, characterized in that: When the system detects a fault in the power switching device of the third bridge arm, a fault between the middle node and the right node of the A-phase winding, a fault between the middle node and the right node of the B-phase winding, or a fault between the left node and the middle node of the C-phase winding, the power switching device of the third bridge arm is turned off, the second bidirectional thyristor is turned off, the fourth bidirectional thyristor is turned off, the fifth bidirectional thyristor is turned off, the first bidirectional thyristor is turned on, the third bidirectional thyristor is turned on, the sixth bidirectional thyristor is turned on, and the ninth power switching device is turned on. The AC motor is driven by the first bridge arm, the second bridge arm, and the fourth bridge arm. This is a three-phase series winding AC motor drive topology in the second fault-tolerant operation mode, which is suitable for fault-tolerant operation of the motor within the full speed range. Due to the winding current limit, the output torque needs to be reduced.

6. The switching method for a three-phase series winding AC motor drive topology fault-tolerant reconstruction circuit according to claim 3, characterized in that: When the system detects a fault in the power switching device of the first bridge arm, a fault between the left node and the middle node of the A-phase winding, a fault between the left node and the middle node of the B-phase winding, or a fault between the left node and the middle node of the C-phase winding, the power switching device of the first bridge arm is turned off, the first bidirectional thyristor is turned off, the third bidirectional thyristor is turned off, the fifth bidirectional thyristor is turned off, the second bidirectional thyristor is turned on, the fourth bidirectional thyristor is turned on, the sixth bidirectional thyristor is turned on, and the ninth power switching device is turned on. The AC motor is driven by the second bridge arm, the third bridge arm, and the fourth bridge arm. This is a three-phase series winding AC motor drive topology in the third fault-tolerant operation mode, which is suitable for fault-tolerant operation of the motor within the full speed range. Due to the winding current limit, the output torque needs to be reduced.

7. The switching method for a three-phase series winding AC motor drive topology fault-tolerant reconstruction circuit according to claim 3, characterized in that: When the system detects a fault in the power switching device of the fourth bridge arm, a fault between the middle node and the right node of the A-phase winding, a fault between the middle node and the right node of the B-phase winding, or a fault between the middle node and the right node of the C-phase winding, the power switching device of the fourth bridge arm is turned off, the second bidirectional thyristor is turned off, the fourth bidirectional thyristor is turned off, the sixth bidirectional thyristor is turned off, the first bidirectional thyristor is turned on, the third bidirectional thyristor is turned on, the fifth bidirectional thyristor is turned on, and the ninth power switching device is turned on. The AC motor is driven by the first bridge arm, the second bridge arm, and the third bridge arm. This is a three-phase series winding AC motor drive topology in the fourth fault-tolerant operation mode, which is suitable for fault-tolerant operation of the motor within the full speed range. Due to the winding current limit, the output torque needs to be reduced.

8. The switching method for a three-phase series winding AC motor drive topology fault-tolerant reconstruction circuit according to claim 3, characterized in that: When the system detects a fault in the power switching device of the fourth bridge arm or a fault between the left node and the right node of the C-phase winding, the power switching device of the fourth bridge arm is turned off, the fifth bidirectional thyristor is turned off, the sixth bidirectional thyristor is turned off, the first bidirectional thyristor is turned on, the second bidirectional thyristor is turned on, the third bidirectional thyristor is turned on, the fourth bidirectional thyristor is turned on, and the ninth power switching device is turned off. The AC motor is driven by the first bridge arm, the second bridge arm, and the third bridge arm. This is a three-phase series winding AC motor drive topology in the fifth fault-tolerant operation mode, which is suitable for fault-tolerant operation of the motor within the full speed range. The motor works in the two-phase operation mode, and the output torque needs to be reduced.

9. The switching method for a three-phase series winding AC motor drive topology fault-tolerant reconstruction circuit according to claim 3, characterized in that: When the system detects a fault between the left node and the right node of the B-phase winding, the third bidirectional thyristor, the fourth bidirectional thyristor, and the ninth power switch device are turned off, the first bidirectional thyristor, the second bidirectional thyristor, the fifth bidirectional thyristor, and the sixth bidirectional thyristor are turned on, and the AC motor is driven by the first bridge arm, the second bridge arm, the third bridge arm, and the fourth bridge arm. This is the three-phase series winding AC motor drive topology in the sixth fault-tolerant operation mode, which is suitable for fault-tolerant operation of the motor in the full speed range. The motor works in the two-phase operation mode, and the output torque needs to be reduced.

10. The switching method for a three-phase series winding AC motor drive topology fault-tolerant reconstruction circuit according to claim 3, characterized in that: When the system detects a fault in the power switching device of the first bridge arm or a fault between the left node and the right node of the A-phase winding, the power switching device of the first bridge arm is turned off, the first bidirectional thyristor is turned off, the second bidirectional thyristor is turned off, the third bidirectional thyristor is turned on, the fourth bidirectional thyristor is turned on, the fifth bidirectional thyristor is turned on, the sixth bidirectional thyristor is turned on, and the ninth power switching device is turned off. The AC motor is driven by the second bridge arm, the third bridge arm, and the fourth bridge arm. This is the three-phase series winding AC motor drive topology in the seventh fault-tolerant operation mode, which is suitable for fault-tolerant operation of the motor within the full speed range. The motor works in the two-phase operation mode, and the output torque needs to be reduced.

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