Fault detection system and method for open-winding permanent magnet synchronous motor drive circuit

Abstract

The invention discloses a fault detection system for a drive circuit of an open-winding permanent magnet synchronous motor. The fault detection system comprises four sampling resistors, a voltage collector and a control processor, the first sampling resistor is connected in series with the A-phase winding; the second sampling resistor is connected in series with the B-phase winding; the third sampling resistor is connected in series with the C-phase winding; the fourth sampling resistor is connected in series with the cathode of the direct-current power supply; the voltage collector is connected with the control processor and is used for collecting the voltage of the four sampling resistors; the control processor is connected with grid electrodes of all power switch devices in an inverter of the open-winding permanent magnet synchronous motor drive circuit, and the control processor is used for generating signals for controlling on-off of the power switch devices and determining the fault type of the motor drive circuit according to voltage signals fed back by the sampling resistor. According to the invention, faults of the power switch device and the winding are detected through the current condition on the resistor; the problems that a traditional switch tube fault detection method is complex and fault detection is limited are solved.

Description

Technical Field

[0001] The invention relates to the technical field of motor drive circuit fault detection, and in particular to a system and method for detecting a fault in an open-winding permanent magnet synchronous motor drive circuit. Background Art

[0002] The open-winding permanent magnet synchronous motor opens the neutral point of the traditional three-phase permanent magnet synchronous motor to form an open winding structure with dual ports. It has the advantages of high efficiency, good performance, and high torque density. It has been widely used in electric vehicles, aerospace, and household appliances.

[0003] Since short circuit or open circuit faults of the switch tube or winding in the open-winding permanent magnet synchronous motor drive circuit will affect the stable operation and performance of the motor, it is necessary to detect faults in the drive circuit. The traditional open-winding permanent magnet synchronous motor drive circuit fault detection method is to determine the combination of the faulty phase and the faulty switch tube by calculating the average value of the phase current, and use the current Hall sensor to detect the direction of the back electromotive force to determine the open circuit fault of the specific switch tube. However, this method can only detect the open circuit condition of the switch tube, but not the short circuit condition. In addition, the high dependence on sensor accuracy may lead to diagnostic delays or misjudgments under rapidly changing working conditions. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a system and method for detecting faults in an open-winding permanent magnet synchronous motor drive circuit, so as to solve the technical problems in the prior art that the existing detection is prone to delays and misjudgments and does not have a short-circuit detection function.

[0005] The present invention provides an open-winding permanent magnet synchronous motor drive circuit fault detection system, comprising: a first sampling resistor, a second sampling resistor, a third sampling resistor, a fourth sampling resistor, a voltage collector and a control processor;

[0006] The first sampling resistor is connected in series with the A-phase winding; the second sampling resistor is connected in series with the B-phase winding; the third sampling resistor is connected in series with the C-phase winding; the fourth sampling resistor is connected in series with the negative pole of the DC power supply; the voltage collector is connected to the control processor, and the voltage collector is used to collect the voltages of the four sampling resistors; the control processor is connected to the gates of all power switching devices in the inverter of the open-winding permanent magnet synchronous motor drive circuit, and the control processor is used to generate a signal to control the on and off of the power switching device and determine the fault type of the motor drive circuit according to the voltage signal fed back by the sampling resistor.

[0007] Furthermore, the four sampling resistors are adjustable resistors.

[0008] Furthermore, the maximum resistance of the four sampling resistors is: 1 ohm.

[0009] The present invention also provides an open-winding permanent magnet synchronous motor drive circuit fault detection method, which is applicable to the above-mentioned open-winding permanent magnet synchronous motor drive circuit fault detection system, and the method includes: a power switch device short circuit detection process, a power switch device open circuit detection process and a winding open circuit detection process;

[0010] The short circuit detection process of the power switch device includes:

[0011] A pulse signal is injected into an upper / lower bridge arm power switch device in an inverter, and the voltage of the sampling resistor connected in series with the corresponding phase winding and the voltage of the fourth sampling resistor are collected at this time.

[0012] When the corresponding sampling resistor voltage and the fourth sampling resistor voltage both change, a short circuit fault occurs in the corresponding lower / upper bridge arm power switch device in the other inverter;

[0013] When the corresponding sampling resistor voltage does not change and the fourth sampling resistor voltage changes, a short circuit fault occurs in the corresponding lower / upper bridge arm power switch device in the same inverter;

[0014] When the corresponding sampling resistor voltage and the fourth sampling resistor voltage do not change, a short circuit fault occurs in the corresponding lower / upper bridge arm power switch devices in the two inverters.

[0015] Furthermore, the power switch device open circuit detection process includes:

[0016] An upper bridge arm power switch device in one inverter is set to be in a conducting state, a pulse signal is injected into the corresponding lower bridge arm power switch device in another inverter, and the voltage of the sampling resistor connected in series with the corresponding phase winding and the voltage of the fourth sampling resistor are collected at this time.

[0017] When the corresponding sampling resistor voltage and the fourth sampling resistor voltage both change, no open circuit fault occurs in the current two power switch devices;

[0018] When the corresponding sampling resistor voltage and the fourth sampling resistor voltage do not change, open circuit faults exist in the two current power switch devices.

[0019] Furthermore, the winding open circuit detection process includes:

[0020] A pulse signal is injected into the upper and lower power switch devices in the same bridge arm of an inverter, and the voltage of the fourth sampling resistor is collected at this time.

[0021] When the voltage of the fourth sampling resistor changes, the corresponding phase winding does not have an open circuit fault;

[0022] When the voltage of the fourth sampling resistor does not change, an open circuit fault occurs in the corresponding phase winding.

[0023] Furthermore, the method further includes: when fault detection is not required, adjusting the resistance value of the sampling resistor to zero, so that the sampling resistor is in a short-circuited state.

[0024] Beneficial effects of the present invention:

[0025] The present invention utilizes a sampling resistor in a driving circuit of an open-winding permanent magnet synchronous motor to detect faults of power switch components and windings through current conditions on the resistor, thereby solving the problem that conventional switch tube fault detection methods are complex and have limited fault detection.

[0026] The present invention can quickly and accurately detect the short-circuit fault of a specific switch tube in the short-circuit fault detection of the power switch device of the dual inverter circuit, thereby providing a more reliable guarantee for the stable operation of the motor.

[0027] In the open circuit fault detection of the power switch device of the dual inverter circuit, the present invention detects two power switch devices at the same time, shortens the detection time, and improves the efficiency of fault detection.

[0028] In the dual inverter circuit winding fault detection, the present invention skillfully uses two switch tubes and a sampling resistor to detect the open circuit fault conditions of various windings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0030] Figure 1 Schematic diagram of sampling resistor connection according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0032] The present invention is further illustrated below in conjunction with specific embodiments. Those skilled in the art should understand that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention, and modifications to various equivalent forms of the present invention fall within the scope defined by the appended claims of this application.

[0033] like Figure 1As shown, the present invention provides an open-winding permanent magnet synchronous motor drive circuit fault detection system, including: a sampling resistor Ra, a sampling resistor Rb, a sampling resistor Rc, a sampling resistor Rdc, a voltage collector and a control processor;

[0034] The dual inverter circuit includes power switch devices S1-S6, power switch devices T1-T6, and a DC power supply Vdc;

[0035] The source / emitter of the power switch device S1 is respectively connected to the drain / collector of the power switch device S4 and the A phase of the three-phase stator winding of the permanent magnet synchronous motor, and the drain / collector of the power switch device S1 is connected to the positive pole of the DC power supply Vdc; the source / emitter of the power switch device S3 is respectively connected to the drain / collector of the power switch device S6 and the B phase of the three-phase stator winding of the permanent magnet synchronous motor, and the drain / collector of the power switch device S3 is connected to the positive pole of the DC power supply Vdc; the power switch device The source / emitter of S5 is respectively connected to the drain / collector of the power switch device S2 and the C phase of the three-phase stator winding of the permanent magnet synchronous motor, and the drain / collector of the power switch device S5 is connected to the positive pole of the DC power supply Vdc; the source / emitter of the power switch device S4, the source / emitter of the power switch device S6, and the source / emitter of the power switch device S2 are all connected to one end of the sampling resistor Rdc; the source / emitter of the power switch device T1 is respectively connected to the drain / collector of the power switch device T4, The sampling resistor Ra on phase A is connected, and the drain / collector of the power switch device T1 is connected to the positive electrode of the DC power supply Vdc; the source / emitter of the power switch device T3 is respectively connected to the drain / collector of the power switch device T6 and the sampling resistor Rb on phase B, and the drain / collector of the power switch device T3 is connected to the positive electrode of the DC power supply Vdc; the source / emitter of the power switch device T5 is respectively connected to the drain / collector of the power switch device T2 and the sampling resistor Rc on phase C, and the power switch device The drain / collector of T5 is connected to the positive electrode of the DC power supply Vdc; the source / emitter of the power switch device T4, the source / emitter of the power switch device T6, and the source / emitter of the power switch device T2 are all connected to one end of the sampling resistor Rdc, and one end of the sampling resistor Rdc is connected to the negative electrode of the DC power supply Vdc, which is equivalent to the sampling resistor Rdc being connected in series to the negative electrode of the DC power supply Vdc. Among them, the power switch devices S1~S6 and T1~T6 in the dual inverter circuit can be MOS tubes or IGBTs.

[0036] The sampling resistor Ra is connected in series with the A-phase winding; the sampling resistor Rb is connected in series with the B-phase winding; the sampling resistor Rc is connected in series with the C-phase winding; the sampling resistor Rdc is connected in series with the negative pole of the DC power supply Vdc; the voltage collector is connected to the control processor, and the voltage collector is used to collect the voltages of the four sampling resistors; the control processor is connected to the gates of all power switching devices in the inverter of the open-winding permanent magnet synchronous motor drive circuit, and the control processor is used to generate a signal to control the on and off of the power switching device and determine the fault type of the motor drive circuit according to the voltage signal fed back by the sampling resistor.

[0037] The four sampling resistors are adjustable resistors. When detection is not required, the resistance value of the sampling resistor can be adjusted to zero to put the sampling resistor in a short-circuited state, thereby reducing the impact of the resistor on the drive circuit. The maximum resistance value of the four sampling resistors is: 1 ohm.

[0038] The present invention also provides an open-winding permanent magnet synchronous motor drive circuit fault detection method, which is applicable to the above-mentioned open-winding permanent magnet synchronous motor drive circuit fault detection system, and the method includes: a power switch device short circuit detection process, a power switch device open circuit detection process and a winding open circuit detection process;

[0039] The short circuit detection process of the power switch device includes:

[0040] A pulse signal is injected into an upper / lower bridge arm power switch device in an inverter, and the voltage of the sampling resistor connected in series with the corresponding phase winding and the voltage of the sampling resistor Rdc are collected at this time.

[0041] When the corresponding sampling resistor voltage and the sampling resistor Rdc voltage both change, a short circuit fault occurs in the corresponding lower / upper bridge arm power switch device in the other inverter;

[0042] When the corresponding sampling resistor voltage does not change and the sampling resistor Rdc voltage changes, the corresponding lower / upper arm power switch device in the same inverter has a short circuit fault;

[0043] When the corresponding sampling resistor voltage and the sampling resistor Rdc voltage do not change, the corresponding lower / upper bridge arm power switch devices in the two inverters have a short circuit fault;

[0044] Combination Figure 1 The circuit shown is specifically:

[0045] A pulse signal is injected into the lower bridge arm power switch device S4. When the voltages of the sampling resistors Ra and Rdc change, a short circuit fault occurs in the power switch device T1; when the voltage of the sampling resistor Ra does not change and the voltage of the sampling resistor Rdc changes, a short circuit fault occurs in the power switch device S1; when the voltages of the sampling resistors Ra and Rdc do not change, there is no short circuit fault in the power switch devices T1 and S1;

[0046] A pulse signal is injected into the lower bridge arm power switch device S6. When the voltages of the sampling resistors Rb and Rdc change, a short circuit fault occurs in the power switch device T3; when the voltages of the sampling resistors Rb do not change and the voltages of the sampling resistors Rdc change, a short circuit fault occurs in the power switch device S3; when the voltages of the sampling resistors Rb and Rdc do not change, there is no short circuit fault in the power switch devices T3 and S3;

[0047] A pulse signal is injected into the lower bridge arm power switch device S2. When the voltage of the sampling resistor Rc and the sampling resistor Rdc changes, the power switch device T5 has a short circuit fault; when the voltage of the sampling resistor Rc does not change and the voltage of the sampling resistor Rdc changes, the power switch device S5 has a short circuit fault; when the voltage of the sampling resistor Rc and the sampling resistor Rdc does not change, the power switch devices T5 and S5 do not have a short circuit fault.

[0048] A pulse signal is injected into the upper bridge arm power switch device S1. When the voltages of the sampling resistors Ra and Rdc change, the power switch device T4 has a short circuit fault; when the voltages of the sampling resistors Ra do not change and the voltages of the sampling resistors Rdc change, the power switch device S4 has a short circuit fault; when the voltages of the sampling resistors Ra and Rdc do not change, the power switch devices T4 and S4 do not have a short circuit fault;

[0049] A pulse signal is injected into the upper bridge arm power switch device S3. When the voltages of the sampling resistors Rb and Rdc change, a short circuit fault occurs in the power switch device T6. When the voltages of the sampling resistors Rb do not change and the voltages of the sampling resistors Rdc change, a short circuit fault occurs in the power switch device S6. When the voltages of the sampling resistors Rb and Rdc do not change, there is no short circuit fault in the power switch devices T6 and S6.

[0050] A pulse signal is injected into the upper bridge arm power switch device S5. When the voltages of the sampling resistor Rc and the sampling resistor Rdc change, a short circuit fault occurs in the power switch device T2; when the voltage of the sampling resistor Rc does not change and the voltage of the sampling resistor Rdc changes, a short circuit fault occurs in the power switch device S2; when the voltages of the sampling resistor Rc and the sampling resistor Rdc do not change, there is no short circuit fault in the power switch devices T2 and S2.

[0051] The open circuit detection process of the power switch device includes:

[0052] Set an upper bridge arm power switch device in one inverter to the on state, inject a pulse signal into the corresponding lower bridge arm power switch device in another inverter, and collect the voltage of the sampling resistor connected in series with the corresponding phase winding and the voltage of the sampling resistor Rdc at this time.

[0053] When the corresponding sampling resistor voltage and the sampling resistor Rdc voltage both change, the two current power switch devices do not have an open circuit fault;

[0054] When the corresponding sampling resistor voltage and the sampling resistor Rdc voltage do not change, there is an open circuit fault in the two current power switch devices;

[0055] Combination Figure 1 The circuit shown is specifically:

[0056] Set the upper bridge arm power switch device S1 to the on state, and inject a pulse signal into the lower bridge arm power switch device T4. When the voltage of the sampling resistor Ra and the sampling resistor Rdc changes, the power switch devices S1 and T4 do not have an open circuit fault; when the voltage of the sampling resistor Ra and the sampling resistor Rdc does not change, the power switch devices S1 and T4 have an open circuit fault;

[0057] The upper bridge arm power switch device S3 is set to the on state, and a pulse signal is injected into the lower bridge arm power switch device T6. When the voltage of the sampling resistor Rb and the sampling resistor Rdc changes, there is no open circuit fault in the power switch devices S3 and T6; when the voltage of the sampling resistor Rb and the sampling resistor Rdc does not change, there is an open circuit fault in the power switch devices S3 and T6;

[0058] The upper bridge arm power switch device S5 is set to the on state, and a pulse signal is injected into the lower bridge arm power switch device T2. When the voltage of the sampling resistor Rc and the sampling resistor Rdc changes, there is no open circuit fault in the power switch devices S5 and T2; when the voltage of the sampling resistor Rc and the sampling resistor Rdc does not change, there is an open circuit fault in the power switch devices S5 and T2;

[0059] Set the upper bridge arm power switch device T1 to the on state, and inject a pulse signal into the lower bridge arm power switch device S4. When the voltage of the sampling resistor Ra and the sampling resistor Rdc changes, the power switch devices T1 and S4 do not have an open circuit fault; when the voltage of the sampling resistor Ra and the sampling resistor Rdc does not change, the power switch devices T1 and S4 have an open circuit fault;

[0060] The upper bridge arm power switch device T3 is set to the on state, and a pulse signal is injected into the lower bridge arm power switch device S6. When the voltage of the sampling resistor Rb and the sampling resistor Rdc changes, the power switch devices T3 and S6 do not have an open circuit fault; when the voltage of the sampling resistor Rb and the sampling resistor Rdc does not change, the power switch devices T3 and S6 have an open circuit fault;

[0061] The upper bridge arm power switch device T5 is set to the on state, and a pulse signal is injected into the lower bridge arm power switch device S2. When the voltage of the sampling resistor Rc and the sampling resistor Rdc changes, there is no open circuit fault in the power switch devices T5 and S2; when the voltage of the sampling resistor Rc and the sampling resistor Rdc does not change, there is an open circuit fault in the power switch devices T5 and S2.

[0062] The winding open circuit detection process includes:

[0063] Inject pulse signals into the upper and lower power switch devices in the same bridge arm of an inverter, and collect the voltage of the sampling resistor Rdc at this time.

[0064] When the voltage of the sampling resistor Rdc changes, the corresponding phase winding does not have an open circuit fault;

[0065] When the voltage of the sampling resistor Rdc does not change, an open circuit fault occurs in the corresponding phase winding;

[0066] Combination Figure 1 The circuit shown is specifically:

[0067] Inject pulse signals into the upper and lower power switch devices S1 and S4 of the same bridge arm. When the voltage of the sampling resistor Rdc changes, there is no open circuit fault in the A-phase winding; when the voltage of the sampling resistor Rdc does not change, there is an open circuit fault in the A-phase winding;

[0068] Inject pulse signals into the upper and lower power switch devices S3 and S6 of the same bridge arm. When the voltage of the sampling resistor Rdc changes, there is no open circuit fault in the B-phase winding; when the voltage of the sampling resistor Rdc does not change, there is an open circuit fault in the B-phase winding;

[0069] A pulse signal is injected into the upper and lower power switch devices S5 and S2 of the same bridge arm. When the voltage of the sampling resistor Rdc changes, there is no open circuit fault in the C-phase winding; when the voltage of the sampling resistor Rdc does not change, there is an open circuit fault in the C-phase winding.

[0070] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A fault detection system for an open-winding permanent magnet synchronous motor drive circuit, characterized in that: include: A first sampling resistor, a second sampling resistor, a third sampling resistor, a fourth sampling resistor, a voltage collector and a control processor; The first sampling resistor is connected in series with the A-phase winding; the second sampling resistor is connected in series with the B-phase winding; the third sampling resistor is connected in series with the C-phase winding; the fourth sampling resistor is connected in series with the negative pole of the DC power supply; the voltage collector is connected to the control processor, and the voltage collector is used to collect the voltages of the four sampling resistors; the control processor is connected to the gates of all power switching devices in the inverter of the open-winding permanent magnet synchronous motor drive circuit, and the control processor is used to generate a signal to control the on and off of the power switching device and determine the fault type of the motor drive circuit according to the voltage signal fed back by the sampling resistor.

2. The open-winding permanent magnet synchronous motor drive circuit fault detection system according to claim 1, characterized in that: The four sampling resistors are adjustable resistors.

3. The open-winding permanent magnet synchronous motor drive circuit fault detection system according to claim 1 or 2, characterized in that: The maximum resistance of the four sampling resistors is: 1 ohm.

4. A method for detecting faults in an open-winding permanent magnet synchronous motor drive circuit, applicable to the open-winding permanent magnet synchronous motor drive circuit fault detection system as claimed in any one of claims 1 to 3, characterized in that: The method comprises: a power switch device short circuit detection process, a power switch device open circuit detection process and a winding open circuit detection process; The short circuit detection process of the power switch device includes: A pulse signal is injected into an upper / lower bridge arm power switch device in an inverter, and the voltage of the sampling resistor connected in series with the corresponding phase winding and the voltage of the fourth sampling resistor are collected at this time. When the corresponding sampling resistor voltage and the fourth sampling resistor voltage both change, a short circuit fault occurs in the corresponding lower / upper bridge arm power switch device in the other inverter; When the corresponding sampling resistor voltage does not change and the fourth sampling resistor voltage changes, a short circuit fault occurs in the corresponding lower / upper bridge arm power switch device in the same inverter; When the corresponding sampling resistor voltage and the fourth sampling resistor voltage do not change, a short circuit fault occurs in the corresponding lower / upper bridge arm power switch devices in the two inverters.

5. The open-winding permanent magnet synchronous motor drive circuit fault detection method according to claim 4, characterized in that: The power switch device open circuit detection process includes: An upper bridge arm power switch device in one inverter is set to be in a conducting state, a pulse signal is injected into the corresponding lower bridge arm power switch device in another inverter, and the voltage of the sampling resistor connected in series with the corresponding phase winding and the voltage of the fourth sampling resistor are collected at this time. When the corresponding sampling resistor voltage and the fourth sampling resistor voltage both change, no open circuit fault occurs in the current two power switch devices; When the corresponding sampling resistor voltage and the fourth sampling resistor voltage do not change, open circuit faults exist in the two current power switch devices.

6. The open-winding permanent magnet synchronous motor drive circuit fault detection method according to claim 4, characterized in that: The winding open circuit detection process includes: A pulse signal is injected into the upper and lower power switch devices in the same bridge arm of an inverter, and the voltage of the fourth sampling resistor is collected at this time. When the voltage of the fourth sampling resistor changes, the corresponding phase winding does not have an open circuit fault; When the voltage of the fourth sampling resistor does not change, an open circuit fault occurs in the corresponding phase winding.

7. The open-winding permanent magnet synchronous motor drive circuit fault detection method according to any one of claims 4 to 6, characterized in that: Also includes: When fault detection is not required, the resistance value of the sampling resistor is adjusted to zero, so that the sampling resistor is in a short-circuited state.

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