Phase relay fault detection system, motor controller and vehicle

Abstract

The invention relates to a phase relay fault detection system, a motor controller and a vehicle, the phase relay fault detection system comprises a full-bridge inverter circuit, a three-phase relay, a three-phase sampling circuit and a control circuit, and the control circuit is used for controlling the on-off state of a three-phase full-bridge arm and the three-phase relay. Enabling the upper bridge arm of the target phase to be in an on state and the rest bridge arms to be in an off state, obtaining a rest phase sampling signal through a three-phase sampling circuit, and determining a fault detection result of the to-be-detected phase relay according to the rest phase sampling signal; wherein the to-be-measured phase is any one phase or two phases in the three phases, the target phase and the to-be-measured phase are different phases correspondingly, the target phase comprises two phases or one phase, and the remaining phase and the to-be-measured phase are the same phase correspondingly. By adopting the fault detection system for the phase relay, fault detection of the phase relay can be realized more accurately and comprehensively.

Description

Technical Field

[0001] The present application relates to the field of vehicle detection technology, and in particular to a phase relay fault detection system, a motor controller and a vehicle. Background Art

[0002] In the vehicle motor control system, a corresponding phase relay is generally set for each phase of the motor. When a phase of the motor fails, the phase relay can shut down the faulty phase. In order to ensure that the phase relay can shut down the faulty phase normally, it is usually necessary to perform fault detection on the phase relay before the car drives. However, the fault detection of the phase relay is not accurate enough. Summary of the invention

[0003] Based on this, it is necessary to provide a phase relay fault detection system, a motor controller and a vehicle.

[0004] In a first aspect, the present application provides a phase relay fault detection system, comprising:

[0005] A full-bridge inverter circuit includes a three-phase full-bridge arm;

[0006] A three-phase relay, wherein the three-phase relay is connected to the midpoint of the three-phase full-bridge arm and the motor respectively;

[0007] A three-phase sampling circuit, wherein the three-phase sampling circuits are respectively connected to the midpoints of the bridge arms of the three-phase full bridge;

[0008] A control circuit is respectively connected to the control end of the three-phase full-bridge arm, the control end of the three-phase relay and the three-phase sampling circuit, and is used to control the on-off state of the three-phase full-bridge arm and the three-phase relay, so that the upper bridge arm of the target phase is in the on state and the remaining bridge arms are in the off state, and obtain the remaining phase sampling signal through the three-phase sampling circuit, and determine the fault detection result of the phase relay to be tested according to the remaining phase sampling signal;

[0009] The phase to be measured is any one or two phases of the three phases, the target phase corresponds to a different phase from the phase to be measured, and the target phase includes two phases or one phase, and the remaining phases correspond to the same phase as the phase to be measured.

[0010] In one embodiment, the fault detection result includes an open circuit detection result; the three phases include a first phase, a second phase and a third phase; the target phase includes a first phase, and the phase to be tested includes at least one of the second phase and the third phase;

[0011] The control circuit is also used to control the first-phase upper bridge arm and the three-phase relay to be in an on state, and control the remaining bridge arms to be in an off state, obtain at least one of the second-phase sampling signal and the third-phase sampling signal, and determine the open circuit detection result of the second-phase relay according to the second-phase sampling signal, and / or determine the open circuit detection result of the third-phase relay according to the third-phase sampling signal.

[0012] In one embodiment, the fault detection result includes an open circuit detection result; the three phases include a first phase, a second phase, and a third phase; the target phase includes a first phase and a second phase, and the phase to be tested includes a third phase;

[0013] The control circuit is also used to control the first-phase upper bridge arm, the second-phase upper bridge arm and the three-phase relay to be in an on state, and control the remaining bridge arms to be in an off state, obtain the third-phase sampling signal, and determine the open circuit detection result of the third-phase relay according to the third-phase sampling signal.

[0014] In one embodiment, the fault detection result includes a short circuit detection result; the three phases include a first phase, a second phase and a third phase; the target phase includes a first phase and a second phase, and the phase to be tested includes a third phase;

[0015] The control circuit is also used to control the first-phase upper bridge arm, the second-phase upper bridge arm, the first-phase relay and the second-phase relay to be in an on state, and to control the remaining bridge arms and the third-phase relay to be in an off state, obtain the third-phase sampling signal, and determine the short-circuit detection result of the third-phase relay according to the third-phase sampling signal.

[0016] In one embodiment, the fault detection result includes a short circuit detection result; the three phases include a first phase, a second phase and a third phase; the target phase includes a first phase, and the phase to be tested includes at least one of the second phase and the third phase;

[0017] The control circuit is also used to control the first-phase upper bridge arm and the first-phase relay to be in an on state, and control the remaining bridge arms, the second-phase relay, and the third-phase relay to be in an off state, obtain at least one of the second-phase sampling signal and the third-phase sampling signal, and determine the short-circuit detection result of the second-phase relay according to the second-phase sampling signal, and / or determine the short-circuit detection result of the third-phase relay according to the third-phase sampling signal.

[0018] In one embodiment, the control circuit comprises:

[0019] A driving unit connected to the control end of the three-phase full-bridge arm, used to control the on-off state of the three-phase full-bridge arm, so that the upper bridge arm of the target phase is in the on state and the remaining bridge arms are in the off state;

[0020] A control unit is connected to the control end of the three-phase relay, and is used to control the on-off state of the three-phase relay, obtain the remaining phase sampling signal, and query the preset relationship library according to the remaining phase sampling signal, the on-off state of the three-phase full-bridge arm corresponding to the remaining phase sampling signal, and the on-off state of the three-phase relay to determine the fault detection result of the phase relay to be tested; the preset relationship library is used to represent the on-off state of the three-phase full-bridge arm, the on-off state of the three-phase relay, the correlation relationship between the three-phase sampling signal and the fault detection result.

[0021] In one embodiment, the residual phase sampling signal includes a residual phase sampling voltage; the preset relationship library includes a plurality of truth tables;

[0022] The control circuit further comprises a comparison unit connected to the three-phase sampling circuit, and configured to compare the remaining phase sampling voltage with a preset voltage threshold to obtain a remaining phase comparison result;

[0023] The control unit is also connected to the comparison unit, and the control unit is also used to match each truth table according to the remaining phase comparison result, the on-off state of the three-phase full-bridge arm corresponding to the remaining phase comparison result, and the on-off state of the three-phase relay, so as to determine the fault detection result of the phase relay to be tested.

[0024] In one embodiment, the three-phase sampling circuit includes a three-phase sampling unit, each phase sampling unit includes a first resistor and a second resistor, wherein the first end of the first resistor is connected to the midpoint of the corresponding phase full-bridge arm, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is grounded.

[0025] In one embodiment, a power supply is further included, wherein the power supply is used to provide a supply voltage;

[0026] Wherein, a first end of the full-bridge inverter circuit is connected to the power supply, and a second end of the full-bridge inverter circuit is grounded;

[0027] The preset voltage threshold is less than the product of the supply voltage and a voltage division coefficient; the voltage division coefficient is a ratio of the second resistor to a total resistance, and the total resistance is the sum of the first resistor and the second resistor.

[0028] In a second aspect, the present application also provides a motor controller, comprising the phase relay fault detection system provided by any of the above embodiments.

[0029] In a third aspect, the present application also provides a vehicle, comprising a motor controller provided by any of the above embodiments.

[0030] In the above-mentioned phase relay fault detection system, motor controller and vehicle, the control circuit can be used to control the conduction of the bridge arm of the target phase, and the on-off state of the three-phase relay can be controlled by the control circuit to form an open circuit detection circuit and a short circuit detection circuit of the phase relay to be tested. Furthermore, the fault detection result of the phase relay to be tested is determined based on the remaining phase sampling signals collected by the three-phase sampling circuit, which can realize more accurate and comprehensive fault detection of the phase relay to be tested, so that the driver can discover the fault of the phase relay in time and improve the safety of vehicle driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 One of the phase relay fault detection systems provided by an embodiment;

[0033] Figure 2 It is the flow direction of the electrical signal when the upper bridge arm of the U phase and the three-phase relay are turned on;

[0034] Figure 3 It is the flow direction of the electrical signal when the upper bridge arm of the V phase and the three-phase relay are turned on;

[0035] Figure 4 It is the flow direction of the electrical signal when the W-phase upper bridge arm and the three-phase relay are turned on;

[0036] Figure 5 The direction of the electrical signal when the U-phase upper bridge arm, the V-phase upper bridge arm and the three-phase relay are turned on;

[0037] Figure 6 It is the flow direction of the electrical signal when the U-phase upper bridge arm, the W-phase upper bridge arm and the three-phase relay are turned on;

[0038] Figure 7 It is the flow direction of the electrical signal when the W-phase upper bridge arm, the V-phase upper bridge arm and the three-phase relay are turned on;

[0039] Figure 8 A second phase relay fault detection system provided by an embodiment;

[0040] Fig. 9 This is a third phase relay fault detection system provided in an embodiment. DETAILED DESCRIPTION

[0041] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0043] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0044] It can be understood that “at least one” means one or more, “plurality” means two or more, and “at least part of an element” means part or all of an element.

[0045] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0046] It should be noted that the first phase, second phase and third phase mentioned in the embodiments of the present application are only for distinguishing different phases of the motor. Without departing from the scope of the present application, the first phase can be called the second phase or the first phase, and the second phase can also be called the first phase or the third phase, etc.

[0047] In one embodiment, Figure 1 As shown, the present application provides a phase relay fault detection system, including a full-bridge inverter circuit 100, a three-phase relay 200, a three-phase sampling circuit 300 and a control circuit (the control circuit is not shown). The three-phase relay 200 is respectively connected to the three-phase sampling circuit 300, the midpoint of the three-phase full-bridge bridge arm and the motor 400.

[0048] The full-bridge inverter circuit 100 may include a three-phase full-bridge arm, and the three-phase full-bridge arm includes a first-phase full-bridge arm, a second-phase full-bridge arm, and a third-phase full-bridge arm. Each phase full-bridge arm includes a first field effect tube (i.e., U1, V1, or W1) and a second field effect tube (i.e., U2, V2, or W2) connected in series, and the connection point between the first field effect tube and the second field effect tube serves as the midpoint of the bridge arm. The full-bridge inverter circuit 100 can be used to convert a DC signal into an AC signal and output it to the motor 400.

[0049] The three-phase relay may include a first phase relay, a second phase relay and a third phase relay. The three-phase relays are respectively connected to the U phase, V phase and W phase of the motor, that is, the U phase relay U3 is connected to the U phase of the motor, the V phase relay V3 is connected to the V phase of the motor, and the W phase relay W3 is connected to the W phase of the motor. When a fault occurs in the U phase, V phase or W phase of the motor, the circuit connection of the faulty phase can be disconnected by controlling the corresponding phase relay to turn off.

[0050] The three-phase sampling circuit 300 can be used to obtain the sampling signal of the corresponding phase and send the sampling signal to the control circuit. The three-phase sampling circuit 300 can be an optical coupling isolation sampling circuit, a voltage divider circuit or an ADC sampling circuit.

[0051] The control circuit is connected to the control end of the three-phase full-bridge arm, the control end of the three-phase relay 200, and the three-phase sampling circuit 300, respectively. The control circuit can be used to control the on-off state of the three-phase full-bridge arm and the three-phase relay 200, so that the upper bridge arm of the target phase is in the on state and the remaining bridge arm is in the off state, and the remaining phase sampling signal is obtained through the three-phase sampling circuit 300, and the fault detection result of the phase relay to be tested is determined according to the remaining phase sampling signal. The fault detection result includes an open circuit detection result and a short circuit detection result. The possible faults of the phase relay to be tested include an open circuit fault or a short circuit fault. Therefore, the control circuit can be used to control the conduction of the upper bridge arm of the target phase and the on-off state of the three-phase relay to form an open circuit detection circuit and a short circuit detection circuit of the phase relay to be tested, and the open circuit detection and short circuit detection are performed on the phase relay to be tested respectively to obtain the fault detection result.

[0052] Wherein, the phase to be measured is any one or two phases among the three phases, the target phase is a different phase from the phase to be measured, and the target phase includes two phases or one phase, and the remaining phase is the same phase as the phase to be measured. Exemplarily, the phase to be measured is U phase, the target phase can be V phase or W phase or V phase and W phase, and the remaining phase can be U phase; the phase to be measured is V phase, the target phase can be U phase or W phase or U phase and W phase, and the remaining phase can be V phase; the phase to be measured is W phase, the target phase can be U phase or V phase or V phase and U phase, and the remaining phase can be W phase; the phase to be measured is U phase and V phase, the target phase can be W phase, and the remaining phase can be U phase and V phase; the phase to be measured is U phase and W phase, the target phase can be V phase, and the remaining phase can be U phase and W phase; the phase to be measured is W phase and V phase, the target phase can be U phase, and the remaining phase can be W phase and V phase.

[0053] In an embodiment of the present application, a phase relay fault detection system includes a full-bridge inverter circuit 100, a three-phase relay 200, a three-phase sampling circuit 300, and a control circuit. The control circuit can be used to control the on-off state of the three-phase full-bridge bridge arm and the three-phase relay 200, so that the bridge arm of the target phase is in the on state and the remaining bridge arm is in the off state, and the remaining phase sampling signal is obtained through the three-phase sampling circuit 300, and the fault detection result of the phase relay to be tested is determined according to the remaining phase sampling signal. It can be understood that the control circuit can control the bridge arm of the target phase to be turned on, and the open circuit detection circuit and the short circuit detection circuit of the phase relay to be tested can be formed by controlling the on-off state of the three-phase relay 200. Further, the fault detection result of the phase relay to be tested is determined according to the remaining phase sampling signal collected by the three-phase sampling circuit 300, and the fault detection of the phase relay to be tested can be realized, so that the driver can find the fault of the phase relay in time, and improve the safety of vehicle driving.

[0054] In one embodiment, the target phase includes the first phase. The phase to be tested includes at least one of the second phase and the third phase. The control circuit is also used to control the bridge arm of the first phase and the three-phase relay to be in the on state, and control the remaining bridge arms to be in the off state, obtain at least one of the second phase sampling signal and the third phase sampling signal, and determine the open circuit detection result of the second phase relay according to the second phase sampling signal, and / or determine the open circuit detection result of the third phase relay according to the third phase sampling signal. Among them, the second phase sampling signal includes the second phase sampling voltage, the third phase sampling signal includes the third phase sampling voltage, and the open circuit detection result includes being in a normal state and having an open circuit fault.

[0055] Taking the first phase as the U phase, the second phase as the V phase, and the third phase as the W phase as an example, when the U phase upper bridge arm U1 and the three-phase relay 200 are turned on, the flow direction of the electrical signal is as follows: Figure 2As shown by the arrow in the middle. If the second-phase sampling voltage is greater than the preset voltage threshold, it can be determined that the open circuit detection result of the V-phase relay V3 is in a normal state; if the second-phase sampling voltage is approximately 0, it can be determined that the open circuit detection result of the V-phase relay V3 is an open circuit fault. If the third-phase sampling voltage is greater than the preset voltage threshold, it can be determined that the open circuit detection result of the W-phase relay W3 is in a normal state; if the third-phase sampling voltage is approximately 0, it can be determined that the open circuit detection result of the W-phase relay W3 is an open circuit fault. The preset voltage threshold is greater than 0.

[0056] Taking the first phase as V phase, the second phase as U phase, and the third phase as W phase as an example, when the upper bridge arm V1 of the V phase and the three-phase relay 200 are turned on, the flow direction of the electrical signal is as follows: Figure 3 As shown by the arrow in the middle. If the second-phase sampling voltage is greater than the preset voltage threshold, it can be determined that the open circuit detection result of the U-phase relay U3 is in a normal state; if the second-phase sampling voltage is approximately 0, it can be determined that the open circuit detection result of the U-phase relay U3 is an open circuit fault. If the third-phase sampling voltage is greater than the preset voltage threshold, it can be determined that the open circuit detection result of the W-phase relay W3 is in a normal state; if the third-phase sampling voltage is approximately 0, it can be determined that the open circuit detection result of the W-phase relay W3 is an open circuit fault.

[0057] Taking the first phase as W phase, the second phase as U phase, and the third phase as V phase as an example, when the upper bridge arm W1 of the W phase and the three-phase relay 200 are turned on, the flow direction of the electrical signal is as follows: Figure 4 As shown by the arrow in the middle. If the second-phase sampling voltage is greater than the preset voltage threshold, it can be determined that the open circuit detection result of the U-phase relay U3 is in a normal state; if the second-phase sampling voltage is approximately 0, it can be determined that the open circuit detection result of the U-phase relay U3 is an open circuit fault. If the third-phase sampling voltage is greater than the preset voltage threshold, it can be determined that the open circuit detection result of the V-phase relay V3 is in a normal state; if the third-phase sampling voltage is approximately 0, it can be determined that the open circuit detection result of the V-phase relay V3 is an open circuit fault.

[0058] In addition, it should be noted that in this embodiment, if the open circuit detection results of the second-phase relay and the third-phase relay are both open circuit faults, it may also be caused by an open circuit fault in the first-phase relay. In this case, the bridge arm of the first-phase upper bridge can be controlled to be turned off, and the bridge arm of the third-phase upper bridge can be controlled to be turned on, and the second-phase sampling signal can be obtained again. If it is determined based on the second-phase sampling signal obtained again that the open circuit detection result of the second-phase relay is still an open circuit fault, it can be determined that the second-phase relay has an open circuit fault. Similarly, the bridge arm of the first-phase upper bridge can be controlled to be turned off, and the bridge arm of the second-phase upper bridge can be controlled to be turned on, and the third-phase sampling signal can be obtained again. If it is determined based on the third-phase sampling signal obtained again that the open circuit detection result of the third-phase relay is still an open circuit fault, it can be determined that the third-phase relay has an open circuit fault.

[0059] In this embodiment, the control circuit can be used to control the first-phase upper bridge arm and the three-phase relay to be in the on state, and control the remaining bridge arms to be in the off state, obtain the second-phase sampling signal and the third-phase sampling signal, determine the open-circuit detection result of the second-phase relay according to the second-phase sampling signal, and determine the open-circuit detection result of the third-phase relay according to the third-phase sampling signal, thereby realizing the open-circuit detection of the phase relay to be tested.

[0060] Optionally, in one embodiment, the target phase includes a first phase and a second phase, and the phase to be tested includes a third phase. The control circuit is also used to control the first phase upper bridge arm, the second phase upper bridge arm and the three-phase relay to be in an on state, and control the remaining bridge arms to be in an off state, obtain the third phase sampling signal, and determine the open circuit detection result of the third phase relay according to the third phase sampling signal. The third phase sampling signal includes the third phase sampling voltage, and the open circuit detection result includes being in a normal state and having an open circuit fault.

[0061] Taking the first phase as the U phase, the second phase as the V phase, and the third phase as the W phase as an example, when the U phase upper bridge arm U1, the V phase upper bridge arm V1 and the three-phase relay 200 are turned on, the flow direction of the electrical signal is as follows: Figure 5 If the third-phase sampling voltage is greater than the preset voltage threshold, it can be determined that the open circuit detection result of the W-phase relay W3 is in a normal state; if the third-phase sampling voltage is approximately 0, it can be determined that the open circuit detection result of the W-phase relay W3 is an open circuit fault.

[0062] Taking the first phase as the U phase, the second phase as the W phase, and the third phase as the V phase as an example, when the U phase upper bridge arm U1, the W phase upper bridge arm W1 and the three-phase relay 200 are turned on, the flow direction of the electrical signal is as follows: Figure 6If the third-phase sampling voltage is greater than the preset voltage threshold, it can be determined that the open circuit detection result of the V-phase relay V3 is in a normal state; if the third-phase sampling voltage is approximately 0, it can be determined that the open circuit detection result of the V-phase relay V3 is an open circuit fault.

[0063] Taking the first phase as V phase, the second phase as W phase, and the third phase as U phase as an example, when the W phase upper bridge arm W1, the V phase upper bridge arm V1 and the three-phase relay 200 are turned on, the flow direction of the electrical signal is as follows: Figure 7 If the third-phase sampling voltage is greater than the preset voltage threshold, it can be determined that the open circuit detection result of the U-phase relay U3 is in a normal state; if the third-phase sampling voltage is approximately 0, it can be determined that the open circuit detection result of the U-phase relay U3 is an open circuit fault.

[0064] In this embodiment, the control circuit can be used to control the first-phase upper bridge arm, the second-phase upper bridge arm and the three-phase relay to be in the on state, and the remaining bridge arms to be in the off state, so as to obtain the third-phase sampling signal, determine the open circuit detection result of the third-phase relay according to the third-phase sampling signal, and realize the open circuit detection of the phase relay to be tested.

[0065] In one embodiment, the target phase includes the first phase, and the phase to be tested includes at least one of the second phase and the third phase. The control circuit is also used to control the bridge arm of the first phase and the first phase relay to be in the on state, and control the remaining bridge arms, the second phase relay, and the third phase relay to be in the off state, obtain at least one of the second phase sampling signal and the third phase sampling signal, and determine the short circuit detection result of the second phase relay according to the second phase sampling signal, and / or determine the short circuit detection result of the third phase relay according to the third phase sampling signal. Among them, the second phase sampling signal includes the second phase sampling voltage, the third phase sampling signal includes the third phase sampling voltage, and the short circuit detection result includes being in a normal state and having a short circuit fault.

[0066] For example, when the first phase is U phase, the second phase is V phase, and the third phase is W phase, the U phase relay U3 and the U phase upper bridge arm U1 are in the on state, and the remaining bridge arms, V phase relay V3 and W phase relay W3 are all in the off state, you can refer to Figure 2 If the second phase sampling voltage is about 0, it can be determined that the short circuit detection result of the V phase relay V3 is in a normal state; if the second phase sampling voltage is greater than the preset voltage threshold, it can be determined that the short circuit detection result of the V phase relay V3 is a short circuit fault. If the third phase sampling voltage is about 0, it can be determined that the short circuit detection result of the W phase relay W3 is in a normal state; if the third phase sampling voltage is greater than the preset voltage threshold, it can be determined that the short circuit detection result of the W phase relay W3 is a short circuit fault.

[0067] For example, when the first phase is V phase, the second phase is U phase, and the third phase is W phase, the V phase relay V3 and the V phase upper bridge arm V1 are in the on state, and the remaining bridge arms, U phase relay U3, and W phase relay W3 are all in the off state, you can refer to Figure 3 If the second phase sampling voltage is approximately 0, it can be determined that the short circuit detection result of the U phase relay U3 is in a normal state; if the second phase sampling voltage is greater than the preset voltage threshold, it can be determined that the short circuit detection result of the U phase relay U3 is a short circuit fault. If the third phase sampling voltage is approximately 0, it can be determined that the short circuit detection result of the W phase relay W3 is in a normal state; if the third phase sampling voltage is greater than the preset voltage threshold, it can be determined that the short circuit detection result of the W phase relay W3 is a short circuit fault.

[0068] Take the first phase as W phase, the second phase as U phase, and the third phase as V phase as an example. When the W phase relay W3 and the W phase upper bridge arm W1 are in the on state, and the remaining bridge arms, U phase relay U3, and V phase relay V3 are all in the off state, you can refer to Figure 4 If the second phase sampling voltage is about 0, it can be determined that the short circuit detection result of the U phase relay U3 is in a normal state; if the second phase sampling voltage is greater than the preset voltage threshold, it can be determined that the short circuit detection result of the U phase relay U3 is a short circuit fault. If the third phase sampling voltage is about 0, it can be determined that the short circuit detection result of the V phase relay V3 is in a normal state; if the third phase sampling voltage is greater than the preset voltage threshold, it can be determined that the short circuit detection result of the V phase relay V3 is a short circuit fault.

[0069] In this embodiment, the control circuit controls the first-phase upper bridge arm and the first-phase relay to be in the on state, and controls the remaining bridge arms, the second-phase relay, and the third-phase relay to be in the off state, obtains the second-phase sampling signal and the third-phase sampling signal, determines the short-circuit detection result of the second-phase relay according to the second-phase sampling signal, and determines the short-circuit detection result of the third-phase relay according to the third-phase sampling signal, thereby realizing short-circuit detection of the second-phase relay and the third-phase relay.

[0070] Optionally, in one embodiment, the target phase includes a first phase and a second phase, and the phase to be tested includes a third phase. The control circuit is also used to control the first phase upper bridge arm, the second phase upper bridge arm, the first phase relay and the second phase relay to be in an on state, and control the remaining bridge arms and the third phase relay to be in an off state, obtain the third phase sampling signal, and determine the short circuit detection result of the third phase relay according to the third phase sampling signal. The third phase sampling signal includes the third phase sampling voltage, and the short circuit detection result includes being in a normal state and having a short circuit fault.

[0071] Take the first phase as U phase, the second phase as V phase, and the third phase as W phase as an example. When the U phase upper bridge arm U1, the V phase upper bridge arm V1, the U phase relay U3 and the V phase relay V3 are turned on, and the remaining bridge arms and the W phase relay W3 are turned off, refer to Figure 5 If the third-phase sampling voltage is approximately 0, it can be determined that the short-circuit detection result of the W-phase relay W3 is in a normal state; if the third-phase sampling voltage is greater than the preset voltage threshold, it can be determined that the short-circuit detection result of the W-phase relay W3 is a short-circuit fault.

[0072] Taking the first phase as U phase, the second phase as W phase, and the third phase as V phase as an example, when the U phase upper bridge arm U1, the W phase upper bridge arm W1, the U phase relay U3 and the W phase relay W3 are turned on, and the remaining bridge arms and the V phase relay V3 are turned off, refer to Figure 6 If the third-phase sampling voltage is approximately 0, it can be determined that the short-circuit detection result of the V-phase relay V3 is in a normal state; if the third-phase sampling voltage is greater than the preset voltage threshold, it can be determined that the short-circuit detection result of the V-phase relay V3 is a short-circuit fault.

[0073] Taking the first phase as V phase, the second phase as W phase, and the third phase as U phase as an example, when the upper bridge arm V1 of the V phase, the upper bridge arm W1 of the W phase, the V phase relay V3 and the W phase relay W3 are turned on, and the remaining bridge arms and the U phase relay U3 are turned off, refer to Figure 7 If the third-phase sampling voltage is approximately 0, it can be determined that the short-circuit detection result of the U-phase relay U3 is in a normal state; if the third-phase sampling voltage is greater than the preset voltage threshold, it can be determined that the short-circuit detection result of the U-phase relay U3 is a short-circuit fault.

[0074] In this embodiment, the control circuit can be used to control the first-phase upper bridge arm, the second-phase upper bridge arm, the first-phase relay and the second-phase relay to be in the on state, and control the remaining bridge arms and the third-phase relay to be in the off state, obtain the third-phase sampling signal, determine the short-circuit detection result of the third-phase relay according to the third-phase sampling signal, and realize short-circuit detection of the third-phase relay.

[0075] In one embodiment, Figure 8 As shown, the control circuit includes a driving unit 510 and a control unit 520 .

[0076] The driving unit 510 is connected to the control end of the three-phase full-bridge arm, and is used to control the on-off state of the three-phase full-bridge arm, so that the upper bridge arm of the target phase is in the on state and the remaining bridge arms are in the off state. The driving unit 520 can control the on-off state of the three-phase full-bridge arm by outputting a PWM signal to the control end of the three-phase full-bridge arm.

[0077] The control unit 520 is connected to the control end of the three-phase relay, and is used to control the on-off state of the three-phase relay, obtain the remaining phase sampling signal, and query the preset relationship library according to the remaining phase sampling signal, the on-off state of the three-phase full-bridge arm corresponding to the remaining phase sampling signal, and the on-off state of the three-phase relay to determine the fault detection result of the phase relay to be tested. The preset relationship library is used to represent the on-off state of the three-phase full-bridge arm, the on-off state of the three-phase relay, the correlation between the three-phase sampling signal and the fault detection result. The preset relationship library can be stored in the control unit in advance, so that when performing open circuit detection or short circuit detection, the control unit can directly call the preset relationship library. The preset relationship library may include multiple truth tables, and the truth tables can intuitively reflect the corresponding relationship between the on-off state of the three-phase full-bridge arm, the on-off state of the three-phase relay, the three-phase sampling signal and the fault detection result.

[0078] Furthermore, the control circuit also includes a comparison unit 530. The comparison unit 530 is connected to the three-phase sampling circuit 300 and the control unit 520 respectively, and can be used to compare the remaining phase sampling voltage with the preset voltage threshold to obtain a remaining phase comparison result. The preset voltage threshold can be a fixed level. The remaining comparison result can be a logical value, for example, the logical values ​​"ON" and "OFF" are defined. If the remaining phase sampling voltage is greater than the preset voltage threshold, the remaining comparison result is determined to be "ON"; if the remaining phase sampling voltage is less than the preset voltage threshold, the remaining comparison result is determined to be "OFF".

[0079] The control unit 520 is also used to match the remaining phase comparison results, the on-off states of the three-phase full-bridge arms corresponding to the remaining phase comparison results, and the on-off states of the three-phase relays with each truth table to determine the fault detection result of the phase relay to be tested.

[0080] When performing fault detection, different detection methods correspond to different truth tables. The detection method may include a first detection method and a second detection method, the first detection method includes a method of controlling the conduction of the bridge arm of one phase each time, and the second detection method includes a method of controlling the conduction of the bridge arm of two phases each time. Accordingly, the truth table may include a first truth table corresponding to the first detection method and a second truth table corresponding to the second detection method. Exemplarily, taking the phase to be tested as the V phase as an example, the first truth table corresponding to the first detection method may be as shown in Tables 1-3, and the second truth table corresponding to the second detection method may be as shown in Tables 4-6. Among them, U1, V1, and W1 respectively represent the on-off status of the three-phase upper bridge arm, U3, V3, and W3 respectively represent the on-off status of the three-phase relay, CHKU represents the comparison result of the U phase, CHKV represents the comparison result of the V phase, and CHKW represents the comparison result of the W phase. The logical value in the brackets represents the actual state of the phase relay. For example, the "OFF (ON)" corresponding to the V phase relay in Table 2 means that the control unit controls the V phase relay to turn off, but the V phase relay has a short circuit fault, which is equivalent to being in the on state.

[0081] Table 1- Truth table of the three-phase relay in normal state when the first detection method is used

[0082]

[0083] Table 2 - Truth table of the first detection method, assuming that the V phase relay has a short circuit fault

[0084]

[0085] Table 3 - Truth table of the first detection method, assuming that the V phase relay has an open circuit fault

[0086]

[0087] Table 4- Truth table of the three-phase relay in normal state when the second detection method is used

[0088]

[0089] Table 5 - Truth table of the second detection method, assuming that the V phase relay has a short circuit fault

[0090]

[0091] Table 6 - Truth table of the second detection method, assuming an open circuit fault on the V-phase relay

[0092]

[0093] When the first detection method is adopted, the control unit 520 can determine that the fault detection result of the phase relay to be tested is normal when the remaining phase comparison results, the on-off states of the three-phase full-bridge arms, the on-off states of the three-phase relays, and the normal state truth table corresponding to the first detection method match; it can determine that the fault detection result of the phase relay to be tested is an open circuit fault when the remaining phase comparison results, the on-off states of the three-phase full-bridge arms, the on-off states of the three-phase relays, and the open circuit fault truth table corresponding to the first detection method match; it can determine that the fault detection result of the phase relay to be tested is a short circuit fault when the remaining phase comparison results, the on-off states of the three-phase full-bridge arms, the on-off states of the three-phase relays, and the short circuit fault truth table corresponding to the first detection method match.

[0094] When the second detection method is adopted, the control unit can determine that the fault detection result of the phase relay to be tested is normal when the remaining phase comparison results, the on-off states of the three-phase full-bridge arms, the on-off states of the three-phase relays, and the normal state truth table corresponding to the second detection method match; it can determine that the fault detection result of the phase relay to be tested is an open circuit fault when the remaining phase comparison results, the on-off states of the three-phase full-bridge arms, the on-off states of the three-phase relays, and the open circuit fault truth table corresponding to the second detection method match; it can determine that the fault detection result of the phase relay to be tested is a short circuit fault when the remaining phase comparison results, the on-off states of the three-phase full-bridge arms, the on-off states of the three-phase relays, and the short circuit fault truth table corresponding to the second detection method match.

[0095] In one embodiment, Fig. 9 As shown, the three-phase sampling circuit 300 includes three-phase sampling units, and each phase sampling unit includes a first resistor (R1, R3 or R5) and a second resistor (R2, R4 or R6), wherein the first end of the first resistor is connected to the midpoint of the corresponding phase full-bridge bridge arm, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is grounded. The phase relay fault detection system also includes a power supply 600. The power supply 600 is used to provide a supply voltage, the power supply 600 is connected to the first end of the full-bridge inverter circuit 100, and the second end of the full-bridge inverter circuit 100 is grounded.

[0096] In some embodiments, the preset voltage threshold is less than the product of the supply voltage and the voltage division coefficient; the voltage division coefficient is the ratio of the second resistor to the total resistance, and the total resistance is the sum of the first resistor and the second resistor.

[0097] Taking the V phase as an example, when the U-phase upper bridge arm U1 and the three-phase relay 200 are turned on, and the remaining bridge arm is turned off, if the V-phase relay V3 is in a normal state, then the remaining phase sampling voltage Vchk=Vin*R4 / (R3+R4), if the V-phase relay V3 has an open circuit fault, then Vchk=0. When the U-phase upper bridge arm U1 and the U-phase relay U3 are turned on, and the remaining bridge arm and the V-phase relay V3 are turned off, if the V-phase relay V3 is in a normal state, then the remaining phase sampling voltage Vchk=0; if the V-phase relay V3 has a short circuit fault, then Vchk=Vin*R4 / (R3+R4). Since the power supply voltage Vin is generally much greater than 0, a fixed level can be selected between 0~Vin*R4 / (R3+R4) as the preset voltage threshold, so that when performing fault detection, there is no need to pay attention to the change of the power supply voltage.

[0098] In addition, if the normal operating range of the power supply voltage is Vin_min~Vin_max, a fixed level can be selected between 0~Vin_min*R4 / (R3+R4) as the preset voltage threshold.

[0099] In one embodiment, the present application further provides a motor controller, comprising the phase relay fault detection system provided by any of the above embodiments.

[0100] In one embodiment, the present application also provides a vehicle, comprising a motor controller provided by any of the above embodiments.

[0101] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0102] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0103] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A phase relay fault detection system, characterized in that: include: A full-bridge inverter circuit includes a three-phase full-bridge arm; A three-phase relay, wherein the three-phase relay is connected to the midpoint of the three-phase full-bridge arm and the motor respectively; A three-phase sampling circuit, wherein the three-phase sampling circuits are respectively connected to the midpoints of the bridge arms of the three-phase full bridge; A control circuit is respectively connected to the control end of the three-phase full-bridge arm, the control end of the three-phase relay and the three-phase sampling circuit, and is used to control the on-off state of the three-phase full-bridge arm and the three-phase relay, so that the upper bridge arm of the target phase is in the on state and the remaining bridge arms are in the off state, and obtain the remaining phase sampling signal through the three-phase sampling circuit, and determine the fault detection result of the phase relay to be tested according to the remaining phase sampling signal; The phase to be measured is any one or two phases of the three phases, the target phase corresponds to a different phase from the phase to be measured, and the target phase includes two phases or one phase, and the remaining phases correspond to the same phase as the phase to be measured.

2. The phase relay fault detection system according to claim 1, characterized in that: The fault detection result includes an open circuit detection result; the three phases include a first phase, a second phase and a third phase; the target phase includes the first phase, and the phase to be tested includes at least one of the second phase and the third phase; The control circuit is also used to control the first-phase upper bridge arm and the three-phase relay to be in an on state, and control the remaining bridge arms to be in an off state, obtain at least one of the second-phase sampling signal and the third-phase sampling signal, and determine the open circuit detection result of the second-phase relay according to the second-phase sampling signal, and / or determine the open circuit detection result of the third-phase relay according to the third-phase sampling signal.

3. The phase relay fault detection system according to claim 1, characterized in that: The fault detection result includes an open circuit detection result; the three phases include a first phase, a second phase and a third phase; the target phase includes a first phase and a second phase, and the phase to be tested includes a third phase; The control circuit is also used to control the first-phase upper bridge arm, the second-phase upper bridge arm and the three-phase relay to be in an on state, and control the remaining bridge arms to be in an off state, obtain the third-phase sampling signal, and determine the open circuit detection result of the third-phase relay according to the third-phase sampling signal.

4. The phase relay fault detection system according to claim 1, characterized in that: The fault detection result includes a short circuit detection result; the three phases include a first phase, a second phase and a third phase; the target phase includes the first phase, and the phase to be tested includes at least one of the second phase and the third phase; The control circuit is also used to control the first-phase upper bridge arm and the first-phase relay to be in an on state, and control the remaining bridge arms, the second-phase relay, and the third-phase relay to be in an off state, obtain at least one of the second-phase sampling signal and the third-phase sampling signal, and determine the short-circuit detection result of the second-phase relay according to the second-phase sampling signal, and / or determine the short-circuit detection result of the third-phase relay according to the third-phase sampling signal.

5. The phase relay fault detection system according to claim 1, characterized in that: The fault detection result includes a short circuit detection result; the three phases include a first phase, a second phase and a third phase; the target phase includes a first phase and a second phase, and the phase to be tested includes a third phase; The control circuit is also used to control the first-phase upper bridge arm, the second-phase upper bridge arm, the first-phase relay and the second-phase relay to be in the on state, and control the remaining bridge arms and the third-phase relay to be in the off state, obtain the third-phase sampling signal, and determine the short-circuit detection result of the third-phase relay according to the third-phase sampling signal.

6. The phase relay fault detection system according to any one of claims 1 to 5, characterized in that: The control circuit comprises: A driving unit connected to the control end of the three-phase full-bridge arm, used to control the on-off state of the three-phase full-bridge arm, so that the upper bridge arm of the target phase is in the on state and the remaining bridge arms are in the off state; A control unit is connected to the control end of the three-phase relay, and is used to control the on-off state of the three-phase relay, obtain the remaining phase sampling signal, and query the preset relationship library according to the remaining phase sampling signal, the on-off state of the three-phase full-bridge arm corresponding to the remaining phase sampling signal, and the on-off state of the three-phase relay to determine the fault detection result of the phase relay to be tested; the preset relationship library is used to represent the on-off state of the three-phase full-bridge arm, the on-off state of the three-phase relay, the correlation relationship between the three-phase sampling signal and the fault detection result.

7. The phase relay fault detection system according to claim 6, characterized in that: The residual phase sampling signal includes a residual phase sampling voltage; the preset relationship library includes a plurality of truth tables; The control circuit further comprises a comparison unit connected to the three-phase sampling circuit, and configured to compare the remaining phase sampling voltage with a preset voltage threshold to obtain a remaining phase comparison result; The control unit is also connected to the comparison unit, and the control unit is also used to match each truth table according to the remaining phase comparison result, the on-off state of the three-phase full-bridge arm corresponding to the remaining phase comparison result, and the on-off state of the three-phase relay, so as to determine the fault detection result of the phase relay to be tested.

8. The phase relay fault detection system according to claim 7, characterized in that: The three-phase sampling circuit includes three-phase sampling units, and each phase sampling unit includes a first resistor and a second resistor, wherein the first end of the first resistor is connected to the midpoint of the corresponding phase full-bridge bridge arm, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is grounded.

9. The phase relay fault detection system according to claim 8, characterized in that: Also includes a power supply, the power supply is used to provide a supply voltage; Wherein, a first end of the full-bridge inverter circuit is connected to the power supply, and a second end of the full-bridge inverter circuit is grounded; The preset voltage threshold is less than the product of the supply voltage and a voltage division coefficient; the voltage division coefficient is a ratio of the second resistor to a total resistance, and the total resistance is the sum of the first resistor and the second resistor.

10. A motor controller, characterized in that: It comprises a phase relay fault detection system as described in any one of claims 1 to 9.

11. A vehicle, characterized in that: Comprising the motor controller as claimed in claim 10.

Images