Motor control circuit, motor system and vehicle
By setting up a fault detection branch in the motor control circuit and using the voltage detection signal to determine the fault of the switch module, the damage caused by current imbalance in the traditional motor controller is solved, and the reliability and safety of the system are improved.
Patent Information
- Application Number
- CN202420749962.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-11
- Publication Date
- 2025-01-14
- Estimated Expiration
- 2034-04-11
AI Technical Summary
When a traditional motor controller is connected in parallel with power devices, current imbalance caused by different on-resistance, which may damage some power devices, thereby threatening the safety and reliability of the entire motor controller.
Design a motor control circuit, by setting a fault detection branch at the midpoint of the bridge arm unit, and using the controller to determine whether there is a fault in the switch module based on the voltage detection signal, and take corresponding control measures, such as power reduction operation to protect other components .
Improve the reliability and safety of the motor control system, prevent the expansion of faults and extend the service life of the motor controller.
Smart Images
Figure CN222356230U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of motor control, in particular to a motor control circuit, a motor system and a vehicle. Background Art
[0002] Traditional motor controllers can increase the output power of motor controllers by connecting power devices in parallel. However, there are differences between power devices, resulting in inconsistent on-currents of each power device after parallel connection. Some have small on-resistance and large current distribution, while others have large on-resistance and small current distribution. As a result, power devices with small on-resistance may be damaged if large current passes through them for a long time. If some power devices are damaged, the entire motor controller may be damaged if the motor controller is not allowed to reduce power. Therefore, it is urgent to design a motor controller that can detect power device failures. Utility Model Content
[0003] In order to solve the above technical problem or at least partially solve the above technical problem, the utility model provides a motor control circuit, a motor system and a vehicle.
[0004] To achieve the above object, the first aspect of the present invention provides a motor control circuit, the motor control circuit comprising:
[0005] A voltage conversion circuit, comprising a positive bus, a negative bus and a plurality of bridge arm units, wherein the positive bus and the negative bus are used to receive a DC voltage, the plurality of bridge arm units are connected in parallel between the positive bus and the negative bus, and each of the bridge arm units comprises an upper arm switch module, a lower arm switch module and a midpoint;
[0006] a controller, electrically connected to both the upper arm switch modules and the lower arm switch modules of the plurality of bridge arm units; and
[0007] At least one fault detection branch, each fault detection branch is electrically connected to the midpoint of the two bridge arm units and the controller;
[0008] When any fault detection branch is turned on, and the first switch module of one of the bridge arm units connected to the fault detection branch and the second switch module of the other bridge arm unit are both turned on, the fault detection branch outputs a voltage detection signal to the controller based on the voltage between the midpoints of the two correspondingly connected bridge arm units; the controller is used to determine whether the first switch module and the second switch module have faults according to the voltage detection signal; wherein the first switch module is one of the upper arm switch module and the lower arm switch module, and the second switch module is the other of the upper arm switch module and the lower arm switch module.
[0009] The motor control circuit provided by the utility model sets a fault detection branch between the midpoints of the two bridge arm units, and when the electrical connection between the positive bus and the negative bus is turned on through the fault detection branch and the first switch module of one of the bridge arm units and the second switch module of the other bridge arm unit connected to it, the fault detection branch outputs a voltage detection signal to the controller based on the voltage between the midpoints of the two correspondingly connected bridge arm units, and the controller determines whether the first switch module and the second switch module are faulty according to the voltage detection signal. In this way, corresponding control measures can be taken when a fault is detected in the switch module in the motor control circuit, thereby improving the reliability and safety of the system.
[0010] In some embodiments, the fault detection branch includes a detection resistor and a first switching element connected in series between the midpoints of two correspondingly connected bridge arm units. The first switching element is also electrically connected to the controller and is used to be turned on or off under the control of the controller.
[0011] In some embodiments, the fault detection branch also includes an operational amplifier circuit, which is electrically connected to the detection resistor and the controller, and is used to collect the voltage across the detection resistor, and perform signal processing on the voltage across the detection resistor to obtain the voltage detection signal and output it to the controller.
[0012] In some embodiments, the resistance value of the detection resistor is between 10 ohms and 50 ohms.
[0013] In some embodiments, the first switch element includes at least one of a relay, an insulated gate bipolar transistor IGBT, a triode, and an insulated gate field effect transistor MOS.
[0014] In some embodiments, the number of the multiple bridge arm units is N, and the number of the fault detection branches is N-1, wherein different fault detection branches are electrically connected between midpoints of two different bridge arm units among the N bridge arm units.
[0015] In some embodiments, the plurality of bridge arm units include a U-phase bridge arm unit, a V-phase bridge arm unit and a W-phase bridge arm unit, the midpoint of the U-phase bridge arm unit is electrically connected to the U-phase winding of the motor, the midpoint of the V-phase bridge arm unit is electrically connected to the V-phase winding of the motor, and the midpoint of the W-phase bridge arm unit is electrically connected to the W-phase winding of the motor;
[0016] The voltage conversion circuit is also used to convert the received DC voltage into AC voltage to drive the motor to operate under the control of the controller.
[0017] In some embodiments, the upper arm switch module of each of the bridge arm units includes multiple upper arm branches connected in parallel between the midpoint of the bridge arm unit and the positive bus, and the upper arm switch module of each of the bridge arm units includes multiple lower arm branches connected in parallel between the midpoint of the bridge arm unit and the negative bus, and each upper arm branch and each lower arm branch includes a second switching element and a fuse connected in series.
[0018] In some embodiments, the number of upper arm branches in each of the upper arm switch modules and the number of lower arm branches in each of the lower arm switch modules are equal.
[0019] In some embodiments, the controller is used to determine that the first switch module and the second switch module are both normal when the voltage value corresponding to the voltage detection signal is within a preset voltage threshold range, and to determine that at least one of the first switch module and the second switch module is faulty when the voltage value corresponding to the voltage detection signal is not within the preset voltage threshold range.
[0020] A second aspect of the present invention further provides a motor system, the motor system comprising:
[0021] Motors; and
[0022] As described in the first aspect above, the motor control circuit is electrically connected to the motor.
[0023] A third aspect of the present utility model further provides a vehicle, the vehicle comprising:
[0024] the vehicle body; and
[0025] As described in the second aspect above, the motor system is arranged in the vehicle body.
[0026] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 It is a schematic diagram of the topological structure of the motor control circuit provided by the embodiment of the utility model;
[0028] Figure 2 yes Figure 1 A current flow diagram of a motor control circuit shown;
[0029] Figure 3 yes Figure 1 The circuit structure diagram of the motor control circuit shown;
[0030] Figure 4It is a schematic diagram of the topological structure of a vehicle provided in an embodiment of the utility model.
[0031] The following are the descriptions of the reference numerals:
[0032] Motor control circuit 100
[0033] Voltage conversion circuit 10
[0034] Positive busbarBattery+
[0035] Negative busbar Battery-
[0036] Controller 20
[0037] Fault detection branches 31, 32
[0038] Detection resistor R1
[0039] The first switching element T1
[0040] Operational Amplifier Circuit 311
[0041] U phase bridge arm unit 11
[0042] V phase bridge arm unit 12
[0043] W phase bridge arm unit 13
[0044] Upper arm switch modules 111, 121, 131
[0045] Lower arm switch modules 112, 122, 132
[0046] Midpoint U, V, W
[0047] Motor 200
[0048] U phase winding WU
[0049] V phase winding WV
[0050] W phase winding WW
[0051] The second switching element T2
[0052] Fuse R2
[0053] Control signals S_U1, S_V1, S_W1, S_U2, S_V2, S_W2
[0054] Motor system 1
[0055] Vehicle 1000
[0056] Vehicle body 2
[0057] The following specific implementation manner will illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION
[0058] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0059] In addition, the terms "first", "second" and the like in the specification of the utility model are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the utility model described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any of their variations are intended to cover non-exclusive inclusions, for example, the process, method, system, product or equipment comprising a series of steps or units need not be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment. The term "connection" may include meanings such as direct connection or indirect connection.
[0060] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.
[0061] Please also read Figure 1 to Figure 3 ,in, Figure 1 It is a schematic diagram of the topological structure of the motor control circuit provided by the embodiment of the utility model; Figure 2 yes Figure 1 A current flow diagram of a motor control circuit shown; Figure 3 yes Figure 1 The circuit structure diagram of the motor control circuit is shown in FIG. The motor control circuit 100 comprises a voltage conversion circuit 10, a controller 20 and at least one fault detection branch.
[0062] Among them, the voltage conversion circuit 10 includes a positive bus Battery+, a negative bus Battery- and a plurality of bridge arm units, the positive bus Battery+ and the negative bus Battery- are used to receive a DC voltage, the plurality of bridge arm units are connected in parallel between the positive bus Battery+ and the negative bus Battery-, and each of the bridge arm units includes an upper arm switch module, a lower arm switch module and a midpoint.
[0063] The controller 20 is electrically connected to both the upper arm switch modules and the lower arm switch modules of the plurality of bridge arm units.
[0064] Each of the fault detection branches is electrically connected to the midpoint of the two bridge arm units and the controller 20 .
[0065] When any fault detection branch is turned on, and the first switch module of one of the bridge arm units and the second switch module of the other bridge arm unit connected to the fault detection branch are both turned on, the fault detection branch outputs a voltage detection signal to the controller 20 based on the voltage between the midpoints of the two correspondingly connected bridge arm units. The controller 20 is used to determine whether the first switch module and the second switch module have faults according to the voltage detection signal. The first switch module is one of the upper arm switch module and the lower arm switch module, and the second switch module is the other of the upper arm switch module and the lower arm switch module.
[0066] Among them, when any fault detection branch is turned on, and the first switch module of one of the bridge arm units connected to the fault detection branch and the second switch module of another bridge arm unit are both turned on, the positive bus Battery+ and the negative bus Battery- form a loop through the fault detection branch and the first switch module of one of the bridge arm units connected to the fault detection branch and the second switch module of another bridge arm unit. When the controller 20 detects that the first switch module and the second switch module are faulty, it can take corresponding control measures, for example, control the voltage conversion circuit 10 to stop running or reduce power, so as to protect other normal components and avoid further expansion of the fault range.
[0067] The motor control circuit 100 provided by the utility model sets a fault detection branch between the midpoints of the two bridge arm units, and when the electrical connection between the positive bus Battery+ and the negative bus Battery- is turned on through the fault detection branch and the first switch module of one of the bridge arm units and the second switch module of the other bridge arm unit connected to it, the fault detection branch outputs a voltage detection signal to the controller 20 based on the voltage between the midpoints of the two correspondingly connected bridge arm units, and the controller 20 determines whether the first switch module and the second switch module are faulty according to the voltage detection signal. In this way, when it is detected that a fault exists in the switch module in the motor control circuit 100, corresponding control measures can be taken, thereby improving the reliability and safety of the system.
[0068] In some embodiments, the number of the multiple bridge arm units is N, and the number of the fault detection branches is N-1, wherein different fault detection branches are electrically connected between midpoints of two different bridge arm units among the N bridge arm units.
[0069] In this way, the switch module in each bridge arm unit can perform fault detection through at least one fault detection branch.
[0070] For example, Figure 1 As shown, the number of the multiple bridge arm units is 3, including a U-phase bridge arm unit 11, a V-phase bridge arm unit 12 and a W-phase bridge arm unit 13. The U-phase bridge arm unit 11 includes an upper arm switch module 111, a lower arm switch module 112 and a midpoint U, the V-phase bridge arm unit 12 includes an upper arm switch module 121, a lower arm switch module 122 and a midpoint V, and the W-phase bridge arm unit 13 includes an upper arm switch module 131, a lower arm switch module 132 and a midpoint W.
[0071] The midpoint U of the U-phase bridge arm unit 11 is electrically connected to the U-phase winding WU of the motor 200 , the midpoint V of the V-phase bridge arm unit 12 is electrically connected to the V-phase winding WV of the motor 200 , and the midpoint W of the W-phase bridge arm unit 13 is electrically connected to the W-phase winding WW of the motor 200 .
[0072] The voltage conversion circuit 10 is also used to convert the received DC voltage into AC voltage to drive the motor 200 to operate under the control of the controller 20 .
[0073] In some embodiments, Figure 1 As shown, the at least one fault detection branch includes a fault detection branch 31 and a fault detection branch 32, the fault detection branch 31 is electrically connected between the midpoint U of the U-phase bridge arm unit 11 and the midpoint V of the V-phase bridge arm unit 12, and the fault detection branch 32 is electrically connected between the midpoint W of the W-phase bridge arm unit 13 and the midpoint V of the V-phase bridge arm unit 12.
[0074] In some embodiments, the fault detection branch includes a detection resistor R1 and a first switch element T1 connected in series between the midpoints of two correspondingly connected bridge arm units. The first switch element T1 is also electrically connected to the controller 20 and is used to be turned on or off under the control of the controller 20.
[0075] In some embodiments, the fault detection branch also includes an operational amplifier circuit 311, which is electrically connected to the detection resistor R1 and the controller 20, and is used to collect the voltage across the detection resistor R1, and perform signal processing on the voltage across the detection resistor R1 to obtain the voltage detection signal and output it to the controller 20.
[0076] In some embodiments, the upper arm switch module of each bridge arm unit includes a plurality of upper arm branches connected in parallel between the midpoint of the bridge arm unit and the positive bus Battery+, and the upper arm switch module of each bridge arm unit includes a plurality of lower arm branches connected in parallel between the midpoint of the bridge arm unit and the negative bus Battery-, and each upper arm branch and each lower arm branch include a second switch element T2 and a fuse R2 connected in series. Exemplarily, the fuse R2 may be a fuse.
[0077] In some embodiments, the number of upper arm branches in each of the upper arm switch modules and the number of lower arm branches in each of the lower arm switch modules are equal.
[0078] For example Figure 3 As shown, the upper arm switch modules 111 to 131 and the lower arm switch modules 112 to 132 each include five switch branches. In this way, when the motor control circuit 100 is running, the currents shared by the second switch elements T2 can be kept similar, thereby avoiding overheating of the switch elements due to current imbalance.
[0079] It should be noted that, in the embodiment of the present utility model, the on-off states of all the second switch elements T2 in the same switch module are the same, and are all controlled by the same control signal output by the controller 20, such as Figure 3 As shown, all the second switch elements T2 in the upper arm switch module 111 are controlled by the control signal S_U1, all the second switch elements T2 in the upper arm switch module 121 are controlled by the control signal S_V1, all the second switch elements T2 in the upper arm switch module 131 are controlled by the control signal S_W1, all the second switch elements T2 in the lower arm switch module 112 are controlled by the control signal S_U2, all the second switch elements T2 in the lower arm switch module 122 are controlled by the control signal S_V2, and all the second switch elements T2 in the lower arm switch module 132 are controlled by the control signal S_W2.
[0080] In some embodiments, the motor control circuit 100 may also include a bus capacitor (not shown) electrically connected between the positive bus Battery+ and the negative bus Battery-, and the bus capacitor is used to maintain the DC voltage received by the positive bus Battery+ and the negative bus Battery- stable.
[0081] During operation, when it is necessary to drive the motor 200 to operate, the controller 20 can control the first switching elements T1 in all fault detection branches to be disconnected, and control the voltage conversion circuit 10 to operate in the inverter mode to convert the received DC voltage into AC voltage and provide it to the motor 200.
[0082] like Figure 2-3 As shown, when it is necessary to detect the upper arm switch module 111 of the U-phase bridge arm unit 11 and the lower arm switch module 122 of the V-phase bridge arm unit 12, the controller 20 can control all the second switch elements T2 in the upper arm switch module 111, the first switch element T1 in the fault detection branch 31 and all the second switch elements T2 in the lower arm switch module 122 to be turned on. It is not difficult to understand that at this time, if all the second switch elements T2 in the upper arm switch module 111 and all the second switch elements T2 in the lower arm switch module 122 are normal, the resistance value between the positive bus Battery+ and the negative bus Battery- will be stable within a preset resistance value range, so that the voltage value corresponding to the voltage detection signal will be within the preset voltage threshold range; if at least one second switch element T2 in the upper arm switch module 111 and the lower arm switch module 122 fails, the fuse R2 connected to the failed second switch element T2 will be blown, so that the resistance value between the positive bus Battery+ and the negative bus Battery- will increase, and then the voltage value corresponding to the voltage detection signal will be reduced to below the preset voltage threshold range. Therefore, in the embodiment of the utility model, the controller 20 is also used to determine that the first switch module and the second switch module are both normal when the voltage value corresponding to the voltage detection signal is within the preset voltage threshold range, and to determine that at least one of the first switch module and the second switch module is faulty when the voltage value corresponding to the voltage detection signal is not within the preset voltage threshold range. The preset voltage threshold range can be obtained by testing the motor control circuit 100 when all the second switch elements T2 in the motor control circuit 100 are normal.
[0083] Similarly, when it is necessary to detect the lower arm switch module 132 of the W-phase bridge arm unit 13 and the upper arm switch module 121 of the V-phase bridge arm unit 12, the controller 20 can control the lower arm switch module 132, the first switch element T1 in the fault detection branch 32 and the upper arm switch module 121 to be turned on.
[0084] Exemplarily, the resistance value of the detection resistor R1 is between 10 ohms and 50 ohms.
[0085] Exemplarily, the first switch element T1 includes at least one of a relay, an insulated gate bipolar transistor IGBT, a triode, and an insulated gate field effect transistor MOS.
[0086] It should be noted that, when the motor control circuit 100 is subjected to fault detection, the windings of the motor 200 will be connected in parallel to both ends of the fault detection branch, and the resistance value of the windings of the motor 200 will be affected by the temperature, so that the temperature of the motor 200 will also affect the accuracy of the detection. Therefore, in order to improve the accuracy of the detection, the motor control circuit 100 may further include a temperature detection module (not shown) electrically connected to the controller 20, and the temperature detection module is used to detect the temperature of the motor 200. The controller 20 may control the motor control circuit 100 to perform fault detection only when the temperature of the motor 200 is within a preset temperature range.
[0087] Please refer again Figure 1 Based on the same concept, the utility model also provides a motor system 1, which includes a motor 200 and a motor control circuit 100 as described in any of the above embodiments, and the motor control circuit 100 is electrically connected to the motor 200.
[0088] See also Figure 4 Based on the same concept, the utility model also provides a vehicle 1000 , wherein the vehicle 1000 includes a vehicle body 2 and a motor system 1 as described in the above embodiment, wherein the motor system 1 is disposed in the vehicle body 2 .
[0089] The motor system 1 and vehicle 1000 provided by the utility model are configured to set a fault detection branch between the midpoints of the two bridge arm units of the motor control circuit 100, and when the electrical connection between the positive bus Battery+ and the negative bus Battery- is turned on through the fault detection branch and the first switch module of one of the bridge arm units and the second switch module of the other bridge arm unit connected to it, the fault detection branch outputs a voltage detection signal to the controller 20 based on the voltage between the midpoints of the two correspondingly connected bridge arm units, and the controller 20 determines whether the first switch module and the second switch module are faulty according to the voltage detection signal. In this way, when it is detected that a fault exists in the switch module in the motor control circuit 100, corresponding control measures can be taken, thereby improving the reliability and safety of the system.
[0090] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.
Claims
1. A motor control circuit, characterized in that: The motor control circuit comprises: A voltage conversion circuit, comprising a positive bus, a negative bus and a plurality of bridge arm units, wherein the positive bus and the negative bus are used to receive a DC voltage, the plurality of bridge arm units are connected in parallel between the positive bus and the negative bus, and each of the bridge arm units comprises an upper arm switch module, a lower arm switch module and a midpoint; a controller, electrically connected to both the upper arm switch modules and the lower arm switch modules of the plurality of bridge arm units; and At least one fault detection branch, each fault detection branch is electrically connected to the midpoint of the two bridge arm units and the controller; When any fault detection branch is turned on, and the first switch module of one of the bridge arm units connected to the fault detection branch and the second switch module of the other bridge arm unit are both turned on, the fault detection branch outputs a voltage detection signal to the controller based on the voltage between the midpoints of the two correspondingly connected bridge arm units; the controller is used to determine whether the first switch module and the second switch module have faults according to the voltage detection signal; wherein the first switch module is one of the upper arm switch module and the lower arm switch module, and the second switch module is the other of the upper arm switch module and the lower arm switch module.
2. The motor control circuit according to claim 1, characterized in that: The fault detection branch includes a detection resistor and a first switch element connected in series between the midpoints of two correspondingly connected bridge arm units. The first switch element is also electrically connected to the controller and is used to be turned on or off under the control of the controller.
3. The motor control circuit according to claim 2, characterized in that: The fault detection branch also includes an operational amplifier circuit, which is electrically connected to the detection resistor and the controller and is used to collect the voltage across the detection resistor and perform signal processing on the voltage across the detection resistor to obtain the voltage detection signal and output it to the controller.
4. The motor control circuit according to claim 2, characterized in that: The resistance value of the detection resistor is between 10 ohms and 50 ohms.
5. The motor control circuit according to claim 2, characterized in that: The first switch element includes at least one of a relay, an insulated gate bipolar transistor IGBT, a triode and an insulated gate field effect transistor MOS.
6. The motor control circuit according to claim 1, characterized in that: The number of the plurality of bridge arm units is N, and the number of the fault detection branches is N-1, wherein different fault detection branches are electrically connected between midpoints of two different bridge arm units among the N bridge arm units.
7. The motor control circuit according to claim 1, characterized in that: The plurality of bridge arm units include a U-phase bridge arm unit, a V-phase bridge arm unit and a W-phase bridge arm unit, the midpoint of the U-phase bridge arm unit is electrically connected to the U-phase winding of the motor, the midpoint of the V-phase bridge arm unit is electrically connected to the V-phase winding of the motor, and the midpoint of the W-phase bridge arm unit is electrically connected to the W-phase winding of the motor; The voltage conversion circuit is also used to convert the received DC voltage into AC voltage to drive the motor to operate under the control of the controller.
8. The motor control circuit according to claim 1, characterized in that: The upper arm switch module of each bridge arm unit includes multiple upper arm branches connected in parallel between the midpoint of the bridge arm unit and the positive bus, and the upper arm switch module of each bridge arm unit includes multiple lower arm branches connected in parallel between the midpoint of the bridge arm unit and the negative bus, and each upper arm branch and each lower arm branch include a second switching element and a fuse connected in series.
9. The motor control circuit according to claim 8, characterized in that: The number of upper arm branches in each of the upper arm switch modules is equal to the number of lower arm branches in each of the lower arm switch modules.
10. The motor control circuit according to claim 1, characterized in that: The controller is used to determine that the first switch module and the second switch module are both normal when the voltage value corresponding to the voltage detection signal is within a preset voltage threshold range, and to determine that at least one of the first switch module and the second switch module is faulty when the voltage value corresponding to the voltage detection signal is not within the preset voltage threshold range.
11. A motor system, characterized in that: The motor system comprises: Motors; and The motor control circuit according to any one of claims 1 to 10, wherein the motor control circuit is electrically connected to the motor.
12. A vehicle, characterized in that: The vehicle comprises: the vehicle body; and The motor system according to claim 11, wherein the motor system is disposed in the vehicle body.