A power supply control circuit

Abstract

This application discloses a power supply control circuit, including: a boost circuit, a first switching transistor, a second switching transistor, and a third switching transistor; a first terminal of the first switching transistor is connected to the positive terminal of a DC power supply, a second terminal of the first switching transistor is connected to the first terminal of the second switching transistor, and the second terminal of the second switching transistor is used to supply power to the motor control system; the second terminal of the first switching transistor is also connected to the first terminal of the third switching transistor, the second terminal of the third switching transistor is connected to the input terminal of the boost circuit, and the output terminal of the boost circuit is used to supply power to the actuator. This technical solution can provide power to the motor control system and the actuator independently through two separate paths, allowing the other to continue operating normally in the event of a failure in one path.

Description

Technical Field

[0001] This application relates to the field of power supply technology for control circuits, specifically to a power supply control circuit. Background Technology

[0002] Currently, in new energy vehicles, the control circuits for actuators are generally integrated with the motor controller. For example, the actuator can be a clutch or a solenoid valve. That is, the original motor controller only controls the motor, while the integrated power supply control circuit must control both the motor and the clutch or solenoid valve.

[0003] Therefore, the integrated control method results in the actuators and motor control system using a common power supply. If one of them fails, the common power supply needs to be disconnected, which will force the other to stop working as well. Utility Model Content

[0004] In view of this, this application provides a power supply control circuit that can supply power to the motor control system and actuators through two independent paths, so that the other can continue to work normally in the event of a failure in one path.

[0005] This application provides a power supply control circuit, including: a boost circuit, a first switching transistor, a second switching transistor, and a third switching transistor; a first terminal of the first switching transistor is connected to the positive terminal of a DC power supply, a second terminal of the first switching transistor is connected to the first terminal of the second switching transistor, and the second terminal of the second switching transistor is used to supply power to a motor control system; the second terminal of the first switching transistor is also connected to the first terminal of the third switching transistor, the second terminal of the third switching transistor is connected to the input terminal of the boost circuit, and the output terminal of the boost circuit is used to supply power to an actuator.

[0006] One possible implementation further includes: a first diode, a fourth switch, and a controller; the cathode of the first diode is connected to the output terminal of the boost circuit, the cathode of the first diode is connected to the positive input terminal of the actuator, and the anode of the first diode is connected to the negative input terminal of the actuator; the anode of the first diode is grounded through the fourth switch; the controller is connected to the control terminal of the fourth switch and is used to control the fourth switch.

[0007] One possible implementation further includes: a first fault detection circuit; a first input terminal of the first fault detection circuit is connected to the positive input terminal of the actuator, a second input terminal of the first fault detection circuit is connected to the second terminal of the second switching transistor; the first input terminal of the first fault detection circuit is grounded through a first voltage divider circuit, a second diode is connected between the positive input terminal of the actuator and the second terminal of the second switching transistor, and the output terminal of the first fault detection circuit is connected to the first detection pin of the controller.

[0008] In one possible implementation, the voltage divider terminal of the first voltage divider circuit is connected to the output terminal of the first fault detection circuit through a first current-limiting resistor; the anode of the second diode is connected to the second terminal of the second switching transistor through a tenth resistor, and the cathode of the second diode is connected to the positive input terminal of the actuator.

[0009] One possible implementation further includes: a second fault detection circuit; a first input terminal of the second fault detection circuit is connected to the negative input terminal of the actuator, a second input terminal of the second fault detection circuit is connected to the second terminal of the second switching transistor; the first input terminal of the second fault detection circuit is grounded through a second voltage divider circuit, a third diode is connected between the negative input terminal of the actuator and the second terminal of the second switching transistor, and the output terminal of the second fault detection circuit is connected to the second detection pin of the controller.

[0010] In one possible implementation, the voltage divider terminal of the second voltage divider circuit is connected to the output terminal of the second fault detection circuit through a second current-limiting resistor; the anode of the third diode is connected to the second terminal of the second switching transistor through a fourteenth resistor, and the cathode of the third diode is connected to the negative input terminal of the actuator.

[0011] One possible implementation further includes an auxiliary power supply; the input terminal of the auxiliary power supply is connected to the second terminal of the second switching transistor, and the output terminal of the auxiliary power supply is connected to the power supply pin of the controller for supplying power to the controller.

[0012] One possible implementation is that the actuator includes at least one of a clutch or a solenoid valve.

[0013] One possible implementation is that the DC power source is a low-voltage battery of an electric vehicle.

[0014] One possible implementation further includes a current sensing resistor; the first terminal of the fourth switching transistor is connected to the negative input terminal of the actuator, the second terminal of the fourth switching transistor is grounded through the current sensing resistor, and the two ends of the current sensing resistor are connected to the current sensing pin of the controller. The power supply control circuit provided in this application embodiment has separate switching transistors for the power supply branches of the actuator and the motor control system. When one power supply branch fails, the faulty power supply branch can be disconnected independently, while the other normal power supply branch can continue to operate normally, without having to disconnect all power supply branches and affect the operation of the normal power supply branch. Brief description of the attached figures

[0015] Figure 1 A schematic diagram of a power supply control circuit provided in an embodiment of this application;

[0016] Figure 2 A schematic diagram of the first fault detection circuit provided in an embodiment of this application;

[0017] Figure 3 This is a schematic diagram of the second fault detection circuit provided in an embodiment of this application. Detailed Implementation

[0018] See Figure 1 The figure is a schematic diagram of a power supply control circuit provided in an embodiment of this application.

[0019] The power supply control circuit provided in this application includes: a boost circuit, a first switch Q60, a second switch Q6, and a third switch Q603.

[0020] The first terminal of the first switching transistor Q60 is connected to the positive terminal of the DC power supply V1. The second terminal of the first switching transistor Q60 is connected to the first terminal of the second switching transistor Q6. The second terminal of the second switching transistor Q6 is used to supply power to the motor control system M1. The positive input terminal of the motor control system M1 is connected to the power supply B+.

[0021] The positive input terminal of the motor control system M1 is also used to ground through the third capacitor C3, and the positive input terminal of the motor control system M1 is also used to ground through the fourth capacitor C4. The main functions of the third capacitor C3 and the fourth capacitor C4 are filtering and voltage regulation.

[0022] The actuator may include at least one of a clutch or a solenoid valve.

[0023] For example, when the power supply control circuit is applied to an electric vehicle, the DC power source is the low-voltage battery of the electric vehicle.

[0024] The second terminal of the first switching transistor Q60 is also connected to the first terminal of the third switching transistor Q603. The second terminal of the third switching transistor Q603 is connected to the input terminal of the boost circuit. The output terminal of the boost circuit is used to power the actuator M2.

[0025] Among them, the first switch Q60 is located in the power supply main circuit, the second switch Q6 is located in the power supply branch of the motor control system M1, and the third switch Q603 is located in the power supply branch of the actuator M2.

[0026] This embodiment uses a Boost circuit as an example to illustrate the boost circuit. The Boost circuit includes an inductor L1, a diode D1, and a switching transistor Q2. To limit the current of Q2, a first resistor R1 is also included, which is connected in series with the switching transistor Q2. The Boost circuit also includes an input capacitor C1 and an output capacitor C2.

[0027] from Figure 1It can be seen that the second switch Q6 can control the disconnection of the power supply path to the motor control system M1, and the third switch Q603 can control the disconnection of the power supply path to the actuator M2. For example, when the actuator fails, the third switch Q603 can be disconnected. The second switch Q6 can then continue to conduct to supply power to the motor control system M1.

[0028] The power supply control circuit provided in this application embodiment has separate switching transistors for the power supply branches of the actuators and the motor control system. When one power supply branch fails, the faulty branch can be disconnected while the other normal power supply branch continues to operate normally, without having to disconnect all power supply branches and affect the operation of the normal power supply branch. The power supply control circuit provided in this application embodiment can achieve independent control of two power supply branches using simple discrete switching transistors, eliminating the need for complex control chips. This technology is simple to implement and low in cost.

[0029] See also Figure 1 The power supply control circuit provided in this application embodiment further includes: a first diode D2, a fourth switching transistor Q3, and a controller (not shown in the figure). This application does not specifically limit the specific type of the controller, such as a microcontroller, a microprocessor, or a digital processor.

[0030] The power supply control circuit provided in this application embodiment also includes an auxiliary power supply (not shown in the figure).

[0031] The input terminal of the auxiliary power supply is connected to the second terminal of the second switching transistor Q6, and the output terminal of the auxiliary power supply is connected to the power supply pin of the controller. The auxiliary power supply can supply power to the controller, that is, the auxiliary power supply steps down and regulates the voltage at the B+ terminal to supply power to the controller.

[0032] The cathode of the first diode D2 is connected to the output terminal of the boost circuit, the cathode of the first diode D2 is connected to the positive input terminal VALPOW of the actuator M2, and the anode of the first diode D2 is connected to the negative input terminal VALVE0_L of the actuator M2.

[0033] The anode of the first diode D2 is grounded through the fourth switch Q3.

[0034] The controller is connected to the control terminal of the fourth switch Q4 to control the switching state of the fourth switch Q3. It should be understood that only when the second switch Q6 is turned on will there be voltage at the B+ terminal, and thus power at the output terminal of the auxiliary power supply, allowing the controller to operate and control the action of Q3.

[0035] The power supply control circuit provided in this application embodiment further includes a current sensing resistor R2; the first end of the fourth switch Q3 is connected to the negative input terminal of the actuator M2, the second end of the fourth switch Q3 is grounded through the current sensing resistor R2, and the two ends of the current sensing resistor R2 are connected to the current sensing pin of the controller.

[0036] The controller is used to control the duty cycle of the drive signal of Q3 based on the current flowing through the current sensing resistor R2, thereby adjusting the current of the current sensing resistor R2 so that the current of the current sensing resistor R2 reaches the preset value. This part is a typical control method of switching power supply and will not be described in detail here.

[0037] To ensure the safe operation of the power supply control circuit provided in this application embodiment, a pre-power-on self-test is required. The self-test method provided in this application embodiment is described below with reference to the accompanying drawings. The following self-test method mainly detects whether a short-circuit fault to ground occurs at the positive input terminal of the actuator, and whether a short-circuit fault to ground occurs at the negative input terminal of the actuator.

[0038] See Figure 2 The figure is a schematic diagram of the first fault detection circuit provided in an embodiment of this application.

[0039] The power supply control circuit provided in this application embodiment further includes: a first fault detection circuit.

[0040] The first input terminal of the first fault detection circuit is connected to the positive input terminal VALPOW of the actuator. The second input terminal of the first fault detection circuit is connected to the second terminal (B+) of the second switching transistor. The first input terminal of the first fault detection circuit is grounded through a first voltage divider circuit. Specifically, the first voltage divider resistors include a fourth resistor R4 and a fifth resistor R5. The first terminal of the fourth resistor R4 is connected to the positive input terminal VALPOW of the actuator, and the second terminal of the fourth resistor R4 is grounded through the fifth resistor R5. A second diode D3 is connected between the positive input terminal VALPOW of the actuator and the second terminal of the second switching transistor. The output terminal of the first fault detection circuit is connected to the first detection pin V1 of the controller.

[0041] Specifically, the second end of the fourth resistor R4 serves as the voltage divider of the first voltage divider circuit. The voltage divider of the first voltage divider circuit is connected to the output of the first fault detection circuit through the first current limiting resistor R6. The anode of the second diode D3 is connected to the second end of the second switching transistor Q6 through the tenth resistor R10, and the cathode of the second diode D3 is connected to the positive input terminal VALPOW of the actuator.

[0042] The first fault detection circuit also includes a fifth capacitor C5. The first terminal of the fifth capacitor C5 is connected to the second terminal of the first current-limiting resistor R6, and the first terminal of the first current-limiting resistor R6 is connected to the second terminal of the fourth resistor R4. The function of the fifth capacitor C5 is for filtering and voltage regulation.

[0043] exist Figure 1 With the second switch Q6 turned on and the third switch Q603 off, the positive input terminal of actuator M2 can be connected to the B+ terminal via the tenth resistor R10 and the second diode D3. If there is no short-circuit fault to ground at the positive input terminal VALPOW, a voltage divider is generated at the B+ terminal through the tenth resistor R10 and the fifth resistor R5, which the controller can detect. If a short-circuit fault to ground occurs at the positive input terminal VALPOW, the B+ terminal is pulled to ground through the tenth resistor R10 and the second diode D3. At this time, the voltage at both the positive input terminal VALPOW and the B+ terminal is less than 0.7V (the voltage drop across the second diode D3). The controller detects this low level and considers a short-circuit fault to ground at the positive input terminal VALPOW.

[0044] Therefore, the power supply control circuit provided in this application embodiment can realize fault detection before the third switch Q603 is turned on, so as to avoid the situation where the positive input terminal VALPOW of the actuator has already experienced a short circuit to ground, and then turn on the third switch Q603, which would cause a short circuit between the positive and negative terminals of the DC source, which would burn out the fuse or affect the operation of another power supply branch.

[0045] See Figure 3 The figure is a schematic diagram of the second fault detection circuit provided in an embodiment of this application.

[0046] The power supply control circuit provided in this application embodiment further includes: a second fault detection circuit.

[0047] The first input terminal of the second fault detection circuit is connected to the negative input terminal VALVE0_L of the actuator. The second input terminal of the second fault detection circuit is connected to the second terminal, B+, of the second switching transistor. The first input terminal of the second fault detection circuit is grounded through the second voltage divider circuit. The negative input terminal VALVE0_L of the actuator and the second terminal of the second switching transistor are connected to the third diode D4. The output terminal of the second fault detection circuit is connected to the second detection pin V2 of the controller.

[0048] The second voltage divider circuit includes a seventh resistor R7 and an eighth resistor R8. The first end of the seventh resistor R7 is connected to the negative input terminal VALVE0_L of the actuator, and the second end of the seventh resistor R7 is grounded through the eighth resistor R8.

[0049] Specifically, the voltage divider terminal of the second voltage divider circuit is connected to the output terminal of the second fault detection circuit through the second current limiting resistor R9; the anode of the third diode D4 is connected to the second terminal, namely the B+ terminal, of the second switching transistor through the fourteenth resistor R14, and the cathode of the third diode D4 is connected to the negative input terminal VALVE0_L of the actuator.

[0050] The second fault detection circuit also includes a sixth capacitor C6. The first terminal of the sixth capacitor C6 is connected to the second terminal of the second current-limiting resistor R9, and the first terminal of the second current-limiting resistor R9 is connected to the second terminal of the fourth resistor R4. The function of the sixth capacitor C6 is for filtering and voltage regulation.

[0051] exist Figure 1 When the second switch Q6 is turned on and the third switch Q603 is not turned on, there is no short-circuit fault to ground at the negative input terminal VALVE0_L of the actuator. At this time, the voltage division generated at the B+ terminal through the fourteenth resistor R14 and the eighth resistor R8 can be detected by the controller. If a short-circuit fault to ground occurs at the negative input terminal VALVE0_L of the actuator, the B+ terminal is pulled to ground through the fourteenth resistor R10 and the third diode D4. At this time, the voltage difference between the negative input terminal VALVE0_L and the B+ terminal is less than 0.7V. The controller detects this low level and considers a short-circuit fault to ground at the negative input terminal VALVE0_L of the actuator. This achieves short-circuit fault detection before the third switch Q603 is turned on, preventing a short circuit between the positive and negative terminals of the DC source if a short circuit fault has occurred at the negative input terminal VALVE0_L. This would potentially burn out the fuse or affect the normal operation of another power supply branch.

[0052] The power supply control circuit provided in this application only controls the third switch to turn on and supply power to the actuator when the positive input terminal of the actuator in the first fault detection circuit is normal and the negative input terminal of the actuator in the second fault detection circuit is normal.

[0053] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0054] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power supply control circuit, characterized by comprising: include: The boost circuit consists of a first switching transistor, a second switching transistor, and a third switching transistor. The first terminal of the first switching transistor is used to connect to the positive terminal of the DC power supply, the second terminal of the first switching transistor is connected to the first terminal of the second switching transistor, and the second terminal of the second switching transistor is used to supply power to the motor control system. The second end of the first switching transistor is also connected to the first end of the third switching transistor, the second end of the third switching transistor is connected to the input end of the boost circuit, and the output end of the boost circuit is used to power the actuator.

2. The power supply control circuit of claim 1, wherein Also includes: First diode, fourth switching transistor, and controller; The cathode of the first diode is connected to the output terminal of the boost circuit, the cathode of the first diode is connected to the positive input terminal of the actuator, and the anode of the first diode is connected to the negative input terminal of the actuator. The anode of the first diode is grounded through the fourth switch. The controller is connected to the control terminal of the fourth switching transistor and is used to control the fourth switching transistor.

3. The power supply control circuit of claim 2, wherein, Also includes: First fault detection circuit; The first input terminal of the first fault detection circuit is connected to the positive input terminal of the actuator, and the second input terminal of the first fault detection circuit is connected to the second terminal of the second switching transistor. The first input terminal of the first fault detection circuit is grounded through the first voltage divider circuit. A second diode is connected between the positive input terminal of the actuator and the second terminal of the second switching transistor. The output terminal of the first fault detection circuit is connected to the first detection pin of the controller.

4. The power supply control circuit of claim 3, wherein, The voltage divider terminal of the first voltage divider circuit is connected to the output terminal of the first fault detection circuit through the first current limiting resistor; the anode of the second diode is connected to the second terminal of the second switching transistor through the tenth resistor, and the cathode of the second diode is connected to the positive input terminal of the actuator.

5. The power supply control circuit according to claim 2, characterized in that, Also includes: Second fault detection circuit; The first input terminal of the second fault detection circuit is connected to the negative input terminal of the actuator, and the second input terminal of the second fault detection circuit is connected to the second terminal of the second switching transistor. The first input terminal of the second fault detection circuit is grounded through the second voltage divider circuit. A third diode is connected between the negative input terminal of the actuator and the second terminal of the second switching transistor. The output terminal of the second fault detection circuit is connected to the second detection pin of the controller.

6. The power supply control circuit of claim 5, wherein, The voltage divider terminal of the second voltage divider circuit is connected to the output terminal of the second fault detection circuit through the second current limiting resistor; the anode of the third diode is connected to the second terminal of the second switching transistor through the fourteenth resistor, and the cathode of the third diode is connected to the negative input terminal of the actuator.

7. A power supply control circuit according to any one of claims 2 to 6, characterised in that, It also includes auxiliary power supply; The input terminal of the auxiliary power supply is connected to the second terminal of the second switching transistor, and the output terminal of the auxiliary power supply is connected to the power supply pin of the controller to supply power to the controller.

8. The power supply control circuit according to any one of claims 1 to 6, characterized by, The actuator includes at least one of a clutch or a solenoid valve.

9. The power supply control circuit according to any one of claims 1 to 6, characterized by, The DC power source is the low-voltage battery of the electric vehicle.

10. The power supply control circuit according to any one of claims 2 to 6, characterized by It also includes a current sensing resistor; The first end of the fourth switching transistor is connected to the negative input terminal of the actuator, the second end of the fourth switching transistor is grounded through the current sensing resistor, and the two ends of the current sensing resistor are connected to the current sensing pin of the controller.

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