Circuit for realizing H-bridge driving by using low-side switch driving and control method

Abstract

The invention relates to a circuit for realizing H-bridge driving by using low-side switch driving and a control method, and solves the problem of high cost of H-bridge driving. The control method comprises the following steps: in the H-bridge driving circuit, designing two five-pin relays, namely a relay A and a relay B, designing pins Pin1 and Pin2 of the ECU controller as low-side driving pins, designing pins Pin3 and Pin4 to supply power and ground to the ECU controller, and realizing that the pins Pin1 and Pin2 of the BDC are positive and negative driving control pins. The circuit comprises an ECU controller with four pins, a BDC with two pins, a five-pin relay A and a five-pin relay B. Two pins of the ECU controller are low-side drive control pins, the other two pins of the ECU controller are respectively connected with a KL30 power supply and a GND power supply, the other control end 85 of the high-frequency relay A and the other control end 85 of the high-frequency relay B are connected with the KL30 power supply, and the other control end 85 of the high-frequency relay A and the other control end 85 of the high-frequency relay B are connected with the GND power supply. The output end 30 of the high-frequency relay A is connected with one control pin of the BDC, and the output end 30 of the high-frequency relay B is connected with the other control pin of the BDC. According to the invention, the design cost and the production cost of the ECU can be greatly reduced.

Description

Technical Field

[0001] This invention relates to a control method, specifically to a circuit and control method for implementing H-bridge driving using a low-side switch. Background Technology

[0002] Brushed DC motors (BDC) are widely used in various power devices, such as proportional three-way valves in integrated thermal management systems for new energy vehicles, due to their simple structure, convenient operation, low cost, and good starting and speed regulation performance. BDC motors typically use H-bridge drive control. However, the cooling circuit of integrated thermal management systems for new energy vehicles is relatively complex, involving a large number of proportional three-way valves. This places high demands on the H-bridge drive resources for thermal management control, and the high cost of H-bridge drives poses a significant challenge to the overall cost. This invention will introduce a circuit principle and control method for implementing H-bridge drive using low-side switch drive, achieving low-cost control and effectively solving the problem of control hardware resources. Summary of the Invention

[0003] The purpose of this invention is to realize the principle and control method of low-cost H-bridge drive circuit by designing low-side switch drivers in hardware, thereby reducing the impact of H-bridge drive requirements on the selection of control hardware resources and reducing the cost of control hardware.

[0004] This invention is achieved through the following technical solutions:

[0005] A control method for H-bridge drive using low-side switch driving is proposed. In the H-bridge drive circuit, two five-pin relays, relay A and relay B, are designed. ECU controller pins Pin1 and Pin2 are designed as low-side drive pins, and Pin3 and Pin4 are designed as ECU controller power supply and ground. Pin1 and Pin2 of the BDC are then used as forward and reverse drive control pins. The specific steps are as follows:

[0006] Step 1: Connect the control terminal 86 of high-frequency relay A to the low-side drive control pin of the ECU, connect the control terminal 85 to the power supply of KL30, and connect the output terminal 30 to the BDC control pin 1. By controlling the switching of the logic structure of the high-frequency relay, the switching of the connection between BDC control pin 1 and KL30 and GND can be achieved.

[0007] Step 2: Connect the control terminal 86 of the high-frequency relay B to the low-side drive control pin of the ECU, connect 85 to the power supply of KL30, and connect the output terminal 30 to the BDC control pin 1. By controlling the switching of the logic structure of the high-frequency relay, the switching between connecting the BDC control pin 2 to KL30 and GND can be achieved.

[0008] Step 3: When the ECU requests the BDC to rotate clockwise, the ECU outputs a GND signal on Pin1 and leaves Pin2 floating, causing high-frequency relay A to engage and high-frequency relay B to disengage, thus forming a conduction circuit where Pin1 of the BDC is positive and Pin2 is negative, thereby fulfilling the requirement of clockwise rotation.

[0009] Step 4: When the ECU requests the BDC to rotate counterclockwise, Pin1 of the ECU is left floating, and Pin2 outputs a GND signal, causing high-frequency relay A to disconnect and high-frequency relay B to engage, thus forming a conducting circuit where Pin2 of the BDC is positive and Pin1 is negative, thereby fulfilling the requirement of counterclockwise rotation.

[0010] A circuit for implementing H-bridge drive using low-side switching includes an ECU controller, a BDC with two pins, and two five-pin relays, relay A and relay B. The ECU controller has four pins, two of which are low-side drive control pins, connected to the control terminals 86 of high-frequency relay A and B, respectively. The other two pins are connected to KL30 and GND, respectively. The other control terminal 85 of high-frequency relays A and B is connected to KL30. The output terminal 30 of high-frequency relay A is connected to one control pin of BDC, and the output terminal 30 of high-frequency relay B is connected to the other control pin of BDC.

[0011] This invention can significantly reduce the impact of H-bridge drive resource requirements on ECU hardware design, which are characterized by high requirements, high cost, poor reliability, and low maintainability. It can also improve the feasibility and scalability of controller hardware design and reduce the design and production costs of ECUs. Attached Figure Description

[0012] Figure 1 Schematic diagram of forward and reverse control principle for BDC driven by two H-bridges;

[0013] Figure 2 This is a schematic diagram of the low-side drive circuit implementing the H-bridge function. Detailed Implementation

[0014] Typically, the actuators required for H-bridge drive control are mainly DC brushed motors, such as... Figure 1 This diagram illustrates the BDC forward and reverse rotation control principle. The two H-bridge drivers in the control unit (hereinafter referred to as "ECU") output complementary PWM frequency signals to achieve the conversion between the positive and negative poles of the BDC, thus realizing forward rotation, reverse rotation, and speed regulation. Since the proportional three-way valve control in the integrated thermal management system for new energy uses forward and reverse rotation to achieve closed-loop control of the valve opening and does not require speed regulation, this invention designs a circuit principle and control method that uses a low-side switch drive instead of an H-bridge drive to achieve forward and reverse rotation control of the BDC.

[0015] This invention implements H-bridge driving through the design of a low-side drive circuit, and the circuit principle for achieving forward and reverse control of the BDC is as follows: Figure 2 As shown, in the design of the H-bridge drive circuit, two five-pin relays are designed. The ECU controller pins Pin1 and Pin2 are designed as low-side drive pins, and the ECU controller pins Pin3 and Pin4 are designed as power supply and ground pins. The BDC pins Pin1 and Pin2 are used as forward and reverse drive control pins. The specific implementation steps are as follows.

[0016] Step 1: Connect the control terminal 86 of the high-frequency relay A to the low-side drive control pin of the ECU, connect terminal 85 to the power supply of KL30, and connect the output terminal 30 to the BDC control pin 1. By controlling the switching of the logic structure of the high-frequency relay, the switching between connecting KL30 and GND by the BDC control pin 1 can be achieved.

[0017] Step 2: Connect the control terminal 86 of the high-frequency relay B to the low-side drive control pin of the ECU, connect 85 to the power supply of KL30, and connect the output terminal 30 to the BDC control pin 1. By controlling the switching of the logic structure of the high-frequency relay, the switching between connecting the BDC control pin 2 to KL30 and GND can be achieved.

[0018] Step 3: When the ECU requests the BDC to rotate clockwise, the ECU outputs a GND signal on Pin1 and leaves Pin2 floating, causing high-frequency relay 1 to engage and high-frequency relay 2 to disengage, thus forming a conduction circuit where Pin1 of the BDC is positive and Pin2 is negative, thereby fulfilling the requirement of clockwise rotation.

[0019] Step 4: When the ECU requests the BDC to rotate counterclockwise, Pin1 of the ECU is left floating, and Pin2 outputs a GND signal, causing high-frequency relay 1 to disconnect and high-frequency relay 2 to engage, thus forming a conducting circuit where Pin2 of the BDC is positive and Pin1 is negative, thereby fulfilling the requirement of counterclockwise rotation.

[0020] This invention relates to the use of a designed low-side drive circuit to achieve the function of driving the BDC forward and reverse rotation of the H-bridge, thereby reducing costs and increasing efficiency.

Claims

1. A control method for implementing H-bridge driving using low-side switch driving, characterized in that: In the H-bridge drive circuit, two five-pin relays, relay A and relay B, are designed. ECU controller pins Pin1 and Pin2 are designed as low-side drive pins, and Pin3 and Pin4 are designed as ECU controller power supply and ground. This enables Pin1 and Pin2 of the BDC to be used as forward and reverse drive control pins. The specific steps are as follows: Step 1: Connect the control terminal 86 of high-frequency relay A to the low-side drive control pin of the ECU, connect the control terminal 85 to the power supply of KL30, and connect the output terminal 30 to the BDC control pin 1. By controlling the switching of the logic structure of the high-frequency relay, the switching of the connection between BDC control pin 1 and KL30 and GND can be achieved. Step 2: Connect the control terminal 86 of the high-frequency relay B to the low-side drive control pin of the ECU, connect 85 to the power supply of KL30, and connect the output terminal 30 to the BDC control pin 1. By controlling the switching of the logic structure of the high-frequency relay, the switching between connecting the BDC control pin 2 to KL30 and GND can be achieved. Step 3: When the ECU requests the BDC to rotate clockwise, the ECU outputs a GND signal on Pin1 and leaves Pin2 floating, causing high-frequency relay A to engage and high-frequency relay B to disengage, thus forming a conduction circuit where Pin1 of the BDC is positive and Pin2 is negative, thereby fulfilling the requirement of clockwise rotation. Step 4: When the ECU requests the BDC to rotate counterclockwise, Pin1 of the ECU is left floating, and Pin2 outputs a GND signal, causing high-frequency relay A to disconnect and high-frequency relay B to engage, thus forming a conducting circuit where Pin2 of the BDC is positive and Pin1 is negative, thereby fulfilling the requirement of counterclockwise rotation.

2. A circuit for implementing H-bridge driving using low-side switches, characterized in that: The system includes an ECU controller, a BDC with two pins, and two five-pin relays, relay A and relay B. The ECU controller has four pins, two of which are low-side drive control pins, connected to the control terminals 86 of high-frequency relay A and B, respectively. The other two pins are connected to KL30 and GND, respectively. The other control terminal 85 of high-frequency relays A and B is connected to KL30. The output terminal 30 of high-frequency relay A is connected to one control pin of BDC, and the output terminal 30 of high-frequency relay B is connected to the other control pin of BDC.

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