A control circuit for a DC brushless inverter motor used in a parking air conditioner

Abstract

This utility model discloses a control circuit for a DC brushless inverter motor used in parking air conditioners, including a main control circuit, a drive circuit, an inverter circuit, a speed feedback circuit, a speed regulation circuit, and a rotor position detection circuit. The main control circuit includes a control chip U5; the drive circuit includes drive chips U7, U2, and U3, which are electrically connected to the control chip U5. This utility model aims to solve the problems of high energy consumption, strong battery dependence, insufficient control accuracy, slow stall detection response, poor voltage compatibility, and EMC non-compliance in existing parking air conditioner motor control circuits.

Description

Technical Field

[0001] This utility model belongs to the field of vehicle air conditioning technology, specifically relating to a control circuit for a DC brushless inverter motor used in parking air conditioning. Background Technology

[0002] With the rapid development of the commercial vehicle and RV markets, the shortcomings of traditional vehicle air conditioners in parking conditions are becoming increasingly apparent. When the vehicle is stationary, the parking air conditioner relies on the car battery for power, and prolonged operation will consume a large amount of battery power, seriously affecting battery life. In addition, existing parking air conditioner motor control devices generally suffer from insufficient control precision, high energy consumption, poor adaptability to different voltages, slow response to motor stall detection, and non-compliance with electromagnetic compatibility (EMI / EMS) standards. Therefore, there is an urgent need for a parking air conditioner motor control circuit that is highly efficient, energy-saving, precise in control, and highly adaptable. Utility Model Content

[0003] The main purpose of this utility model is to provide a control circuit for a DC brushless inverter motor for parking air conditioners, aiming to solve the problems of high energy consumption, strong battery dependence, insufficient control accuracy, slow stall detection response, poor voltage compatibility and EMC non-compliance in the existing parking air conditioner motor control circuit.

[0004] To achieve the above objectives, this utility model provides a control circuit for a DC brushless inverter motor used in parking air conditioning, including a main control circuit, a drive circuit, an inverter circuit, a speed feedback circuit, a speed regulation circuit, and a rotor position detection circuit, wherein: The main control circuit includes a control chip U5; The driving circuit includes driving chip U7, driving chip U2 and driving chip U3, and driving chip U7, driving chip U2 and driving chip U3 are electrically connected to the control chip U5 respectively; The inverter circuit includes field-effect transistors Q5-Q10. Field-effect transistors Q5-Q7 form the upper bridge arm, and field-effect transistors Q8-Q10 form the lower bridge arm. The bases of field-effect transistors Q5, Q6, and Q7 are electrically connected to pins 7 of driver chip U7, U2, and U3, respectively. The bases of field-effect transistors Q8, Q9, and Q10 are electrically connected to pins 5 of driver chip U7, U2, and U3, respectively. The speed feedback circuit includes a transistor Q1. The base of the transistor Q1 is electrically connected to pin 7 of the control chip U5 through a resistor R10. The collector of the transistor Q1 outputs an FG signal through a resistor R30. The speed control circuit includes resistors R12, R16, and R17. One end of resistor R12 is connected to the VSP signal, and the other end of resistor R12 is electrically connected to pin 2 of the control chip U5 through resistors R16 and R17 in sequence. The rotor position detection circuit includes Hall sensor HU, Hall sensor HV, and Hall sensor HW placed at 120° on the motor control board. The output terminal of Hall sensor HU is electrically connected to pin 18 of the control chip U5, the output terminal of Hall sensor HV is electrically connected to pin 19 of the control chip U5, and the output terminal of Hall sensor HW is electrically connected to pin 20 of the control chip U5.

[0005] As a further preferred embodiment of the above technical solution, pin 2 of the driver chip U7 is electrically connected to pin 9 of the control chip U5 through resistor R4, and pin 3 of the driver chip U7 is electrically connected to pin 10 of the control chip U5 through resistor R21. Pin 2 of the driver chip U2 is electrically connected to pin 11 of the control chip U5 through resistor R5, and pin 3 of the driver chip U2 is electrically connected to pin 12 of the control chip U5 through resistor R20. Pin 2 of the driver chip U3 is electrically connected to pin 13 of the control chip U5 through resistor R6, and pin 3 of the driver chip U3 is electrically connected to pin 14 of the control chip U5 through resistor R18.

[0006] As a further preferred embodiment of the above technical solution, the source of field-effect transistor Q5 is electrically connected to the drain of field-effect transistor Q8 and both are connected to the U-phase winding of the motor; the source of field-effect transistor Q6 is electrically connected to the drain of field-effect transistor Q9 and both are connected to the V-phase winding of the motor; and the source of field-effect transistor Q7 is electrically connected to the drain of field-effect transistor Q10 and both are connected to the W-phase winding of the motor.

[0007] As a further preferred technical solution of the above technical solution, the source of field-effect transistor Q8, the source of field-effect transistor Q9 and the source of field-effect transistor Q10 are all grounded through resistor R18A, and resistors R18B, R18C and R18D are respectively connected in parallel across the two ends of resistor R18A.

[0008] As a further preferred embodiment of the above technical solution, a capacitor C19 is connected between pins 2 and 3 of the control chip U5, and pin 3 of the control chip U5 is electrically connected to the common terminal of resistors R12 and R16 through resistor R9.

[0009] The beneficial effects of this utility model are as follows: 1. High efficiency and energy saving: The VSP speed control circuit combined with the temperature sensor dynamically adjusts the speed to reduce ineffective energy consumption; the dual-loop (speed loop and current loop) control improves the motor's operating efficiency and reduces battery consumption.

[0010] 2. Precise control: The rotor position detection circuit provides accurate rotor position through three Hall sensors placed at 120°, which, together with vector control based on current detection, achieves low torque pulsation and high-precision operation.

[0011] 3. Fast response: The Hall pulse frequency detection method is used to detect motor stall, which has a faster response than the traditional current detection method, thus improving motor safety.

[0012] 4. Electromagnetic compatibility: The addition of Y capacitor banks meets EMI and EMS standards, reducing interference to other electronic equipment.

[0013] 5. Space optimization: The motor control board is built into the motor, and the Hall sensor is integrated into the layout, saving installation space. Attached Figure Description

[0014] Figure 1 This is a diagram of the main control circuit, speed feedback circuit, and speed regulation circuit of this utility model.

[0015] Figure 2 This is the driving circuit diagram of this utility model.

[0016] Figure 3 This is the inverter circuit diagram of this utility model.

[0017] Figure 4 This is a circuit diagram of the rotor position detection circuit of this utility model.

[0018] Figure 5 This is the power supply circuit diagram of this utility model.

[0019] Figure 6 This is a distribution diagram of the Hall sensor of this utility model on the motor control board.

[0020] Figure 7 This is a distribution diagram of the Y-capacitor group of this utility model on the motor control board. Detailed Implementation

[0021] The following description is intended to disclose the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the present invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0022] This utility model discloses a control circuit for a DC brushless inverter motor for a parking air conditioner. The specific embodiments of the utility model are further described below with reference to preferred embodiments.

[0023] In the embodiments of this utility model, those skilled in the art will note that the parking air conditioner, motor, etc. involved in this utility model can be regarded as prior art.

[0024] Preferred embodiment.

[0025] like Figures 1-7 As shown, this utility model discloses a control circuit for a DC brushless inverter motor used in parking air conditioning, including a main control circuit, a drive circuit, an inverter circuit, a speed feedback circuit, a speed regulation circuit, and a rotor position detection circuit (all of the above circuits are integrated into the motor control board), wherein: The main control circuit includes a control chip U5; The driving circuit includes driving chip U7, driving chip U2 and driving chip U3, and driving chip U7, driving chip U2 and driving chip U3 are electrically connected to the control chip U5 respectively; The inverter circuit includes field-effect transistors Q5-Q10. Field-effect transistors Q5-Q7 form the upper bridge arm, and field-effect transistors Q8-Q10 form the lower bridge arm. The bases of field-effect transistors Q5, Q6, and Q7 are electrically connected to pins 7 of driver chip U7, U2, and U3, respectively. The bases of field-effect transistors Q8, Q9, and Q10 are electrically connected to pins 5 of driver chip U7, U2, and U3, respectively. The speed feedback circuit includes a transistor Q1. The base of the transistor Q1 is electrically connected to pin 7 (FG terminal) of the control chip U5 through a resistor R10. The collector of the transistor Q1 outputs an FG signal (output speed information) through a resistor R30. The speed control circuit includes resistors R12, R16, and R17. One end of resistor R12 is connected to the VSP signal, and the other end of resistor R12 is electrically connected to pin 2 of the control chip U5 through resistors R16 and R17 in sequence. The rotor position detection circuit includes Hall sensor HU, Hall sensor HV, and Hall sensor HW placed at 120° on the motor control board. The output terminal of Hall sensor HU is electrically connected to pin 18 of the control chip U5, the output terminal of Hall sensor HV is electrically connected to pin 19 of the control chip U5, and the output terminal of Hall sensor HW is electrically connected to pin 20 of the control chip U5.

[0026] Specifically, pin 2 of the driver chip U7 is electrically connected to pin 9 of the control chip U5 through resistor R4, and pin 3 of the driver chip U7 is electrically connected to pin 10 of the control chip U5 through resistor R21. Pin 2 of the driver chip U2 is electrically connected to pin 11 of the control chip U5 through resistor R5, and pin 3 of the driver chip U2 is electrically connected to pin 12 of the control chip U5 through resistor R20. Pin 2 of the driver chip U3 is electrically connected to pin 13 of the control chip U5 through resistor R6, and pin 3 of the driver chip U3 is electrically connected to pin 14 of the control chip U5 through resistor R18.

[0027] More specifically, the source of field-effect transistor Q5 is electrically connected to the drain of field-effect transistor Q8 and both are connected to the U-phase winding of the motor; the source of field-effect transistor Q6 is electrically connected to the drain of field-effect transistor Q9 and both are connected to the V-phase winding of the motor; and the source of field-effect transistor Q7 is electrically connected to the drain of field-effect transistor Q10 and both are connected to the W-phase winding of the motor.

[0028] Preferably, the sources of MOSFETs Q8, Q9, and Q10 are all grounded through resistor R18A. Resistors R18B, R18C, and R18D are connected in parallel across R18A (the sampling resistors are placed on the low-voltage side; there are four sampling resistors in total: R18A, R18B, R18C, and R18D. This parallel connection reduces the power load of individual resistors, improves heat dissipation, reduces parasitic inductance, enhances high-frequency response, improves sampling stability and reliability, optimizes PCB layout, and increases accuracy. The sampling terminal ISN1 is connected to the OCP pin in chip U5, acquiring data from the circuit across the sampling resistors. The data is then calculated by the internal operational amplifier circuit of chip U5, and the three-phase current value is calculated using an algorithm. This value is used for coordinate transformation calculations in vector control and overcurrent protection calculations in the motor controller.)

[0029] Preferably, a capacitor C19 is connected between pins 2 and 3 of the control chip U5, and pin 3 of the control chip U5 is electrically connected to the common terminal of resistors R12 and R16 through resistor R9.

[0030] like Figure 1 As shown, the main control circuit: the control chip U5 receives the rotor position signal from the Hall position sensor, the current signal from the current detection circuit, and the voltage signal from the speed regulation circuit. After processing by the internal algorithm, it outputs a PWM control signal to the drive circuit.

[0031] like Figure 2As shown, the driving circuit consists of driving chips U7, U2, and U3 (model T2324D) that receive PWM signals from the main control circuit and drive the upper bridge arm MOSFETs Q5, Q6, and Q7 and the lower bridge arm MOSFETs Q8, Q9, and Q10 (model NCE6080K) to turn on and off respectively, thereby achieving three-phase AC power output. like Figure 3 As shown, the inverter circuit consists of MOSFETs Q5-Q10 forming a three-phase bridge inverter circuit, which converts the DC power output from the power supply circuit into three-phase AC power, and drives the condenser fan and evaporator fan of the parking air conditioner through the U, V, and W interfaces.

[0032] like Figure 1 As shown, the speed control circuit receives a 0-6.5V input signal, which is read by the main control chip U5 in the main control circuit. The motor speed is then adjusted based on the speed curve corresponding to the voltage. A temperature sensor (i.e., ...) is also added. Figure 1 The NTC1 resistor in the circuit feeds back temperature data to pin 8 of the control chip U5 to monitor the temperature inside the vehicle. Based on the temperature inside the vehicle and the temperature selected by the driver, the motor speed is adjusted. For example, when the temperature inside the vehicle reaches the temperature set by the driver, the motor power is reduced and the speed is reduced, thereby achieving energy saving. The speed feedback circuit outputs the Hall signal frequency through the FG port to realize real-time speed monitoring.

[0033] like Figure 4 , 6 As shown, three Hall effect sensors (model A18S, labeled 1 / 2 / 3) are arranged at 120° intervals on the motor control board. They detect the rotor magnetic field position in real time and transmit the signal to the control chip U5. The Hall position sensors output 1 when they detect the rotor magnetic field position and 0 otherwise, ensuring accurate motor commutation. The 120° placement of the Hall position sensors on the motor control board monitors the motor's angular position, saving space since the control board is integrated into the motor. During the start-up and low-speed phases of the air conditioner motor, the motor controller can directly detect the Hall signals to provide the rotor position. Using Hall pulse frequency detection, the motor stall condition can be determined, offering a faster response compared to current detection methods.

[0034] like Figure 5 As shown, the XL7005A chip U6 converts 12V / 24V / 48V input to 12V, and the 78L05 chip U4 converts 12V to 5V; capacitors C16 and C18 are used for filtering to ensure stable output voltage. The power supply circuit supports multiple voltage inputs of 12V, 24V, and 48V, making it suitable for different types of commercial vehicles and RVs.

[0035] like Figure 7As shown, the Y capacitor bank (labeled 4 in the attached figure) on the control board suppresses electromagnetic interference and ensures that the circuit complies with EMI / EMS standards.

[0036] It is worth mentioning that the technical features of parking air conditioners, motors, etc. involved in this utility model patent application should be regarded as prior art. The specific structure, working principle, and possible control methods and spatial arrangement of these technical features can be adopted using conventional choices in the field, and should not be regarded as the inventive point of this utility model patent. This utility model patent will not be further elaborated in detail.

[0037] For those skilled in the art, modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A control circuit for a direct current brushless variable frequency motor for a stationary air conditioner, characterized by, It includes a main control circuit, a drive circuit, an inverter circuit, a speed feedback circuit, a speed regulation circuit, and a rotor position detection circuit, among which: The main control circuit includes a control chip U5; The driving circuit includes driving chip U7, driving chip U2 and driving chip U3, and driving chip U7, driving chip U2 and driving chip U3 are electrically connected to the control chip U5 respectively; The inverter circuit includes field-effect transistors Q5-Q10. Field-effect transistors Q5-Q7 form the upper bridge arm, and field-effect transistors Q8-Q10 form the lower bridge arm. The bases of field-effect transistors Q5, Q6, and Q7 are electrically connected to pins 7 of driver chip U7, U2, and U3, respectively. The bases of field-effect transistors Q8, Q9, and Q10 are electrically connected to pins 5 of driver chip U7, U2, and U3, respectively. The speed feedback circuit includes a transistor Q1. The base of the transistor Q1 is electrically connected to pin 7 of the control chip U5 through a resistor R10. The collector of the transistor Q1 outputs an FG signal through a resistor R30. The speed control circuit includes resistors R12, R16, and R17. One end of resistor R12 is connected to the VSP signal, and the other end of resistor R12 is electrically connected to pin 2 of the control chip U5 through resistors R16 and R17 in sequence. The rotor position detection circuit includes Hall sensor HU, Hall sensor HV, and Hall sensor HW placed at 120° on the motor control board. The output terminal of Hall sensor HU is electrically connected to pin 18 of the control chip U5, the output terminal of Hall sensor HV is electrically connected to pin 19 of the control chip U5, and the output terminal of Hall sensor HW is electrically connected to pin 20 of the control chip U5.

2. The control circuit of the direct-current brushless variable-frequency motor for the parking air conditioner according to claim 1, characterized in that, Pin 2 of the driver chip U7 is electrically connected to pin 9 of the control chip U5 through resistor R4, and pin 3 of the driver chip U7 is electrically connected to pin 10 of the control chip U5 through resistor R21. Pin 2 of the driver chip U2 is electrically connected to pin 11 of the control chip U5 through resistor R5, and pin 3 of the driver chip U2 is electrically connected to pin 12 of the control chip U5 through resistor R20. Pin 2 of the driver chip U3 is electrically connected to pin 13 of the control chip U5 through resistor R6, and pin 3 of the driver chip U3 is electrically connected to pin 14 of the control chip U5 through resistor R18.

3. The control circuit of the direct-current brushless variable-frequency motor for a parking air conditioner according to claim 2, characterized in that, The source of field-effect transistor Q5 is electrically connected to the drain of field-effect transistor Q8 and both are connected to the U-phase winding of the motor. The source of field-effect transistor Q6 is electrically connected to the drain of field-effect transistor Q9 and both are connected to the V-phase winding of the motor. The source of field-effect transistor Q7 is electrically connected to the drain of field-effect transistor Q10 and both are connected to the W-phase winding of the motor.

4. The control circuit of the direct-current brushless variable-frequency motor for a parking air conditioner according to claim 3, characterized in that, The sources of field-effect transistors Q8, Q9, and Q10 are all grounded through resistor R18A. Resistors R18B, R18C, and R18D are connected in parallel across the two ends of resistor R18A, respectively.

5. The control circuit of a direct-current brushless variable-frequency motor for a parking air conditioner according to claim 4, characterized in that, A capacitor C19 is connected between pins 2 and 3 of the control chip U5. Pin 3 of the control chip U5 is electrically connected to the common terminal of resistors R12 and R16 through resistor R9.

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