Brushless motor FOC drive circuit device

Abstract

The utility model relates to the technical field of brushless motor drive circuits, in particular to a brushless motor FOC drive circuit device, which comprises a drive circuit with a bridge gate driver, a three-phase half-bridge circuit, a feedback circuit and an electrical angle feedback sensor. The driving circuit with the bridge type gate driver receives a three-phase signal sent by an external MCU (Microprogrammed Control Unit) to form an SVPWM (Space Vector Pulse Width Modulation) driving signal and sends the SVPWM driving signal to the three-phase half-bridge circuit; the output end of the three-phase half-bridge circuit is connected with a three-phase motor; the feedback circuit collects A-phase and B-phase current signals of the output end of the three-phase half-bridge circuit, amplifies the A-phase and B-phase current signals and feeds back the A-phase and B-phase current signals to the external MCU; the electrical angle feedback sensor collects the motor rotation angle of the three-phase motor and feeds back the motor rotation angle to the external MCU. According to the utility model, the problems of certain current noise and low efficiency in the prior art can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of brushless motor drive circuits, in particular to a brushless motor FOC drive circuit device. Background Technique

[0002] The brushless motor is developed on the basis of the brushed DC motor and has the advantages of non-polar speed regulation, wide speed regulation range, strong overload capacity, good linearity, long service life, small volume, light weight and large output, solving a series of problems existing in the brushed motor. In the drive mode of the brushless motor, since the brushless motor does not have a brush for automatic commutation, an electronic commutator needs to be used for commutation. Therefore, the function of this electronic commutator is realized by the brushless motor drive device. Traditional brushless motor drive devices mostly adopt control methods such as square wave control and sine wave control. The square wave control has disadvantages such as large torque ripple, certain current noise and low efficiency. The sine wave control realizes the control of the voltage vector and indirectly realizes the control of the current magnitude, but cannot directly control the current direction.

[0003] The application number is CN202110522800, a DC brushless motor drive circuit, which uses a pulse width modulation signal to drive a DC brushless motor and diagnoses mechanical faults of the motor by monitoring the duty cycle, motor speed, motor input current, motor input voltage, motor temperature or ambient temperature, and can report warnings or errors of the motor state to an external host. In terms of design, due to the driving method using a pulse width modulation signal, there are problems of certain current noise and low efficiency. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a brushless motor FOC drive circuit device, which can solve the problems of certain current noise and low efficiency that appear in the above background technique.

[0005] The utility model adopts the following technical solutions to achieve the above purpose:

[0006] A brushless motor FOC drive circuit device includes a drive circuit with a bridge gate driver, a three-phase half-bridge circuit, a feedback circuit and an electrical angle feedback sensor; the drive circuit with the bridge gate driver receives three-phase signals sent by an external MCU to form an SVPWM drive signal and sends it to the three-phase half-bridge circuit; the output end of the three-phase half-bridge circuit is connected to a three-phase motor; the feedback circuit collects the A and B phase current signals at the output end of the three-phase half-bridge circuit, and after amplification, feeds them back to the external MCU; the electrical angle feedback sensor collects the motor rotation angle of the three-phase motor and feeds it back to the external MCU.

[0007] Preferably, the bridge gate driver is designed with an EG2133 three-phase gate controller chip.

[0008] Preferably, the three-phase half-bridge circuit is formed by connecting three sets of three-phase half-wave rectifier circuits in series; the three-phase half-wave rectifier circuit includes a first MOS transistor and a second MOS transistor;

[0009] The output terminals of the first pin, the second pin, and the third pin of the first MOS transistor are grounded. The output terminal of the fourth pin of the first MOS transistor is connected to one end of a first resistor and the positive electrode of a first diode. The negative electrode of the first diode is connected to the other end of the first resistor. The output terminals of the fifth pin, the sixth pin, the seventh pin, the eighth pin, and the ninth pin of the first MOS transistor are connected to the output terminals of the first pin, the second pin, and the third pin of the second MOS transistor and are commonly output through a second resistor. The output terminals of the fifth pin, the sixth pin, the seventh pin, the eighth pin, and the ninth pin of the first MOS transistor of one set of three-phase half-wave rectifier circuits are only connected to the output terminals of the first pin, the second pin, and the third pin of the second MOS transistor;

[0010] The output terminal of the fourth pin of the second MOS transistor is connected to one end of a third resistor and the positive electrode of a second diode. The negative electrode of the second diode is connected to the other end of the third resistor. The output terminals of the fifth pin, the sixth pin, the seventh pin, the eighth pin, and the ninth pin of the second MOS transistor are connected to the VCC terminal.

[0011] Preferably, the feedback circuit includes two current sampling circuits, and the current sampling circuit uses an INA181 bidirectional current detection amplifier.

[0012] Preferably, the current sampling circuit includes an INA181 bidirectional current detection amplifier. The output terminal of the second pin of the INA181 bidirectional current detection amplifier is grounded. The output terminal of the fifth pin of the INA181 bidirectional current detection amplifier is connected to one end of a fourth resistor and one end of a fifth resistor. The other end of the fourth resistor is connected to one end of a sixth resistor. The other end of the sixth resistor is connected to a 3.2V power supply. The other end of the fifth resistor is grounded. The output terminal of the sixth pin of the INA181 bidirectional current detection amplifier is connected to one end of a first capacitor and connected to the 3.2V power supply. The other end of the first capacitor is grounded.

[0013] Preferably, there are six sets of driving circuits with bridge gate drivers, and each set of driving circuits with bridge gate drivers drives a three-phase motor through a three-phase half-bridge circuit.

[0014] Preferably, the electrical angle feedback sensor is a magnetic encoder.

[0015] Advantages of the present invention:

[0016] (1) It is beneficial for brushless motors to be controlled at low speeds. Due to the difference in control principles, traditional brushless electronic speed controllers can only control the motor to operate at high speeds and cannot control it at low speeds; while using an FOC controller has no such limitation and can achieve precise control at any speed.

[0017] (2) It can efficiently and smoothly switch the forward and reverse rotation of the motor. Since traditional electronic speed controllers cannot feedback the rotor position, it is very difficult to achieve the commutation of the forward and reverse rotation of the motor, and a sensor-based electronic speed controller must be used to achieve it. However, the commutation performance of the FOC driver is extremely excellent, and the forward and reverse rotation switching can be very smooth at the highest speed.

[0018] (3) It can perform precise torque control. Ordinary electronic speed controllers can only control the motor speed, while FOC can perform three closed-loop controls of current (torque), speed, and position.

[0019] (4) It can effectively reduce the motor operation noise. The noise of the FOC driver is much smaller than that of the electronic speed controller. The reason is that the ordinary traditional designed electronic speed controller uses square wave drive, while FOC uses sine wave, which can effectively reduce the operation noise generated by electronic commutation. Description of the Drawings

[0020] Figure 1 is the principle block diagram of the present utility model.

[0021] Figure 2 is the schematic diagram of the bridge gate driver.

[0022] Figure 3 is the schematic diagram of the three-phase half-bridge circuit.

[0023] Figure 4 is the schematic diagram of the feedback circuit.

[0024] Figure 5 is the schematic diagram of the interface for the control signal of the external MCU.

[0025] Figure 6 is the schematic diagram of the power supply interface.

[0026] Figure 7 is the schematic diagram of the output interface of the three-phase motor.

[0027] Figure 8 is the PCB diagram (top view) of the present device.

[0028] Figure 9 is the PCB diagram (bottom view) of the present device. Detailed Implementation Manner

[0029] The following further describes the present utility model in conjunction with the drawings.

[0030] As Figure 1As shown in the figure, a brushless motor FOC drive circuit device includes a drive circuit with a bridge gate driver, a three-phase half-bridge circuit, a feedback circuit, and an electrical angle feedback sensor. The drive circuit with the bridge gate driver receives three-phase signals sent by an external MCU to form an SVPWM drive signal and sends it to the three-phase half-bridge circuit. The output end of the three-phase half-bridge circuit is connected to a three-phase motor. The feedback circuit collects the A and B phase current signals at the output end of the three-phase half-bridge circuit, amplifies them, and then feeds them back to the external MCU. The electrical angle feedback sensor collects the motor rotation angle of the three-phase motor and feeds it back to the external MCU. In terms of the functions of the overall device, it can be used to improve the maintainability of the control system, improve reusability and flexibility.

[0031] As Figure 2 shown in the figure, the bridge gate driver is designed using an EG2133 three-phase gate controller chip. This chip integrates three independent half-bridge drives, with built-in dead-time control and latching functions, which can effectively prevent shoot-through caused by incorrect upper and lower transistor conduction sequences due to controller program errors or external interference in the bridge circuit, thus burning out the circuit. The built-in independent half-bridges also help to decouple the circuit modules, ensure the working independence between the half-bridges, and reduce interference. Therefore, the various characteristics of this chip make it perform excellently in the application of driving a three-phase full bridge.

[0032] As Figure 3 shown in the figure, the three-phase half-bridge circuit is composed of three groups of three-phase half-wave rectifier circuits connected in series. The three-phase half-wave rectifier circuit includes a first MOS tube and a second MOS tube.

[0033] The output ends of the first, second, and third pins of the first MOS tube are grounded. The output end of the fourth pin of the first MOS tube is connected to one end of a first resistor and the positive pole of a first diode. The negative pole of the first diode is connected to the other end of the first resistor. The output ends of the fifth, sixth, seventh, eighth, and ninth pins of the first MOS tube are connected to the output ends of the first, second, and third pins of the second MOS tube and are commonly output through a second resistor. The output ends of the fifth, sixth, seventh, eighth, and ninth pins of the first MOS tube in one group of the three-phase half-wave rectifier circuit are only connected to the output ends of the first, second, and third pins of the second MOS tube, but are not commonly output through the second resistor. Figure 3 VS21_OUT and VS22_OUT in

[0034] The output terminal of the fourth pin of the second MOS transistor is connected to one end of the third resistor and the positive electrode of the second diode, and the negative electrode of the second diode is connected to the other end of the third resistor; the output terminals of the fifth, sixth, seventh, eighth, and ninth pins of the second MOS transistor are connected to the VCC terminal.

[0035] The three-phase half-bridge circuit design uses MOS transistor drive. The MOS transistor used is AP30H80Q, which is an N-channel MOS with 30V and 70A. When VGS is 12V, RDS(ON) is less than 6mΩ. At the same time, this MOS transistor is packaged as PDFN3X3-8L, which ensures a small volume while meeting sufficient power, facilitating integration, and can greatly reduce the circuit layout space and the volume of the controller. To ensure the working stability and safety of the controller, a gate-limiting resistor and a junction-capacitance discharge diode are provided for each MOS transistor. This solution can help the MOS transistor switch off more quickly and reduce the ringing phenomenon.

[0036] As Figure 4 shown, the feedback circuit includes two current sampling circuits, and the current sampling circuit uses an INA181 bidirectional current detection amplifier.

[0037] The current sampling circuit includes an INA181 bidirectional current detection amplifier. The output terminal of the second pin of the INA181 bidirectional current detection amplifier is grounded; the output terminal of the fifth pin of the INA181 bidirectional current detection amplifier is connected to one end of the fourth resistor and one end of the fifth resistor. The other end of the fourth resistor is connected to one end of the sixth resistor, and the other end of the sixth resistor is connected to the 3.2V power supply. The other end of the fifth resistor is grounded; the output terminal of the sixth pin of the INA181 bidirectional current detection amplifier is connected to one end of a first capacitor and connected to the 3.2V power supply, and the other end of the first capacitor is grounded.

[0038] The current sampling circuit design uses an INA181 bidirectional current detection amplifier. This integrated op-amp controller has a matching resistor gain network, providing four fixed gain options, which can reserve a certain design margin and flexibility for this design to minimize gain error and reduce temperature drift. The three-phase current sampling circuit composed of it, where the resistors R79~R84 are rough measurement values and can be changed according to the actual current magnitude. They are voltage division correction resistors for the amplification factor. Pins 3 and 4 of the chip in the circuit are the positive and negative terminals of the sampling resistor. The sampling resistors can be seen Figure 3 as the R35 and R36 resistors in Figure 3 with a resistance value of 0.01Ω. In a three-phase half-bridge circuit, only the current parameters of two paths need to be sampled to calculate the current value of the third path. Therefore,

[0039] As Figure 1 shown, in an embodiment of the present utility model, there are six groups of driving circuits with bridge gate drivers, and each driving circuit with a bridge gate driver drives a three-phase motor through a three-phase half-bridge circuit.

[0040] In an embodiment of the present utility model, the electrical angle feedback sensor can be a magnetic encoder, but is not limited thereto.

[0041] In an embodiment of the present utility model, the interface for the control signal of the external MCU can adopt the pin arrangement as Figure 5 shown. It uses 2.54-pin headers of 2*18 as the external interface for the control signal. The arrangement order of the data pins is from right to left and from top to bottom in the figure. The 1st pins of the headers H2 and H3 are two logic signal reference levels VDD, which are agreed to be 3.2V; the 2nd pin of header H3 and the 2nd pin of header H2 are the two-way current signal outputs IS42 and IS41 of the bridge circuit, see Figure 1 the two-phase current signals after being amplified by the sampling circuit; the 3rd, 4th pins of header H3 and the 3rd pin of header H2 are respectively the three-phase bridge control signal inputs PHASE_C4, PHASE_A4, PHASE_B4 of the fourth group, corresponding to Figure 1 the three-way signals A, B, and C input by the external MCU to the bridge driving circuit; the 5th to 16th pins of header H3 and the 4th to 16th pins of header H2 are respectively the current sampling and drive control signals of the other five groups Bridge circuit ; the 17th and 18th pins of headers H2 and H3 are the two-way motor working voltage inputs and two-way reference ground planes, which are used for the power supply of the motor and the three-phase full bridge.

[0042] As Figure 6 shown, in an embodiment of the present utility model, the power supply interface design in this device adopts 3.81 quick-wiring terminals, whose rated voltage / current is 150V / 10A, and the recommended input voltage of this device is DC9~20V, with a power of 300W; therefore, the 3.81 quick-wiring terminals can meet the power demand range of this device.

[0043] As Figure 7 shown, in an embodiment of the present utility model, the output interface of the three-phase motor adopts a 3-way 3.81 wiring socket, which can support the access of the three-phase motor.

[0044] In an embodiment of the present utility model, the PCB diagram of this device is as Figures 8 - 9 shown. The present utility model is only briefly introduced and is not required to be protected.

[0045] The above are only the preferred embodiments of the present utility model, and should not be construed as limitations to this application. Any equivalent changes and modifications made in accordance with the scope of the patent application of the present utility model shall fall within the scope covered by the present utility model.

Claims

1. A brushless motor FOC drive circuit device, characterized in that, It includes a driving circuit with a bridge gate driver, a three-phase half-bridge circuit, a feedback circuit, and an electrical angle feedback sensor; the driving circuit with the bridge gate driver receives three-phase signals sent by an external MCU to form an SVPWM driving signal and sends it to the three-phase half-bridge circuit; the output end of the three-phase half-bridge circuit is connected to a three-phase motor; the feedback circuit collects the A and B phase current signals at the output end of the three-phase half-bridge circuit, amplifies them, and then feeds them back to the external MCU; the electrical angle feedback sensor collects the motor rotation angle of the three-phase motor and feeds it back to the external MCU.

2. The brushless motor FOC drive circuit device according to claim 1, characterized in that The bridge gate driver is designed using an EG2133 three-phase gate controller chip.

3. The brushless motor FOC drive circuit device according to claim 1, characterized in that, The three-phase half-bridge circuit is composed of three groups of three-phase half-wave rectifier circuits connected in series; the three-phase half-wave rectifier circuit includes a first MOS tube and a second MOS tube. The output ends of the first pin, second pin, and third pin of the first MOS tube are grounded. The output end of the fourth pin of the first MOS tube is connected to one end of a first resistor and the positive pole of a first diode. The negative pole of the first diode is connected to the other end of the first resistor. The output ends of the fifth pin, sixth pin, seventh pin, eighth pin, and ninth pin of the first MOS tube are connected to the output ends of the first pin, second pin, and third pin of the second MOS tube and are jointly output through a second resistor. The output ends of the fifth pin, sixth pin, seventh pin, eighth pin, and ninth pin of the first MOS tube in one group of three-phase half-wave rectifier circuits are only connected to the output ends of the first pin, second pin, and third pin of the second MOS tube. The output end of the fourth pin of the second MOS tube is connected to one end of a third resistor and the positive pole of a second diode. The negative pole of the second diode is connected to the other end of the third resistor. The output ends of the fifth pin, sixth pin, seventh pin, eighth pin, and ninth pin of the second MOS tube are connected to the VCC terminal.

4. The brushless motor FOC drive circuit device according to claim 1, characterized in that, The feedback circuit includes two current sampling circuits, and the current sampling circuit uses an INA181 bidirectional current detection amplifier.

5. The brushless motor FOC drive circuit device according to claim 4, wherein The current sampling circuit includes an INA181 bidirectional current detection amplifier. The output end of the second pin of the INA181 bidirectional current detection amplifier is grounded. The output end of the fifth pin of the INA181 bidirectional current detection amplifier is connected to one end of a fourth resistor and one end of a fifth resistor. The other end of the fourth resistor is connected to one end of a sixth resistor. The other end of the sixth resistor is connected to a 3.2V power supply. The other end of the fifth resistor is grounded. The output end of the sixth pin of the INA181 bidirectional current detection amplifier is connected to one end of a first capacitor and connected to the 3.2V power supply. The other end of the first capacitor is grounded.

6. The brushless motor FOC drive circuit device according to claim 1, wherein There are six groups of driving circuits with bridge gate drivers, and each group of driving circuits with bridge gate drivers drives a three-phase motor through a three-phase half-bridge circuit.

7. The brushless motor FOC drive circuit device according to claim 1, characterized in that, The electrical angle feedback sensor is a magnetic encoder.

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