Motor controller with novel anti-surge protection circuit and ECM motor

Abstract

A, B and C three-phase power supply lines are formed on the alternating current input side of a three-phase power supply, one end of a piezoresistor VAR1 is connected with the A-phase power supply line, one end of a piezoresistor VAR2 is connected with the B-phase power supply line, one end of a piezoresistor VAR3 is connected with the C-phase power supply line, and the other end of the piezoresistor VAR4 is connected with the C-phase power supply line. The other ends of the piezoresistor VAR1, the piezoresistor VAR2 and the piezoresistor VAR3 are connected with a common point G. After the discharge tube SPG1 and the discharge tube SPG2 are connected in series, the two ends of the discharge tube SPG1 and the two ends of the discharge tube SPG2 are connected with the common point G and a grounding point PE respectively. The two ends of the discharge tube SPG1 are connected in parallel with a safety capacitor C1, and the two ends of the discharge tube SPG2 are connected in parallel with a safety capacitor C2. The surge absorption effect is good, the protection performance is excellent, the insulation and voltage resistance requirements of products are considered, pulse current peaks generated in the conduction process of the discharge tubes are inhibited, EMI parameters are improved, and misoperation is reduced.

Description

Technical field:

[0001] The utility model relates to a motor controller with a novel anti-surge protection circuit and an ECM motor. Background technology:

[0002] ECM motor (Electronically Commutated Motor) is an electronically commutated motor with the advantages of high efficiency, low noise, high reliability, etc. It is widely used in many fields. The structure of ECM motor is mainly composed of stator, rotor, electronic commutator, bearings and other parts. The stator is usually composed of iron core and winding. It is the main part of the motor and is responsible for generating the magnetic field. The rotor is generally composed of iron core, permanent magnet and bearing, which is responsible for rotation. The electronic commutator is the core part of the ECM motor, which is responsible for the drive control of the motor.

[0003] The current ECM motor includes a motor body and a motor controller. The motor body includes a stator assembly and a rotor assembly. The motor controller includes a surge protection circuit, a rectifier filter circuit, a DC bus electrolytic capacitor C and a motor control drive module. The motor control drive module includes a microprocessor MCU, an inverter circuit, and a rotor position detection circuit. The EMI parameters of the existing ECM motor surge protection circuit are difficult to meet the standards, and the surge current absorption solution is still imperfect (either there is only differential mode absorption but no common mode absorption), which is prone to generate pulse current spikes and easily cause malfunctions. Summary of the invention:

[0004] The purpose of the utility model is to provide a motor controller and an ECM motor with a novel surge protection circuit, so as to solve the technical problems in the prior art that the EMI parameters of the surge protection circuit are difficult to meet the standards, the surge current absorption scheme is still imperfect, and pulse current spikes are easily generated, resulting in malfunctions.

[0005] The purpose of the utility model is achieved through the following technical solutions.

[0006] A motor controller with a novel surge protection circuit comprises a surge protection circuit and a three-phase rectifier filter circuit, wherein the surge protection circuit comprises a varistor VAR1, a varistor VAR2, a varistor VAR3, a discharge tube SPG1, a discharge tube SPG2, a safety capacitor C1 and a safety capacitor C2; the three-phase power supply AC input side forms A, B, and C three-phase power supply lines; one end of the varistor VAR1 is connected to the A-phase power supply line, the other end of the varistor VAR1 is connected to a common point G, one end of the varistor VAR2 is connected to the B-phase power supply line, the other end of the varistor VAR2 is connected to the common point G, one end of the varistor VAR3 is connected to the C-phase power supply line, the other end of the varistor VAR3 is connected to the common point G, the discharge tube SPG1 and the discharge tube SPG2 are connected in series, and the two ends are respectively connected to the common point G and the grounding point PE; the two ends of the discharge tube SPG1 are connected in parallel with the safety capacitor C1, and the two ends of the discharge tube SPG2 are connected in parallel with the safety capacitor C2.

[0007] The above-mentioned three-phase rectification and filtering circuit includes a three-phase rectifier bridge BG1, a film capacitor C3, a varistor VAR4 and an aluminum electrolytic capacitor EC1. The output end of the three-phase rectifier bridge BG1 is connected to the film capacitor C3. The varistor VAR4 and the aluminum electrolytic capacitor EC1 are connected in series and then connected in parallel at both ends of the film capacitor C3. The A, B, and C three-phase power supply lines are rectified by the three-phase rectifier bridge BG1 and then output to store the electric energy in the film capacitor C3. The voltage on the film capacitor C is used as the DC bus voltage Vdc.

[0008] The above-mentioned motor controller also includes a motor control drive module, which includes a microprocessor MCU, an inverter circuit and a back electromotive force detection circuit. The back electromotive force detection circuit obtains the phase current signal and sends it to the microprocessor MCU. The microprocessor MCU outputs a control signal to control the operation of the inverter circuit.

[0009] An ECM motor comprises a motor body and a motor controller, wherein the motor body comprises a stator assembly and a rotor assembly, and is characterized in that the motor controller adopts the above-mentioned motor controller with a novel anti-surge protection circuit.

[0010] Compared with the prior art, the utility model has the following effects:

[0011] Effect 1: In the surge protection circuit of the utility model, the differential mode surge and the common mode surge share a varistor: the differential mode surge protection phase is absorbed by two varistors in series, and the common mode surge is absorbed by a varistor and a discharge tube. The scheme is perfect, the surge absorption effect is good, and the protection performance is excellent;

[0012] Effect 2: Two discharge tubes are connected in series to absorb common-mode surges, which can take into account the insulation withstand voltage requirements of the product. Each discharge tube is connected in parallel with a safety capacitor, which can also suppress the pulse current spikes generated during the discharge tube conduction process, improve EMI parameters, and reduce false operations. Description of the drawings:

[0013] Figure 1 It is a circuit block diagram of the first embodiment of the utility model;

[0014] Figure 2 yes Figure 1 The circuit diagram corresponding to the surge protection circuit;

[0015] Figure 3 yes Figure 1 The circuit diagram corresponding to the three-phase rectifier and filter circuit;

[0016] Figure 4 yes Figure 1 The circuit diagram corresponding to the motor control drive module;

[0017] Figure 5 is a three-dimensional diagram of an ECM motor according to a second embodiment of the present utility model;

[0018] Figure 6 It is an exploded view of the ECM motor of the second embodiment of the utility model;

[0019] Figure 7 It is a structural cross-sectional view of the ECM motor of the second embodiment of the utility model. Specific implementation method:

[0020] The present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0021] Embodiment one:

[0022] like Figures 1 to 4As shown, this embodiment provides a motor controller with a novel surge protection circuit, including a surge protection circuit and a three-phase rectifier filter circuit, characterized in that: the surge protection circuit includes a varistor VAR1, a varistor VAR2, a varistor VAR3, a discharge tube SPG1, a discharge tube SPG2, a safety capacitor C1 and a safety capacitor C2, the three-phase power supply AC input side forms A, B, C three-phase power supply lines, one end of the varistor VAR1 is connected to the A-phase power supply line, the other end of the varistor VAR1 is connected to the common point G, one end of the varistor VAR2 is connected to the B-phase power supply line, the other end of the varistor VAR2 is connected to the common point G, one end of the varistor VAR3 is connected to the C-phase power supply line, the other end of the varistor VAR3 is connected to the common point G, the discharge tube SPG1 and the discharge tube SPG2 are connected in series, and the two ends are respectively connected to the common point G and the grounding point PE; the two ends of the discharge tube SPG1 are connected in parallel with the safety capacitor C1, and the two ends of the discharge tube SPG2 are connected in parallel with the safety capacitor C2.

[0023] The above three-phase rectification and filtering circuit includes a three-phase rectifier bridge BG1, a film capacitor C3, a varistor VAR4 and an aluminum electrolytic capacitor EC1. The output end of the three-phase rectifier bridge BG1 is connected to the film capacitor C3. The varistor VAR4 and the aluminum electrolytic capacitor EC1 are connected in series and then connected in parallel at both ends of the film capacitor C3. The A, B, and C three-phase power supply lines are rectified by the three-phase rectifier bridge BG1 and then output to store the electric energy in the film capacitor C3. The voltage on the film capacitor C3 is used as the DC bus voltage Vdc. The film capacitor C3 has a small capacity and limited energy storage function. The circuit formed by the parallel varistor VAR4 and the aluminum electrolytic capacitor EC1 can effectively absorb the surge voltage superimposed on the DC bus. Since the parallel part of the circuit will only act when a surge voltage occurs, the capacity of the aluminum electrolytic capacitor can be selected to be relatively small, and the cost is low.

[0024] The above-mentioned motor controller also includes a motor control drive module, which includes a microprocessor MCU, an inverter circuit and a back electromotive force detection circuit. The back electromotive force detection circuit obtains the phase current signal and sends it to the microprocessor MCU. The microprocessor MCU outputs a control signal to control the operation of the inverter circuit.

[0025] The utility model has the following advantages: the three-phase power supply AC input side R, S, T forms the A, B, C three-phase power supply lines after passing through the fuse tube F and the common-mode inductor L1, the fuse tube F comprises a fuse F1, a fuse F2, and a fuse F3, the fuses F1, F2, and F3 are respectively connected to the A, B, and C three-phase power supply lines, once the current is too large, they will be fused for protection; the common-mode inductor L1 is conducive to improving EMI parameters, the differential-mode surge and the common-mode surge in the surge protection circuit of the utility model share a varistor, the differential-mode surge protection phase is absorbed by two varistors in series, and the common-mode surge is absorbed by a varistor and a discharge tube, the scheme is perfect, the surge absorption effect is good, and the protection performance is excellent. For example: varistors VAR1 and VAR2 are connected between the A-phase power supply line and the B-phase power supply line to achieve differential-mode surge protection. The A-phase power supply line is connected to the grounding point PE through the varistor VAR1, the discharge tube SPG1, and the discharge tube SPG2 to achieve common-mode surge protection; that is, the varistor VAR1 participates in both differential-mode surge protection and common-mode surge protection. Similarly, the varistor VAR2 and the varistor VAR3 participate in both differential-mode surge protection and common-mode surge protection. After the discharge tube SPG1 and the discharge tube SPG2 are connected in series, the two ends are connected to the common point G and the grounding point PE respectively, which can take into account the insulation withstand voltage requirements of the product. Each discharge tube is connected in parallel with a safety capacitor, which can also suppress the pulse current spikes generated during the discharge tube conduction process, improve EMI parameters, and reduce false operations.

[0026] Embodiment 2:

[0027] like Figures 1 to 7 As shown, the ECM motor provided in this embodiment includes a motor body 100 and a motor controller 200, wherein the motor body 100 includes a permanent magnet rotor assembly 12, a stator assembly 11 and a housing assembly 13; the motor controller 200 includes a control box 21 and a control circuit board 22 installed in the control box 21, the control circuit board 22 is integrated with an anti-surge protection circuit, a three-phase rectifier filter circuit and a motor control drive module, wherein the motor control drive module includes a microprocessor MCU, an inverter circuit, and a back electromotive force detection circuit, the back electromotive force detection circuit obtains a phase current signal and sends it to the microprocessor MCU, the microprocessor MCU outputs a plurality of PWM signals to control the inverter circuit to work, the output end of the inverter circuit is connected to the coil winding in the stator assembly 11, and is characterized in that: the motor controller 200 adopts a motor controller with a new anti-surge protection circuit as described in Example 1.

[0028] The ECM motor of the utility model has good surge absorption effect and excellent protection performance, can take into account the insulation withstand voltage requirements of the product, suppress the pulse current spike generated during the discharge tube conduction process, improve EMI parameters, and reduce false operations.

[0029] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited thereto. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention are equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A motor controller with a novel surge protection circuit, including a surge protection circuit and a three-phase rectifier filter circuit, characterized in that: The surge protection circuit includes a varistor VAR1, a varistor VAR2, a varistor VAR3, a discharge tube SPG1, a discharge tube SPG2, a safety capacitor C1 and a safety capacitor C2. The three-phase power supply AC input side forms three-phase power supply lines A, B, and C. One end of the varistor VAR1 is connected to the A-phase power supply line, and the other end of the varistor VAR1 is connected to the common point G. One end of the varistor VAR2 is connected to the B-phase power supply line, and the other end of the varistor VAR2 is connected to the common point G. One end of the varistor VAR3 is connected to the C-phase power supply line, and the other end of the varistor VAR3 is connected to the common point G. After the discharge tube SPG1 and the discharge tube SPG2 are connected in series, the two ends are respectively connected to the common point G and the grounding point PE; the two ends of the discharge tube SPG1 are connected in parallel with the safety capacitor C1, and the two ends of the discharge tube SPG2 are connected in parallel with the safety capacitor C2.

2. A motor controller with a novel surge protection circuit according to claim 1, characterized in that: The three-phase rectification and filtering circuit includes a three-phase rectifier bridge BG1, a film capacitor C3, a varistor VAR4 and an aluminum electrolytic capacitor EC1. The output end of the three-phase rectifier bridge BG1 is connected to the film capacitor C3. The varistor VAR4 and the aluminum electrolytic capacitor EC1 are connected in series and then in parallel at both ends of the film capacitor C3. The A, B, and C three-phase power supply lines are rectified by the three-phase rectifier bridge BG1 and then output to store the electric energy in the film capacitor C3. The voltage on the film capacitor C3 is used as the DC bus voltage Vdc.

3. A motor controller with a novel surge protection circuit according to claim 1 or 2, characterized in that: It also includes a motor control drive module, which includes a microprocessor MCU, an inverter circuit and a back electromotive force detection circuit. The back electromotive force detection circuit obtains the phase current signal and sends it to the microprocessor MCU. The microprocessor MCU outputs a control signal to control the operation of the inverter circuit.

4. An ECM motor, comprising a motor body and a motor controller, wherein the motor body comprises a stator assembly and a rotor assembly, characterized in that: The motor controller adopts a motor controller with a novel anti-surge protection circuit as described in any one of claims 1 to 3.

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