阅读说明：本技术 一种双绕组无刷直流电机半波（半控）驱动电路 (Half-wave (half-control) drive circuit of double-winding brushless direct current motor ) 是由 于昊昱 于佳衣 衣美凤 于 2020-03-11 设计创作，主要内容包括：本发明是关于一种采用NMOS的双绕组无刷直流电机半波驱动电路,属无刷直流电机技术领域,可用于径向两极、双绕组无刷直流电机的驱动,这种无刷直流电机可用于车用电动水泵。发明的目的是为提高驱动电路的驱动能力。其特征是,采用锁存型双输出霍尔器件,并通过电阻分压电平转换电路分别控制NMOS驱动输出级的开关,进而控制电机绕组产生交变磁场,用稳压管吸收驱动电路内的过电压,续流电路采用稳压管和肖特基二极管串联电路。(The invention relates to a half-wave drive circuit of a double-winding brushless direct current motor adopting an NMOS (N-channel metal oxide semiconductor), which belongs to the technical field of brushless direct current motors and can be used for driving a radial two-pole double-winding brushless direct current motor. The purpose of the invention is to improve the driving capability of a driving circuit. The circuit is characterized in that a latch type double-output Hall device is adopted, a resistor voltage division level conversion circuit is used for respectively controlling the switching of an NMOS drive output stage, a motor winding is further controlled to generate an alternating magnetic field, a voltage stabilizing tube is used for absorbing overvoltage in a drive circuit, and a follow current circuit adopts a series circuit of the voltage stabilizing tube and a Schottky diode.)

1. A half-wave (half-control) drive circuit of a double-winding brushless direct current motor consists of a latch type double-output Hall device, a high-low level inversion and level conversion circuit, a drive output stage, a motor winding follow current discharge circuit, an anti-reverse connection diode and an overvoltage absorption voltage-stabilizing tube, and is characterized in that the latch type double-output Hall device is used for driving an integrated electric water pump of the brushless direct current motor which adopts a radial two-pole permanent magnet rotor and a double-motor winding half-control (half-wave) drive, the latch type double-output Hall device detects the polarity of the permanent magnet rotor of the motor and outputs two paths of control signals with complementary high and low levels (one is high and one is low) according to the polarity (change), the two paths of control signals output by the latch type double-output Hall device are respectively connected to the two paths of high-low level inversion and level conversion circuits behind the latch type double-output Hall device to respectively carry out high, two control signals generated by the high-low level inversion and level conversion circuit are respectively connected to the following driving output stage to respectively control the switch (on and off) of the driving output stage so as to respectively control the exciting currents of the two groups of motor windings to work alternately, thereby generating an alternating magnetic field in a stator magnetic circuit, each circuit of motor winding follow current discharge circuit is connected in parallel to each group of motor windings to provide a follow current path for the motor windings so as to reduce the overvoltage of the motor windings, an anti-reverse connection diode is connected in series to a power supply of the driving circuit so as to prevent the driving circuit from being damaged due to the misconnection of the power supply, and an overvoltage absorption voltage regulator is arranged between the positive electrode.

2. The half-wave (half-controlled) driving circuit of a dual-winding brushless DC motor as claimed in claim 1, wherein the high-low level inversion and level conversion circuit employs a PNP type common-emitter amplifier circuit.

3. A half-wave (half-controlled) driving circuit of a dual-winding brushless dc motor as claimed in claim 1, wherein the driving output stage employs NMOS field effect transistors.

4. A half-wave (half-controlled) driving circuit of a dual-winding brushless dc motor as claimed in claim 1, wherein the follow current discharge circuit of the motor winding is a series circuit of a voltage regulator tube and a schottky diode.

5. The half-wave (half-controlled) driving circuit of the double-winding brushless direct current motor as claimed in claim 1, wherein the reverse connection preventing diode is connected in series with the positive pole or the negative pole of the driving circuit power supply.

6. The half-wave (half-controlled) driving circuit of the double-winding brushless direct current motor as claimed in claim 1 or 5, wherein the reverse connection preventing diode is a Schottky diode.

7. A half-wave (semi-controlled) driver circuit for a dual-winding brushless dc motor according to claim 1, 2, 3, 4, 5 or 6, wherein the driver circuit and the motor windings are encapsulated in an encapsulating material.

Technical Field

The invention relates to a half-wave (half-control) driving circuit of a double-winding brushless direct current motor, which belongs to the technical field of brushless direct current (micro) motors, can be used for driving a radial two-pole permanent magnet rotor and a double-winding half-wave (half-control) brushless direct current motor, and can be used for an electric water pump for vehicles (a water cooling system of an internal combustion engine, a water cooling system of a power motor of an electric vehicle, a circulating pump or a booster pump of a warm air system of the motor vehicle and the like), and can also be used for circulating pumps of water cooling systems of other electrical appliances or equipment, water pumps of other purposes and fans (micro fans) with similar structures.

Background

In recent years, some automobile parts manufacturers have attempted to develop and manufacture an Electric circulation Pump for an engine cooling system, which is generally called an Electric Water Pump (EWP). Some automobile manufacturers (BMW, Toyota, etc.) have also begun to attempt to use electric water pumps. The engine cooling system based on the electric water pump technology can adjust the flow of the electric water pump and the heat dissipation capacity of the cooling system according to the temperature and the load of an engine, the power consumption of the electric water pump is low, the temperature of the engine is quickly raised, and therefore the fuel efficiency of the engine can be obviously improved, the emission is reduced, and the like.

The electric water pump comprises a water pump, a brushless direct current motor (B L DCM) and a driving circuit thereof, and has various technical schemes, wherein the technical scheme comprises a technical scheme (patent number: Z L201010185641.0) named as 'an integrated and liquid lubrication permanent magnet brushless direct current motor electric water pump', the electric water pump is of an inner rotor structure, a rotor is arranged in the water pump, the motor is a single-phase two-pole brushless direct current motor with a U-shaped stator core, the rotor adopts a radial two-pole magnetizing magnet (pole) structure, two opposite pole shoes are arranged at the end part of the U-shaped core, the pole arc shape of the pole shoes can form an asymmetric air gap beneficial to improving the performance of the motor, a centralized stator winding is arranged on the stator core to form a stator, the driving circuit is connected to the winding in a full-control (full-wave) or half-control (half-wave) driving mode, a potting material encapsulates the stator and the driving circuit required to be arranged in a stator slot, and actually the scheme adopts a half-control (half-wave) driving mode, namely, the driving circuit drives two independent motor windings to alternately work to generate a pulse vibration magnetic field, and the two-pole rotor (pulse vibration) of the alternating current driving circuit of the brushless direct current motor.

The integrated and liquid-lubricated permanent magnet brushless direct current motor electric water pump has the remarkable advantage of simple structure, and particularly, the integrated structure ensures that the integrated structure has no dynamic seal (a permanent magnet rotor is in the water pump, so that a shaft of the permanent magnet rotor does not need to be in dynamic seal); and the actually adopted semi-control (half-wave) driving mode and driving circuit also have the advantages of simplicity and practicability. However, the existing drive circuit adopting the semi-control (half-wave) drive mode has problems and defects, and mainly the overall (structural) design of the drive circuit is incomplete; the driving output stage is easy to heat; the principle of the brushless direct current motor is not known, the follow current discharge circuit design of the windings is biased, actually, the two motor windings are tightly coupled, the mutual inductance is very large, when the working current is large, two groups of driving output stages can induce very large overvoltage (peak impact) at two ends of the motor windings during switching (switching on and switching off), the driving circuit can be damaged by breakdown, and the normal alternating magnetic field can be seriously interfered to cause abnormal operation of the permanent magnet rotor and the motor. These problems and defects affect the reliability of the driving circuit and limit the output current, and the output current of the driving circuit of the current half-control (half-wave) driving mode is small, and therefore the output power of the motor is small.

Disclosure of Invention

The invention aims to provide a half-wave (half-controlled) driving circuit of a double-winding brushless direct current motor, which is used for improving the driving circuit of the existing half-controlled (half-wave) driving mode of the electric water pump and mainly perfects the overall (structural) design of the driving circuit; selecting an NMOS device as a driving output stage; the follow current discharge circuit of the motor winding is improved, and the improvement achieves the purpose of improving the reliability of a driving circuit and outputting current and power.

The device of the invention is realized by the following technical scheme:

a half-wave (half-control) drive circuit of a double-winding brushless direct current motor consists of a latch type double-output Hall device, a high-low level inversion and level conversion circuit, a drive output stage, a motor winding follow current discharge circuit, an anti-reverse connection diode and an overvoltage absorption voltage-stabilizing tube, and is characterized in that the latch type double-output Hall device is used for driving an integrated electric water pump of the brushless direct current motor which adopts a radial two-pole permanent magnet rotor and a double-motor winding half-control (half-wave) drive, detects the polarity of the permanent magnet rotor of the motor and outputs two paths of control signals with complementary high and low levels (one is high and one is low) according to the polarity (change), the two paths of control signals output by the latch type double-output Hall device are respectively connected to the two subsequent high-low level inversion and level conversion circuits to respectively carry out high-low level inversion and level conversion and generate two paths of control signals with complementary high and low, two control signals generated by the high-low level inversion and level conversion circuit are respectively connected to the subsequent driving output stage to respectively control the switch (on and off) of the driving output stage so as to respectively control the exciting currents of the two groups of motor windings to work alternately, thereby generating an alternating magnetic field in a stator magnetic circuit, each circuit of motor winding follow current discharge circuit is connected in parallel to each group of motor windings to provide a follow current path for the motor windings so as to reduce the overvoltage of the motor windings, an anti-reverse connection diode is connected in series on a power supply of the driving circuit so as to prevent the driving circuit from being damaged due to the misconnection of the power supply, and an overvoltage absorption voltage regulator is arranged between the positive electrode and the negative electrode of the. The high-low level inversion and level conversion circuit adopts a PNP type common-emitter amplification circuit; the drive output stage adopts an NMOS field effect transistor; the motor winding follow current discharge circuit adopts a series circuit of a voltage regulator tube and a Schottky diode; the reverse connection preventing diode is connected in series with the positive pole or the negative pole of the driving circuit power supply; the reverse connection prevention diode adopts a Schottky diode; the drive circuit and the motor windings are encapsulated with an encapsulating material.

The working principle of the invention is as follows:

the invention improves the drive circuit of the existing semi-control (half-wave) drive mode according to the basic structure of the integrated and liquid lubrication permanent magnet brushless direct current motor electric water pump, and according to the basic structure, the latching type double-output Hall device is arranged in a stator groove of the electric water pump, facing a permanent magnet rotor, so as to detect the position (polarity) of the permanent magnet rotor and generate a corresponding control signal.

The latching type double-output Hall device detects the polarity of a permanent magnet rotor of the motor and outputs two paths of control signals with complementary high and low levels (one is high and the other is low) according to the polarity (change), and the polarity is changed to change the two paths of output signals, namely, the two paths of control signals are inverted; because the latch type dual-output Hall device is output by an OC gate or an OD gate, and the drive output stage of the invention adopts an NMOS (compared with a PMOS, the on-resistance, the tube voltage drop and the power consumption of the NMOS are smaller, but the gate source electrode needs to be conducted by a positive bias drain source electrode), a proper high-low level inversion and level conversion circuit is needed between the two to provide a proper control signal for the drive output stage, and a typical PNP type common-emitter amplification circuit can realize the level inversion and level conversion and provide a proper control signal for the drive output stage, so that two paths of control signals output by the latch type dual-output Hall device are respectively connected to the two subsequent high-low level inversion and level conversion circuits to respectively carry out the level inversion and level conversion and generate two paths of control signals which are complementary with the high-low level matched with the drive output stage; two paths of control signals generated by the high-low level inversion and level conversion circuit are respectively connected to the subsequent driving output stage to respectively control the switches (on and off) of the driving output stage so as to respectively control the excitation currents of the two groups of motor windings to alternately work, thereby generating an alternating magnetic field meeting the requirement of the rotation work of the permanent magnet rotor in a stator magnetic circuit; the follow current discharge circuits of the two motor windings are respectively connected in parallel on each group of motor windings to provide a follow current path for the motor windings so as to reduce the overvoltage of the motor windings, the follow current discharge circuits of the motor windings adopt a voltage stabilizing tube and a Schottky diode series circuit, the Schottky diode has high working frequency and can realize better follow current protection, and the voltage stabilizing tube can improve the conduction voltage of the follow current discharge circuits of the motor windings, so that the follow current discharge current can be reduced, and the discharge starting time can be delayed so as to reduce the interference of the follow current discharge current of the motor windings on a normal alternating magnetic field and the adverse effect on the running of a permanent magnet rotor motor; the reverse connection preventing diode is connected in series with the positive electrode or the negative electrode input end of the power supply of the driving circuit to prevent the driving circuit from being damaged due to the misconnection of the power supply, and the Schottky diode is smaller in conduction voltage drop and more suitable for being used as the reverse connection preventing diode in the invention; the overvoltage absorption voltage-regulator tube is arranged between the anode and the cathode of a power supply in the driving circuit to provide a discharge current path for overvoltage in the driving circuit so as to filter the overvoltage. The drive circuit and the motor winding are encapsulated by encapsulating materials, so that the protection effect can be achieved, and the heat dissipation is facilitated.

The invention has the following beneficial effects:

1. the invention can obviously improve the driving capability of the driving circuit, thereby being capable of manufacturing the electric water pump with enough power, and having simple and compact structure and high reliability, and having positive significance for the practicability of the electric water pump for vehicles.

2. Compared with the existing three-phase brushless direct current motor electric water pump, the driving circuit and the electric water pump have the advantages of obvious cost and price, high reliability and positive significance for the practicability of the electric water pump for the vehicle.

Drawings

Fig. 1 is a circuit diagram of the present invention.

In an attached figure 1, the circuit comprises a latch type double-output Hall device 1, a high-low level reversal and level conversion circuit 2, a driving output stage 3, a motor winding follow current discharge circuit 4, a reverse connection prevention diode 5, an overvoltage absorption voltage stabilizing tube 6 and a motor winding follow current discharge circuit.

Detailed Description

Fig. 1 illustrates the technical solution, technical features and working principle of the present invention.

In the attached drawing 1, the latch type dual-output hall device (1) is also called as a latch type (dual-output) hall circuit (or switch), and the principle and function of different latch type dual-output hall devices (1) are basically the same, including that the polarity of a permanent magnet rotor of a motor can be detected, and two paths of control signals with complementary high and low levels (one high and one low) are output according to the polarity (change), the polarity changes the two paths of output, namely, the two paths are inverted, and the output of an OC gate or an OD gate is adopted, so that the latch type dual-output hall device can be used as a hall sensor of the micro fan or the micro brushless direct current motor with dual-motor windings or can directly drive the micro fan or the micro brushless direct current motor, and various brands and models. The high-low level inversion and level conversion circuit (2), the driving output stage (3) and the motor winding follow current discharge circuit (4) are respectively marked with one path. The high-low level inversion and level conversion circuit (2) is only one structure of a typical PNP common-emitter amplification circuit, and can be changed into other typical PNP common-emitter amplification circuits. The motor winding follow current discharge circuit (4) adopts a series circuit of a voltage regulator tube and a Schottky diode, and the voltage regulator tube and the Schottky diode are connected in series without any difference.

Figure 1 also discloses specific embodiments and examples of the invention.

In fig. 1, a power supply V_SIs 12V (such as power supply source)V_SFor 24V, a step-down (voltage-stabilizing) circuit (or device) is generally designed for the latch-type dual-output hall device (1), such as a voltage regulator tube Z added in fig. 1₄，Z₄The power supply can be connected in series to the positive electrode or the negative electrode of a power supply of the latching type double-output Hall device (1), and is connected in series to the negative electrode shown in the attached figure 1; the other main devices are that the latch type double-output Hall device (1) adopts a 284 type latch type double-output Hall device (pins 1 and 4 are the positive and negative poles of a power supply respectively, pins 2 and 3 are two paths of OC gate outputs respectively, and a motor stalling prevention restart logic circuit is arranged in the latch type double-output Hall device); t in high-low level inversion and level conversion circuit (2)₁、T₂A commonly used 9012PNP transistor is adopted; driving T in an output stage (3)₃、T₄Compared with a 284-model latch-type double-output Hall device (capable of directly driving the electric water pump, but the driving output current of the NMOS is limited to be less than 0.5A), the drive output stage (3) of the embodiment obviously has larger driving capability, can provide the maximum working current of 1.5A for the matched electric water pump (brushless direct current motor), and can reach 18W at the maximum power, so that the performance of the electric water pump is greatly improved, the lift of the electric water pump can reach 1.8m, the flow can reach 20L/min, and the motor is not easy to stall due to the increase of the starting current and the starting torque, and the working reliability is greatly improved.

In specific embodiments and embodiments, a control circuit may be added to control the start/stop or the number of rotations of the brushless dc motor (PWM speed regulation may be implemented by different technical solutions) based on the present invention, so as to control the flow rate of the electric water pump. The added control circuit can be installed on the electric water pump (can be integrated on the PCB of the invention) or can be additionally installed outside the electric water pump.