阅读说明：本技术 一种有外续流放电电路的双绕组无刷直流电机半波驱动电路 (Double-winding brushless direct current motor half-wave driving circuit with external follow current discharge circuit ) 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：本发明是关于一种有外续流放电电路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,可用于径向两极转子、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。发明的目的是为降低UDN3625/3626芯片(或类似芯片)的过热。其特征是,由UDN3625/3626芯片及其典型应用电路和增加的外续流放电电路组成,外续流放电电路采用稳压管和肖特基二极管串联电路,其导通电压低于芯片内续流放电电路的导通电压从而代替芯片内续流放电电路为电机绕组提供续流放电通路。(The invention relates to a half-wave drive circuit of a double-winding brushless direct current motor with an external follow current discharge circuit, which belongs to the technical field of brushless direct current motors and can be used for driving a radial two-pole rotor and the double-winding brushless direct current motor. The invention aims to reduce the overheating of a UDN3625/3626 chip (or similar chips). The device is characterized by comprising a UDN3625/3626 chip, a typical application circuit thereof and an added external follow current discharge circuit, wherein the external follow current discharge circuit adopts a voltage stabilizing tube and Schottky diode series circuit, and the conduction voltage of the external follow current discharge circuit is lower than that of the on-chip follow current discharge circuit, so that the on-chip follow current discharge circuit is replaced to provide a follow current discharge path for a motor winding.)

1. A half-wave drive circuit of a double-winding brushless direct current motor with an external follow current discharge circuit is composed of a UDN3625/3626 chip (or other similar chips with the same principle) and a typical application circuit thereof and the external follow current discharge circuit, and is characterized in that the half-wave drive circuit 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 is driven by double-winding half control (half-wave), and each external follow current discharge circuit is connected in parallel on each group of motor windings to provide a follow current discharge path for the motor windings.

2. A half-wave driving circuit of a dual-winding brushless DC motor with an external follow current discharge circuit as claimed in claim 1, wherein the external follow current discharge circuit is a series circuit of a voltage regulator tube and a Schottky diode.

3. A half-wave driving circuit of a dual-winding brushless DC motor with an external follow current discharging circuit as claimed in claim 1 or 2, wherein the on-voltage of the external follow current discharging circuit is lower than that of the follow current discharging circuit in UDN3625/3626 chip (or other similar chips with the same principle).

4. A half-wave driving circuit of a dual-winding brushless DC motor with an external follow current discharging circuit as claimed in claim 1, 2 or 3, wherein the external follow current discharging circuit replaces the internal follow current discharging circuit of UDN3625/3662 chip (or other similar chip with the same principle) to provide a follow current discharging path for each set of motor windings.

5. A half-wave driving circuit of a dual-winding brushless DC motor with an external follow current discharge circuit as claimed in claim 1, 2, 3 or 4, wherein the driving circuit and the motor winding are encapsulated with encapsulating material.

Technical Field

The invention relates to a half-wave driving circuit of a double-winding brushless direct current motor with an external follow current discharge circuit, which belongs to the technical field of brushless direct current (micro) motors and can be used for driving a radial two-pole permanent magnet rotor and a double-winding half-wave driving brushless direct current motor.

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 a 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 in fact the scheme mostly adopts a half-control (half-wave) driving mode, namely, the motor has two independent windings, the two windings drive circuit of the two permanent magnet windings which alternately work to generate two-pole vibration poles, so-called as an improved radial electric water pump.

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); the driving method and the driving circuit are mostly adopted in practice, namely, a half-control (half-wave) driving mode and a driving circuit are adopted, and the driving method and the driving circuit have the advantages of simplicity and practicability.

The semi-controlled (half-wave) driving circuit is integrated in circuit for many years, and various models of products are provided by various manufacturers, wherein the comprehensive performance of the chip is better than that of a UDN3625/3626 sensor/driver chip of Allegro microsystem, a Hall device, a logic control circuit, a driving output stage, an overheating protection circuit, an overcurrent protection circuit and the like are integrated in the chip, and a PWM signal control end can control (adjust) the working current of the driving output stage, so that the revolution of the electric water pump can be adjusted, and the performance is relatively perfect. The chip has the defects that the driving capability is weak, the maximum output load current is very small, the UDN3625 can only reach about 1A actually, and the UDN 3626 can only reach about 0.5A (the data of factory data is slightly larger, and the data cannot be reached in practical application).

The inventor finds out through analysis and experiments that the defect of weak drive capability of the UDN3625/3626 chip is caused by design bias of manufacturers, mainly the defect of insufficient knowledge of the energy storage size of a motor winding is that a follow current discharge circuit is designed in the chip, when the working current is large, the energy storage of the motor winding is increased sharply (the energy storage of the winding (inductance) is in direct proportion to the square of the current), and the chip is overheated during follow current discharge, so that the chip is subjected to overheating protection and stops working. The invention relates to the improvement of the chip and the typical application circuit, and is also applicable to other similar chips and typical application circuits with the same principle.

Disclosure of Invention

The invention aims to provide a half-wave drive circuit of a double-winding brushless direct current motor with an external follow current discharge circuit, which solves the overheating problem of chips of the type by adding an additional follow current discharge circuit outside the chips so as to eliminate the defects in practical use.

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

a double-winding brushless DC motor half-wave drive circuit with an external follow current discharge circuit is composed of a UDN3625/3626 chip (or other similar chips with the same principle) and a typical application circuit thereof as well as an added external follow current discharge circuit, and is characterized in that the drive circuit is used for driving an integrated electric water pump of a brushless DC motor which adopts a radial two-pole permanent magnet rotor and is driven by double-winding half control (half-wave), and each external follow current discharge circuit is connected in parallel on each group of motor windings to provide a follow current discharge path for the motor windings; the external follow current discharge circuit adopts a series circuit of a voltage regulator tube and a Schottky diode; the conduction voltage of the external freewheeling discharge circuit is lower than that of the UDN3625/3626 on-chip freewheeling discharge circuit; and the external follow current discharge circuit replaces an UDN3625/3662 on-chip follow current discharge circuit to provide a follow current discharge path for each group of motor windings. The drive circuit and the motor windings are encapsulated with an encapsulating material.

The working principle of the invention is as follows:

the invention is made according to the basic structure of the above-mentioned electric water pump and principle and its typical application circuit of UDN3625/3626 chip, it is an improvement to the typical application circuit of existing UDN3625/3662 chip among them, its working principle is, every external freewheel discharge circuit connects in parallel on every group of motor winding to provide the freewheel discharge path for motor winding in order to reduce its overvoltage; the external follow current discharge circuit adopts a series circuit of a voltage regulator tube and a Schottky diode, wherein the Schottky diode has high working frequency and can realize better follow current protection, and the voltage regulator tube can improve the conduction voltage of the follow current discharge circuit of the motor winding, thereby reducing the follow current discharge current and delaying the discharge starting time so as to reduce the interference of the follow current discharge current of the motor winding on a normal alternating magnetic field and the adverse effect on the running of the permanent magnet rotor motor; the conduction voltage of the external follow current discharge circuit is lower than that of the UDN3625/3626 chip follow current discharge circuit, so that the conduction discharge of the external follow current discharge circuit can be ensured, and the conduction discharge of the UDN3625/3626 chip follow current discharge circuit is not conducted; in addition, a follow current discharging circuit replaces a follow current discharging circuit in the UDN3625/3662 chip to provide a follow current discharging path for each group of motor windings, and the follow current discharging circuit in the UDN3625/3662 chip does not work any more and does not generate heat. 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 reduce the heating power of the UDN3625/3626 chip and improve the driving capability thereof, has simple and reliable improvement scheme and has particularly positive significance for the practicability of the electric water pump for the vehicle.

2. Unlike other conventional methods of improving the performance of the UDN3625/3626 chip (e.g., adding a new (off-chip) driving output stage), the present invention does not change or degrade any performance of the UDN3625/3626 chip and its application circuits, thereby fully exploiting the advantages of the UDN3625/3626 chip and its application circuits.

3. The invention has low cost, and compared with the existing three-phase brushless direct current motor electric water pump, the electric water pump manufactured by the invention has obvious advantages in cost and price, and has high reliability, thereby having positive significance for the practicability of the vehicle electric water pump.

Drawings

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

In FIG. 1, a UDN3625/3626 chip and a typical application circuit thereof, and 2, an external freewheeling discharge circuit.

Other similar chips having the same principles as the UDN3625/3626 chips and their typically applied circuits are the same or similar to the principles and structure of fig. 1. The chip can be directly used for driving the brushless direct current motor with the double-motor winding, has output of an OC gate or an OD gate, and is internally provided with a follow current discharge circuit for follow current discharge of the double-motor winding. The invention is applicable to such chips and to the circuits typically used for them.

Detailed Description

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

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

The UDN3625/3626 chip and the typical application circuit (1) are from a data table (DATASHEET) of Allegro microsystems, and the UDN3625/3626 chip and the typical application circuit (1) are enclosed by dotted lines and labeled with the number 1 in the attached FIG. 1, wherein the PMW input circuit does not adopt a totem-pole circuit in the typical application circuit, but adopts an OC gate according to the prompt; according to the data sheet, some of the peripheral elements are optional elements, butFor simplicity, they are shown as mounted elements in fig. 1 (shown by dotted lines in the original drawing of the data sheet, and shown by solid lines in fig. 1); the external follow current discharge circuit (2) has two paths in the attached figure 1, and only one path is marked with a serial number 2; the external follow current discharge circuit (2) adopts a voltage stabilizing tube (Z)_M) And a Schottky diode (Z)_D) And the series circuit is connected with the two circuits in series without any sequence.

In fig. 1, a power supply V_SThe actual maximum output load current of the present embodiment can reach 1.3A, which is significantly improved compared with the original typical application circuit, so that the performance of the electric water pump is greatly improved, the lift can reach 1.5m, and the flow can reach 20L/min, thereby proving the actual effect and practicability of the present invention.