CN216216539U

CN216216539U - Flyback circuit applied to electric automobile compressor controller

Info

Publication number: CN216216539U
Application number: CN202122782433.5U
Authority: CN
Inventors: 刘付斌; 郑惠凤; 周磊
Original assignee: Shenzhen Yuxinhe Technology Co ltd
Current assignee: Shenzhen Yuxinhe Technology Co ltd
Priority date: 2021-11-12
Filing date: 2021-11-12
Publication date: 2022-04-05
Anticipated expiration: 2031-11-12

Abstract

The flyback circuit applied to the electric automobile compressor controller comprises an input voltage, a power supply control chip, a switch MOS (metal oxide semiconductor) tube, a transformer and a feedback circuit; the input voltage is the output electric energy of the power supply control chip and the transformer; the primary side of the transformer is grounded through the drain electrode and the source electrode of the switch MOS tube, and the grid electrode of the switch MOS tube is used for receiving the output signal of the power supply control chip; the transformer secondary side output three groups, wherein two sets of feedback signal that are used for IGBT drive circuit and singlechip power supply, a set of output of surplus with feedback circuit connects, feedback circuit still with power control chip's feedback pin is connected, so that power control chip through feedback information output signal extremely on the grid of switch MOS pipe, the technique that this application was current relatively has reduced compressor research and development cost effectively, and is more suitable on the application of middle-size and small-size car, has optimized the feedback circuit of flyback circuit for reaction rate is faster.

Description

Flyback circuit applied to electric automobile compressor controller

Technical Field

The utility model relates to the field of electric automobile compressor controller assembly, in particular to a flyback circuit applied to an electric automobile compressor controller.

Background

The air conditioning system of the electric automobile and the traditional fuel automobile on the market at present comprises a compressor, a condenser, an evaporator, a cooling fan, a blower, an expansion valve, high-low pressure pipeline accessories and the like. The traditional automobile compressor is driven by an engine transmission belt through an electromagnetic clutch, while the electric automobile adopts an electric compressor which is driven by a power battery to provide high-voltage electricity. The electric compressor is provided with a driving power supply by high voltage electricity and is also provided with a driving signal by an AC air conditioner controller to control the starting, namely the external wiring of the general electric compressor is mainly divided into a high-voltage side and a low-voltage side. The electric control inverter circuit inverts and converts high-voltage direct current provided by the whole vehicle into alternating current and outputs the alternating current to the three-phase alternating current motor, the single chip microcomputer on the low-voltage side receives CAN bus signals, enabling signals, PWM signals and LINK signals, namely signals for controlling the inverter circuit to start, stop and switch off, the low-voltage side circuit also needs an extra power supply to supply power, the low-voltage side is mainly a switching power supply and a control communication side, and the switching power supply converts the low-voltage power supply into specific working voltage required by the control panel single chip microcomputer.

The flyback switching power supply is widely applied to the field of motor control due to the characteristics of simple structure, high efficiency, low cost and the like. In the field of power electronics, a great deal of research results on switching power supplies are already available, but many problems still exist in the related application of motor control. The voltage stabilizing feedback loop of the traditional flyback switching power supply basically adopts a resistor voltage dividing sampling mode, and has the advantages of no isolation, poor anti-interference capability, slow response speed, large output voltage ripple, poor anti-interference capability and slow response speed.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems, the technical scheme provides the flyback circuit applied to the compressor controller of the electric automobile, the flyback circuit is used for reducing the cost, increasing the multi-path output voltage, and the reaction speed is high through design.

In order to achieve the purpose, the technical scheme is as follows:

the flyback circuit applied to the electric automobile compressor controller comprises an input voltage, a power supply control chip, a switch MOS (metal oxide semiconductor) tube, a transformer and a feedback circuit;

the input voltage is the output electric energy of the power supply control chip and the transformer;

the primary side of the transformer is grounded through the drain electrode and the source electrode of the switch MOS tube, and the grid electrode of the switch MOS tube is used for receiving the output signal of the power supply control chip;

and the secondary side of the transformer outputs three groups, wherein two groups of secondary sides are used for supplying power for the IGBT driving circuit and the single chip microcomputer, the feedback signal output by the rest group of secondary sides is connected with the feedback circuit, and the feedback circuit is also connected with a feedback pin of the power supply control chip, so that the power supply control chip outputs a signal to the grid electrode of the switch MOS tube through feedback information.

In some embodiments, the feedback circuit includes an optocoupler U1, through which the feedback signal is grounded at the led end, and the switch pins of the optocoupler U1 are connected to the power control chip and the ground, respectively.

In some embodiments, an RCD circuit is further provided between the input voltage and the transformer.

In some embodiments, the RCD circuit includes a resistor R9, a capacitor C7, and a diode D3 connected to the transformer.

In some embodiments, a resistor R4 is connected to the power control chip, and two ends of the resistor R4 are grounded through a capacitor C3 and a capacitor C5, respectively.

In some embodiments, the power control chip model is UC 2845.

The beneficial effect of this application does:

compared with the prior art, the compressor research and development cost is effectively reduced, the application of small and medium-sized automobiles is more suitable, the feedback circuit of the flyback circuit is optimized, and the reaction speed is higher.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below.

FIG. 1 is a block diagram of an embodiment of the present invention;

FIG. 2 is a schematic circuit diagram of an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a power control chip according to an embodiment of the utility model.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

Referring to fig. 1-3, a flyback circuit applied to a compressor controller of an electric vehicle includes an input voltage, a power control chip (UC2845), a switching MOS transistor, a transformer, and a feedback circuit;

the secondary side of the transformer outputs three groups, wherein two groups of secondary sides of the transformer are used for supplying power for the IGBT driving circuit and the single chip microcomputer, the feedback signal output by the other group of secondary sides of the transformer is connected with the feedback circuit, and the feedback circuit is also connected with a feedback pin of the power supply control chip so that the power supply control chip outputs a signal to a grid electrode of the switch MOS tube through feedback information;

specifically, referring to fig. 2, an input voltage of 12V is grounded through

pins

1 and 2 of the transformer and the drain and source of the MOS transistor, 12V further enters a pin 7 of the power control chip U3 through two resistors, 18V output by the transformer supplies power to the IGBT driving circuit, and two sets of 5V are also output, in order to prevent interference, wherein a 5V power supply is provided only for the feedback signal, this 5V is fed through the feedback circuit to

pins

1 and 2 of the power control chip U3, therefore, the pin 6 generates the conditions of on-off of the duty ratio control MOS tube Q3, sudden rise or fall of the input voltage UO (namely at 5V), and the like, the error amplifier also has quite quick response to the changes, since the VFB pin No. 2 is the input pin of the error amplifier as shown in fig. 3, when there is no voltage due to a fault on the side of the optocoupler, no. 6 output pin of power control chip UC2845B stops working, and switch MOS pipe also stops working.

In this embodiment, feedback circuit includes opto-coupler U1, and feedback signal is through its emitting diode end ground connection, opto-coupler U1's switch pin respectively with power control chip and ground connection, after 5V feedback signal output, opto-coupler U1's diode gets electric, and its

3 and 4 communicate to power control chip U3's

1 and 2 communicate, sample 5V output voltage, send the voltage error to UC 2845B's 1 foot through opto-coupler PC817A, produce the break-make of duty ratio control MOS pipe Q3.

Since the input voltage is well within the supply and start-up voltage range of the power control chip, there is no need for an auxiliary winding to power the power chip, as compared to conventional designs. In order to inhibit the peak voltage caused by the leakage inductance of the transformer, the primary sides of the transformers are connected with an RCD absorption circuit in parallel, an RCD circuit is further arranged between the input voltage and the transformers, and the RCD circuit comprises a resistor R9, a capacitor C7 and a diode D3 which are connected with the transformers.

In this embodiment, the power control chip is connected to a resistor R4, two ends of the resistor R4 are grounded through a capacitor C3 and a capacitor C5, an internal logic circuit of the UC2845B chip is as shown in fig. 3, a 1 pin COMP is an error amplifier OUTPUT pin and is provided for a photodiode of the optocoupler PC817, a light emitting diode inside the optocoupler is used in cooperation with a TL431, the TL431 is a three-terminal adjustable shunt reference source, the frequency OUTPUT by the OUTPUT is related to Rt and Ct connected to a pin No. 4, where f is 1.72/(Rt × Ct), where R4 is 8.6k Ω, C3 is 1nF, and the switching frequency is 200kHz by substituting the formula. A voltage regulator tube TL431 is used as a voltage reference source and an error amplifier, 5V output voltage is sampled, a voltage error is transmitted to a pin 1 of a UC2845B through an optocoupler PC817A, and the duty ratio is generated to control the on-off of an MOS tube Q3.

The above description is only for the purpose of illustrating the preferred embodiments of the present application and is not intended to limit the scope of the present application, which is within the scope of the present application, except that the same or similar principles and basic structures as the present application may be used.

Claims

1. The flyback circuit applied to the electric automobile compressor controller is characterized by comprising an input voltage, a power supply control chip, a switch MOS (metal oxide semiconductor) tube, a transformer and a feedback circuit;

2. The flyback circuit applied to the compressor controller of the electric vehicle according to claim 1, wherein: the feedback circuit comprises an optocoupler U1, a feedback signal is grounded through a light emitting diode end of the optocoupler U1, and a switch pin of the optocoupler U1 is connected with the power supply control chip and a ground wire respectively.

3. The flyback circuit applied to the compressor controller of the electric vehicle according to claim 1, wherein: and an RCD circuit is also arranged between the input voltage and the transformer.

4. The flyback circuit applied to the compressor controller of the electric vehicle according to claim 3, wherein: the RCD circuit includes a resistor R9, a capacitor C7, and a diode D3 connected to the transformer.

5. The flyback circuit applied to the compressor controller of the electric vehicle according to claim 1, wherein: the power control chip is connected with a resistor R4, and two ends of the resistor R4 are grounded through a capacitor C3 and a capacitor C5 respectively.

6. The flyback circuit applied to the compressor controller of the electric vehicle according to claim 1, wherein: the model of the power supply control chip is UC 2845.