CN203086345U - A power conversion device - Google Patents

Abstract

The utility model discloses a power conversion device, include: an input filter circuit for filtering the power supply; a push-pull driving circuit for converting the filtered power supply into a constant voltage signal; an output filter circuit for filtering the constant voltage signal; a pulse voltage control circuit for generating a pulse voltage signal by using the filtered constant voltage signal; an output feedback circuit for acquiring the voltage value of the constant voltage signal; a protection circuit for outputting a shutdown signal when the operating parameter exceeds a corresponding threshold; the control signal input end is connected with the signal output end of the protection circuit, the voltage signal input end is connected with the voltage signal output end of the output feedback circuit, and the signal output end is connected with the push-pull control circuit of the control end of the push-pull drive circuit. The utility model discloses a power conversion device can generate constant voltage signal and pulse voltage signal simultaneously, still can continue work when protection circuit breaks down, has improved the reliability.

Description

A power conversion device

technical field

The utility model belongs to the technical field of power conversion, in particular to a power conversion device.

Background technique

With the advancement of science and technology and the improvement of people's living standards, more and more motor vehicles appear in people's lives, and motor vehicles will produce a large amount of noise pollution during the whistle process. In order to reduce the noise pollution of motor vehicles, there is currently a sound limiting controller applied to motor vehicles.

The hum limiter controller needs constant voltage and pulse voltage to supply power to its internal modules during operation, and the existing power conversion devices can only output constant voltage or pulse voltage, which cannot meet the power demand of the hum limiter controller.

Utility model content

In view of this, the purpose of the utility model is to provide a power conversion device, which can output constant voltage and pulse voltage at the same time, and can meet the power consumption demand of the sound limiting controller of the motor vehicle.

In order to achieve the above object, the utility model provides the following technical solutions:

A power conversion device, comprising:

Connected to the power supply, an input filter circuit for filtering the power supply;

The input end is connected to the output end of the input filter circuit, and the push-pull drive circuit converts the filtered power supply into a constant voltage signal;

The input terminal is connected to the output terminal of the push-pull drive circuit, and an output filter circuit for filtering the constant voltage signal;

The input end is connected to the output end of the output filter circuit, and a pulse voltage control circuit for generating a pulse voltage signal by using the filtered constant voltage signal;

An output feedback circuit that collects the voltage value of the filtered constant voltage signal;

A protection circuit for collecting operating parameters of the power conversion device, and outputting a shutdown signal when the operating parameters exceed a corresponding threshold;

The control signal input terminal is connected to the signal output terminal of the protection circuit, the voltage signal input terminal is connected to the voltage signal output terminal of the output feedback circuit, and the signal output terminal is connected to the control terminal of the push-pull drive circuit. circuit.

Preferably, in the above power conversion device, the protection circuit includes an over-temperature protection circuit, an over-current protection circuit and an over-voltage protection circuit.

Preferably, the above-mentioned power conversion device further includes a short-circuit protection circuit connected between the power supply and the input filter circuit.

Preferably, in the above-mentioned power conversion device, the short-circuit protection circuit is a fast-acting fuse.

Preferably, in the above power conversion device, the input filter circuit is an electromagnetic compatibility (EMC) filter circuit.

Preferably, in the above power conversion device, the EMC filter circuit includes a variable resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first common-mode inductor, and a differential-mode inductor;

The variable resistor is connected between the first input terminal and the second input terminal of the EMC filter circuit;

The first capacitor is connected in parallel with the variable resistor;

The same-named end of the first coil in the first common-mode inductor is connected to the first input end of the EMC filter circuit, and the different-named end is connected to the first end of the second capacitor, and in the first common-mode inductor The same-named end of the second coil is connected to the second input end of the EMC filter circuit, and the different-named end is connected to the second end of the second capacitor;

The first end of the third capacitor is connected to the first end of the second capacitor, the second end of the third capacitor is connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is terminal is connected to the second terminal of the second capacitor, and the common terminal of the third capacitor and the fourth capacitor is connected to an equipotential surface;

One end of the differential mode inductor is connected to the first end of the third capacitor, the other end of the differential mode inductor is connected to the first end of the fifth capacitor, and the second end of the fifth capacitor is connected to a second terminal of the second capacitor;

The first end of the fifth capacitor is the first output end of the EMC filter circuit, and the second end of the fifth capacitor is the second output end of the EMC filter circuit.

Preferably, in the above power conversion device, the push-pull drive circuit includes a high-frequency transformer, a first switch tube, a second switch tube, a first diode, a second diode, a third diode and a first switch tube. Four diodes, the output filter circuit includes a sixth capacitor, a seventh capacitor, a first electrolytic capacitor, a second electrolytic capacitor, an inductor, and a second common-mode inductor;

The first end of the first switching tube is connected to the same-named end of the primary winding of the high-frequency transformer, the second end is connected to the second output end of the EMC filter circuit, and the control end is connected to the push-pull control A signal output terminal of the circuit;

The first end of the second switch tube is connected to the opposite end of the primary winding of the high frequency transformer, the second end is connected to the second end of the first switch tube, and the control end is connected to the push-pull Another signal output terminal of the control circuit, a Zener diode is connected in parallel between the first end and the second end of the first switch tube, and a Zener diode is connected in parallel between the first end and the second end of the second switch tube. voltage diode;

The cathode of the first diode is connected to the first end of the first switch tube, the cathode of the second diode is connected to the first end of the second switch tube, and the first diode The anodes of the tube and the second diode are connected to the second end of the first switching tube;

The center tap of the primary winding of the high-frequency transformer is connected to the first output end of the EMC filter circuit, and the terminal with the same name of the secondary winding of the high-frequency transformer is connected to the anode of the third diode, so The cathode of the third diode is connected to the first end of the sixth capacitor, the middle tap of the secondary winding of the high frequency transformer is connected to the second end of the sixth capacitor, and the high frequency transformer The opposite end of the secondary winding is connected to the anode of the fourth diode, and the cathode of the fourth diode is connected to the first end of the sixth capacitor;

The positive pole of the first electrolytic capacitor is connected to the first terminal of the sixth capacitor through the inductor, and the negative pole of the first electrolytic capacitor is connected to the second terminal of the sixth capacitor;

The same-named end of the first coil in the second common-mode inductor is connected to the positive pole of the first electrolytic capacitor, the opposite-named end is connected to the positive pole of the second electrolytic capacitor, and the second coil in the second common-mode inductor The same end of the coil is connected to the negative pole of the first electrolytic capacitor, the opposite end is grounded, and the negative pole of the second electrolytic capacitor is grounded;

The seventh capacitor is connected in parallel to both ends of the second electrolytic capacitor, and the anode of the second electrolytic capacitor is the output end of the output filter circuit.

Preferably, in the above power conversion device, the pulse voltage control circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a fifth diode, a photocoupler, and a PNP transistor , a third switching tube and a pulse signal generator;

One end of the first resistor is connected to an external control signal, the other end is simultaneously connected to the cathode of the fifth diode and the first input end of the photocoupler, and the anode of the fifth diode is connected to the first input end of the photocoupler. The second input terminal of the optocoupler is grounded;

The first output terminal of the photocoupler is connected to a DC power supply through the second resistor, and the second output terminal of the photocoupler is grounded;

The emitter of the PNP transistor is connected to the DC power supply, the base is connected to the first output terminal of the photocoupler through the third resistor, and the collector is connected to the first input of the pulse signal generator terminal, the second input terminal of the pulse signal generator is grounded;

The output end of the pulse signal generator is grounded through the fourth resistor and the fifth resistor in turn, the first end of the third switching tube is connected to the output end of the output filter circuit, and the control end is connected to the first The common end and the second end of the fourth resistor and the fifth resistor are grounded, and a Zener diode is connected in parallel between the first end and the second end of the third switching tube.

Preferably, the above-mentioned power conversion device further includes a casing.

Preferably, the above-mentioned power conversion device further includes a fan disposed inside the housing, detecting the temperature inside the housing and adjusting the rotation speed according to the detected temperature value.

It can be seen that the beneficial effects of the utility model are: the power conversion device disclosed in the utility model includes a push-pull drive circuit and a pulse voltage control circuit, the push-pull drive circuit can convert the filtered power supply into a constant voltage signal output, and at the same time The pulse voltage control circuit can use the constant voltage signal output by the push-pull drive circuit to generate a pulse voltage signal. Therefore, the power conversion device disclosed in the utility model can generate a constant voltage signal and a pulse voltage signal at the same time, which can meet the power requirements of the limiter controller. need. In addition, the protection circuit in the power conversion device disclosed in the utility model adopts a separate design, and when the protection circuit fails, the power conversion device can still continue to work, which improves reliability.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present utility model. Those skilled in the art can also obtain other drawings based on these drawings without any creative work.

Fig. 1 is a schematic structural diagram of a power conversion device disclosed by the utility model;

Fig. 2 is a schematic structural diagram of another power conversion device disclosed in the present invention;

Fig. 3 is the circuit diagram of the disclosed EMC filter circuit of the utility model;

Fig. 4 is the circuit diagram of the push-pull drive circuit and the output filter circuit disclosed by the utility model;

Fig. 5 is a circuit diagram of the pulse voltage control circuit disclosed by the utility model.

Detailed ways

Explain the technical terms that appear below:

EMC: Electro Magnetic Compatibility, electromagnetic compatibility;

MOS tube: metal (metal)-oxide (oxid)-semiconductor (semiconductor) field effect transistor;

IGBT: Insulated Gate Bipolar Transistor), insulated gate bipolar transistor;

MOSFET: Metal-Oxide-Semiconductor Field-Effect Transistor, Metal-Oxide-Semiconductor-Field-Effect Transistor, referred to as Metal-Oxide-Semiconductor Field-Effect Transistor.

In order to make the purpose, technical solutions and advantages of the embodiments of the utility model more clear, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the utility model. Obviously, the described The embodiments are some embodiments of the present utility model, but not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

The utility model discloses a power conversion device, which can output constant voltage and pulse voltage at the same time, and can meet the power consumption demand of the sound limiting controller of the motor vehicle.

Referring to FIG. 1 , FIG. 1 is a schematic structural diagram of a power conversion device disclosed in the present invention. The power conversion device includes an input filter circuit 100 , a push-pull drive circuit 200 , an output filter circuit 300 , a pulse voltage control circuit 400 , an output feedback circuit 500 , a protection circuit 600 and a push-pull control circuit 700 .

in:

The input filter circuit 100 is connected to the power supply and used for filtering the power supply.

The input terminal of the push-pull drive circuit 200 is connected with the output terminal of the input filter circuit 100, the control terminal of the push-pull drive circuit 200 is connected with the signal output terminal of the push-pull control circuit 700, and the push-pull drive circuit 200 is used to pass through the input filter circuit 100 filter processed power supply is transformed into a constant voltage signal.

The input end of the output filter circuit 300 is connected to the output end of the push-pull drive circuit 200 for filtering the constant voltage signal output by the push-pull drive circuit 200 .

The input terminal of the pulse voltage control circuit 400 is connected to the output terminal of the output filter circuit 300, and the pulse voltage signal is generated by using the filtered constant voltage signal.

The output feedback circuit 500 is used to collect the voltage value of the constant voltage signal filtered by the output filter circuit 300 , and transmit the collected voltage value to the push-pull control circuit 700 . The push-pull control circuit 700 uses the voltage value to realize closed-loop control and stabilize the output voltage.

The protection circuit 600 is used to collect operating parameters of the power conversion device, compare the collected operating parameters with corresponding thresholds, and output a shutdown signal when the operating parameters exceed the corresponding thresholds. The shutdown signal is used to control the push-pull control circuit 700 to block the push-pull drive circuit 200 and turn off the output.

The control signal input end of the push-pull control circuit 700 is connected to the signal output end of the protection circuit 600, the voltage signal input end of the push-pull control circuit 700 is connected to the voltage signal output end of the output feedback circuit 500, and the signal output of the push-pull control circuit 700 The terminal is connected to the control terminal of the push-pull drive circuit 200. The push-pull control circuit 700 is used to control the push-pull drive circuit 200 to transform the power filtered by the input filter circuit 100 into a constant voltage signal.

The power conversion device disclosed in the utility model includes a push-pull drive circuit and a pulse voltage control circuit. The push-pull drive circuit can convert the filtered power supply into a constant voltage signal output, and at the same time, the pulse voltage control circuit can use the output voltage of the push-pull drive circuit. The constant voltage signal generates a pulse voltage signal, therefore, the power conversion device disclosed in the utility model can generate a constant voltage signal and a pulse voltage signal at the same time, which can meet the power demand of the ring limit controller. In addition, the protection circuit in the power conversion device disclosed in the utility model adopts a separate design, and when the protection circuit fails, the power conversion device can still continue to work, which improves reliability.

Referring to FIG. 2 , FIG. 2 is a schematic structural diagram of another power conversion device disclosed in the utility model.

The power conversion device includes an input filter circuit 100 , a push-pull drive circuit 200 , an output filter circuit 300 , a pulse voltage control circuit 400 , an output feedback circuit 500 , a protection circuit 600 , a push-pull control circuit 700 and a short circuit protection circuit 800 . Only the differences from the power conversion device shown in FIG. 1 will be described, and other parts refer to the previous description.

The short circuit protection circuit 800 is connected between the power supply and the input filter circuit 100, which can quickly cut off the faulty circuit and reduce the impact on the external power supply system. In practice, the short-circuit protection circuit 800 may use a fuse or a fuse, preferably, a fast-acting fuse.

The protection circuit 600 includes an over-temperature protection circuit 601 , an over-current protection circuit 602 and an over-voltage protection circuit 603 . in:

The over-temperature protection circuit 601 is used to collect the temperature in the power conversion device, and compare the collected temperature value with the corresponding temperature threshold value, and when the collected temperature value exceeds the temperature threshold value, send a control signal to the push-pull control circuit 700 The input terminal outputs a shutdown signal. Since the push-pull drive circuit 200 will generate a lot of heat during the operation of the power conversion device, the temperature sensing element of the over-temperature protection circuit 601 can be arranged close to the push-pull drive circuit 200 to prevent the temperature of the push-pull drive circuit 200 from being too high When the over-temperature protection circuit 601 has not output the shutdown signal.

The overcurrent protection circuit 602 is used to detect the current value output by the power conversion device, and compare the collected current value with the corresponding current threshold value. When the collected current value exceeds the current threshold value, the push-pull control circuit 700 will control The signal input terminal outputs a shutdown signal.

The overvoltage protection circuit 603 is used to detect the output voltage value of the power conversion device, and compare the collected voltage value with the corresponding voltage threshold value, and when the collected voltage value exceeds the voltage threshold value, send a control signal to the push-pull control circuit 700 The input terminal outputs a shutdown signal.

The signal output terminals of the temperature protection circuit 601, the overcurrent protection circuit 602 and the overvoltage protection circuit 603 are connected with the control signal input terminal of the push-pull control circuit 700 at the same time, when the temperature protection circuit 601, the overcurrent protection circuit 602 and the overvoltage protection circuit When one of 603 outputs a shutdown signal, the push-pull drive circuit 200 is blocked and the output is turned off, thereby preventing the power conversion device from operating under overheating, overcurrent or overvoltage conditions, thereby ensuring the stable operation of the power conversion device.

In the power conversion device shown in FIG. 1 and FIG. 2 , the input filter circuit 100 can use an EMC filter circuit, which can suppress and eliminate strong electromagnetic interference and spark interference on site to ensure stable operation of the power conversion device. In implementation, a structure of the EMC filter circuit is shown in FIG. 3 .

Referring to Fig. 3, Fig. 3 is a circuit diagram of the EMC filter circuit disclosed by the utility model.

The EMC filter circuit includes a variable resistor RV1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a first common mode inductor B1 and a differential mode inductor L1.

in:

The variable resistor RV1 is connected between the first input terminal and the second input terminal of the EMC filter circuit.

The first capacitor C1 is connected in parallel with the variable resistor RV1.

The same name end of the first coil in the first common mode inductor B1 is connected to the first input end of the EMC filter circuit, the different name end is connected to the first end of the second capacitor C2, and the same name end of the second coil in the first common mode inductor B1 The end is connected to the second input end of the EMC filter circuit, and the opposite end is connected to the second end of the second capacitor C2.

The first end of the third capacitor C3 is connected to the first end of the second capacitor C2, the second end of the third capacitor C3 is connected to the first end of the fourth capacitor C4, and the second end of the fourth capacitor C4 is connected to the second The second end of the capacitor C2, the common end of the third capacitor C3 and the fourth capacitor C4 are connected to an equipotential surface E.

One end of the differential mode inductor L1 is connected to the first end of the third capacitor C3, the other end of the differential mode inductor L1 is connected to the first end of the fifth capacitor C5, and the second end of the fifth capacitor C5 is connected to the second end of the second capacitor C2 second end.

The first end of the fifth capacitor C5 is the first output end of the EMC filter circuit, and the second end of the fifth capacitor C5 is the second output end of the EMC filter circuit.

In the EMC filter circuit shown in Figure 3, the first common-mode inductor B1, the first capacitor C1 and the second capacitor C2 form a common-mode interference signal suppression circuit, and the differential-mode inductor L1, the third capacitor C3, and the fourth capacitor C4 and the fifth capacitor C5 form a differential-mode interference signal suppression circuit, therefore, the EMC filter circuit shown in FIG. 3 can simultaneously suppress common-mode interference signals and differential-mode interference signals in the circuit, effectively eliminating interference.

The circuit structure of the push-pull drive circuit and the output filter circuit in the utility model is shown in Figure 4. The push-pull drive circuit includes a high-frequency transformer, a first switch tube Q1, a second switch tube Q2, a first diode D1, a second switch tube Q2, and a first switch tube Q2. Two diodes D2, a third diode D3 and a fourth diode D4, the output filter circuit includes a sixth capacitor C6, a seventh capacitor C7, a first electrolytic capacitor C8, a second electrolytic capacitor C9, an inductor L2 and a Two common mode inductors B2.

in:

The first end of the first switching tube Q1 is connected to the same name end of the primary winding of the high frequency transformer, the second end is connected to the second output end of the EMC filter circuit, and the control end is connected to a signal output end of the push-pull control circuit.

The first end of the second switching tube Q2 is connected to the opposite end of the primary winding of the high-frequency transformer, the second end is connected to the second end of the first switching tube Q1, and the control end is connected to another signal of the push-pull control circuit output. Both ends of the first switching tube Q1 and the second switching tube Q2 are respectively connected in parallel with a Zener diode, specifically, a first Zener diode ZD1 is connected in parallel between the first end and the second end of the first switching tube Q1, and the second switch A second Zener diode ZD2 is connected in parallel between the first terminal and the second terminal of the tube Q2.

The cathode of the first diode D1 is connected to the first end of the first switching transistor Q1, the cathode of the second diode D2 is connected to the first end of the second switching transistor Q2, the first diode D1 and the second two The anode of the transistor D2 is connected to the second end of the first switching transistor Q1.

The middle tap of the primary winding of the high-frequency transformer is connected to the first output terminal of the EMC filter circuit, the terminal of the same name of the secondary winding of the high-frequency transformer is connected to the anode of the third diode D3, and the cathode of the third diode D3 Connected to the first end of the sixth capacitor C6, the middle tap of the secondary winding of the high-frequency transformer is connected to the second end of the sixth capacitor C6, and the opposite end of the secondary winding of the high-frequency transformer is connected to the fourth diode The anode of D4 and the cathode of the fourth diode D4 are connected to the first terminal of the sixth capacitor C6.

The positive pole of the first electrolytic capacitor C8 is connected to the first terminal of the sixth capacitor C6 through the inductor L2, and the negative pole of the first electrolytic capacitor C8 is connected to the second terminal of the sixth capacitor C6.

The same-named end of the first coil in the second common-mode inductor B2 is connected to the positive pole of the first electrolytic capacitor C8, the different-named end is connected to the positive pole of the second electrolytic capacitor C9, and the same-named end of the second coil in the second common-mode inductor B2 Connected to the negative pole of the first electrolytic capacitor C8, the opposite terminal is grounded, and the negative pole of the second electrolytic capacitor C9 is grounded.

The seventh capacitor C7 is connected in parallel with both ends of the second electrolytic capacitor C9, and the anode of the second electrolytic capacitor C9 is the output terminal of the output filter circuit.

The push-pull driving circuit shown in FIG. 4 is composed of two switching tubes and a high-frequency transformer. The two signal output terminals of the pulse voltage control circuit 400 output control signals to the first switching tube Q1 and the second switching tube Q2 respectively, to control the first switching tube Q1 and the second switching tube Q2. A diode Q1 and a second diode Q2 are turned on alternately, combined with the function of a high-frequency transformer, the power is converted into a constant voltage signal. The output filter circuit shown in Figure 4 is composed of a power inductor and an electrolytic capacitor to minimize the ripple voltage of the output signal.

The circuit structure of the pulse voltage control circuit in the utility model is shown in Figure 5, including a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a fifth diode D5, A photocoupler, a PNP transistor Q4, a third switch tube Q3 and a pulse signal generator.

in:

One end of the first resistor R1 is connected to an external control signal, and the other end is simultaneously connected to the cathode of the fifth diode D5 and the first input end of the photocoupler, and the anode of the fifth diode D5 and the second input end of the photocoupler The input is grounded.

The first output terminal of the photocoupler is connected to the DC power supply VCC1 through the second resistor R2, and the second output terminal of the photocoupler is grounded.

The emitter of the PNP transistor Q4 is connected to the DC power supply VCC1, the base is connected to the first output end of the photocoupler through the third resistor R3, and the collector is connected to the first input end of the pulse signal generator. The second input terminal is grounded.

The output terminal of the pulse signal generator is grounded sequentially through the fourth resistor R4 and the fifth resistor R5, the first terminal of the third switching tube Q3 is connected to the output terminal V ₀ of the output filter circuit, and the control terminal is connected to the fourth resistor R4 and the fifth resistor R4. The common terminal and the second terminal of the five resistors R5 are grounded, and a Zener diode is connected in parallel between the first terminal and the second terminal of the third switch tube Q3.

In the pulse voltage control circuit shown in Figure 5, the output of the pulse voltage is determined by the external control signal, and the pulse signal generator can set the frequency and amplitude of the pulse signal according to the needs, and control the opening and closing of the switch tube.

As a preferred solution, a casing can be further provided in the power conversion device, and the above-mentioned circuit structures are all arranged in the casing, so as to facilitate the movement and transportation of the power conversion device.

Since the power conversion device will generate a lot of heat during operation, in order to ensure the stable operation of the power conversion device and prolong the service life of its internal electronic components, a fan can be further installed in the power conversion device during implementation. Inside the casing, the inside of the power conversion device is cooled by a fan.

In order to reduce the power consumption of the fan, a fan with a temperature detection function and speed adjustment can be used. The fan can detect the temperature inside the casing of the power conversion device and adjust its own speed according to the detected temperature value. When the internal temperature is high, the fan speed is increased, when the internal temperature is low, the fan speed is reduced, and when the internal temperature is lower than the preset temperature, the fan stops rotating, thus ensuring that the power conversion device operates at a lower temperature , to reduce fan power consumption.

In addition, one side of the casing can also be set as a heat dissipation plate structure for auxiliary heat dissipation, thereby forming a heat dissipation redundant structure with the heat dissipation through the fan.

In implementation, each switch tube may use an IGBT or a MOS tube such as a MOSFET. When the switch tube is an IGBT, the first end of the switch tube is a collector, the second end is an emitter, and the control end is a gate. When the switch tube is a MOS tube, the first end of the switch tube is a drain, the second end is a source, and the control end is a gate.

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.

The above description of the disclosed embodiments enables those skilled in the art to realize or use the utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A power conversion device, characterized in that, comprising: Connected to the power supply, an input filter circuit for filtering the power supply; The input end is connected to the output end of the input filter circuit, and the push-pull drive circuit converts the filtered power supply into a constant voltage signal; The input terminal is connected to the output terminal of the push-pull drive circuit, and an output filter circuit for filtering the constant voltage signal; The input end is connected to the output end of the output filter circuit, and a pulse voltage control circuit for generating a pulse voltage signal by using the filtered constant voltage signal; An output feedback circuit that collects the voltage value of the filtered constant voltage signal; A protection circuit for collecting operating parameters of the power conversion device, and outputting a shutdown signal when the operating parameters exceed a corresponding threshold; The control signal input terminal is connected to the signal output terminal of the protection circuit, the voltage signal input terminal is connected to the voltage signal output terminal of the output feedback circuit, and the signal output terminal is connected to the control terminal of the push-pull drive circuit. circuit. 2. The power conversion device according to claim 1, wherein the protection circuit comprises an over-temperature protection circuit, an over-current protection circuit and an over-voltage protection circuit. 3. The power conversion device according to claim 1 or 2, further comprising a short circuit protection circuit connected between the power supply and the input filter circuit. 4. The power conversion device according to claim 3, wherein the short-circuit protection circuit is a fast-acting fuse. 5. The power conversion device according to claim 3, wherein the input filter circuit is an electromagnetic compatibility (EMC) filter circuit. 6. The power conversion device according to claim 5, wherein the EMC filter circuit comprises a variable resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first common mode inductors and differential mode inductors; The variable resistor is connected between the first input terminal and the second input terminal of the EMC filter circuit; The first capacitor is connected in parallel with the variable resistor; The same-named end of the first coil in the first common-mode inductor is connected to the first input end of the EMC filter circuit, and the different-named end is connected to the first end of the second capacitor, and in the first common-mode inductor The same-named end of the second coil is connected to the second input end of the EMC filter circuit, and the different-named end is connected to the second end of the second capacitor; The first end of the third capacitor is connected to the first end of the second capacitor, the second end of the third capacitor is connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is terminal is connected to the second terminal of the second capacitor, and the common terminal of the third capacitor and the fourth capacitor is connected to an equipotential surface; One end of the differential mode inductor is connected to the first end of the third capacitor, the other end of the differential mode inductor is connected to the first end of the fifth capacitor, and the second end of the fifth capacitor is connected to a second terminal of the second capacitor; The first end of the fifth capacitor is the first output end of the EMC filter circuit, and the second end of the fifth capacitor is the second output end of the EMC filter circuit. 7. The power conversion device according to claim 6, wherein the push-pull drive circuit comprises a high-frequency transformer, a first switching tube, a second switching tube, a first diode, a second diode, a third diode and a fourth diode, wherein the output filter circuit includes a sixth capacitor, a seventh capacitor, a first electrolytic capacitor, a second electrolytic capacitor, an inductor, and a second common-mode inductor; The first end of the first switching tube is connected to the same-named end of the primary winding of the high-frequency transformer, the second end is connected to the second output end of the EMC filter circuit, and the control end is connected to the push-pull control A signal output terminal of the circuit; The first end of the second switch tube is connected to the opposite end of the primary winding of the high frequency transformer, the second end is connected to the second end of the first switch tube, and the control end is connected to the push-pull Another signal output terminal of the control circuit, a Zener diode is connected in parallel between the first end and the second end of the first switch tube, and a Zener diode is connected in parallel between the first end and the second end of the second switch tube. voltage diode; The cathode of the first diode is connected to the first end of the first switch tube, the cathode of the second diode is connected to the first end of the second switch tube, and the first diode The anodes of the tube and the second diode are connected to the second end of the first switching tube; The center tap of the primary winding of the high-frequency transformer is connected to the first output end of the EMC filter circuit, and the terminal with the same name of the secondary winding of the high-frequency transformer is connected to the anode of the third diode, so The cathode of the third diode is connected to the first end of the sixth capacitor, the middle tap of the secondary winding of the high frequency transformer is connected to the second end of the sixth capacitor, and the high frequency transformer The opposite end of the secondary winding is connected to the anode of the fourth diode, and the cathode of the fourth diode is connected to the first end of the sixth capacitor; The positive pole of the first electrolytic capacitor is connected to the first terminal of the sixth capacitor through the inductor, and the negative pole of the first electrolytic capacitor is connected to the second terminal of the sixth capacitor; The same-named end of the first coil in the second common-mode inductor is connected to the positive pole of the first electrolytic capacitor, the opposite-named end is connected to the positive pole of the second electrolytic capacitor, and the second coil in the second common-mode inductor The same end of the coil is connected to the negative pole of the first electrolytic capacitor, the opposite end is grounded, and the negative pole of the second electrolytic capacitor is grounded; The seventh capacitor is connected in parallel to both ends of the second electrolytic capacitor, and the anode of the second electrolytic capacitor is the output end of the output filter circuit. 8. The power conversion device according to claim 7, wherein the pulse voltage control circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a fifth diode, Photocoupler, PNP transistor, third switch tube and pulse signal generator; One end of the first resistor is connected to an external control signal, the other end is simultaneously connected to the cathode of the fifth diode and the first input end of the photocoupler, and the anode of the fifth diode is connected to the first input end of the photocoupler. The second input terminal of the optocoupler is grounded; The first output terminal of the photocoupler is connected to a DC power supply through the second resistor, and the second output terminal of the photocoupler is grounded; The emitter of the PNP transistor is connected to the DC power supply, the base is connected to the first output terminal of the photocoupler through the third resistor, and the collector is connected to the first input of the pulse signal generator terminal, the second input terminal of the pulse signal generator is grounded; The output end of the pulse signal generator is grounded through the fourth resistor and the fifth resistor in turn, the first end of the third switching tube is connected to the output end of the output filter circuit, and the control end is connected to the first The common end and the second end of the fourth resistor and the fifth resistor are grounded, and a Zener diode is connected in parallel between the first end and the second end of the third switching tube. 9. The power conversion device according to claim 8, further comprising a housing. 10 . The power conversion device according to claim 9 , further comprising a fan disposed inside the housing, detecting the temperature inside the housing and adjusting the rotation speed according to the detected temperature value. 11 .

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