CN104578712A - Water-cooled high-voltage power amplifier - Google Patents

Abstract

The invention provides a water-cooled high-voltage power amplifier, which includes a control module, a start-up circuit, a rectifier circuit and a power module connected in sequence; the input end of the control module is connected to the output end of the power module; one of the control modules The output branch is connected to the power module, and the other output branch is connected to the display protection circuit; the output end of the power module is the output end of the amplifier; the control module is based on the output signal of the power module and the A fixed signal is used to perform feedback control on the power module, and adjust the on and off of its internal full control devices to adjust the output signal. Compared with the prior art, the water-cooled high-voltage power amplifier provided by the present invention solves the cooling problem of ordinary high-voltage power amplifiers, improves the output power of a single module of the power amplifier, is suitable for high-thrust electric vibration table tests, and meets the requirements of electric vibration The station conducts the reliability test of the whole machine for large-scale equipment such as satellites and missiles.

Description

A water-cooled high-voltage power amplifier

technical field

The invention relates to a power amplifier, in particular to a water-cooled high-voltage power amplifier.

Background technique

A power amplifier (Power Amplifier) refers to an amplifier that can generate maximum power output to drive a certain load (such as a speaker) under a given distortion rate. As the key equipment of the electrodynamic vibration test system, the power amplifier itself and its matching with the vibration table are directly related to the performance of the system. In the field of electric vibrating tables, the development of power amplifiers has gone through two stages: linear power amplifiers and switching power amplifiers. Switching power amplifiers have completely replaced linear power amplifiers with their advantages of high efficiency, low loss, high power and high reliability. The research on switching power amplifier abroad has reached a very high level, but the effective value of the output voltage is only about 100V. The SPAK switching power amplifier of British LDS company adopts the parallel connection technology of multiple modules, and the maximum power is 280KW. The power amplifiers used by several major vibration table equipment suppliers in China are basically early power amplifiers imported from abroad, or their imitations. In recent years, domestic power amplifier technology has developed rapidly. A high-voltage and high-power switching power amplifier has been developed. Based on IGBT full-bridge inverter circuit and PWM integrated control circuit, the effective value of the output voltage is 320V, the output power is 480KVA, and the output power of a single module is 17.6KVA. , has achieved the largest power in China, which can meet the needs of the vibration table below 35 tons. Because the cooling method of the power amplifier is air cooling, the rated power of the selected IGBT is limited, so the output power of the power amplifier module encounters a bottleneck. In recent years, with the development of aviation, aerospace, high-speed rail and other industries, electric vibration tables with greater thrust are required to conduct complete machine reliability tests for large-scale equipment such as satellites and missiles, which cannot be satisfied by ordinary high-voltage power amplifiers.

Contents of the invention

In order to meet the needs of the prior art, the present invention provides a water-cooled high-voltage power amplifier, the amplifier includes a control module, and a starting circuit, a rectifier circuit and a power module connected in sequence; the input terminal of the control module and the power module connected to the output end of the control module; one output branch of the control module is connected to the power module, and the other output branch is connected to the display protection circuit;

The output end of the power module is the output end of the amplifier;

The control module performs feedback control on the power module according to the output signal and the given signal of the power module, and adjusts the opening and closing of its internal full control devices to adjust the output signal.

Preferably, the power module includes an inverter unit and a filter unit;

The inverter unit is used to adjust the direct current output by the rectification circuit into a pulsed alternating current;

The filtering unit filters the pulsed alternating current and outputs it through the output terminal of the power module;

Preferably, the control module includes a signal processing circuit, and a first PWM modulation circuit and a second PWM modulation circuit;

The first PWM modulation circuit receives the output signal of the power module and the given signal;

The signal processing circuit compares the output signal with a given signal, and sends a modulated signal to the power module according to the difference between the two;

The second PWM modulation circuit sends the modulation signal to the power module to control the opening and closing of the full control device;

Preferably, a drive circuit is also connected between the control module and the power module; the drive circuit includes a drive chip, a control signal interface circuit, a power filter circuit, an input signal conditioning circuit, an error signal processing circuit, a dead time Generating circuit, fully controlled device interface circuit, active clamp circuit, overcurrent protection circuit and fully controlled device absorbing circuit;

The control signal interface circuit is used to divide the modulated signal output by the control module into two, and send them to the two full-control device units of the inverter unit in the power module respectively;

The power supply filter circuit includes a capacitor array for filtering out the clutter signal on the power supply of the driver chip;

The input signal conditioning circuit filters the modulated signal transmitted by the control signal interface circuit, and then sends it to the driver chip;

The full-control device interface circuit turns on or off the full-control device in the inverter unit according to the drive signal output by the drive chip;

The fully-controlled device absorbing circuit is used to absorb the peak voltage generated when the fully-controlled device is turned on and off;

The active clamping circuit is used to clamp the collector potential of the fully controlled device;

The overcurrent protection circuit detects the potential between the collector and the emitter of the fully controlled device; the driver chip compares the potential with a threshold voltage, and if the potential exceeds the threshold voltage, the fully controlled device is turned off ;

The error signal processing circuit receives the error information transmitted by the driver chip, and sends the error information to the control module through the control signal interface circuit; the error signal includes a power supply undervoltage signal, a full control device short circuit signal and a full control device overcurrent signal;

The dead time generation circuit is used to provide dead time to the driver chip to prevent the upper and lower bridge arms of the full control device from passing through;

Preferably, the display protection circuit is used to monitor the working status of the full control devices in the power module;

The starting circuit is used to control the on-off of the AC contactor to realize the soft start of the amplifier;

The rectifier circuit converts the three-phase AC voltage output by the starting circuit into a DC voltage;

Preferably, the power module includes a water-cooled radiator arranged on its back plate; the two full-control device units of the inverter unit in the power module are respectively installed on both sides of the water-cooled radiator;

Preferably, the rectifier circuit includes a water-cooled radiator; each rectifier unit in the rectifier circuit is provided with the same side of the water-cooled radiator, and the other side of the water-cooled radiator is fixed on the bottom plate of the amplifier cabinet through a bracket.

Compared with the closest prior art, the excellent effect of the present invention is:

1. In the technical solution of the present invention, the power module structure provided with a water-cooled radiator can maximize the use of the internal space of the power module and the heat dissipation surface of the water-cooled radiator, and the layout is compact to maximize the output power;

2. In the technical solution of the present invention, a rectifier circuit equipped with a water-cooled radiator has a better cooling effect and takes up less space than the air-cooled heat dissipation method;

3. A water-cooled high-voltage power amplifier provided by the present invention solves the cooling problem of ordinary high-voltage power amplifiers, improves the output power of a single module of the power amplifier, and is suitable for high-thrust electric shaking table tests, satisfying that the electric shaking table is used for satellites and missiles And other large-scale equipment for the reliability test of the whole machine.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Fig. 1: a schematic structural diagram of a water-cooled high-voltage power amplifier in an embodiment of the present invention;

Figure 2: The installation diagram of the water-cooled radiator in the power module in the embodiment of the present invention;

Fig. 3: the installation diagram of the water-cooled radiator in the rectifier circuit in the embodiment of the present invention;

Figure 4: Structural schematic diagram of the driving circuit in the embodiment of the present invention;

Among them, 1: power module box; 2: water-cooled radiator; 3: IGBT module; 4: water-cooled radiator adapter; 5: rectifier unit; 6: water-cooled radiator; 7: water-cooled radiator adapter.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

A water-cooled high-voltage power amplifier provided in the embodiment of the present invention solves the cooling problem of ordinary high-voltage power amplifiers, improves the output power of a single module of the power amplifier, and can output a super-high-power high-voltage power amplifier system. The output power of a single module is higher than that of existing modules. 4 times.

1. The structure of the water-cooled high-voltage power amplifier in this embodiment;

Including the control module, and the starting circuit, rectification circuit and power module connected in sequence; the input terminal of the control module is connected with the output terminal of the power module; one output branch of the control module is connected with the power module, and the other output branch is connected with the display protection circuit connection. In this embodiment, the output end of the amplifier is the output end of the power module, so that the expected waveform is output to the electrodynamic vibration table for electrodynamic vibration test.

Among them, the control module performs feedback control on the power module according to the output signal and the given signal of the power module, and adjusts the opening and closing of its internal full control devices to adjust the output signal. The given signal is a signal with a preset value, which is used to compare with the output signal, and adjust the modulation signal output by the control module according to the deviation between the output signal and the given signal.

1. Power module;

Including inverter unit and filter unit;

The inverter unit is used to adjust the direct current output by the rectification circuit into pulsed alternating current. The inverter unit includes two full-control device units. In this implementation, the full-control device uses IGBT.

The filtering unit is used to filter the pulsed alternating current and output it through the output terminal of the power module.

2. Control module;

1. It includes a signal processing circuit, a first PWM modulation circuit and a second PWM modulation circuit;

The first PWM modulation circuit receives the output signal of the power module and the given signal, processes the above signal and sends it to the signal processing circuit.

The signal processing circuit compares the output signal with the given signal, and sends a modulated signal to the power module according to the difference between the two, that is, feedback control.

The second PWM modulation circuit processes the modulated signal and sends it to the power module to control the turn-on and turn-off of the full control device.

2. As shown in FIG. 2 , the power module includes a water-cooling radiator arranged on its back panel.

The two full-control device units of the inverter unit in the power module are respectively installed on both sides of the water-cooled radiator.

In this embodiment, the water-cooling radiator 2 of the power module is 20mm thick, and is vertically installed on the rear panel of the power module box 1, and is located in the middle of the power module box 1, so that the internal space of the module and the water-cooling radiator can be used to the maximum extent. Excellent heat dissipation surface, compact layout and maximum output power. The water-cooling radiator adapter 4 is punched out from the back of the power module case 1 for connection.

The two full-control device units are respectively installed on the left and right sides of the water-cooling radiator 2 . In this embodiment, each full-control device unit includes two IGBT modules. As shown in FIG. 2 , four IGBT modules 3 are installed on the left and right sides of the heat sink 2 of the power module respectively.

In this embodiment, the IGBT module is selected as the KS4 series half-bridge module produced by Infineon Corporation, and the model is FF300R12KS4. Its withstand voltage is 1200V, and it can still output a rated current of 300A at a junction temperature of 150 degrees, which is very cost-effective. The switching loss is small, and has a positive temperature coefficient, which is more suitable for parallel connection, and is very suitable for parallel power amplifier system.

3. Drive circuit;

In order to utilize the IGBT module with maximum efficiency, a driving circuit based on 2SC0435T is also connected between the control module and the power module in this embodiment. As shown in Figure 4, it includes driver chip, control signal interface circuit, power filter circuit, input signal conditioning circuit, error signal processing circuit, dead time generation circuit, full control device interface circuit, active clamping circuit, overcurrent protection circuit and fully controlled device sink circuit. In this embodiment, the driver chip is a 2SC0435T driver chip.

(1), control signal interface circuit;

It is used to divide the modulation signal output by the control module into two, and send them to the two full-control device units of the inverter unit in the power module respectively, and can also exchange the enable signal and the protection signal at the same time. in,

The enable signal refers to the signal that enables the full control device to be turned on;

The protection signal refers to the signal sent to the control module after the error signal given by the driving signal chip is processed.

(2) Power filter circuit;

It includes a capacitor array to filter out the clutter signal on the driver chip power supply.

(3) Input signal conditioning circuit;

After the modulated signal transmitted by the control signal interface circuit is filtered, it is sent to the driver chip. Specifically, it receives the PWM signal transmitted by the control signal interface circuit, and then transmits it to the driver chip after filtering and triggering processing, which has the functions of anti-interference and improving the steepness of the PWM waveform.

(4) Full control device interface circuit;

According to the driving signal output by the driving chip, the full control device in the inverter unit is turned on or off.

(5) Full control device absorption circuit;

It is used to absorb the peak voltage generated when the full control device is turned on and off;

(6) Active clamping circuit;

Used to clamp the collector potential of fully controlled devices.

(7) Overcurrent protection circuit;

Detect the potential between the collector and emitter in the fully controlled device, and send the potential to the driver chip. The driver chip compares the potential with the threshold voltage. If the potential exceeds the threshold voltage, the full-control device will be turned off, thereby protecting the full-control device from being burned due to overcurrent or short circuit, and improving system reliability.

(8) Error signal processing circuit;

Receive the error information transmitted by the driver chip, and send the error information to the control module through the control signal interface circuit; the error signal includes the power supply undervoltage signal, the full control device short circuit signal and the full control device overcurrent signal. Specifically, the error signal processing circuit receives the error information transmitted by the drive chip, and then performs pull-up, clamping, and buffer processing before sending it to the control signal interface circuit. Its role is to transmit the error signal to the control module accurately and in real time.

(9) dead time generation circuit;

It is used to provide dead time to the driver chip to prevent the upper and lower bridge arms of the full control device from passing through.

4. Display protection circuit;

It is used to monitor the working status of all control devices in the power module. The display protection circuit obtains the working status information of the power amplifier from the control module for display, and monitors the operating parameters of the power amplifier for real-time protection.

5. Start the circuit;

It is used to control the on-off of the AC contactor to realize the soft start of the amplifier in this embodiment.

6. Rectifier circuit;

1. Convert the three-phase AC voltage output by the starting circuit into DC voltage.

2. The rectifier circuit also includes a water-cooled radiator; each rectifier unit in the rectifier circuit is provided with the same side of the water-cooled radiator, and the other side of the water-cooled radiator is fixed on the bottom plate of the amplifier cabinet through a bracket. This embodiment includes three rectifying units composed of rectifying diodes.

As shown in Figure 3, the back of the water-cooling radiator 6 is installed on the bottom plate of the power amplifier cabinet through brackets, and the three rectifier units 5 are evenly distributed on the front of the water-cooling radiator 6, and the water-cooling radiator adapter 7 is located inside the power amplifier cabinet, so that it can be hidden The water pipe has a compact and beautiful structure. Compared with the previous air-cooled heat dissipation method, this method has a better cooling effect and takes up less space.

Finally, it should be noted that the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

Claims (7)

1. A water-cooled high-voltage power amplifier is characterized in that, the amplifier includes a control module, and a starting circuit, a rectifier circuit and a power module connected in sequence; the input end of the control module is connected with the output end of the power module; One output branch of the control module is connected to the power module, and the other output branch is connected to the display protection circuit; The output end of the power module is the output end of the amplifier; The control module performs feedback control on the power module according to the output signal and the given signal of the power module, and adjusts the opening and closing of its internal full control devices to adjust the output signal. 2. The amplifier according to claim 1, wherein the power module comprises an inverter unit and a filtering unit; The inverter unit is used to adjust the direct current output by the rectification circuit into a pulsed alternating current; The filtering unit filters the pulsed alternating current and outputs it through the output terminal of the power module. 3. The amplifier according to claim 1, wherein the control module comprises a signal processing circuit, and a first PWM modulation circuit and a second PWM modulation circuit; The first PWM modulation circuit receives the output signal of the power module and the given signal; The signal processing circuit compares the output signal with a given signal, and sends a modulated signal to the power module according to the difference between the two; The second PWM modulation circuit sends the modulation signal to the power module to control the turn-on and turn-off of the full control device. 4. The amplifier according to claim 1, wherein a drive circuit is also connected between the control module and the power module; the drive circuit includes a drive chip, a control signal interface circuit, a power filter circuit, an input Signal conditioning circuit, error signal processing circuit, dead time generating circuit, fully controlled device interface circuit, active clamp circuit, overcurrent protection circuit and fully controlled device absorbing circuit; The control signal interface circuit is used to divide the modulated signal output by the control module into two, and send them to the two full-control device units of the inverter unit in the power module respectively; The power supply filter circuit includes a capacitor array for filtering out the clutter signal on the power supply of the driver chip; The input signal conditioning circuit filters the modulated signal transmitted by the control signal interface circuit, and then sends it to the driver chip; The full-control device interface circuit turns on or off the full-control device in the inverter unit according to the drive signal output by the drive chip; The fully-controlled device absorbing circuit is used to absorb the peak voltage generated when the fully-controlled device is turned on and off; The active clamping circuit is used to clamp the collector potential of the fully controlled device; The overcurrent protection circuit detects the potential between the collector and the emitter of the fully controlled device; the driver chip compares the potential with a threshold voltage, and if the potential exceeds the threshold voltage, the fully controlled device is turned off ; The error signal processing circuit receives the error information transmitted by the driver chip, and sends the error information to the control module through the control signal interface circuit; the error signal includes a power supply undervoltage signal, a full control device short circuit signal and a full control device overcurrent signal; The dead time generating circuit is used to provide dead time to the driving chip to prevent the upper and lower bridge arms of the full control device from being directly connected. 5. The amplifier according to claim 1, wherein the display protection circuit is used to monitor the working state of the full control device in the power module; The starting circuit is used to control the on-off of the AC contactor to realize the soft start of the amplifier; The rectification circuit converts the three-phase AC voltage output by the starting circuit into a DC voltage. 6. The amplifier according to claim 1, wherein the power module includes a water-cooled radiator arranged on its back plate; the two full-control device units of the inverter unit in the power module are respectively installed on the water-cooled on both sides of the radiator. 7. The amplifier according to claim 1, wherein the rectifier circuit includes a water-cooled radiator; each rectifier unit in the rectifier circuit is provided with the same side of the water-cooled radiator, and the other side of the water-cooled radiator It is fixed on the bottom plate of the amplifier cabinet through brackets.