Four-quadrant explosion-proof frequency converter control device

Abstract

The four-quadrant explosion-proof frequency converter control device comprises a main control board composed of a DSP chip and an FPGA chip, the DSP chip is connected with an FPGA through a parallel port bus and an SPI bus, and the four-quadrant explosion-proof frequency converter control device is characterized in that the main control board is connected with a rectification side sub-control board and an inversion side sub-control board through receiving and transmitting optical fibers; the rectification side sub-control board and the inversion side sub-control board respectively control the on-off states of IGBT devices in the rectification circuit part and the inversion circuit part of the frequency converter, and the rectification side sub-control board detects the input current of the frequency converter; the rectification side sub-control board and the inversion side sub-control board are connected with an interface board. According to the four-quadrant explosion-proof frequency converter control device provided by the utility model, the existing mode of adopting a rectification main control board and an inversion main control board is combined into one, so that the design of the frequency converter control device is simplified, the volume is reduced, and the cost is reduced.

Description

Technical Field

[0001] The utility model relates to a frequency converter control device, and more specifically, to a four-quadrant explosion-proof frequency converter control device. Background Art

[0002] In recent years, with the improvement of the automation level in coal mines, explosion-proof frequency converters are increasingly used in coal mines. For some loads with power generation working conditions, such as downward belt conveyors, winches, and hoisting machines, these application scenarios require the frequency converter to be four-quadrant, that is, when the load enters the power generation working condition, the rectifier side of the frequency converter can feed back the energy to the power grid. On the other hand, the rectifier side of a two-quadrant frequency converter uses a diode bridge uncontrolled rectifier, and the harmonic injected into the power grid is relatively large. In order to reduce the pollution of the frequency converter to the power grid, some users also require the frequency converter to be four-quadrant in some application scenarios without power generation working conditions, that is, the rectifier side works in a controlled rectification state. Therefore, four-quadrant frequency converters are increasingly used in coal mines.

[0003] For four-quadrant explosion-proof frequency converters, the current solutions of most manufacturers are that the main circuits of the rectifier part and the inverter part are in a back-to-back structure, and their rectifier control part and inverter control part are generally independent control boards, that is, two sets of main control boards are used. In order to coordinate the start-up and shutdown control of the rectifier part and the inverter part, some liaison control signals often need to be added between the main control boards. The four-quadrant frequency converter uses two sets of main control boards. On the one hand, it increases the cost of the whole set of equipment, and the liaison signals between the main control boards also increase the complexity of the process. Once problems such as poor contact occur in the signal lines, it is easy to cause the equipment to malfunction and reduce the reliability of the equipment. Summary of the Invention

[0004] The utility model aims to overcome the above technical problems and provides a four-quadrant explosion-proof frequency converter control device.

[0005] The four-quadrant explosion-proof frequency converter control device of the utility model includes a main control board composed of a DSP chip and an FPGA chip. The DSP chip is connected to the FPGA through a parallel port bus and an SPI bus. The DSP chip detects the input voltage, DC voltage, output voltage, and output current of the frequency converter. It is characterized in that: the main control board is connected to a rectifier side sub-control board and an inverter side sub-control board through optical fibers for receiving and transmitting. The rectifier side sub-control board and the inverter side sub-control board respectively control the on-off states of the IGBT devices in the rectifier circuit part and the inverter circuit part of the frequency converter. The rectifier side sub-control board detects the input current of the frequency converter. Both the rectifier side sub-control board and the inverter side sub-control board are connected to a plurality of interface boards connected to the control ends of the IGBT devices.

[0006] The four - quadrant explosion - proof frequency converter control device of the present utility model, the frequency converter is composed of a filter, a rectifier circuit part, an inverter circuit part and a bus capacitor. The AC power supply is connected to the input end of the rectifier circuit part through the filter. The output end of the rectifier circuit part is connected to the input end of the inverter circuit part through the DC bus, and the bus capacitor is connected to the DC bus. An input voltage sensor connected to the DSP chip is arranged on the input end of the filter. A DC voltage sensor connected to the DSP chip is arranged on the bus capacitor. An output voltage sensor and an output current sensor connected to the DSP chip are arranged on the output end of the inverter circuit part. An input current sensor connected to the rectifier - side sub - control board is arranged on the output end of the filter.

[0007] For the four - quadrant explosion - proof frequency converter control device of the present utility model, the rectifier - side sub - control board and the inverter - side sub - control board are composed of a CPLD chip or an FPGA chip.

[0008] The beneficial effects of the present utility model are as follows: The four - quadrant explosion - proof frequency converter control device of the present utility model is provided with a main control board composed of a DSP chip and an FPGA chip. The main control board controls the rectifier circuit part and the inverter circuit part of the frequency converter respectively through the rectifier - side sub - control board and the inverter - side sub - control board which are in optical fiber communication with it. It combines the existing method of using a rectifier main control board and an inverter main control board into one, simplifies the design of the frequency converter control device, reduces the volume, and lowers the cost. The main control board and the two sub - control boards use optical fiber communication, eliminating the connection signal lines between the two main control boards, improving the reliability of the whole machine, further simplifying the wiring process of the control device, improving the reliability and reducing the cost. Description of the Drawings

[0009] Figure 1 is the schematic diagram of the four - quadrant explosion - proof frequency converter control device of the present utility model;

[0010] Figure 2 is the circuit diagram of the four - quadrant explosion - proof frequency converter in the present utility model.

[0011] In the figure: 1 main control board, 2 rectifier - side sub - control board, 3 inverter - side sub - control board, 4 DSP chip, 5 FPGA chip, 6 interface board, 7 rectifier circuit part, 8 inverter circuit part, 9 filter, 10 bus capacitor, 11 input voltage sensor, 12 input current sensor, 13 output voltage sensor, 14 output current sensor, 15 DC voltage sensor. Detailed Embodiments

[0012] The present utility model will be further described below in conjunction with the drawings and embodiments.

[0013] Such as Figure 1As shown in the figure, the schematic diagram of the four - quadrant explosion - proof frequency converter control device of the present utility model is given. It is composed of a main control board 1, a rectifier - side sub - control board 2, and an inverter - side sub - control board 3. The main control board 1 is composed of a DSP chip 4 and an FPGA chip 5. The DSP chip 4 is connected to the FPGA chip 5 via a parallel port bus and an SPI bus to realize data transmission between the DSP chip 4 and the FPGA chip 5. The DSP chip 4 in the main control board 1 detects the input voltage, DC bus voltage, output voltage, and output current signals in the frequency converter through sensors, and samples the input voltage and current analog signals through the DSP chip 4. The FPGA chip 5 in the main control board 1 is connected to the rectifier - side sub - control board 2 and the inverter - side sub - control board 3 via optical fibers for receiving and transmitting to realize communication between the main control board 1 and the two sub - control boards (the rectifier - side sub - control board 2 and the inverter - side sub - control board 3).

[0014] As shown, the rectifier - side sub - control board 2 detects the input current of the frequency converter. A plurality of interface boards 6 are provided on both the rectifier - side sub - control board 2 and the inverter - side sub - control board 3. The interface board 6 is connected to the control terminals of IGBT devices in the rectifier circuit part 7 and the inverter circuit part 8 of the frequency converter to control the on - off state of the IGBT devices, realizing rectification of the rectifier circuit part 7 and inversion of the inverter circuit part 8. The rectifier - side sub - control board 2 and the inverter - side sub - control board 3 are composed of CPLD chips or low - configuration FPGA chips.

[0015] As Figure 2 As shown in the figure, the circuit diagram of the four - quadrant explosion - proof frequency converter in the present utility model is given. The shown four - quadrant explosion - proof frequency converter has a three - level topology. The shown four - quadrant explosion - proof frequency converter is composed of a filter 9, a bus capacitor 10, a rectifier circuit part 7, and an inverter circuit part 8. The three - phase power supply is connected to the input end of the filter 9. The output end of the filter 9 is connected to the input end of the rectifier circuit part 7. The output end of the rectifier circuit part 7 is connected to the DC bus. The input end of the inverter circuit part 8 is also connected to the DC bus. The output end of the inverter circuit part 8 is connected to the load motor.

[0016] The input alternating current is filtered by the filter and then input to the rectifier circuit part. Under the control of the main control board 1 and the rectifier - side sub - control board 2, the rectifier circuit part rectifies the filtered alternating current into direct current and inputs it to the DC bus; under the control of the main control board 1 and the inverter - side sub - control board 3, the inverter circuit part 8 converts the direct current on the DC bus into alternating current with a controllable frequency to drive the load to work.

[0017] An input voltage sensor 11 and an input current sensor 12 are respectively arranged on the input end and the output end of the shown filter 9. The input voltage sensor 11 and the input current sensor 12 are respectively connected to the DSP chip 4 in the main control board 1 and the rectifier side sub-control board 2 to respectively realize the measurement of the input voltage signal and the input current signal. A DC voltage sensor 15 is arranged on the bus capacitor 10, and an output voltage sensor 13 and an output current sensor 14 are arranged on the output end of the inverter circuit part 8. The DC voltage sensor 15, the output voltage sensor 13 and the output current sensor 14 are connected to the DSP chip 4 in the main control board 1 to realize the measurement of the DC voltage, the output current and the voltage signal.

[0018] It can be seen that since the four-quadrant explosion-proof frequency converter control device of the present invention uses one main control board 1 and uses the fiber optic communication between one main control board 1 and the rectifier side sub-control board 2 and the inverter side sub-control board 3 to realize the control of the rectifier current part 7 and the inverter circuit part 8, the existing method using the rectifier main control board and the inverter main control board is combined into one, which simplifies the design of the frequency converter control device, reduces the volume and lowers the cost.

[0019] For the four-quadrant explosion-proof frequency converter control device of the present invention, the working process of the rectifier part is as follows. The DSP chip 4 in the main control board 1 collects the input voltage data and the DC voltage data, and through phase-locked control and voltage closed-loop control, obtains the three-phase voltage control instruction and the three-phase current control instruction. The control instructions are sent to the FPGA chip 5 in the main control board 1 through the parallel bus, and then the control data is sent to the rectifier side sub-control board 2 through the optical fiber. The rectifier side sub-control board 2 completes the current closed-loop control through the received voltage and current control instructions and the input current data detected by itself, and obtains the final PWM drive signal to control the on and off of the IGBT device in the rectifier circuit part 7.

[0020] The working process of the inverter part is as follows. The DSP chip 4 in the main control board 1 collects the output current and output voltage on the inverter side, completes the control algorithm of the load motor to obtain the three-phase comparison loading value, and sends the loading value to the FPGA chip 5 in the main control board 1 through the parallel bus. The modulation is completed in the FPGA chip 5 to obtain the PWM drive signal on the inverter side, which is formed into a serial code and sent to the inverter side sub-control board 3 through the optical fiber. After receiving the data, the inverter side sub-control board 3 decodes it to obtain the final PWM drive signal to control the on and off of the IGBT device in the inverter circuit part 8. Some status information obtained by the rectifier side sub-control board 2 and the inverter side sub-control board 3 is transmitted to the FPGA chip 5 in the main control board 1 through the upstream optical fiber, and then transmitted to the DSP chip 4 in the main control board 1 through the SPI interface for some protection logic judgment and display.

Claims

1. A four-quadrant explosion-proof inverter control device, comprising a main control board (1) composed of a DSP chip (4) and an FPGA chip (5), wherein the DSP chip is connected to the FPGA via a parallel bus and an SPI bus, and the DSP chip detects the input voltage, DC voltage, output voltage and output current of the inverter; characterized in that: The main control board is connected to a rectifier-side sub-control board (2) and an inverter-side sub-control board (3) via transceiver optical fibers. The rectifier-side sub-control board and the inverter-side sub-control board respectively control the on / off states of the IGBT devices in the rectifier circuit part (7) and the inverter circuit part (8) of the frequency converter. The rectifier-side sub-control board detects the input current of the frequency converter. The rectifier-side sub-control board and the inverter-side sub-control board are both connected to a plurality of interface boards (6) connected to the control ends of the IGBT devices.

2. The four-quadrant explosion-proof inverter control device according to claim 1, characterized in that: The frequency converter is composed of a filter (9), a rectifier circuit part (7), an inverter circuit part (8) and a bus capacitor (10); an AC power supply is connected to the input end of the rectifier circuit part via the filter; the output end of the rectifier circuit part is connected to the input end of the inverter circuit part via a DC bus; and the bus capacitor is connected to the DC bus; an input voltage sensor (11) connected to a DSP chip (4) is arranged on the input end of the filter; a DC voltage sensor (15) connected to the DSP chip is arranged on the bus capacitor; an output voltage sensor (13) and an output current sensor (14) connected to the DSP chip are arranged on the output end of the inverter circuit part; and an input current sensor (12) connected to a rectifier-side sub-control board (2) is arranged on the output end of the filter.

3. The four-quadrant explosion-proof inverter control device according to claim 1 or 2, characterized in that: The rectifier-side sub-control board (2) and the inverter-side sub-control board (3) are composed of a CPLD chip or an FPGA chip.

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