Three-phase inverter circuit applied to safety tester and having feedback and isolation functions

Abstract

The utility model relates to a three-phase inverter circuit applied to a safety tester and having feedback and isolation functions, which is characterized by comprising a main control module, an isolation circuit, a filtering module, a three-phase inverter bridge circuit, a voltage feedback measurement module, a current feedback measurement module, a frequency feedback measurement module and an inverter circuit temperature detection module, the main control module is connected with the isolating circuit, the isolating circuit is connected with the filtering module, the filtering module is connected with the three-phase inverter bridge type circuit, and the voltage feedback measurement module, the frequency feedback measurement module, the current feedback measurement module and the inverter circuit temperature detection module are respectively connected with the three-phase inverter bridge type circuit. And the signals are fed back to the main control module. According to the utility model, a GD32F103CGT6 chip is adopted as a main control module, and a filtering module, an isolation module and a voltage, current, frequency and temperature feedback measurement module are added for a three-phase inverter circuit, so that the reliability and the accuracy of output signals are ensured.

Description

Technical Field

[0001] The utility model relates to a three-phase inverter circuit applied to a safety tester and with feedback and isolation functions. Background Art

[0002] With the development of power electronics technology, the application of three-phase inverter circuits is becoming more and more extensive. For example, the traditional three-phase inverter circuit applied to a safety tester has disadvantages such as low reliability, complex circuit, excessive components, lack of isolation and feedback. If the three-phase inverter circuit lacks isolation, the strong electric part in the circuit is likely to cause electromagnetic interference to the weak electric part and the measurement part, thus affecting the normal operation of the entire circuit; if the three-phase inverter circuit lacks feedback, it may be impossible to judge the magnitudes of the current, voltage, frequency, etc. of the PWM output. If the output is too large, the equipment is likely to be burned out. If the output is too small, it cannot work stably. Content of the Utility Model

[0003] In order to solve the above problems, the utility model provides a three-phase inverter circuit applied to a safety tester and with feedback and isolation functions. Specifically, an isolation module and a feedback module are introduced into the traditional three-phase inverter circuit, and a three-phase inverter circuit with high precision and high reliability is designed.

[0004] The technical solution of the utility model to solve the above technical problems is: The utility model relates to a three-phase inverter circuit applied to a safety tester and with feedback and isolation, mainly including a main control module, an isolation circuit module, a filtering module, a three-phase inverter bridge circuit module, a voltage feedback measurement module, a current feedback measurement module, a frequency measurement feedback module, and an inverter circuit temperature detection module. The utility model uses GD32F103CGT6 as the control chip of the main circuit, and adds voltage, current, frequency feedback modules and temperature detection modules on the basis of adding a filtering module and an isolation module for the three-phase inverter circuit, ensuring the reliability and accuracy of the output signal.

[0005] First, the three-phase inverter circuit with feedback and isolation functions uses a high-performance 32-bit low-power ARM microprocessor GD32F103CGT6 as the main controller, replacing the traditional 8-bit single-chip microcomputer, improving the real-time performance and control performance of the entire circuit. Second, an isolation circuit module is added, making the signal transmission more reliable and improving the reliability of the output signal. Third, a feedback module is added, improving the accuracy of the output signal.

[0006] The main controller module is a high-performance 32-bit ARM processor, with the model of GD32F103CGT6. The processor has a built-in Flash memory of 128K bytes and an SRAM of 20K bytes.

[0007] The isolation module is based on an optocoupler isolator and is used to isolate the signal transmission between the three-phase inverter control circuit and the three-phase inverter power amplifier circuit.

[0008] The voltage feedback measurement module mainly includes a voltage acquisition circuit of a voltage transformer, and the current feedback measurement module mainly includes a current detection circuit of a current transformer and an LM358 amplifier.

[0009] The frequency measurement feedback module mainly includes a frequency feedback acquisition circuit of an LM358 amplifier. The temperature measurement module is mainly connected by a DS18B20 chip and a main control chip. The filtering module is mainly composed of an RC filtering circuit.

[0010] The beneficial effects of the present utility model mainly include three aspects: First, a 32-bit ARM microprocessor is used to replace the traditional 8-bit single-chip microcomputer, improving the real-time performance and performance of the entire circuit. Second, an isolation circuit module is added, making the signal transmission between the two chips more reliable and improving the reliability of the output signal. Third, voltage, current, frequency feedback modules and a temperature detection module are added, improving the accuracy of the output signal. Description of the Drawings

[0011] Figure 1 It is a schematic diagram of the overall structure of the present utility model.

[0012] Figure 2 It is a circuit diagram of the three-phase inverter main control module of the present utility model.

[0013] Figure 3 It is a circuit diagram of the three-phase inverter power amplifier of the present utility model.

[0014] Figure 4 It is a voltage feedback measurement circuit of the present utility model.

[0015] Figure 5 It is a current feedback measurement circuit of the present utility model.

[0016] Figure 6 It is a frequency measurement feedback circuit of the present utility model.

[0017] Figure 7 It is a temperature detection circuit of the present utility model. Detailed Embodiments

[0018] The present utility model will be further described in detail below in conjunction with the drawings and specific embodiments.

[0019] See Figure 1, which is the overall structural schematic diagram of the utility model. It mainly includes a main control module, an isolation circuit module, a filtering module, a three-phase inverter bridge circuit module, a voltage feedback measurement module, a current feedback measurement module, a frequency measurement feedback module, and an inverter circuit temperature detection module. The utility model uses GD32F103CGT6 as the control chip of the main circuit. Based on the three-phase inverter circuit, a voltage, current, frequency feedback module and a temperature detection module are added on the basis of adding a filtering module and an isolation module, ensuring the reliability and accuracy of the output signal.

[0020] The working process of the utility model is as follows: The main control chip outputs three pairs of high and low channel complementary control signals to the circuit. After being processed by optocoupler isolation, RC filtering, etc. successively, three motor signals are finally output. The PWM signal output by the three-phase inverter bridge circuit can detect the magnitude of the voltage and current of the output signal, the accuracy of the frequency, and the temperature change of the inverter circuit through the feedback circuit. Finally, the measured feedback signal is fed back to the main control chip.

[0021] See Figure 2 , which is the schematic diagram of the three-phase inverter control circuit of this embodiment. Three pairs of high and low channel complementary control signals are output through six IO ports, and the operation of the entire circuit can be controlled through the main control chip, and the signals fed back by each feedback circuit can be received and processed.

[0022] See Figure 3 , which is the schematic diagram of the three-phase inverter power amplifier circuit of this embodiment. The control signal transmitted from the main control chip first passes through an optocoupler isolator and an RC filter circuit, and finally outputs a PWM signal through the three-phase inverter bridge circuit.

[0023] See Figure 4 , which is the schematic diagram of the voltage feedback detection circuit of this embodiment. A voltage transformer chip is used, and the function of this chip is to convert the voltage in the circuit into a measurable value one-to-one.

[0024] See Figure 5 , which is the schematic diagram of the current feedback detection circuit of this embodiment. A current transformer and an LM358 amplifier chip are used. First, it is converted into a measurable small current through the current transformer, and then amplified by LM358 to make it easier to detect the current.

[0025] See Figure 6 , which is the circuit diagram of the frequency measurement feedback of this embodiment. The output PWM signal passes through a frequency acquisition circuit mainly composed of an LM358 amplifier, and finally the acquired signal is sent to the main control chip for processing to obtain the frequency of the PWM output signal.

[0026] Participate Figure 7, which is the temperature detection circuit of the present utility model. The DS18B20 chip is connected to the main control chip and is used to measure the temperature of the inverter circuit.

[0027] The above embodiments are only used to illustrate the working principle and functions of the present utility model and do not limit the present utility model.

Claims

1. A three-phase inverter circuit with feedback and isolation for use in a safety tester, characterized in that: It includes a main control module, an isolation circuit, a filtering module, a three-phase inverter bridge circuit, a voltage feedback measurement module, a current feedback measurement module, a frequency feedback measurement module, and an inverter circuit temperature detection module. The main control module is connected to the isolation circuit module, the isolation circuit is connected to the filtering module, the filtering module is connected to the three-phase inverter bridge circuit, the voltage feedback measurement module, the frequency feedback measurement module, the current feedback measurement module, and the inverter circuit temperature detection module are respectively connected to the three-phase inverter bridge circuit and fed back to the main control module.

2. A three-phase inverter circuit with feedback and isolation for use in a safety tester according to claim 1, characterized in that: The main control module is a high-performance 32-bit ARM processor, whose model is GD32F103CGT6. The processor has a built-in 128K-byte Flash memory and a 20K-byte SRAM.

3. A three-phase inverter circuit with feedback and isolation for use in a safety tester according to claim 1, characterized in that: The isolation circuit is based on an optical coupler isolator and is used to isolate the signal transmission between the three-phase inverter control circuit and the three-phase inverter bridge circuit.

4. A three-phase inverter circuit with feedback and isolation for use in a safety tester according to claim 1, characterized in that: The filtering module is composed of an RC filtering circuit.

5. The three-phase inverter circuit with feedback and isolation for use in a safety tester according to claim 1, characterized in that: The voltage feedback measurement module includes a voltage feedback acquisition circuit of a voltage transformer, and the current feedback measurement module includes a current feedback detection circuit composed of a current transformer and an LM358 amplifier.

6. A three-phase inverter circuit with feedback and isolation for use in a safety tester according to claim 1, characterized in that: The operational amplifier used in the frequency feedback measurement module is the LM358 amplifier.

7. A three-phase inverter circuit with feedback and isolation for use in a safety tester according to claim 1, characterized in that: The temperature sensor used in the inverter circuit temperature measurement module is a DS18B20 chip.

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