Frequency converter control circuit

Abstract

The utility model discloses a frequency converter control circuit, comprising a rectification circuit, a power supply inversion circuit module, a power supply voltage reduction circuit, an MCU control unit, an inversion driving circuit module, a current feedback detection circuit and a temperature sampling circuit, the rectification circuit is externally connected with a 220V AC power supply and is used for converting an input 220V AC voltage into a 311V DC voltage, the power supply inversion circuit module is connected with the inversion driving circuit module, and the power supply voltage reduction circuit is connected with the MCU control unit. The power supply inverter circuit module is connected with the output end of the rectifying circuit and used for outputting an inverter power supply, the power supply step-down circuit is connected with the output end of the rectifying circuit, the MCU control unit is connected with the output end of the power supply step-down circuit, and the temperature sampling circuit is arranged adjacent to the IGBT module of the power supply inverter circuit module and used for collecting temperature signals of the IGBT module of the power supply inverter circuit module. And the temperature sampling circuit is in signal connection with the MCU control unit and is used for transmitting a collected temperature signal to the MCU control unit. The utility model has the advantages that under-voltage, over-current and overload protection can be carried out on the circuit, temperature information can be acquired, and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of frequency converters, and particularly relates to a frequency converter control circuit. Background Art

[0002] A frequency converter is a power control device that applies frequency conversion technology and microelectronics technology to control an AC motor by changing the working power frequency of the motor. Most existing frequency converters use a fault protection circuit to cut off power in case of a power supply fault during operation to improve work safety. However, the set fault protection circuit may only have single-layer feedback and cannot ensure the work safety of the frequency converter.

[0003] For example, patent application No. 202322244067.7 discloses a frequency converter circuit. The frequency converter control circuit includes: a power supply module, an electric energy detection module, a power supply detection module, a frequency conversion module, an output module, an electric energy control module, an overvoltage judgment module, and an energy storage control module; the power supply module is used to provide three-phase electric energy and perform three-phase rectification processing on the three-phase electric energy for outputting DC electric energy; the electric energy detection module is connected to the power supply module and is used to isolate and detect the electric energy state of the three-phase electric energy provided by the power supply module and output a first control signal when power is off; the power supply detection module is connected to the power supply module and is used to perform overvoltage judgment on the DC electric energy output by the power supply module and output a second control signal when overvoltage occurs; the frequency conversion module is connected to the power supply module and is used to perform inversion and frequency conversion adjustment processing on the electric energy output by the power supply module and output AC electric energy; the output module is connected to the frequency conversion module and is used to connect to motor equipment and receive the electric energy output by the frequency conversion module; the electric energy control module is connected to the power supply detection module, the electric energy detection module, the power supply module, and the frequency conversion module and is used to receive the first control signal and the second control signal and trigger the operation of the electric energy control circuit, and is used to perform voltage division processing and electric energy storage on the DC electric energy output by the power supply module and the braking electric energy generated by the frequency conversion module through the electric energy control circuit, and is used to perform overvoltage judgment processing on the voltage-divided electric energy and cut off power when overvoltage occurs; the overvoltage judgment module is connected to the electric energy control module and is used to judge whether the electric energy stored in the electric energy control module exceeds a set voltage threshold and output a third control signal when it exceeds; the energy storage control module is connected to the electric energy control module and the overvoltage judgment module and is used to control the energy storage control circuit to store the voltage-divided electric energy of the electric energy control module through the third control signal. This frequency converter control circuit performs specific control through setting multi-layer detection, and the circuit structure is relatively complex. Summary of the Utility Model

[0004] In order to solve the deficiencies in the prior art, the utility model provides a frequency converter control circuit with a multiple feedback circuit for multiple protections.

[0005] To solve the above technical problems, the utility model adopts the following technical solutions:

[0006] A frequency converter control circuit, comprising:

[0007] A rectification circuit, externally connected to a 220V AC power supply and used for converting the input 220V AC voltage into a 311V DC voltage;

[0008] A power inverter circuit module, connected to the output end of the rectification circuit and used for inverting the power output;

[0009] A power step-down circuit, connected to the output end of the rectification circuit;

[0010] An MCU control unit, connected to the output end of the power step-down circuit;

[0011] An inverter drive circuit module, the electrical input end of the inverter drive circuit module is connected to the output end of the power step-down circuit, the signal input end of the inverter drive circuit module is connected to the MCU control unit, the signal output end of the inverter drive circuit module is connected to the power inverter circuit module, the MCU control unit is used for outputting a low-voltage control signal to the inverter drive circuit module, and the inverter drive circuit module is used for converting the received low-voltage control signal into a high-voltage signal and transmitting it to the power inverter circuit module;

[0012] A current feedback detection circuit, connected to the power inverter circuit module and used for collecting an inverter voltage signal and a current signal, the current feedback detection circuit is signal-connected to the MCU control unit, and the current feedback detection circuit is also used for transmitting the collected inverter voltage signal and current signal to the MCU control unit; and

[0013] A temperature sampling circuit, arranged adjacent to the IGBT module of the power inverter circuit module and used for collecting the temperature signal of the IGBT module of the power inverter circuit module, the temperature sampling circuit is signal-connected to the MCU control unit and used for transmitting the collected temperature signal to the MCU control unit.

[0014] Preferably, the current feedback detection circuit includes an undervoltage protection circuit and a current sampling circuit, the undervoltage protection circuit is connected to the power inverter circuit module and used for collecting an inverter voltage signal, the undervoltage protection circuit is signal-connected to the MCU control unit, and the undervoltage protection circuit is also used for transmitting the collected inverter voltage signal to the MCU control unit for undervoltage protection;

[0015] The current sampling circuit is connected to the power inverter circuit module and is used to collect current signals. The current sampling circuit is signal-connected to the MCU control unit, and the current sampling circuit is also used to transmit the collected current signals to the MCU control unit for overloading or overcurrent protection.

[0016] Preferably, the power supply buck circuit includes a DC high-voltage transformer, and the DC high-voltage transformer is respectively connected to the rectifier circuit, the inverter drive circuit module and the MCU control unit.

[0017] Preferably, the MCU control unit is connected to a communication circuit module through a UART module.

[0018] Adopting the above technical solutions, the present utility model has the following beneficial effects:

[0019] (1) The present utility model is provided with circuits such as a current sampling circuit, an undervoltage protection circuit, and a temperature sampling circuit, which can protect the circuit against undervoltage, overcurrent, and overload, etc., and can protect the safety of the frequency converter. Moreover, the temperature sampling circuit can also collect temperature signals, collect the temperature of the IGBT module of the power inverter circuit module, and collect temperature information in a timely manner for further protection;

[0020] (2) The present utility model optimizes the circuit design, reduces costs, improves the performance and stability of the frequency converter, facilitates subsequent control of the motor, and the present utility model has good communication functions and is convenient for communication control;

[0021] In summary, the present utility model has the advantages of being able to protect the circuit against undervoltage, overcurrent, and overload, etc., and being able to collect temperature information, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is the control block diagram of the frequency converter control circuit of the present utility model;

[0023] Figure 2 is the circuit schematic diagram of the rectifier circuit of the present utility model;

[0024] Figure 3 is the circuit schematic diagram of the power supply buck circuit of the present utility model;

[0025] Figure 4 is a partial circuit schematic diagram of the MCU control unit of the present utility model;

[0026] Figure 5 is another partial circuit schematic diagram of the MCU control unit of the present utility model;

[0027] Figure 6 is a partial circuit schematic diagram of the inverter drive circuit module of the present utility model;

[0028] Figure 7 It is another part of the circuit schematic diagram of the inverter drive circuit module of the present utility model;

[0029] Figure 8 It is yet another part of the circuit schematic diagram of the inverter drive circuit module of the present utility model;

[0030] Figure 9 It is yet another part of the circuit schematic diagram of the inverter drive circuit module of the present utility model;

[0031] Figure 10 It is yet another part of the circuit schematic diagram of the inverter drive circuit module of the present utility model;

[0032] Figure 11 It is the circuit schematic diagram of the undervoltage protection circuit of the present utility model;

[0033] Figure 12 It is the circuit schematic diagram of the current sampling circuit of the present utility model;

[0034] Figure 13 It is the circuit schematic diagram of the temperature sampling circuit of the present utility model. Detailed implementation manners

[0035] Next, the technical solutions of the present utility model will be described clearly and completely in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of the embodiments.

[0036] Generally, the components of the embodiments of the present utility model described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the claimed present utility model, but merely represents the selected embodiments of the present utility model.

[0037] Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present utility model.

[0038] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0039] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0040] Embodiment 1

[0041] In this embodiment, an inverter control circuit is proposed, which has undervoltage, overcurrent, and overload protection functions, and can also collect the temperature of the IGBT module of the power inverter circuit module, facilitating the timely collection of temperature information for further protection.

[0042] Such as Figure 1 And Figure 2As shown in the figure, in an embodiment of the present utility model, the frequency converter control circuit of the present utility model includes a rectification circuit 10, a power inverter circuit module 20, a power step-down circuit 30, an MCU control unit 40, an inverter drive circuit module 50, a current feedback detection circuit 60, and a temperature sampling circuit. Among them, the rectification circuit 10 is externally connected to a 220V AC power supply and is used to convert the input 220V AC voltage into a 311V DC voltage. The 220V AC power supply outputs a DC power supply after passing through the rectification circuit 10, providing an input power supply for the subsequent power step-down circuit 30 and the power inverter circuit module 20. The rectification circuit 10 includes at least one rectifier bridge. The power inverter circuit module 20 is connected to the output end of the rectification circuit 10 and is used for inverting the power output. The power step-down circuit 30 is connected to the output end of the rectification circuit 10. The power step-down circuit 30 includes a DC high-voltage transformer, and the DC high-voltage transformer is respectively connected to the rectification circuit 10, the inverter drive circuit module 50, and the MCU control unit 40. The DC high-voltage transformer steps down the high-voltage DC and outputs the DC voltage required by the inverter drive circuit module 50 and the MCU control unit 40 of the present utility model. Moreover, through the change of DC-DC, the DC high-voltage transformer provides relevant power supplies for the MCU control unit 40 and the inverter drive circuit module 50 to use. The MCU control unit 40 is connected to the output end of the power step-down circuit 30. The electrical input end of the inverter drive circuit module 50 is connected to the output end of the power step-down circuit 30. The signal input end of the inverter drive circuit module 50 is connected to the MCU control unit 40. The signal output end of the inverter drive circuit module 50 is connected to the power inverter circuit module 20. The MCU control unit 40 is used to output a low-voltage control signal to the inverter drive circuit module 50. The inverter drive circuit module 50 is used to convert the received low-voltage control signal into a high-voltage signal and transmit it to the power inverter circuit module 20. The MCU control unit 40 is connected to a communication circuit module through a UART module;

[0043] Specifically, the MCU control unit 40 can perform human-computer interaction with the user of the present utility model through the communication circuit module, perform calculations through the relevant operations of the user, output the low-voltage control signal (vector signal) required by the inverter drive circuit module 50 to the inverter drive circuit module 50, and the inverter drive circuit module 50 then outputs a high-voltage signal to the power inverter circuit module 20 (inverter circuit), thereby completing the inversion process of converting direct current into alternating current;

[0044] The current feedback detection circuit 60 of the present utility model is connected to the power inverter circuit module 20 and is used to collect the inverter voltage signal and the current signal. The current feedback detection circuit 60 is signal-connected to the MCU control unit 40. The current feedback detection circuit 60 is also used to transmit the collected inverter voltage signal and current signal to the MCU control unit 40. Specifically, the current feedback detection circuit 60 includes an undervoltage protection circuit and a current sampling circuit. The undervoltage protection circuit is connected to the power inverter circuit module 20 and is used to collect the inverter voltage signal. The undervoltage protection circuit is signal-connected to the MCU control unit 40. The undervoltage protection circuit is also used to transmit the collected inverter voltage signal to the MCU control unit 40 for undervoltage protection. The current sampling circuit is connected to the power inverter circuit module 20 and is used to collect the current signal. The current sampling circuit is signal-connected to the MCU control unit 40. The current sampling circuit is also used to transmit the collected current signal to the MCU control unit 40 for overload or overcurrent protection.

[0045] The temperature sampling circuit of the present utility model is disposed adjacent to the IGBT module of the power inverter circuit module 20 and is used to collect the temperature signal of the IGBT module of the power inverter circuit module 20. The temperature sampling circuit is signal-connected to the MCU control unit 40 and is used to transmit the collected temperature signal to the MCU control unit 40. The temperature sampling circuit specifically includes an NTC thermistor. By placing the NTC thermistor close to the IGBT module, temperature information can be collected, and further protection can be achieved. In the present utility model, the MCU control unit 40 performs feedback sampling of the voltage and current of the power inverter circuit module 20, monitors the working state of the frequency converter, and adjusts or shuts down the abnormal working state to ensure the working safety of modules such as the inverter drive circuit module 50. The MCU control unit 40 of the present utility model can select the TMS320F28034 chip.

[0046] This embodiment does not impose any formal restrictions on the shape, material, structure, etc. of the present utility model. Any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present utility model all fall within the protection scope of the technical solution of the present utility model.

Claims

1. Inverter control circuit, characterized in that, Comprising: A rectification circuit, externally connected to a 220V AC power supply and used to convert the input 220V AC voltage into a 311V DC voltage; A power inverter circuit module, connected to the output terminal of the rectification circuit and used for inverting the power output; A power step-down circuit, connected to the output terminal of the rectification circuit; An MCU control unit, connected to the output terminal of the power step-down circuit; An inverter drive circuit module, the electrical input terminal of the inverter drive circuit module is connected to the output terminal of the power step-down circuit, the signal input terminal of the inverter drive circuit module is connected to the MCU control unit, the signal output terminal of the inverter drive circuit module is connected to the power inverter circuit module, the MCU control unit is used to output a low-voltage control signal to the inverter drive circuit module, and the inverter drive circuit module is used to convert the received low-voltage control signal into a high-voltage signal and transmit it to the power inverter circuit module; A current feedback detection circuit, connected to the power inverter circuit module and used to collect the inverter voltage signal and current signal, the current feedback detection circuit is signal-connected to the MCU control unit, and the current feedback detection circuit is also used to transmit the collected inverter voltage signal and current signal to the MCU control unit; and A temperature sampling circuit, arranged adjacent to the IGBT module of the power inverter circuit module and used to collect the temperature signal of the IGBT module of the power inverter circuit module, the temperature sampling circuit is signal-connected to the MCU control unit and used to transmit the collected temperature signal to the MCU control unit.

2. The frequency converter control circuit according to claim 1, characterized in that: The current feedback detection circuit includes an undervoltage protection circuit and a current sampling circuit, the undervoltage protection circuit is connected to the power inverter circuit module and used to collect the inverter voltage signal, the undervoltage protection circuit is signal-connected to the MCU control unit, and the undervoltage protection circuit is also used to transmit the collected inverter voltage signal to the MCU control unit for undervoltage protection; The current sampling circuit is connected to the power inverter circuit module and used to collect the current signal, the current sampling circuit is signal-connected to the MCU control unit, and the current sampling circuit is also used to transmit the collected current signal to the MCU control unit for overloading or overcurrent protection.

3. The frequency converter control circuit according to claim 1, wherein: The power step-down circuit includes a DC high-voltage transformer, and the DC high-voltage transformer is respectively connected to the rectification circuit, the inverter drive circuit module and the MCU control unit.

4. The frequency converter control circuit according to claim 1, wherein: The MCU control unit is connected to a communication circuit module through a UART module.

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