Low-voltage frequency conversion control cabinet circuit capable of automatically switching faults

Abstract

A low-voltage frequency conversion control cabinet circuit capable of automatically switching faults is characterized in that one end of a change-over switch SA1 is connected with an input end, the other end of the change-over switch SA1 is respectively provided with a conduction end of a contactor KA3, a conduction end of a contactor KA6 and a conduction end of an intermediate relay KT, the conduction end of the contactor KA3 is connected with a coil end of the intermediate relay KT, and the conduction end of the contactor KA3 is connected with a coil end of the intermediate relay KT; the conduction end of the intermediate relay KT is connected with the coil end of the intermediate relay KA, the switch SF1 is further connected with the coil end of an intermediate relay KA1, and the conduction end of the intermediate relay KA1 is connected with the control end of the first frequency converter. One end of the change-over switch SA2 is connected with the input end, the switch SF2 is connected with the coil end of an intermediate relay KA4, the conducting end of the intermediate relay KA4 is connected with the control end of the second frequency converter, one end of the conducting end of the intermediate relay KA is connected with the change-over switch SA2, the other end of the conducting end of the intermediate relay KA is connected with the coil end of the intermediate relay KA4, one end of the conducting end of the intermediate relay KA is connected with the change-over switch SA1, and the other end of the conducting end of the intermediate relay KA is connected with the control end of the second frequency converter. And the other end is connected with the coil end of the intermediate relay KA1.

Description

Technical Field

[0001] This utility model relates to the field of frequency converter cabinets, and in particular to a low-voltage frequency converter control cabinet circuit with automatic fault switching. Background Technology

[0002] The current inverter control circuit scheme is only a single inverter circuit, which realizes the functions of manual / automatic switching and remote control start, but there is no second inverter circuit as a backup inverter circuit in case of failure of the primary inverter. The existing inverter control circuit lacks fault tolerance for inverter failure. When the inverter controlling the motor operation fails, the entire motor circuit loses its working ability, affecting work efficiency. Utility Model Content

[0003] To address the aforementioned issues, this technical solution provides a low-voltage frequency converter control cabinet circuit with automatic fault switching.

[0004] To achieve the above objectives, the technical solution is as follows:

[0005] A low-voltage variable frequency control cabinet circuit with automatic fault switching includes a switching switch SA1 and a switching switch SA2. One end of the switching switch SA1 is connected to the input terminal, and the other end is respectively provided with the conducting terminal of contactor KA3, the conducting terminal of contactor KA6, and the conducting terminal of intermediate relay KT. The conducting terminals of contactor KA3 and contactor KA6 are connected together and then connected to the coil terminal of intermediate relay KT. The conducting terminal of intermediate relay KT is connected to the coil terminal of intermediate relay KA1. The other end of the switching switch SA1 is provided with a switch SS1 and a switch SF1 in sequence. The switch SF1 is also connected to the coil terminal of intermediate relay KA1. The conducting terminal of intermediate relay KA1 is connected to the control terminal of a first frequency converter.

[0006] One end of the switching switch SA2 is connected to the input terminal, and the other end is sequentially equipped with switch SS2 and switch SF2. Switch SF2 is connected to the coil terminal of intermediate relay KA4. The conducting terminal of intermediate relay KA4 is connected to the control terminal of the second frequency converter. One end of the conducting terminal of intermediate relay KA is connected to the switching switch SA2, and the other end is connected to the coil terminal of intermediate relay KA4. One end of the conducting terminal of intermediate relay KA is connected to the switching switch SA1, and the other end is connected to the coil terminal of intermediate relay KA1.

[0007] In some embodiments, a receiving unit 1AT connected to the input terminal for receiving a first inverter fault signal is also included. The receiving unit 1AT is connected to an indicator light HR1 and an indicator light HY1, respectively.

[0008] In some embodiments, a receiving unit 2AT connected to the input terminal for receiving a second inverter fault signal is also included. The receiving unit 2AT is connected to an indicator light HR2 and an indicator light HY2, respectively.

[0009] In some embodiments, the input terminal is connected to indicator lights HW, HW1, and HW2, respectively.

[0010] The beneficial effects of this application are:

[0011] This application adds an N+1th inverter control loop, namely a backup inverter control loop. This one-in-one-outverter inverter control scheme significantly improves fault tolerance. When the primary inverter control loop fails, only the faulty inverter is isolated, and the backup inverter control loop can quickly take over to ensure the normal operation of the motor. The main equipment can operate alternately, avoiding long-term full-load operation of a single device, reducing wear and tear, and extending service life. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0013] Figure 1 This is a schematic diagram of the electrical structure of an embodiment of this utility model;

[0014] Figure 2 This is a schematic diagram of the inverter structure according to an embodiment of the present utility model;

[0015] Figure 3 This is a schematic diagram of the control logic of an embodiment of the present invention. Detailed Implementation

[0016] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0017] Please refer to Figure 1-3As shown, a low-voltage frequency converter control cabinet circuit with automatic fault switching includes a switching switch SA1 and a switching switch SA2. One end of the switching switch SA1 is connected to the input terminal, and the other end is respectively provided with the conducting terminal of contactor KA3, the conducting terminal of contactor KA6, and the conducting terminal of intermediate relay KT. The conducting terminals of contactor KA3 and contactor KA6 are connected together and then connected to the coil terminal of intermediate relay KT. The conducting terminal of intermediate relay KT is connected to the coil terminal of intermediate relay KA1. The other end of the switching switch SA1 is provided with a switch SS1 and a switch SF1 in sequence. The switch SF1 is also connected to the coil terminal of intermediate relay KA1. The conducting terminal of intermediate relay KA1 is connected to the control terminal of the first frequency converter.

[0018] One end of the switching switch SA2 is connected to the input terminal, and the other end is sequentially equipped with switch SS2 and switch SF2. Switch SF2 is connected to the coil terminal of intermediate relay KA4. The conducting terminal of intermediate relay KA4 is connected to the control terminal of the second frequency converter. One end of the conducting terminal of intermediate relay KA is connected to the switching switch SA2, and the other end is connected to the coil terminal of intermediate relay KA4. One end of the conducting terminal of intermediate relay KA is connected to the switching switch SA1, and the other end is connected to the coil terminal of intermediate relay KA1.

[0019] This application utilizes a changeover switch to achieve three inverter control modes: manual, automatic, and standby. Two power indicator lights are installed in the inverter control circuit. When the inverter is operating, the running indicator light in the circuit illuminates; when a fault occurs in the inverter, the fault contact closes, and the fault indicator light illuminates.

[0020] When the selector switch is switched to manual mode, the inverter cabinet is equipped with start and stop buttons, and the motor field control box can also be equipped with start and stop buttons, which can be used to manually control the motor operation.

[0021] When the first motor selector switch is switched to automatic mode, the second standby motor is switched to standby mode. If the first motor malfunctions, the KA3 coil is energized and engages, simultaneously energizing the time relay. After a 30-second delay, the time relay KT closes, energizing the KA coil. At this point, the second motor is in standby mode. Once the KA coil is energized and closes, the KA4 switch, which controls the frequency converter start of the second motor, is energized and engages, automatically starting the second motor and ensuring reliable power supply. The reverse is also true. The selector switch and motor operation / stop status can also be connected to the backend for remote monitoring.

[0022] In this embodiment, a receiving unit 1AT connected to the input terminal for receiving the first inverter fault signal is also included. The receiving unit 1AT is connected to an indicator light HR1 and an indicator light HY1.

[0023] In this embodiment, a receiving unit 2AT connected to the input terminal for receiving fault signals from the second frequency converter is also included. The receiving unit 2AT is connected to indicator lights HR2 and HY2 respectively.

[0024] In this embodiment, the input terminal is connected to indicator lights HW, HW1, and HW2, respectively.

[0025] The above description is only a preferred embodiment of this application and is not intended to limit the scope of implementation of this application. Any other embodiments whose principles and basic structures are the same as or similar to those of this application are within the protection scope of this application.

Claims

1. A low-voltage frequency converter control cabinet circuit with automatic fault switching, characterized in that, The system includes a switching switch SA1 and a switching switch SA2. One end of the switching switch SA1 is connected to the input terminal, and the other end is respectively provided with the conducting terminal of contactor KA3, the conducting terminal of contactor KA6, and the conducting terminal of intermediate relay KT. The conducting terminals of contactor KA3 and contactor KA6 are connected together and then connected to the coil terminal of intermediate relay KT. The conducting terminal of intermediate relay KT is connected to the coil terminal of intermediate relay KA1. The other end of the switching switch SA1 is provided with a switch SS1 and a switch SF1 in sequence. The switch SF1 is also connected to the coil terminal of intermediate relay KA1. The conducting terminal of intermediate relay KA1 is connected to the control terminal of the first frequency converter. One end of the switching switch SA2 is connected to the input terminal, and the other end is sequentially equipped with switch SS2 and switch SF2. Switch SF2 is connected to the coil terminal of intermediate relay KA4. The conducting terminal of intermediate relay KA4 is connected to the control terminal of the second frequency converter. One end of the conducting terminal of intermediate relay KA is connected to the switching switch SA2, and the other end is connected to the coil terminal of intermediate relay KA4. One end of the conducting terminal of intermediate relay KA is connected to the switching switch SA1, and the other end is connected to the coil terminal of intermediate relay KA1.

2. The low-voltage frequency converter control cabinet circuit with automatic fault switching according to claim 1, characterized in that: It also includes a receiving unit 1AT connected to the input terminal for receiving fault signals from the first frequency converter. The receiving unit 1AT is connected to indicator lights HR1 and HY1 respectively.

3. The low-voltage frequency converter control cabinet circuit with automatic fault switching according to claim 2, characterized in that: It also includes a receiving unit 2AT connected to the input terminal for receiving fault signals from the second frequency converter. The receiving unit 2AT is connected to indicator lights HR2 and HY2 respectively.

4. The low-voltage frequency converter control cabinet circuit with automatic fault switching according to claim 1, characterized in that: The input terminals are respectively connected to indicator lights HW, HW1, and HW2.

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