Anti-interference electricity motor control circuit
By using an anti-power fluctuation motor control circuit, which combines time relays and intermediate relays, the problem of motor shutdown under power fluctuation conditions is solved, ensuring stable motor operation and avoiding production accidents and increased costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGXI TELLHOW INTELLIGENT POWER TECH CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-05-08
AI Technical Summary
Existing anti-power fluctuation devices increase costs for businesses when there are many motors, and cannot effectively prevent motors from stopping under power fluctuation conditions.
A motor control circuit designed to prevent voltage fluctuations is adopted, which uses a time relay to control the coordination of a contactor and an intermediate relay to ensure that the motor can still start normally when the mains voltage is momentarily interrupted.
It effectively prevents the motor from stopping under power fluctuations, avoiding production accidents and economic losses, while also saving costs.
Smart Images
Figure CN224218305U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of power systems, and in particular to a motor control circuit for preventing power fluctuations. Background Technology
[0002] Voltage fluctuations are a common phenomenon in power systems, typically manifesting as momentary drops or brief interruptions in grid voltage, followed by a rapid return to normal. Current solutions primarily involve using anti-voltage fluctuation devices, employing dedicated modules to hold and control contactors, thereby enhancing the circuit's resistance to voltage fluctuations. While anti-voltage fluctuation devices effectively solve the problem, they increase costs for businesses, especially when dealing with a large number of motors. Utility Model Content
[0003] To solve the above problems, this technical solution provides a motor control circuit to prevent power fluctuations.
[0004] To achieve the above objectives, the technical solution is as follows:
[0005] A motor control circuit for preventing voltage fluctuations includes an input switch QF, one end of which receives voltage and the other end is connected to the conducting terminal of a contactor KM. The conducting terminal of the contactor KM is connected to the motor M through the coil terminal of a thermal relay KH.
[0006] One end of the coil of the contactor KM is connected to phase N, and the other end is connected to phase L in sequence through the normally closed terminal of the thermal relay KH, the normally closed terminal of the intermediate relay TJ, and the normally open terminal of the time relay KT. The normally open terminal of the time relay KT is connected in parallel with the normally open terminal of the contactor KM.
[0007] It also includes an intermediate relay HJ, the coil terminal of which is connected in parallel with the coil terminal of the time relay KT. One end of the coil terminal of the intermediate relay HJ is connected to the negative terminal of the power supply, and the other end is connected to the positive terminal of the power supply through the button HA and the conducting terminal of the contactor KM respectively.
[0008] One end of the coil of the intermediate relay TJ is connected to the negative terminal of the power supply, and the other end is connected to the positive terminal of the power supply through the button TA. The other end is also connected to the positive terminal of the power supply through the normally open terminal of the intermediate relay TJ and the normally open terminal of the time relay KT in sequence.
[0009] In some embodiments, one normally open terminal of the intermediate relay HJ is connected to the positive terminal of the power supply, and the other terminal is connected to the negative terminal of the power supply via an indicator light HD.
[0010] In some embodiments, one end of the normally closed terminal of the intermediate relay HJ is connected to the positive terminal of the power supply, and the other end is connected to the negative terminal of the power supply through an indicator light LD.
[0011] In some embodiments, a fuse FU connected to phase L is also included.
[0012] In some embodiments, the system further includes fuses FU1 and FU2 connected to the power supply.
[0013] The beneficial effects of this application are:
[0014] This application can effectively address the problem of power fluctuations by using time relay control, preventing production accidents, avoiding unnecessary economic losses, and effectively saving costs. Attached Figure Description
[0015] 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.
[0016] Figure 1 This is a schematic diagram of the main circuit structure of an embodiment of this utility model;
[0017] Figure 2 This is a schematic diagram of the circuit structure of an embodiment of the present utility model. Figure 1 ;
[0018] Figure 3 This is a schematic diagram of the circuit structure of an embodiment of the present utility model. Figure 2 . Detailed Implementation
[0019] 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.
[0020] Please refer to Figure 1-3 As shown, a motor control circuit for preventing voltage fluctuation includes an input switch QF. One end of the input switch QF receives voltage, and the other end is connected to the conducting end of a contactor KM. The conducting end of the contactor KM is connected to the motor M through the coil end of a thermal relay KH.
[0021] One end of the coil of the contactor KM is connected to phase N, and the other end is connected to phase L in sequence through the normally closed terminal of the thermal relay KH, the normally closed terminal of the intermediate relay TJ, and the normally open terminal of the time relay KT. The normally open terminal of the time relay KT is connected in parallel with the normally open terminal of the contactor KM.
[0022] It also includes an intermediate relay HJ, the coil terminal of which is connected in parallel with the coil terminal of the time relay KT. One end of the coil terminal of the intermediate relay HJ is connected to the negative terminal of the power supply, and the other end is connected to the positive terminal of the power supply through the button HA and the conducting terminal of the contactor KM respectively.
[0023] One end of the coil of the intermediate relay TJ is connected to the negative terminal of the power supply, and the other end is connected to the positive terminal of the power supply through the button TA. The other end is also connected to the positive terminal of the power supply through the normally open terminal of the intermediate relay TJ and the normally open terminal of the time relay KT in sequence.
[0024] In this embodiment, one end of the normally open terminal of the intermediate relay HJ is connected to the positive terminal of the power supply, and the other end is connected to the negative terminal of the power supply through the indicator light HD.
[0025] In this embodiment, one end of the normally closed terminal of the intermediate relay HJ is connected to the positive terminal of the power supply, and the other end is connected to the negative terminal of the power supply through the indicator light LD.
[0026] In this embodiment, a fuse FU connected to phase L is also included.
[0027] In this embodiment, fuses FU1 and FU2 connected to the power supply are also included.
[0028] This application relates to a motor control circuit for preventing power fluctuations, which is intended to address the need for motors to remain running even when power is fluctuating. For example, in chemical and mining production, short-term interruptions in grid voltage can cause a large number of motors to trip and equipment to stop. After the voltage is restored, the motors may not be able to start automatically, potentially leading to major production and equipment accidents and resulting in huge economic losses.
[0029] The main circuit schematic diagram of the motor control circuit for the anti-voltage flickering method in this application is as follows: Figure 1 As shown in the diagram. QF is the incoming line switch, KM is the AC contactor, KH is the thermal relay, and M is the motor. The control circuit schematic of this utility model is as follows: Figure 2 , Figure 3 As shown, FU, FU1, and FU2 are fuses, KT is a time relay (power-off delay; normally open contacts 3 / 4 and 5 / 6 of KT are power-off delay disconnect contacts), HJ and TJ are intermediate relays, and HD and LD are indicator lights. Figure 2 The control power supply L11 is taken from the lower output side of the incoming line switch QF. Figure 3 The control power supply is taken from an external power source.
[0030] During normal operation, QF is closed. Pressing the start button HA energizes the HJ and KT coils, closing the normally open contact of KT and energizing the KM coil, thus starting the motor. Simultaneously, the normally open contact of KM closes for self-locking, the normally open contact of HJ closes, and the running indicator HD illuminates. To stop the motor, pressing the stop button TA energizes the TJ coil, closing its normally open contact and opening its normally closed contact, de-energizing the KM coil and stopping the motor. Simultaneously, the HJ coil de-energizes, and the stop indicator LD illuminates.
[0031] When the start button HA is pressed, the motor is in normal operating condition. At this time, a power fluctuation occurs, and the mains voltage is briefly interrupted, meaning the control power supply L11 suddenly disappears. The KM coil loses power, the KM contact self-locking fails, and the HJ coil loses power. At this time, the normally open contact of HJ opens after a delay of t1 (the delay time t1 is adjustable and can be set according to specific circumstances). During the time t1, the normally open contact of HJ remains closed. Figure 2 When the control circuit of the KM coil is in the ON state, when the grid voltage recovers within time t1, that is, when the control power supply L11 recovers within time t1, the KM coil is energized at the moment of recovery, and the motor can still start working at the moment of voltage recovery. This can effectively deal with power fluctuations and avoid the situation where the motor stops after the grid voltage recovers.
[0032] 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 motor control circuit for preventing voltage fluctuations, characterized in that, It includes an incoming line switch QF, one end of which receives voltage and the other end is connected to the conducting end of a contactor KM. The conducting end of the contactor KM is connected to a motor M through the coil end of a thermal relay KH. One end of the coil of the contactor KM is connected to phase N, and the other end is connected to phase L in sequence through the normally closed terminal of the thermal relay KH, the normally closed terminal of the intermediate relay TJ, and the normally open terminal of the time relay KT. The normally open terminal of the time relay KT is connected in parallel with the normally open terminal of the contactor KM. It also includes an intermediate relay HJ, the coil terminal of which is connected in parallel with the coil terminal of the time relay KT. One end of the coil terminal of the intermediate relay HJ is connected to the negative terminal of the power supply, and the other end is connected to the positive terminal of the power supply through the button HA and the conducting terminal of the contactor KM respectively. One end of the coil of the intermediate relay TJ is connected to the negative terminal of the power supply, and the other end is connected to the positive terminal of the power supply through the button TA. The other end is also connected to the positive terminal of the power supply through the normally open terminal of the intermediate relay TJ and the normally open terminal of the time relay KT in sequence.
2. The motor control circuit for preventing power fluctuations according to claim 1, characterized in that: One normally open terminal of the intermediate relay HJ is connected to the positive terminal of the power supply, and the other terminal is connected to the negative terminal of the power supply via an indicator light HD.
3. The motor control circuit for preventing power fluctuations according to claim 2, characterized in that: One normally closed terminal of the intermediate relay HJ is connected to the positive terminal of the power supply, and the other terminal is connected to the negative terminal of the power supply through the indicator light LD.
4. The motor control circuit for preventing power fluctuations according to claim 1, characterized in that: It also includes the fuse FU connected to phase L.
5. The motor control circuit for preventing power fluctuations according to claim 3, characterized in that: It also includes fuses FU1 and FU2, which are connected to the power supply.