System for monitoring running state of three-phase synchronous motor and motor thereof

Abstract

The utility model discloses a system for monitoring the running state of a three-phase synchronous motor and a motor thereof. The system is characterized in that a coil side of a running signal output relay is electrically connected with a normally open auxiliary contact of an alternating current contactor; the coil side of the stop signal output relay is electrically connected with a normally closed auxiliary contact of the alternating current contactor; the coil side of the current signal relay is electrically connected between the wire outlet end of the alternating current contactor and the wire inlet end of the three-phase synchronous motor; the feedback module is electrically connected with the contact side of the operation signal output relay, the contact side of the stop signal output relay and the contact side of the current signal relay; and when and only when at least two of the received three contact side signals are in an activated state, the feedback module displays a motor operation signal. According to the utility model, the operation state of the three-phase synchronous motor can be correctly judged through the other two signal sources, and the reliability of monitoring the operation state of the three-phase synchronous motor is obviously improved.

Description

Technical Field

[0001] The utility model relates to the technical field of three-phase motor control, in particular to the technical field of an operation judgment circuit for a three-phase synchronous motor. Background Art

[0002] Three-phase synchronous motors are widely used in industrial automation and precision control of power systems due to their high efficiency and excellent speed stability. These motors often carry critical loads such as driving pumps, fans, compressors, and various machining equipment. To ensure the stable operation of three-phase synchronous motors, timely and accurate monitoring of their operating status is crucial.

[0003] Existing three-phase synchronous motor operating status monitoring technologies mostly use a single-point judgment mechanism. This mechanism primarily relies on the operation of the auxiliary node of the motor's power control contactor to provide motor operating feedback. Specifically, when the motor starts and the contactor closes, its auxiliary node also closes, signaling to the control system that the motor is running. When the motor stops, the contactor opens, and the auxiliary node also disconnects.

[0004] However, this single-point judgment mechanism has significant limitations. First, because it relies solely on a single auxiliary node signal, the mechanism has low reliability and is susceptible to contactor failure, signal interference, or external environmental factors, leading to false operation or missed judgments. Second, when this single-point judgment mechanism is used for protection signals or interlocking control signals for important equipment, a misjudgment can not only mislead operators' decisions but also trigger a chain reaction of false operations in related equipment, affecting the stable operation of the entire production line and even causing safety accidents. Utility Model Content

[0005] The present invention aims to solve the technical problems mentioned in the above background technology by adopting the following technical solutions:

[0006] A system for monitoring the operating status of a three-phase synchronous motor, comprising:

[0007] An operation signal output relay, wherein the coil side of the operation signal output relay is electrically connected to the normally open auxiliary contact of the AC contactor;

[0008] a stop signal output relay, wherein the coil side of the stop signal output relay is electrically connected to the normally closed auxiliary contact of the AC contactor;

[0009] A current signal relay, the coil side of which is electrically connected between the output terminal of the AC contactor and the input terminal of the three-phase synchronous motor;

[0010] A feedback module is electrically connected to the contact side of the operation signal output relay, the contact side of the stop signal output relay, and the contact side of the current signal relay; the feedback module displays the motor operation signal when and only when at least two of the three contact side signals received are in an activated state.

[0011] Optionally, the feedback module is composed of three parallel sub-circuits, and the three parallel sub-circuits include: a first sub-circuit, a second sub-circuit and a third sub-circuit;

[0012] The first sub-circuit is provided with a contact side of a run signal output relay and a contact side of a stop signal output relay connected in series;

[0013] The second sub-circuit is provided with a contact side of an operation signal output relay and a contact side of a current signal relay connected in series;

[0014] The third sub-circuit is provided with a contact side of a stop signal output relay and a contact side of a current signal relay connected in series.

[0015] Optionally, each of the sub-circuits includes an intermediate relay, and the coil input end of each intermediate relay is respectively connected in series with the contact side and the contact side, or the contact side and the contact side, or the contact side and the contact side; the normally open contact of the intermediate relay is connected to a display signal device to display the motor operation signal.

[0016] Optionally, an inverter circuit is connected to the contact side or the coil side of the stop signal output relay.

[0017] Optionally, the inverting circuit is provided with an intermediate relay or a non-logical control unit.

[0018] Optionally, the feedback module is further provided with an output interface, and the output interface is used to output a judgment signal of the motor operation state.

[0019] Optionally, the run signal output relay and the stop signal output relay are both connected to a neutral line.

[0020] Optionally, the coil side is electrically connected to any one of the three phases of the input terminal of the three-phase synchronous motor.

[0021] Optionally, it further includes a power supply module for receiving an external 220VAC power supply, and the power supply module is electrically connected to the three-phase synchronous motor via the main circuit of the AC contactor.

[0022] A three-phase synchronous motor includes a system connected to the above-mentioned system for monitoring the operating status of the three-phase synchronous motor.

[0023] The beneficial effects of the utility model are:

[0024] The utility model adopts a feedback module with three-out-of-two logic. Even when a signal source fails, the utility model can still correctly judge the operating status of the three-phase synchronous motor through the other two signal sources, thereby significantly improving the reliability of the operating status monitoring of the three-phase synchronous motor and avoiding the possibility of malfunction when using a single loop to judge the motor operating status. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the AC contactor, the run signal output relay, and the stop signal output relay of the three-phase synchronous motor of the present invention;

[0026] Figure 2 This is a schematic diagram of the current signal relay of the utility model connected to a three-phase synchronous motor and an AC contactor;

[0027] Figure 3 This is a schematic diagram of a system for monitoring the operating status of a three-phase synchronous motor according to the present invention;

[0028] Figure 4 Schematic diagram of the feedback module of the present invention.

[0029] In the picture:

[0030] Coil side of the running signal output relay: 11

[0031] Contact side of the operation signal output relay: 12

[0032] Coil side of stop signal output relay: 21

[0033] Contact side of stop signal output relay: 22

[0034] Coil side of current signal relay: 31

[0035] Contact side of current signal relay: 32

[0036] AC contactor: 4

[0037] Normally open auxiliary contacts of AC contactor: 41

[0038] Normally closed auxiliary contacts of AC contactor: 42

[0039] AC contactor output terminal: 5

[0040] Three-phase synchronous motor input terminal: 6

[0041] Feedback modules: 7

[0042] Output interface: 71 DETAILED DESCRIPTION

[0043] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is further described below with reference to specific illustrations.

[0044] like Figure 1-4 As shown, the operation judgment circuit of the three-phase synchronous motor includes:

[0045] An operating signal output relay, wherein the coil side 11 of the operating signal output relay is electrically connected to the normally open auxiliary contact 41 of the AC contactor 4;

[0046] A stop signal output relay, wherein the coil side 21 of the stop signal output relay is electrically connected to the normally closed auxiliary contact 42 of the AC contactor 4;

[0047] A current signal relay, the coil side 31 of the current signal relay is electrically connected between the output terminal 5 of the AC contactor 4 and the input terminal 6 of the three-phase synchronous motor;

[0048] Feedback module 7, feedback module 7 is electrically connected to the contact side 12 of the run signal output relay, the contact side 22 of the stop signal output relay and the contact side 32 of the current signal relay; feedback module 7 displays the motor running signal when and only when at least two of the three contact side signals received are in an activated state.

[0049] The present invention provides a coil side 11 of a run signal output relay on the side of the normally open auxiliary contact 41 of the AC contactor 4. This ensures that when the normally open auxiliary contact 41 closes, the contact side 21 of the run signal output relay also closes, thereby acquiring the run signal. Furthermore, the normally closed auxiliary contact 42 of the AC contactor 4 is connected to the coil side 21 of the stop signal output relay. When the normally closed auxiliary contact 42 opens, the stop signal output relay activates, and its contact side 22 displays an open signal. At this point, the present invention introduces an inverting circuit, so that the stop signal received by the feedback module 7 is a closed signal, thereby acquiring and inverting the stop signal. Furthermore, the present invention utilizes a current signal relay to monitor the current between the output terminal 5 of the AC contactor 4 and the input terminal 6 of the three-phase synchronous motor in real time. When current is flowing, the contact side 32 of the current signal relay closes, providing a current signal indicating the motor's operation. Finally, the feedback module 7 implements logical operations on the running signal, the stop signal and the current signal, so that the three-phase synchronous motor is displayed as being in the running state only when at least two of the received running signals, the stop signal and the current signal are in the activated (i.e. closed) state, thereby effectively reducing the possibility of malfunction in judging the motor running state by a single circuit.

[0050] In some embodiments, as Figure 1 and 2As shown, the feedback module is composed of three parallel sub-circuits, which include: a first sub-circuit, a second sub-circuit and a third sub-circuit; specifically, the first sub-circuit is provided with a contact side 12 of a running signal output relay and a contact side 22 of a stop signal output relay connected in series; the first sub-circuit can realize AND logic processing of the running signal and the stop signal, that is, when the running signal and the stop signal are both in the closed state, the output result indicates that the three-phase synchronous motor is operating normally.

[0051] The second sub-circuit is provided with a contact side 12 of an operation signal output relay and a contact side 32 of a current signal relay connected in series with each other; the second sub-circuit can realize AND logic processing of the operation signal and the current signal, that is, when the operation signal and the current signal are both in a closed state, the output result is that the three-phase synchronous motor is operating normally.

[0052] The third subcircuit includes the contact side 22 of the stop signal output relay and the contact side 32 of the current signal relay, which are connected in series. This subcircuit enables AND logic processing of the stop signal and the current signal. Specifically, when both the stop signal and the current signal are closed, the output indicates that the three-phase synchronous motor is operating normally.

[0053] In some embodiments, the subcircuits utilize intermediate relays. Specifically, corresponding to the first subcircuit, the coil input terminals of the intermediate relay are connected in series with contact side 12 and contact side 22, respectively, and the normally open contact of the intermediate relay is connected to a display signal device to display the motor operation signal. Corresponding to the second subcircuit, the coil input terminals of the intermediate relay are connected in series with contact side 12 and contact side 32, respectively, and the normally open contact of the intermediate relay is connected to a display signal device to display the motor operation signal. Corresponding to the third subcircuit, the coil input terminals of the intermediate relay are connected in series with contact side 22 and contact side 32, respectively, and the normally open contact of the intermediate relay is connected to a display signal device to display the motor operation signal. Using intermediate relays for AND logic provides good electrical isolation, helping to protect the control circuit and operator safety and prevent mutual interference between circuits. Furthermore, relay circuits are relatively simple, easy to design and implement, and facilitate fault diagnosis and on-site repair.

[0054] In some embodiments, such as Figure 1 and 2 As shown, an inverter circuit is connected to the contact side 22 or coil side 21 of the stop signal output relay. The purpose of the inverter circuit is to convert the disconnection signal into an activation signal, thereby ensuring that the feedback module 7 can recognize the stopped state of the motor and perform the AND logic operation.

[0055] In some embodiments, the inverting circuit is equipped with an intermediate relay or a non-logical control unit. In this case, the intermediate relay can be used as a signal buffer and logic inversion element. For example, when the contact side 22 is disconnected, another peripheral circuit can be connected. In this case, the relay coil is connected to the peripheral circuit. When the peripheral circuit is connected, the relay coil is energized, and the contact state changes. If the relay is initially in the normally open state, the contacts close after the coil is energized, achieving a reversal from open to closed.

[0056] In some embodiments, the feedback module 7 is further provided with an output interface 71 , and the output interface 71 is used to output a judgment signal of the motor operation state.

[0057] In some embodiments, both the run signal output relay and the stop signal output relay are connected to a neutral line. This ensures that the system can safely provide signal feedback when the motor power is disconnected. This connection method improves system safety because, even if an accident occurs when the motor is powered off, no current will flow through the relay coil, thus avoiding potential electrical hazards.

[0058] In some embodiments, the coil side 31 is electrically connected to any one of the three phases of the three-phase synchronous motor's incoming line terminal. This design provides flexibility, allowing the system to select the appropriate connection phase based on the actual motor configuration and control requirements. Whether phase A, B, or C is selected, the current signal relay can accurately monitor the motor's current state and convert this state into a signal that can be recognized by the control system. In specific embodiments, appropriate terminal blocks or junction boxes can be used to connect the relay to the motor's incoming line terminal to ensure the stability and reliability of the electrical connection.

[0059] In some embodiments, the system further includes a power module for receiving an external 220VAC power supply. The power module is electrically connected to the three-phase synchronous motor via the main circuit of the AC contactor 4. This connection between the power module and the three-phase synchronous motor through the main circuit of the AC contactor 4 ensures that the power module automatically switches power according to the start and stop states of the motor. When the AC contactor 4 is closed, the power module supplies power to the motor, starting it. When the AC contactor 4 is open, the power module cuts off power, ensuring that the motor stops safely.

[0060] In addition to the above embodiments, the working method of the present invention is:

[0061] When the three-phase synchronous motor needs to be started, the main circuit of the AC contactor 4 is closed, the power module provides power to the motor, and the motor starts to run.

[0062] Signal Monitoring: The run signal output relay, stop signal output relay, and current signal relay monitor the motor status in real time. The contacts (12, 22, and 32) of these relays are connected to the feedback module 7 to provide signals indicating the motor's operating status. The connections between the contacts (12, 22, and 32) and the corresponding coils of these relays have been described above and will not be repeated here.

[0063] Logic Decision: Feedback module 7 receives signals from three relays (the run signal output relay, the stop signal output relay, and the current signal relay) and uses internal logic to determine whether the motor is running. When at least two signals indicate that the motor is running, feedback module 7 activates and displays the motor running signal.

[0064] Status display: Once the feedback module 7 determines that the motor is in operation, it will output the motor's operating status signal through a connected display signal device (such as an indicator light or a display) to provide intuitive status information to the operator.

[0065] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments and that various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed in this invention is defined by the appended claims and their equivalents.

Claims

1. A system for monitoring the operating status of a three-phase synchronous motor, characterized in that: include: An operating signal output relay, wherein the coil side (11) of the operating signal output relay is electrically connected to a normally open auxiliary contact (41) of an AC contactor (4); a stop signal output relay, wherein the coil side (21) of the stop signal output relay is electrically connected to the normally closed auxiliary contact (42) of the AC contactor (4); A current signal relay, wherein the coil side (31) of the current signal relay is electrically connected between the output terminal (5) of the AC contactor (4) and the input terminal (6) of the three-phase synchronous motor; A feedback module (7) is electrically connected to the contact side (12) of the operation signal output relay, the contact side (22) of the stop signal output relay, and the contact side (32) of the current signal relay; the feedback module (7) displays the motor operation signal when and only when at least two of the three contact side signals received are in an activated state.

2. A system for monitoring the operating status of a three-phase synchronous motor according to claim 1, characterized in that: The feedback module is composed of three parallel sub-circuits, and the three parallel sub-circuits include: a first sub-circuit, a second sub-circuit and a third sub-circuit; The first sub-circuit is provided with a contact side (12) of a running signal output relay and a contact side (22) of a stop signal output relay connected in series; The second sub-circuit is provided with a contact side (12) of an operation signal output relay and a contact side (32) of a current signal relay connected in series; The third sub-circuit is provided with a contact side (22) of a stop signal output relay and a contact side (32) of a current signal relay connected in series.

3. The system for monitoring the operating status of a three-phase synchronous motor according to claim 2, characterized in that: The first subcircuit, the second subcircuit, and the third subcircuit each include an intermediate relay. Specifically, in the first subcircuit, the coil input end of the intermediate relay is respectively connected in series with the contact side (12) of the operation signal output relay and the contact side (22) of the stop signal output relay, and the normally open contact of the intermediate relay is connected to a display signal device to display the motor operation signal; in the second subcircuit, the coil input end of the intermediate relay is respectively connected in series with the contact side (12) of the operation signal output relay and the contact side (32) of the current signal relay, and the normally open contact of the intermediate relay is connected to a display signal device to display the motor operation signal; in the third subcircuit, the coil input end of the intermediate relay is respectively connected in series with the contact side (22) of the stop signal output relay and the contact side (32) of the current signal relay, and the normally open contact of the intermediate relay is connected to a display signal device to display the motor operation signal.

4. The system for monitoring the operating status of a three-phase synchronous motor according to claim 1, characterized in that: The contact side (22) or the coil side (21) of the stop signal output relay is connected to an inverting circuit.

5. The system for monitoring the operating status of a three-phase synchronous motor according to claim 4, characterized in that: The inverting circuit is provided with an intermediate relay or a non-logical control unit.

6. The system for monitoring the operating status of a three-phase synchronous motor according to claim 1, characterized in that: The feedback module (7) is also provided with an output interface, and the output interface is used to output a judgment signal of the motor operating state.

7. The system for monitoring the operating status of a three-phase synchronous motor according to claim 1, characterized in that: The operation signal output relay and the stop signal output relay are both connected to a neutral line.

8. The system for monitoring the operating status of a three-phase synchronous motor according to claim 1, characterized in that: The coil side (31) of the current signal relay is electrically connected to any one of the three phases of the incoming line terminal (6) of the three-phase synchronous motor.

9. The system for monitoring the operating status of a three-phase synchronous motor according to claim 1, characterized in that: It also includes a power supply module for receiving an external 220VAC power supply, and the power supply module is electrically connected to the three-phase synchronous motor via the main circuit of the AC contactor (4).

10. A three-phase synchronous motor, characterized in that: The invention comprises a system for monitoring the operating status of a three-phase synchronous motor connected to any one of claims 1 to 9.

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