A direct resistance monitoring device and monitoring method of an electromagnet

Abstract

The present invention belongs to the technical field of electrical maintenance of nuclear power plants, and specifically relates to a direct-current resistance monitoring device for an electromagnet and a monitoring method thereof, comprising: a primary circuit I of a direct-current resistance monitoring device, a secondary circuit II of a direct-current resistance monitoring device, a primary circuit of an electromagnet switch, a secondary circuit of an electromagnet switch, a remote control circuit of an electromagnet switch and a plurality of wires; the primary circuit I of the direct-current resistance monitoring device is connected to the primary circuit of the electromagnet switch through a wire, and the secondary circuit II of the direct-current resistance monitoring device is connected to the secondary circuit of the electromagnet switch through a wire; and the remote control circuit of the electromagnet switch is connected to the secondary circuit of the electromagnet switch through a contact of a closing and tripping command relay.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power plant electrical maintenance, and in particular relates to a direct resistance monitoring device of an electromagnet and a monitoring method thereof. Background Art

[0002] Each of the units 1 and 2 of a nuclear power plant is designed with 4 reactor main coolant pumps (hereinafter referred to as main pumps) in the primary circuit. The main pump bearings are water-lubricated, and each main pump is designed with an electromagnet. The function of the electromagnet is to start the main pump when the primary circuit pressure exceeds 7MPa or to cut off the main pump when the primary circuit pressure exceeds 13MPa. By relying on the force of the electromagnet (downward), the axial force acting on the rotor is reduced to ensure the establishment of the radial-thrust bearing lubricating water film, so that the motor can overcome the friction torque on the rotor.

[0003] The original power supply design of the main pump electromagnet is quite special. The power is taken from the AC UPS. The UPS power is rectified by the rectifier to power the electromagnet. When starting the electromagnet, the rectifier is directly started, and the rectifier starts running with the electromagnet. This starting method requires high impact resistance of electronic components. The impact resistance of the electronic components of the rectifier gradually weakens with the accumulation of running time, and the failure of electronic components is a cliff-like development. Once the rectifier fails at the moment of starting, the rectifier failure will cause the electromagnet to fail to start, endangering the operation safety of the main pump. In order to improve the reliability of the operation of the main pump electromagnet, the electromagnet power supply has been transformed and optimized, and the main pump electromagnet rectifier has been cancelled. The electromagnet power supply is directly taken from the DC bus through the DC switch. The main pump electromagnet is controlled by controlling the on and off of the DC switch to start or exit.

[0004] The availability of the electromagnet directly affects the operating safety of the main pump. Starting and stopping the main pump in the event of an electromagnet failure may cause wear or even burning of the bearing bushing, but in the original design, there is no means of status monitoring during the hot standby period of the electromagnet. Therefore, in order to monitor the availability of the electromagnet in real time and avoid the situation where starting the main pump when the electromagnet fails may endanger the operating safety of the main pump, it is necessary to design an electromagnet direct resistance monitoring device, which can measure the direct resistance value of the electromagnet during the hot standby period of the electromagnet and send it to the main control screen for display. When the direct resistance value of the electromagnet is lower than the manufacturer's standard value, the main control operator can manually adjust the start and stop sequence of the main pump corresponding to the faulty electromagnet, and start and stop the main pump when the pressure in the first circuit meets the requirement that the electromagnet does not need to be started, so as to maximize the operating safety of the main pump. Summary of the invention

[0005] The purpose of the present invention is to design a direct resistance monitoring device and a monitoring method for an electromagnet, so as to solve the technical problem in the prior art that there is no monitoring means during the hot standby period of the electromagnet, resulting in the start and stop of the main pump in the event of an electromagnet failure, causing bearing wear or even burning failure.

[0006] The technical solution of the present invention:

[0007] A direct resistance monitoring device for an electromagnet, comprising: a primary circuit I of the direct resistance monitoring device, a secondary circuit II of the direct resistance monitoring device, a primary circuit of an electromagnet switch, a secondary circuit of an electromagnet switch, a remote control circuit of an electromagnet switch and a plurality of wires;

[0008] The primary circuit I of the direct resistance monitoring device is connected to the primary circuit of the electromagnet switch through a wire, and the secondary circuit II of the direct resistance monitoring device is connected to the secondary circuit of the electromagnet switch through a wire; the remote control circuit of the electromagnet switch is connected to the secondary circuit of the electromagnet switch through the normally open contact K12-1 of the closing command relay K12 and the normally closed contact K11-1 of the tripping command relay K11.

[0009] The primary circuit of the electromagnet switch includes: a positive power bus L+, a negative power bus L-, a primary plug X01, a main switch Q0, a main contact K1-1 of a main contactor K1, an electromagnet AS and a diode D1;

[0010] The positive power bus L+ and the negative power bus L- are connected to the two upper ports of the main switch Q0 through a primary plug X01, and the lower port of the main switch Q0 outputs the positive power supply L1+ and the negative power supply L1-; the positive power supply L1+ is connected to the main contact terminal A of the main contactor K1, the main contact terminal B of the main contactor K1 is short-circuited with the main contact terminal D of the main contactor K1, and the main contact terminal C of the main contactor K1 is connected to the positive pole of the electromagnet AS;

[0011] The negative power supply L1- is connected to the main contact terminal E of the main contactor K1, the main contact terminal F of the main contactor K1 is connected to the negative pole of the electromagnet AS, the positive pole of the diode D1 is connected to the negative pole of the electromagnet AS, and the negative pole of the diode D1 is connected to the positive pole of the electromagnet AS.

[0012] The secondary circuit of the electromagnet switch includes: a control power switch Q1, a fault tripping contact Q0-1 of the main switch Q0, a normally open contact K12-1 of a closing command relay K12, a normally closed contact K11-1 of a tripping command relay K11, a main contactor K1 and a normally open contact K1-2 of the main contactor K1;

[0013] In the secondary circuit of the electromagnet switch: the two upper ports of the control power switch Q1 are respectively connected to the positive power supply L1+ and the negative power supply L1- of the lower port of the main switch Q0 in the primary circuit of the electromagnet switch through wires. The control power switch Q1 outputs the positive control power supply L2+ and the negative control power supply L2-. The positive control power supply L2+ is connected to one end of the fault tripping contact Q0-1 of the main switch Q0, the other end of the fault tripping contact Q0-1 of the main switch Q0 is connected to one end of the normally open contact K12-1 of the closing command relay K12, the other end of the normally open contact K12-1 of the closing command relay K12 is connected to one end of the normally closed contact K11-1 of the tripping command relay K11, the other end of the normally closed contact K11-1 of the tripping command relay K11 is connected to one end of the main contactor K1, the other end of the main contactor K1 is connected to the negative control power supply L2-, the normally open contact K1-2 of the main contactor K1 is connected in parallel with the normally open contact K12-1 of the relay K12.

[0014] The electromagnetic switch remote control circuit includes a closing command relay K12, a tripping command relay K11, a terminal block X10:23, a terminal block X10:24 and a terminal block X10:25;

[0015] One end of the closing command relay K12 is connected to the terminal block X10:25, and the other end of the closing command relay K12 is connected to the terminal block X10:23. One end of the tripping command relay K11 is connected to the terminal block X10:24, and the other end of the tripping command relay K11 is connected to the terminal block X10:23. The terminal blocks X10:23, X10:24 and X10:25 are arranged on the switch cabinet where the electromagnet switch is located.

[0016] The primary circuit I of the direct resistance monitoring device is connected to the positive and negative ends of the electromagnet AS in the primary circuit of the electromagnet switch through a wire;

[0017] The primary circuit I of the DC resistance monitoring device includes: a normally closed contact K1-4 of the main contactor K1, a normally closed contact K1-5 of the main contactor K1, a normally closed node K13-1 of the intermediate relay K13, a normally closed node K13-2 of the intermediate relay K13, a DC resistance transmitter R401, a terminal block X10:21, a terminal block X10:22 and a plurality of wires;

[0018] One input end of the resistance transmitter R401 is connected to one end of the normally closed contact K13-1 of the intermediate relay K13, the other end of the normally closed contact K13-1 of the intermediate relay K13 is connected to one end of the normally closed contact K1-4 of the main contactor K1, and the other end of the normally closed contact K1-4 of the main contactor K1 is connected to the positive pole of the electromagnet AS; the other input end of the resistance transmitter R401 is connected to one end of the normally closed node K13-2 of the intermediate relay K13, the other end of the normally closed node K13-2 of the intermediate relay K13 is connected to one end of the normally closed contact K1-5 of the main contactor K1, and the other end of the normally closed contact K1-5 of the main contactor K1 is connected to the negative pole of the electromagnet AS;

[0019] The resistance transmitter R401 outputs to terminal blocks X10:21 and X10:22, which are arranged on a switch cabinet where the electromagnetic switch is located.

[0020] The secondary circuit II of the DC resistance monitoring device is connected to the lower port of the control power switch Q1 in the secondary circuit of the electromagnet switch through a wire;

[0021] The secondary circuit II of the DC resistance monitoring device includes: a positive control power supply L2+, a negative control power supply L2-, a DC resistance transmitter auxiliary coil R401', an auxiliary power switch Q2, an intermediate relay K13, a main contactor K1 normally open contact K1-3, a time relay T1, a time relay normally open contact T1-1 and a plurality of wires;

[0022] The upper port of the auxiliary power switch Q2 is connected to the positive control power supply L2+, the lower port of the auxiliary power switch Q2 is connected to one end of the auxiliary coil R401' of the DC resistance transmitter, and the other end of the auxiliary coil R401' of the DC resistance transmitter is connected to the negative control power supply L2-;

[0023] One end of the normally open contact K1-3 of the main contactor K1 is connected to the positive control power supply L2+, the other end of the normally open contact K1-3 of the main contactor K1 is connected to one end of the time relay T1, and the other end of the time relay T1 is connected to the negative control power supply L2-;

[0024] One end of the normally open contact T1-1 of the time relay T1 is connected to the positive power supply L2+, the other end of the normally open contact T1-1 of the time relay T1 is connected to one end of the intermediate relay K13, and the other end of the intermediate relay K13 is connected to the negative control power supply L2-.

[0025] A monitoring method of the direct resistance monitoring device of the electromagnet as described above comprises the following steps:

[0026] Step 1: Connect the primary circuit Ⅰ and secondary circuit Ⅱ of the DC resistance monitoring device to the primary circuit and secondary circuit of the electromagnet switch respectively to realize the monitoring of the DC resistance value of the main pump electromagnet; control the DC resistance monitoring device to be put into operation or withdrawn through the main contactor K1 and the time relay T1; the normally open contact T1-1 of the time relay T1 is connected to the coil circuit of the intermediate relay K13 to control whether the intermediate relay K13 is energized; the DC resistance transmitter R401 is connected to the positive and negative ends of the electromagnet AS through the two pairs of normally closed contacts of the intermediate relay K13 and the two pairs of normally closed contacts of the main contactor K1 of the electromagnet switch to control the DC resistance transmitter R401 to be put into operation or withdrawn;

[0027] Step 2: After the main contactor K1 is energized and attracted, the main contact of the main contactor K1 is closed, the electromagnet runs, and at the same time, the normally open contact of the main contactor is instantaneously closed, the time relay T1 is started, the normally open contact T1-1 of the time relay T1 is instantaneously closed, the intermediate relay K13 is energized, and the normally closed contact is opened; the normally closed contact of the intermediate relay and the normally closed contact of the main contactor instantly disconnect the DC resistance transmitter R401 from the electromagnet AS circuit, and the DC resistance transmitter R401 stops running;

[0028] Step 3: After the main contactor K1 is disconnected, the main contact of the main contactor K1 is disconnected, and the electromagnet stops running; at the same time, the normally open contact of the main contactor K1 is disconnected instantaneously, and the time relay T1 is powered off; the normally closed contact of the main contactor K1 is closed instantaneously;

[0029] Step 4: The normally open contact T1-1 of the time relay T1 is opened with a delay of ≥20s. During the delay opening period, the intermediate relay K13 continues to be energized, and the normally closed contacts K13-1 and K13-2 of the intermediate relay K13 are always in the disconnected state. During this period, the electromagnet coil AS and the parallel diode D1 form a conduction circuit, and the reverse potential in the AS coil is discharged through the parallel diode D1. After the set delay is reached, the reverse potential in the coil has been completely released, the normally open contact T1-1 of the time relay T1 is opened, the intermediate relay K13 is de-energized, and the normally closed contact of the intermediate relay is closed;

[0030] Step 5: After the two pairs of normally closed contacts of the electromagnet main contactor K1 and the two pairs of normally closed contacts of the intermediate relay K13 are closed, the DC resistance transmitter R401 is connected to the electromagnet coil circuit;

[0031] Step 6: The DC resistance transmitter R401 monitors the DC resistance value of the main pump electromagnet, and converts the DC resistance value of the electromagnet into a 4-20mA signal and sends it to the main control monitoring system.

[0032] Beneficial effects of the present invention:

[0033] The direct resistance monitoring device of an electromagnet designed by the present invention has the following technical effects:

[0034] 1) It is convenient for the main control personnel to monitor the availability of the electromagnet in real time and optimize the start and stop sequence of the main pump.

[0035] 2) It can ensure the safety of main pump operation to the greatest extent and improve the reliability of main pump operation.

[0036] 3) The monitoring device is simple in design and easy to implement.

[0037] 4) The monitoring device is automatically turned on or off through the main contactor of the electromagnetic switch and the time relay, without the need for manual operation.

[0038] 5) The components used in the monitoring device are universal components, and the modification cost is low.

[0039] 6) Reduce the energized time of components, reduce the probability of component failure due to long-term energization of components, and improve the reliability of device operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a circuit diagram of a primary circuit of an electromagnet direct resistance monitoring device described in the present invention connected to a primary circuit of an electromagnet switch.

[0041] Figure 2 A circuit diagram of a secondary circuit of a direct resistance monitoring device of an electromagnet connected to a secondary circuit of an electromagnet switch according to the present invention;

[0042] Figure 3 This is a circuit diagram of the remote control loop of the electromagnet switch of the present invention;

[0043] Among them: Q0-main switch; Q1-control power switch; Q0-1-main switch fault trip contact; Q2-auxiliary power switch;

[0044] K1-main contactor;

[0045] K1-1: main contact of main contactor K1;

[0046] K1-2: Main contactor K1 normally open contact, K1-3: Main contactor K1 normally open contact;

[0047] K1-4: Normally closed contact of main contactor K1, K1-5: Normally closed contact of main contactor K1;

[0048] K11: trip command relay, K11-1: normally closed contact of trip command relay K11;

[0049] K12: Closing command relay, K12-1: Closing command relay K12 normally open contact;

[0050] K13: intermediate relay; K13-1: normally closed contact of intermediate relay K13;

[0051] K13-2: normally closed contact of intermediate relay K13;

[0052] R401: DC resistance transmitter; R401': DC resistance transmitter auxiliary coil;

[0053] T1: time relay; T1-1: normally open contact of time relay T1;

[0054] L+: positive power bus; L-: negative power bus;

[0055] L1+: positive power supply; L1-: negative power supply;

[0056] L2+: positive control power supply; L2-: negative control power supply;

[0057] D1: diode; AS: main pump solenoid coil; X01: primary plug; X10: terminal block DETAILED DESCRIPTION

[0058] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0059] This patent discloses a direct resistance monitoring device for an electromagnet. The device is divided into a primary circuit I and a secondary circuit II, which are respectively connected to the primary circuit and the secondary circuit of the electromagnet switch. Figure 1-2 In the middle dotted frame, the main contactor K1 of the electromagnetic switch and the time relay T1 are used to control the activation or deactivation of the DC resistance monitoring device.

[0060] The main contactor K1 of the electromagnet switch controls the time relay T1 to be energized or de-energized. The contact capacity of T1 is small and the number of contacts is small, so an intermediate relay K13 is added to increase the contact capacity and expand the number of contacts.

[0061] The direct resistance monitoring device of the electromagnet described in the present invention comprises:

[0062] A primary circuit I of a direct resistance monitoring device, a secondary circuit II of a direct resistance monitoring device, a primary circuit of an electromagnet switch, a secondary circuit of an electromagnet switch, a remote control circuit and a plurality of wires;

[0063] The primary circuit I of the direct resistance monitoring device is connected to the primary circuit of the electromagnet switch through a wire, and the secondary circuit II of the direct resistance monitoring device is connected to the secondary circuit of the electromagnet switch through a wire; the remote control circuit of the electromagnet switch is connected to the secondary circuit of the electromagnet switch through the normally open contact K12-1 of the closing command relay K12 and the normally closed contact K11-1 of the tripping command relay K11.

[0064] The primary circuit of the electromagnet switch includes: a positive power bus L+, a negative power bus L-, a primary plug X01, a main switch Q0, a main contact K1-1 of a main contactor K1, an electromagnet AS and a diode D1;

[0065] The positive power bus L+ and the negative power bus L- are connected to the two upper ports of the main switch Q0 through a primary plug X01, and the lower port of the main switch Q0 outputs the positive power supply L1+ and the negative power supply L1-; the positive power supply L1+ is connected to the main contact terminal A of the main contactor K1, the main contact terminal B of the main contactor K1 is short-circuited with the main contact terminal D of the main contactor K1, and the main contact terminal C of the main contactor K1 is connected to the positive pole of the electromagnet AS;

[0066] The negative power supply L1- is connected to the main contact terminal E of the main contactor K1, the main contact terminal F of the main contactor K1 is connected to the negative pole of the electromagnet AS, the positive pole of the diode D1 is connected to the negative pole of the electromagnet AS, and the negative pole of the diode D1 is connected to the positive pole of the electromagnet AS.

[0067] The secondary circuit of the electromagnet switch also includes: a control power switch Q1, a fault tripping contact Q0-1 of the main switch Q0, a normally open contact K12-1 of the closing command relay K12, a normally closed contact K11-1 of the tripping command relay K11, a main contactor K1 and a normally open contact K1-2 of the main contactor K1;

[0068] In the secondary circuit of the electromagnet switch: the two upper ports of the control power switch Q1 are connected to the positive power supply L1+ and the negative power supply L1- of the lower port of the main switch Q0 in the primary circuit of the electromagnet switch through wires. The control power switch Q1 outputs the positive control power supply L2+ and the negative control power supply L2-. The positive control power supply L2+ is connected to one end of the fault tripping contact Q0-1 of the main switch Q0, the other end of the fault tripping contact Q0-1 of the main switch Q0 is connected to one end of the normally open contact K12-1 of the closing command relay K12, the other end of the normally open contact K12-1 of the closing command relay K12 is connected to one end of the normally closed contact K11-1 of the tripping command relay K11, the other end of the normally closed contact K11-1 of the tripping command relay K11 is connected to one end of the main contactor K1, the other end of the main contactor K1 is connected to the negative control power supply L2-, the normally open contact K1-2 of the main contactor K1 is connected in parallel with the normally open contact K12-1 of the relay K12.

[0069] The electromagnetic switch remote control circuit includes a closing command relay K12, a tripping command relay K11, a terminal block X10:23, a terminal block X10:24 and a terminal block X10:25;

[0070] One end of the closing command relay K12 is connected to the terminal block X10:25, and the other end of the closing command relay K12 is connected to the terminal block X10:23. One end of the tripping command relay K11 is connected to the terminal block X10:24, and the other end of the tripping command relay K11 is connected to the terminal block X10:23. The terminal blocks X10:23, X10:24 and X10:25 are arranged on the switch cabinet where the electromagnet switch is located. The primary circuit I of the direct resistance monitoring device is connected to the positive and negative ends of the electromagnet AS in the primary circuit of the electromagnet switch through a wire;

[0071] The primary circuit I of the DC resistance monitoring device includes: the normally closed contact K1-4 of the main contactor K1, the normally closed contact K1-5 of the main contactor K1, the normally closed node K13-1 of the intermediate relay K13, the normally closed node K13-2 of the intermediate relay K13, the DC resistance transmitter R401, the terminal block X10:21, the terminal block X10:22 and a number of wires;

[0072] One input end of the resistance transmitter R401 is connected to one end of the normally closed contact K13-1 of the intermediate relay K13, the other end of the normally closed contact K13-1 of the intermediate relay K13 is connected to one end of the normally closed contact K1-4 of the main contactor K1, the other end of the normally closed contact K1-4 of the main contactor K1 is connected to the positive pole of the electromagnet AS; the other input end of the resistance transmitter R401 is connected to one end of the normally closed node K13-2 of the intermediate relay K13, the other end of the normally closed node K13-2 of the intermediate relay K13 is connected to one end of the normally closed contact K1-5 of the main contactor K1, the other end of the normally closed contact K1-5 of the main contactor K1 is connected to the negative pole of the electromagnet AS;

[0073] The resistance transmitter R401 outputs to the terminal blocks X10:21 and X10:22, which are arranged on the switch cabinet where the electromagnetic switch is located. The secondary circuit II of the direct resistance monitoring device is connected to the lower port of the control power switch Q1 in the secondary circuit of the electromagnetic switch through a wire;

[0074] The secondary circuit II of the DC resistance monitoring device includes: positive control power supply L2+, negative control power supply L2-, auxiliary coil R401' of the DC resistance transmitter, auxiliary power switch Q2, intermediate relay K13, normally open contact K1-3 of the main contactor K1, time relay T1, normally open contact T1-1 of the time relay and several wires;

[0075] The upper port of the auxiliary power switch Q2 is connected to the positive control power supply L2+, the lower port of the auxiliary power switch Q2 is connected to one end of the auxiliary coil R401' of the direct resistance transmitter, and the other end of the auxiliary coil R401' of the direct resistance transmitter is connected to the negative control power supply L2-;

[0076] One end of the normally open contact K1-3 of the main contactor K1 is connected to the positive control power supply L2+, the other end of the normally open contact K1-3 of the main contactor K1 is connected to one end of the time relay T1, and the other end of the time relay T1 is connected to the negative control power supply L2-;

[0077] One end of the normally open contact T1-1 of the time relay T1 is connected to the positive power supply L2+, and the other end of the normally open contact T1-1 of the time relay T1 is connected to one end of the intermediate relay K13, and the other end of the intermediate relay K13 is connected to the negative control power supply L2-. Due to the physical characteristics of the inductor, a reverse potential will be formed at both ends of the electromagnet AS when the power is cut off. In order to connect the electromagnet to the direct resistance transmitter after the electromagnet is discharged through the diode D1, the delay (delay opening) of the time relay T1 is used to control the power-off time of the intermediate relay K13, and control the time when the data acquisition circuit of the direct resistance transmitter is connected to the electromagnet circuit.

[0078] Since the time relay T1 and the intermediate relay K13 have inherent contact action time, the normally open contact of the main contactor K1 and the normally closed contact of the intermediate relay K13 may be connected at the same time, and the DC high voltage may enter the data acquisition circuit of the DC resistance transmitter R401 and burn the transmitter. In order to prevent the DC voltage from entering the DC resistance value data acquisition circuit of the resistance transmitter R401, the two closed contacts of the main contactor K1 are connected to the transmitter data acquisition circuit to achieve effective isolation between the DC resistance value acquisition circuit of the DC resistance transmitter and the DC high voltage circuit.

[0079] Since the electromagnet is in a non-energized state for a long time during the normal operation of the unit, in order to ensure the reliability of the electromagnet direct resistance monitoring device, in addition to the resistance transmitter R401, the time relay T1 and the intermediate relay K13 are only energized during the operation of the electromagnet, and are in a non-energized state at other times. Reducing the energized time of the time relay and the intermediate relay can reduce the probability of electrical components failing due to long-term energization and improve the reliability of the device operation.

[0080] Through the above design, during the hot standby period of the electromagnet, the direct resistance value of the electromagnet is measured in real time by using the direct resistance transmitter and sent to the main control screen for display. It is convenient for the main control operator to monitor the availability of the electromagnet. When the direct resistance value of the electromagnet is lower than the manufacturer's standard value, the main control operator can manually adjust the start and stop sequence of the main pump corresponding to the faulty electromagnet, and start and stop the main pump when the pressure in the first circuit meets the requirement that the electromagnet does not need to be started, so as to maximize the safety of the main pump operation and improve the reliability of the main pump operation.

[0081] A monitoring method of the direct resistance monitoring device of the electromagnet as described above comprises the following steps:

[0082] Step 1: Connect the primary circuit Ⅰ and secondary circuit Ⅱ of the direct resistance monitoring device to the primary circuit and secondary circuit of the electromagnetic switch respectively to monitor the direct resistance value of the main pump electromagnetic:

[0083] 1.1 The auxiliary coil R401' of the DC resistance transmitter is connected to the auxiliary power supply through the switch Q2.

[0084] 1.2 The normally open contact of the main contactor K1 is connected to the coil circuit of the time relay T1 to control whether the time relay T1 is energized.

[0085] 1.3 The normally open contact (delayed opening) of time relay T1 is connected to the coil circuit of intermediate relay K13 to control whether K13 is energized.

[0086] 1.4 The DC resistance transmitter R401 is connected to the positive and negative ends of the electromagnet AS through the two pairs of normally closed contacts of the intermediate relay K13 and the two pairs of normally closed contacts of the electromagnet switch main contactor K1 to control the DC resistance transmitter R401 to start or stop operation.

[0087] Step 2: After the main contactor K1 is energized and attracted, the main contact of the main contactor K1 is closed, the electromagnet runs, and at the same time, the normally open contact of the main contactor is instantaneously closed, the time relay T1 is started, the normally open contact (delayed opening) of the time relay T1 is instantaneously closed, the intermediate relay K13 is instantaneously energized, and the normally closed contact is opened; the normally closed contact of the intermediate relay and the normally closed contact of the main contactor instantly disconnect the DC resistance transmitter R401 from the electromagnet AS circuit, and the DC resistance transmitter R401 stops running;

[0088] Step 3: After the main contactor K1 is disconnected, the main contact of the main contactor K1 is disconnected, and the electromagnet stops running; at the same time: the normally open contact of the main contactor K1 is instantly disconnected, and the time relay T1 is powered off; the normally closed contact of the main contactor K1 is instantly closed;

[0089] Step 4: The normally open contact of time relay T1 is opened with a delay of ≥20s. During the delay opening period, the intermediate relay K13 continues to be energized, and the normally closed contacts K13-1 and K13-2 of the intermediate relay K13 are always in the disconnected state. During this period, the electromagnet AS coil and the parallel diode D1 form a conduction circuit, and the reverse potential in the AS coil is released in the diode connected in parallel with it. After the set delay is reached, the reverse potential in the coil has been completely released, the normally open contact T1-1 of the time relay T1 is opened, the intermediate relay K13 is de-energized, and the normally closed contact of the intermediate relay is closed;

[0090] Step 5: After the two pairs of normally closed contacts of the electromagnet main contactor K1 and the two pairs of normally closed contacts of the intermediate relay K13 are closed, the DC resistance transmitter R401 is connected to the electromagnet coil circuit;

[0091] Step 6: The DC resistance transmitter R401 monitors the DC resistance value of the main pump electromagnet, and converts the DC resistance value of the electromagnet into a 4-20mA signal and sends it to the main control monitoring system.

[0092] The specific operation of the embodiment is described as follows:

[0093] The electromagnetic switch is connected to the positive power bus L+ and the negative power bus L- through a primary plug X01, and the primary circuit of the electromagnetic switch, the secondary circuit of the electromagnetic switch and the secondary circuit of the DC resistance monitoring device are powered through the main switch Q0.

[0094] After the master controller issues a closing command, the closing command relay K12 is energized instantaneously, the normally open contact K12-1 of the closing command relay K12 is closed, the main contactor K1 of the electromagnet switch is energized and attracted, the main contact K1-1 of the main contactor K1 is closed, the electromagnet AS is energized and runs, the normally open contact K1-2 of the main contactor K1 is closed, the closing command relay K12 is de-energized, and the main contactor K1 maintains the energized state by itself.

[0095] After the master controller issues a trip command, the trip command relay K11 is energized instantaneously, the normally closed contact K11-1 of the trip command relay K11 opens, the main contactor K1 loses power, the main contact K1-1 of the main contactor K1 is disconnected, the normally open contact K1-2 of the main contactor K1 opens, and the electromagnet AS is de-energized.

[0096] When the main contactor K1 is energized and attracted, the normally closed contacts K1-4 and K1-5 of the main contactor K1 are opened, the resistance transmitter R401 is isolated from the primary circuit of the electromagnet switch, and the direct resistance monitoring device exits operation. At the same time, the normally open contact K1-3 of the main contactor K1 is closed, the time relay T1 is energized and operated, the normally open contact (delayed opening) of the time relay T1 is instantaneously closed, the intermediate relay K13 is energized and attracted, and the normally closed contacts K13-1 and K13-2 of the intermediate relay K13 are opened. After the main contactor K1 is powered off, the normally closed contacts K1-4 and K1-5 of the main contactor K1 are closed, the normally open contact K1-3 of the main contactor K1 is opened, the time relay T1 loses power, and the normally open contact T1-1 of the time relay T1 is delayed to open, and the delay is ≥20s. During the time delay of opening the normally open contact T1-1 of the time relay T1, the intermediate relay K13 continues to be energized, and the normally closed contacts K13-1 and K13-2 of the intermediate relay K13 are always in the disconnected state. During this period, the electromagnet coil AS and the parallel diode D1 form a conduction circuit, and the reverse potential in the AS coil is discharged through the parallel diode D1. After the set delay, the reverse potential in the coil has been completely released, the normally open contact T1-1 of the time relay T1 is opened, the intermediate relay K13 is de-energized, and the normally closed contacts K13-1 and K13-2 of the intermediate relay K13 are closed;

[0097] After the two pairs of normally closed contacts of the electromagnet main contactor K1 and the two pairs of normally closed contacts of the intermediate relay K13 are closed, the DC resistance transmitter R401 is connected to the electromagnet coil circuit;

[0098] The DC resistance transmitter R401 monitors the DC resistance value of the main pump electromagnet, and converts the DC resistance value of the electromagnet into a 4-20mA signal and sends it to the main control monitoring system.

[0099] The present invention is described in detail above with reference to the accompanying drawings and embodiments, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the present invention. Any content not described in detail in the present invention can adopt the existing technology.

Claims

1. A direct resistance monitoring device for an electromagnet, characterized in that: include: A primary circuit I of a direct resistance monitoring device, a secondary circuit II of a direct resistance monitoring device, a primary circuit of an electromagnet switch, a secondary circuit of an electromagnet switch, a remote control circuit and a plurality of wires; The primary circuit I of the direct resistance monitoring device is connected to the primary circuit of the electromagnet switch through a wire, and the secondary circuit II of the direct resistance monitoring device is connected to the secondary circuit of the electromagnet switch through a wire; the remote control circuit of the electromagnet switch is connected to the secondary circuit of the electromagnet switch through the normally open contact K12-1 of the closing command relay K12 and the normally closed contact K11-1 of the tripping command relay K11; The primary circuit of the electromagnet switch includes: a positive power bus L+, a negative power bus L-, a primary plug X01, a main switch Q0, a main contact K1-1 of a main contactor K1, an electromagnet AS and a diode D1; The positive power bus L+ and the negative power bus L- are connected to the two upper ports of the main switch Q0 through a primary plug X01, and the lower port of the main switch Q0 outputs the positive power supply L1+ and the negative power supply L1-; the positive power supply L1+ is connected to the main contact terminal A of the main contactor K1, the main contact terminal B of the main contactor K1 is short-circuited with the main contact terminal D of the main contactor K1, and the main contact terminal C of the main contactor K1 is connected to the positive pole of the electromagnet AS; The negative power supply L1- is connected to the main contact terminal E of the main contactor K1, the main contact terminal F of the main contactor K1 is connected to the negative pole of the electromagnet AS, the positive pole of the diode D1 is connected to the negative pole of the electromagnet AS, and the negative pole of the diode D1 is connected to the positive pole of the electromagnet AS; The secondary circuit of the electromagnet switch also includes: a control power switch Q1, a fault tripping contact Q0-1 of the main switch Q0, a normally open contact K12-1 of a closing command relay K12, a normally closed contact K11-1 of a tripping command relay K11, a main contactor K1 and a normally open contact K1-2 of the main contactor K1; in the secondary circuit of the electromagnet switch: the two upper ports of the control power switch Q1 are respectively connected to the positive power supply L1+ and the negative power supply L1- of the lower port of the main switch Q0 in the primary circuit of the electromagnet switch through wires; the control power switch Q1 outputs a positive control power supply L2+ and a negative control power supply L2-; the positive control The control power supply L2+ is connected to one end of the fault tripping contact Q0-1 of the main switch Q0, the other end of the fault tripping contact Q0-1 of the main switch Q0 is connected to one end of the normally open contact K12-1 of the closing command relay K12, the other end of the normally open contact K12-1 of the closing command relay K12 is connected to one end of the normally closed contact K11-1 of the tripping command relay K11, the other end of the normally closed contact K11-1 of the tripping command relay K11 is connected to one end of the main contactor K1, the other end of the main contactor K1 is connected to the negative control power supply L2-, the normally open contact K1-2 of the main contactor K1 is connected in parallel with the normally open contact K12-1 of the relay K12; The electromagnetic switch remote control circuit includes a closing command relay K12, a tripping command relay K11, a terminal block X10:23, a terminal block X10:24 and a terminal block X10:25; One end of the closing command relay K12 is connected to the terminal block X10:25, and the other end of the closing command relay K12 is connected to the terminal block X10:

23. One end of the tripping command relay K11 is connected to the terminal block X10:24, and the other end of the tripping command relay K11 is connected to the terminal block X10:

23. The terminal blocks X10:23, X10:24 and X10:25 are arranged on the switch cabinet where the electromagnet switch is located; The primary circuit I of the direct resistance monitoring device is connected to the positive and negative ends of the electromagnet AS in the primary circuit of the electromagnet switch through a wire; The primary circuit I of the DC resistance monitoring device includes: a normally closed contact K1-4 of the main contactor K1, a normally closed contact K1-5 of the main contactor K1, a normally closed node K13-1 of the intermediate relay K13, a normally closed node K13-2 of the intermediate relay K13, a DC resistance transmitter R401, a terminal block X10:21, a terminal block X10:22 and a plurality of wires; One input end of the direct resistance transmitter R401 is connected to one end of the normally closed contact K13-1 of the intermediate relay K13, the other end of the normally closed contact K13-1 of the intermediate relay K13 is connected to one end of the normally closed contact K1-4 of the main contactor K1, the other end of the normally closed contact K1-4 of the main contactor K1 is connected to the positive pole of the electromagnet AS; the other input end of the direct resistance transmitter R401 is connected to one end of the normally closed node K13-2 of the intermediate relay K13, the other end of the normally closed node K13-2 of the intermediate relay K13 is connected to one end of the normally closed contact K1-5 of the main contactor K1, the other end of the normally closed contact K1-5 of the main contactor K1 is connected to the negative pole of the electromagnet AS; The DC resistance transmitter R401 outputs to the terminal blocks X10:21 and X10:22, and the terminal blocks X10:21 and X10:22 are arranged on the switch cabinet where the electromagnetic switch is located; The secondary circuit II of the DC resistance monitoring device is connected to the lower port of the control power switch Q1 in the secondary circuit of the electromagnet switch through a wire; The secondary circuit II of the DC resistance monitoring device includes: a positive control power supply L2+, a negative control power supply L2-, a DC resistance transmitter auxiliary coil R401', an auxiliary power switch Q2, an intermediate relay K13, a main contactor K1 normally open contact K1-3, a time relay T1, a time relay normally open contact T1-1 and a plurality of wires; The upper port of the auxiliary power switch Q2 is connected to the positive control power supply L2+, the lower port of the auxiliary power switch Q2 is connected to one end of the auxiliary coil R401' of the DC resistance transmitter, and the other end of the auxiliary coil R401' of the DC resistance transmitter is connected to the negative control power supply L2-; One end of the normally open contact K1-3 of the main contactor K1 is connected to the positive control power supply L2+, the other end of the normally open contact K1-3 of the main contactor K1 is connected to one end of the time relay T1, and the other end of the time relay T1 is connected to the negative control power supply L2-; One end of the normally open contact T1-1 of the time relay T1 is connected to the positive power supply L2+, the other end of the normally open contact T1-1 of the time relay T1 is connected to one end of the intermediate relay K13, and the other end of the intermediate relay K13 is connected to the negative control power supply L2-.

2. A monitoring method for the direct resistance monitoring device of an electromagnet as claimed in claim 1, characterized in that The steps include: Step 1: Connect the primary circuit Ⅰ and secondary circuit Ⅱ of the DC resistance monitoring device to the primary circuit and secondary circuit of the electromagnet switch respectively to realize the monitoring of the DC resistance value of the main pump electromagnet; control the DC resistance monitoring device to be put into operation or withdrawn through the main contactor K1 and the time relay T1; the normally open contact T1-1 of the time relay T1 is connected to the coil circuit of the intermediate relay K13 to control whether the intermediate relay K13 is energized; the DC resistance transmitter R401 is connected to the positive and negative ends of the electromagnet AS through the two pairs of normally closed contacts of the intermediate relay K13 and the two pairs of normally closed contacts of the main contactor K1 of the electromagnet switch to control the DC resistance transmitter R401 to be put into operation or withdrawn; Step 2: After the main contactor K1 is energized and attracted, the main contact of the main contactor K1 is closed, the electromagnet runs, and at the same time, the normally open contact of the main contactor is instantaneously closed, the time relay T1 is started, the normally open contact T1-1 of the time relay T1 is instantaneously closed, the intermediate relay K13 is energized, and the normally closed contact is opened; the normally closed contact of the intermediate relay and the normally closed contact of the main contactor instantly disconnect the DC resistance transmitter R401 from the electromagnet AS circuit, and the DC resistance transmitter R401 stops running; Step 3: After the main contactor K1 is disconnected, the main contact of the main contactor K1 is disconnected, and the electromagnet stops running; at the same time, the normally open contact of the main contactor K1 is disconnected instantaneously, and the time relay T1 is powered off; the normally closed contact of the main contactor K1 is closed instantaneously; Step 4: The normally open contact T1-1 of the time relay T1 is opened with a delay of ≥20s. During the delay opening period, the intermediate relay K13 continues to be energized, and the normally closed contacts K13-1 and K13-2 of the intermediate relay K13 are always in the disconnected state. During this period, the electromagnet coil AS and the parallel diode D1 form a conduction circuit, and the reverse potential in the AS coil is discharged through the parallel diode D1. After the set delay is reached, the reverse potential in the coil has been completely released, the normally open contact T1-1 of the time relay T1 is opened, the intermediate relay K13 is de-energized, and the normally closed contact of the intermediate relay is closed; Step 5: After the two pairs of normally closed contacts of the electromagnet main contactor K1 and the two pairs of normally closed contacts of the intermediate relay K13 are closed, the DC resistance transmitter R401 is connected to the electromagnet coil circuit; Step 6: The DC resistance transmitter R401 monitors the DC resistance value of the main pump electromagnet, and converts the DC resistance value of the electromagnet into a 4-20mA signal and sends it to the main control monitoring system.

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