A protection outlet circuit online monitoring device and method

Abstract

A device and method for online monitoring of a protection outlet circuit, comprising an electromagnetic isolation sampling module connected to a contact end near a pressure plate tripping by means of electromagnetic isolation; monitoring the potential and polarity of the contact end near the pressure plate tripping to realize pressure plate state detection, pressure plate post-stage outlet circuit state detection and protection outlet behavior recording; using electromagnetically isolated equipment to collect the potential of the contact end near the protection outlet of the pressure plate, avoiding the risk of short circuit in the protection outlet circuit due to component failure, thereby improving the reliability of the operation of the relay protection device, and will no longer be affected by certain human factors. Abnormal conditions of the protection outlet circuit can also be discovered in time, greatly reducing the probability of protection refusal due to the abnormality of the outlet circuit, and completely eliminating the traditional monitoring blind spot of the protection outlet circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of online monitoring of digital relay protection devices, and more specifically, to an online monitoring device and method for a protection outlet circuit. Background Art

[0002] At present, digital relay protection devices have been widely used, and their perfect self-checking function can reach the output relay. However, the circuit after the output tripping / closing contact is a monitoring blind spot. It is impossible to know whether this circuit is abnormal, whether the protection output contact is working normally, whether the pressure plate is reliably put into operation, etc. Therefore, it is impossible to give early warning and alarm, resulting in reduced reliability of relay protection equipment, and problems such as protection refusal to operate caused by the pressure plate not being put into operation, poor contact of the pressure plate, or abnormal output tripping circuit.

[0003] In the prior art, a Chinese invention patent application (CN105097322) discloses a wire spring type protection outlet pressure plate throw-in / out state identification device, which utilizes the pressure when the pressure plate is put into place to squeeze the wire spring, so that the switch is turned on to identify the throw-in / out state of the pressure plate; the device cannot perform overall online monitoring of the outlet circuit, nor can it record the protection action behavior. A Chinese utility model patent (CN204761164U) discloses a throw-in / out identification device that is only applicable to outlet pressure plates with conductive intermediate movable heads; a Chinese invention patent application (CN106841876) proposes to use the throw-in voltage signal of the lower end connecting column of the protection trip outlet pressure plate and the reclosing outlet pressure plate as the basis, and after the steps of collection, conversion, and judgment, finally output a signal that can correctly reflect the state of the protection trip outlet pressure plate and the reclosing outlet pressure plate, but the device uses transistors and optocoupler relays as the main components connected to the outlet circuit, and the device The outlet control circuit is connected by photoelectric isolation. Due to the electrical characteristics of the transistor and the optocoupler relay, it is very easy to affect the outlet control circuit, and this device cannot be used for monitoring the outlet circuit after the pressure plate and recording the protection action behavior. The Chinese invention patent application (CN1078085162) proposes to install an external auxiliary contact on the protective outlet pressure plate, and the status of the protective outlet pressure plate is reflected by the external auxiliary contact. However, the external auxiliary contact can only reflect the position of the pressure plate, and cannot reflect whether the pressure plate is reliably turned on, and cannot monitor the outlet circuit after the pressure plate and record the protection action behavior.

[0004] In summary, in the prior art, in order to monitor the potential of the pressure plate, the monitoring equipment is directly electrically connected to it. If general components or optocoupler devices are used in the monitoring equipment to form a monitoring circuit, there is a risk of short-circuiting the protection outlet circuit due to component failure, thereby causing the protection outlet to trip in error.

[0005] Therefore, it is urgent to propose an online monitoring device and method for a protection outlet circuit, so as to realize effective online monitoring of the protection outlet circuit and the pressure plate status without affecting the normal operation of the protection outlet circuit. Summary of the invention

[0006] In order to solve the deficiencies in the prior art, the purpose of the present invention is to provide an online monitoring device and method for a protection outlet circuit. In order to avoid the risk of the monitoring device's own failure affecting the outlet control circuit, the electromagnetic isolation technology is used to access the control circuit, and the potential of the pressure plate near the protection outlet contact is collected to judge the on-off state of the pressure plate, and the integrity of the outlet circuit after the pressure plate can be monitored; without affecting the original outlet control circuit, the circuit after the protection outlet contact is effectively monitored, and the action state of the protection outlet contact and the pressure plate input state are collected to realize early warning and alarm for abnormal state of the circuit.

[0007] The present invention adopts the following technical solution.

[0008] A protection outlet loop online monitoring device is connected in series between a positive and negative power supply of a control bus, and comprises: a first current limiting resistor, a second current limiting resistor, a power module, a power protection fuse, a first relay, and a second relay.

[0009] The online monitoring device also includes an electromagnetic isolation sampling module; the first input end of the electromagnetic isolation sampling module is connected to the near tripping contact end of the pressure plate in an electromagnetic isolation manner.

[0010] The second and third input terminals of the electromagnetic isolation sampling module are respectively connected to the first current limiting resistor and the second current limiting resistor to form a sampling branch.

[0011] The first output end of the electromagnetic isolation sampling module is connected to the input end of the first relay, and the second output end is connected to the input end of the second relay.

[0012] The power protection fuse is connected in series with the power module to form a power branch.

[0013] After the sampling branch is connected in parallel with the power branch, it is connected in series between the positive and negative power supplies of the control bus.

[0014] Preferably, in the sampling branch, one end of the first current limiting resistor is connected to the positive power supply of the control bus, and the other end is connected to the second input terminal of the electromagnetic isolation sampling module; one end of the second current limiting resistor is connected to the negative power supply of the control bus, and the other end is connected to the third input terminal of the electromagnetic isolation sampling module; the housing of the electromagnetic isolation sampling module is provided with a shielded ground terminal directly grounded,

[0015] In the power branch, one end of the power protection fuse is connected to the positive power supply of the control bus, and the other end is connected to one end of the power module; the other end of the power module is connected to the negative power supply of the relay protection control bus.

[0016] Preferably, the electromagnetic isolation sampling module comprises: a sampling component, a magnetic sensitive element, a first amplifying component, and a second amplifying component.

[0017] The first input end of the sampling component is the first input end of the electromagnetic isolation sampling module, the second input end of the sampling component is the second input end of the electromagnetic isolation sampling module, and the third input end of the sampling component is the third input end of the electromagnetic isolation sampling module.

[0018] The sampling component is connected to the magnetic sensitive element through electromagnetic induction.

[0019] The first output end of the magnetic sensitive element is connected to the input end of the first amplifying component, and the second output end of the magnetic sensitive element is connected to the input end of the second amplifying component.

[0020] The output end of the first amplifying component is the first output end of the electromagnetic isolation sampling module, and the output end of the second amplifying component is the second output end of the electromagnetic isolation sampling module.

[0021] When direct currents of different directions pass through the sampling component, the direct current magnetic field generated in the sampling component acts on the magnetic sensitive element through electromagnetic induction; the magnetic sensitive element outputs two signals according to the different directions of the direct current: the first signal is amplified by the first amplifying component, and the obtained first driving signal is used to drive the first relay; the second amplified signal is amplified by the second amplifying component, and the obtained second driving signal is used to drive the second relay.

[0022] The first relay outputs a first remote signaling signal, and the second relay outputs a second remote signaling signal.

[0023] The steps of an online monitoring method for protecting an outlet circuit are as follows:

[0024] Step 1, in the current sampling period, using electromagnetic isolation to collect the potential and potential polarity of the contact end of the pressure plate near the tripping switch; collecting external auxiliary state information; wherein the potential and potential polarity of the contact end of the pressure plate near the tripping switch are collected using an electromagnetic isolation sampling module;

[0025] Step 2, when the potential of the contact end near the pressure plate tripping is not zero, the electromagnetic isolation sampling module sends a drive signal to the first relay and the second relay respectively according to the potential polarity of the contact end near the pressure plate tripping; according to the drive signal, the first relay outputs a first remote signaling signal, and the second relay outputs a second remote signaling signal;

[0026] Step 3, based on the first remote signal, the second remote signal and the external auxiliary status information, in the current sampling period, the online monitoring results of the pressure plate input status, the protection output circuit status and the action behavior of the relay protection device can be obtained.

[0027] Preferably, in step 1, external auxiliary status information is obtained through field observation or a monitoring system, and the external auxiliary status information includes: circuit breaker opening and closing status, manual observation results of pressure plate status, protection device action message, device remote signal change time and circuit breaker opening time.

[0028] Preferably, step 2 comprises:

[0029] When the potential of the pressure plate near the tripping contact is not zero and is positive, the electromagnetic isolation sampling module sends a first drive signal to the first relay;

[0030] When the potential of the pressure plate near the tripping contact is not zero and is negative, the electromagnetic isolation sampling module sends a second drive signal to the second relay.

[0031] Preferably, in step 3, when the potential of the pressure plate near the tripping contact end is not zero, in the current sampling period, the online monitoring results of the pressure plate input state, the protection output circuit state and the action behavior of the relay protection device are as follows:

[0032] (1) When the first remote signal is 1 and the second remote signal is 0, and the circuit breaker is in the closed state, it is determined that the pressure plate is in a reliable on-state and the protection output circuit is in a normal state;

[0033] (2) When the first remote signal is 0 and the second remote signal is 1, and the circuit breaker is in the open state, it is determined that the pressure plate is in a reliable on-state and the protection output circuit is in a normal state;

[0034] (3) When the first telesignal signal is 0 and the second telesignal signal is 1, and the circuit breaker is in the closed state and the manual observation result of the pressure plate state is reliable, it is determined that the pressure plate back-stage output circuit is abnormal; (4) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, and the circuit breaker changes from the closed state to the open state, and the protection device has an action message, the monitoring device telesignal change time is earlier than the circuit breaker opening time, it is determined that the pressure plate has been reliably put into operation, the protection output circuit is intact, and the protection device action behavior is normal;

[0035] (4) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, and the circuit breaker changes from the closed state to the open state, and there is no action message of the protection device, the telesignal change time of the monitoring device is later than the circuit breaker tripping time, it can be determined that the pressure plate has been reliably put into operation, the protection outlet circuit is intact, and there are problems with the circuit breaker body and / or the circuit breaker related circuits that cause the circuit breaker to trip incorrectly, but the protection device action behavior is normal;

[0036] (5) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, and the circuit breaker changes from the closed state to the open state, and the protection device has no action output message, the monitoring device telesignal change time is earlier than the circuit breaker tripping time, then it can be determined that the pressure plate has been reliably put into operation, the protection output circuit is intact, the circuit breaker is opened under the drive of the protection device, but the action behavior of the protection device is abnormal;

[0037] (6) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, and the circuit breaker does not trip and the protection device has an action message, it can be determined that the pressure plate has been reliably put into operation, the protection device operates normally, and there is a problem with the subsequent output circuit of the pressure plate and / or the circuit breaker body, causing the circuit breaker to refuse to operate.

[0038] Preferably, in step 3, the potential of the pressure plate near the tripping contact end is zero. In the current sampling period, when the first telesignal signal and the second telesignal signal are both 0 and the circuit breaker is in the closed state, the pressure plate operation instruction is obtained, and the online monitoring results of the pressure plate input state, the protection outlet circuit state and the action behavior of the relay protection device are as follows:

[0039] (1) When the pressure plate operation instruction is to be put into operation, it is determined that the pressure plate is in an unreliable conduction state and / or there is an abnormality in the pressure plate rear-stage outlet circuit;

[0040] (2) When the pressure plate operation instruction requires exiting operation, it is determined that the pressure plate is in a normal exit open state.

[0041] Preferably, step 3 further comprises: indicating the online monitoring result of the protection outlet circuit status by the signal light status and color:

[0042] (1) When the first remote signal and the second remote signal are both 0, the signal light goes out;

[0043] (2) When the first remote signal is 1 and the second remote signal is 0, the signal light is on and turns red, indicating that the circuit breaker is in the closed state;

[0044] (3) When the first remote signal is 0 and the second remote signal is 1, the signal light is on and turns green, indicating that the circuit breaker is in the open state;

[0045] (4) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, the signal light changes from red to green, indicating that the circuit breaker changes from the closed state to the open state.

[0046] The beneficial effects of the present invention are as follows:

[0047] (1) Using electromagnetically isolated equipment, the potential of the contact end of the pressure plate near the protection outlet is collected to determine the on / off state of the pressure plate, and the integrity of the outlet circuit behind the pressure plate can be monitored to avoid the risk of short circuit in the protection outlet circuit due to failure of the monitoring equipment components, so that the reliability of the relay protection equipment is improved and the reliability of the protection equipment will no longer be affected by certain human factors. It can also timely detect abnormal conditions in the protection outlet circuit, greatly reduce the probability of protection refusal due to abnormalities in the outlet circuit, and completely eliminate the traditional monitoring blind spot of the protection outlet circuit; at the same time, the protection outlet action behavior record can also provide relevant evidence information for accident analysis, so that the accident analysis capability is improved and the definition of accident responsibility is clearer.

[0048] (2) Inside the electromagnetically isolated device, only one end of the sampling coil is connected to the contact end of the pressure plate near the protection outlet. Therefore, failure of the internal components of the device will not pose a risk to the protection outlet circuit. In addition, each point inside the device has also undergone multi-level insulation withstand voltage testing to ensure that there will be no short circuit between the circuit boards, thereby affecting the protection outlet circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is the electrical principle wiring diagram of the protection outlet circuit online monitoring device of the present invention;

[0050] The accompanying drawings are described as follows:

[0051] +KM: controls the positive power supply of the bus; -KM: controls the negative power supply of the bus;

[0052] 1RD: Fuse that controls the positive / negative power supply of the bus;

[0053] LP-H: reclosing pressure plate; LP-T: tripping pressure plate; SK: manual control switch;

[0054] DL1: Circuit breaker auxiliary contact 1; DL2: Circuit breaker auxiliary contact 2

[0055] HJ: reclosing relay output contact; HC: closing coil;

[0056] TBJ: jump blocking relay; TWJ: trip position relay; HWJ: closing position relay;

[0057] TQ: tripping coil; TJ: protection output tripping contact;

[0058] Fuse: power protection fuse;

[0059] R 1 : The first current limiting resistor; R 2 : The second current limiting resistor;

[0060] Core: electromagnetic isolation sampling module; Power: power supply module;

[0061] J1: first relay; J2: second relay;

[0062] S-Ground: Shielding ground of monitoring device;

[0063] 5V-Test: 5V test of monitoring device;

[0064] D 1 -D 12 : Terminals 1 to 12 in the monitoring device

[0065] Figure 2 A schematic diagram of electrical terminals of an online monitoring device for a protection outlet circuit of the present invention;

[0066] The accompanying drawings are described as follows:

[0067] D 1 : The outlet pressure plate protects the contact end; D 2 : Boundary empty terminal; D 3 : Connect to the positive power supply of the control bus;

[0068] D 4 : Connect in parallel to terminal No. 3 (open during testing); D 5 : Connect to the negative power supply of the control bus;

[0069] D 6 : Connect in parallel to terminal No. 5 (open during testing); D 7 : Test terminal (for device detection);

[0070] D 8 : Connect to shield ground; D 9 : Boundary empty terminal;

[0071] D 10 : Output signal 1 (connected to protection remote signal 1); D 11 : Output signal common terminal;

[0072] D 12 :Output signal 2 (connect to protection remote signal 2)

[0073] Figure 3 It is a structural schematic diagram of the electromagnetic isolation sampling module of the present invention;

[0074] Figure 4 It is a flow chart of the online monitoring method of the protection outlet circuit of the present invention;

[0075] Figure 5 It is an equivalent circuit diagram of the online monitoring device for the protection outlet circuit of the present invention when the pressure plate is reliably turned on, the circuit after the pressure plate is intact, and is in the closed state;

[0076] Figure 6 This is an equivalent circuit diagram of the online monitoring device for the protection outlet circuit of the present invention when the pressure plate is reliably turned on and is in the open state. DETAILED DESCRIPTION

[0077] The present application is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present application.

[0078] like Figure 1 As shown in the dotted line frame, an online monitoring device for the protection output circuit is connected in series between the positive power supply +KM and the negative power supply -KM of the control bus, including: a first current limiting resistor R 1 , the second current limiting resistor R 2 , power module Power, power protection fuse Fuse, first relay J1, second relay J2.

[0079] The online monitoring device also includes an electromagnetic isolation sampling module Core; the first input terminal of the electromagnetic isolation sampling module Core is connected to the first terminal D in the detection device 1 , and is connected to the near-tripping contact end of the tripping pressure plate LP-T using electromagnetic isolation.

[0080] The second and third input terminals of the electromagnetic isolation sampling module Core are respectively connected to the first current limiting resistor R 1 And the second current limiting resistor R 2 connected to form a sampling branch.

[0081] The first output end of the electromagnetic isolation sampling module Core is connected to the input end of the first relay J1, and the second output end is connected to the input end of the second relay J2.

[0082] The power protection fuse Fuse is connected in series with the power module Power to form a power branch.

[0083] After the sampling branch is connected in parallel with the power branch, it is connected in series between the positive power supply +KM and the negative power supply -KM of the control bus.

[0084] In the preferred embodiment of the present invention, the protection outlet circuit online monitoring device can be used to monitor the state of the circuit after the protection outlet contact. The circuit state can be characterized by the potential of the near trip contact end of the pressure plate LP-T. Therefore, the protection outlet circuit online monitoring device is connected to the end point. By monitoring the potential of the point and adding external auxiliary state information, a variety of online monitoring results such as the pressure plate throw-in and retraction state, the pressure plate circuit after the state and the action behavior of the relay protection device can be obtained. In addition, the online monitoring device is connected to the relay protection control circuit by electromagnetic isolation, which can effectively block the influence of the online monitoring device's own fault on the control circuit or the false operation and refusal to operate caused by the online monitoring device's own fault.

[0085] Technical personnel in the relevant field can design online monitoring devices with different circuit structures to connect to any other contact point of the protection outlet circuit, collect the required signals and obtain various online monitoring results including the status of the protection outlet circuit through numerical calculation. It is worth noting that the inventive concepts of these online monitoring devices using electromagnetic isolation to achieve access to any contact point of the protection outlet circuit all fall within the protection scope of the present invention.

[0086] In a preferred embodiment of the present invention, the first current limiting resistor R 1 and the second current limiting resistor R 2 They are all high-resistance current-limiting resistors, and their resistance values ​​are all greater than 1MΩ. Therefore, the current flowing through the online monitoring device of the protection outlet circuit is less than 220μA. Therefore, when the online monitoring device of the protection outlet circuit is connected to the relay protection control circuit, it will not affect the normal operation of the control circuit.

[0087] It is worth noting that technicians in the field can select the first current limiting resistor R according to the needs of engineering applications. 1 and the second current limiting resistor R 2 The resistance value is set to avoid adverse effects on the normal operation of the control loop after the online monitoring device is connected to the control loop. The resistance value in the preferred embodiment of the present invention is a non-restrictive and preferred choice.

[0088] Specifically, in the sampling branch, the first current limiting resistor R 1 One end of the cable is connected to terminal D 4 Connected to the control bus positive power supply +KM, and the other end is connected to the second input end of the electromagnetic isolation sampling module Core; the second current limiting resistor R 2 One end is connected to terminal D 6 The other end is connected to the negative power supply -KM of the control bus, and the other end is connected to the third input terminal of the electromagnetic isolation sampling module Core; the shell of the electromagnetic isolation sampling module Core is provided with a shielded ground terminal that is directly grounded through terminal D 7 The lead-out monitoring device is connected to the grounding copper busbar of the protection panel cabinet.

[0089] In the power branch, one end of the power protection fuse Fuse is connected to the third terminal D 3 The lead is connected to the control bus positive power supply +KM, and the other end is connected to one end of the power module Power; the other end of the power module is connected to the 5th terminal D 5 Lead out and connect to the negative power supply -KM of the relay protection control bus.

[0090] The power module Power provides working power for the online monitoring device of the protection export circuit to ensure the normal operation of the online monitoring device.

[0091] like Figure 2 The sampling branch is connected to the power branch and the control bus positive power supply +KM through the No. 4 terminal D 4 With terminal D 3 The sampling branch is connected to the power branch and the control bus negative power supply -KM through the No. 6 terminal D 6 With terminal D 5 The short-circuiting is realized by adopting such a short-circuiting method, which makes it easy for the online monitoring device proposed by the present invention to disconnect the electrical connection between the sampling branch and the power supply branch when performing the insulation withstand voltage test. It is worth noting that the short-circuiting method adopted in the preferred embodiment of the present invention is a non-restrictive and preferred choice.

[0092] like Figure 3 The electromagnetic isolation sampling module Core includes: a sampling component, a magnetic sensitive element, a first amplifying component, and a second amplifying component.

[0093] The first input end of the sampling component is the first input end of the electromagnetic isolation sampling module, the second input end of the sampling component is the second input end of the electromagnetic isolation sampling module, and the third input end of the sampling component is the third input end of the electromagnetic isolation sampling module.

[0094] The sampling component and the magnetic sensitive element are connected by electromagnetic induction.

[0095] The first output end of the magnetic sensitive element is connected to the input end of the first amplifying component, and the second output end of the magnetic sensitive element is connected to the input end of the second amplifying component.

[0096] The output end of the first amplifying component is the first output end of the electromagnetic isolation sampling module, and the output end of the second amplifying component is the second output end of the electromagnetic isolation sampling module.

[0097] When direct currents of different directions pass through the sampling component, the direct current magnetic field generated in the sampling component acts on the magnetic sensitive element through electromagnetic induction; the magnetic sensitive element outputs two signals according to the different directions of the direct current: the first signal is amplified by the first amplifying component, and the obtained first driving signal is used to drive the first relay J1; the second amplified signal is amplified by the second amplifying component, and the obtained second driving signal is used to drive the second relay J2.

[0098] The first relay J1 outputs a first remote signaling signal, and the second relay J2 outputs a second remote signaling signal.

[0099] like Figure 4 , a method for online monitoring of a protection export circuit comprises the following steps:

[0100] Step 1: In the current sampling cycle, the potential and potential polarity of the contact end of the pressure plate near the tripping contact are collected by electromagnetic isolation; external auxiliary status information is collected; wherein, the potential and potential polarity of the contact end of the pressure plate near the tripping contact are collected by the electromagnetic isolation sampling module.

[0101] In this preferred embodiment, the external auxiliary status information is obtained through manual observation, integrated system presentation, etc.

[0102] Specifically, in step 1, the external auxiliary status information is obtained through field observation or a monitoring system, and the external auxiliary status information includes: the opening and closing status of the circuit breaker, the manual observation results of the pressure plate status, and the action message of the relay protection device.

[0103] Step 2, when the potential of the pressure plate near tripping contact end is not zero, the electromagnetic isolation sampling module sends a drive signal to the first relay and the second relay respectively according to the potential polarity of the pressure plate near tripping contact end; according to the drive signal, the first relay outputs the first telesignaling signal, and the second relay outputs the second telesignaling signal.

[0104] Specifically, step 2 includes:

[0105] When the potential of the pressure plate near the tripping contact is not zero and is positive, the electromagnetic isolation sampling module sends a first driving signal to the first relay.

[0106] When the potential of the pressure plate near the tripping contact is not zero and is negative, the electromagnetic isolation sampling module sends a second drive signal to the second relay.

[0107] In this preferred embodiment, when the potential of the pressure plate near the tripping contact terminal is not zero and is negative, and the circuit breaker is in the closed state, Figure 5 In the equivalent circuit shown, the following are included in order of current direction: control bus positive power supply +KM, first current limiting resistor R 1, electromagnetic isolation sampling module Core, pressure plate LP-T, anti-trip relay coil TBJ, circuit breaker normally open auxiliary contact DL, trip coil TQ and relay protection control bus negative power supply -KM.

[0108] Among them, terminal D 4 With terminal D 3 Short-circuit, connect resistors in series at the control bus positive power supply +KM and the relay protection control bus negative power supply -KM respectively.

[0109] In this preferred embodiment, when the potential of the pressure plate near the tripping contact terminal is not zero and is positive, and the circuit breaker is in the open state, Figure 6 In the equivalent circuit shown, the following are included in order of current direction: control bus positive power supply +KM, closing position relay coil HWJ, pressure plate LP-T, electromagnetic isolation sampling module Core, second current limiting resistor R 2 And control bus negative power supply -KM.

[0110] Among them, terminal D 6 With terminal D 5 Short-circuit, connect resistors in series at the control bus positive power supply +KM and the control bus negative power supply -KM respectively.

[0111] Step 3, based on the first remote signal, the second remote signal and the external auxiliary status information, in the current sampling period, the online monitoring results of the pressure plate input status, the protection output circuit status and the action behavior of the relay protection device can be obtained.

[0112] Specifically, in step 3, when the potential of the pressure plate near the tripping contact is not zero, the online monitoring results of the pressure plate input state, the protection output circuit state and the action behavior of the relay protection device in the current sampling period are as follows:

[0113] (1) When the first remote signal is 1 and the second remote signal is 0, and the circuit breaker is in the closed state, it is determined that the pressure plate is in a reliable on-state and the protection output circuit is in a normal state;

[0114] (2) When the first remote signal is 0 and the second remote signal is 1, and the circuit breaker is in the open state, it is determined that the pressure plate is in a reliable on-state and the protection output circuit is in a normal state;

[0115] (3) When the first telesignal signal is 0 and the second telesignal signal is 1, and the circuit breaker is in the closed state and the manual observation result of the pressure plate state is reliable, it is determined that the pressure plate back-stage output circuit is abnormal; (4) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, and the circuit breaker changes from the closed state to the open state, and the protection device has an action message, the monitoring device telesignal change time is earlier than the circuit breaker opening time, it is determined that the pressure plate has been reliably put into operation, the protection output circuit is intact, and the protection device action behavior is normal;

[0116] (4) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, and the circuit breaker changes from the closed state to the open state, and there is no action message of the protection device, the telesignal change time of the monitoring device is later than the circuit breaker tripping time, it can be determined that the pressure plate has been reliably put into operation, the protection outlet circuit is intact, and there are problems with the circuit breaker body and / or the circuit breaker related circuits that cause the circuit breaker to trip incorrectly, but the protection device action behavior is normal;

[0117] (5) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, and the circuit breaker changes from the closed state to the open state, and the protection device has no action output message, the monitoring device telesignal change time is earlier than the circuit breaker tripping time, then it can be determined that the pressure plate has been reliably put into operation, the protection output circuit is intact, the circuit breaker is opened under the drive of the protection device, but the action behavior of the protection device is abnormal;

[0118] (6) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, and the circuit breaker does not trip and the protection device has an action message, it can be determined that the pressure plate has been reliably put into operation, the protection device operates normally, and there is a problem with the subsequent output circuit of the pressure plate and / or the circuit breaker body, causing the circuit breaker to refuse to operate.

[0119] Specifically, in step 3, the potential of the pressure plate near the tripping contact is zero. In the current sampling period, when the first telesignal signal and the second telesignal signal are both 0 and the circuit breaker is in the closed state, the pressure plate operation instruction is obtained, and the online monitoring results of the pressure plate input state, the protection output circuit state and the action behavior of the relay protection device are as follows:

[0120] (1) When the pressure plate operation instruction is to be put into operation, it is determined that the pressure plate is in an unreliable conduction state and / or there is an abnormality in the pressure plate rear-stage outlet circuit;

[0121] (2) When the pressure plate operation instruction requires exiting operation, it is determined that the pressure plate is in a normal exit open state.

[0122] In this preferred embodiment, the pressure plate operation instructions include: put into operation and exit operation. If the pressure plate operation instruction is to exit operation, then the two telesignal signals of the online monitoring device are both zero, which is the correct state; if the pressure plate operation instruction is to put into operation, and the two telesignal signals of the online monitoring device are both zero, then it can be determined that the pressure plate is not put into operation or there is a problem with the pressure plate's back-stage circuit. Therefore, when both telesignal signals are zero, it is necessary to obtain the pressure plate operation instruction, and cooperate with the operation instruction to determine the pressure plate input status and the protection outlet circuit status. Generally speaking, the pressure plate operation instruction is determined by the operation mode and is operated by the operator.

[0123] Specifically, step 3 also includes: indicating the online monitoring result of the protection exit circuit status by the status and color of the signal light:

[0124] (1) When the first remote signal and the second remote signal are both 0, the signal light goes out;

[0125] (2) When the first remote signal is 1 and the second remote signal is 0, the signal light is on and turns red, indicating that the circuit breaker is in the closed state;

[0126] (3) When the first remote signal is 0 and the second remote signal is 1, the signal light is on and turns green, indicating that the circuit breaker is in the open state;

[0127] (4) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, the signal light changes from red to green, indicating that the circuit breaker changes from the closed state to the open state.

[0128] In this preferred embodiment, when the relay protection control circuit is operating normally, the protection outlet circuit online monitoring device is used to monitor the throw-in and throw-out status of the outlet pressure plate and whether the outlet circuit is abnormal. The online monitoring device can effectively detect the state where the pressure plate is not put into operation or the state where it is not reliably contacted. If the above situation occurs, the "loop normal" indicator light of the online monitoring device will be off. After the pressure plate is reliably put into operation, the "loop normal" indicator light will be on for a long time. When the circuit breaker is in the closed state, the indicator light is red; when the circuit breaker is in the open state, the indicator light is green.

[0129] The online monitoring device for the protection outlet circuit can not only display the input and output status of the pressure plate on site, but also feedback the output pressure plate status to the protection device through the protection remote signal. Through the definition of the integrated system, the pressure plate status can be accurately presented on the background monitoring system. The operator can remotely monitor the input and output status of the pressure plate in real time, without having to go to the protection screen to observe the input and output status of the pressure plate with the naked eye as in the past.

[0130] The online monitoring device of the protection output circuit can feed back the protection action output status to the protection device through the telesignal. According to the telesignal change, the protection device and the monitoring system can accurately record the output driving tripping coil and the reclosing coil of the protection device tripping and / or non-protection device action, so that the accident analysis can be based on evidence.

[0131] The beneficial effects of the present invention are as follows:

[0132] (1) Using electromagnetically isolated equipment, the potential of the contact end of the pressure plate near the protection outlet is collected to determine the on / off state of the pressure plate, and the integrity of the outlet circuit behind the pressure plate can be monitored to avoid the risk of short circuit in the protection outlet circuit due to component failure, thereby improving the reliability of the relay protection equipment and preventing certain human factors from affecting the reliability of the protection equipment. It can also detect abnormal conditions in the protection outlet circuit in a timely manner, greatly reducing the probability of protection refusal due to abnormalities in the outlet circuit, and completely eliminating the traditional monitoring blind spot of the protection outlet circuit. At the same time, the protection outlet action behavior record can also provide relevant evidence information for accident analysis, thereby improving the accident analysis capability and making the definition of accident responsibility clearer.

[0133] (2) Inside the electromagnetically isolated device, only one end of the sampling coil is connected to the contact end of the pressure plate near the protection outlet. Therefore, failure of the internal components of the device will not pose a risk to the protection outlet circuit. In addition, each point inside the device has also undergone multi-level insulation withstand voltage testing to ensure that there will be no short circuit between the circuit boards, thereby affecting the protection outlet circuit.

[0134] The applicant of the present invention has made a detailed explanation and description of the implementation examples of the present invention in conjunction with the drawings in the specification. However, those skilled in the art should understand that the above implementation examples are only preferred implementation schemes of the present invention, and the detailed description is only to help readers better understand the spirit of the present invention, but not to limit the scope of protection of the present invention. On the contrary, any improvements or modifications based on the inventive spirit of the present invention should fall within the scope of protection of the present invention.

Claims

1. An online monitoring device for a protection outlet circuit, connected in series between the positive and negative power supplies of a control bus, the online monitoring device comprising: A first current limiting resistor, a second current limiting resistor, a power module, a power protection fuse, a first relay, and a second relay, characterized in that: The online monitoring device also includes an electromagnetic isolation sampling module; the electromagnetic isolation sampling module includes: a sampling component, a magnetic sensor, a first amplifying component, and a second amplifying component; the first input end of the sampling component is the first input end of the electromagnetic isolation sampling module, the second input end of the sampling component is the second input end of the electromagnetic isolation sampling module, and the third input end of the sampling component is the third input end of the electromagnetic isolation sampling module; the sampling component and the magnetic sensor are connected through electromagnetic induction; the first output end of the magnetic sensor is connected to the input end of the first amplifying component, and the second output end of the magnetic sensor is connected to the input end of the second amplifying component; the output end of the first amplifying component is the first output end of the electromagnetic isolation sampling module, and the output end of the second amplifying component is the second output end of the electromagnetic isolation sampling module; when direct currents of different directions pass through the sampling component, the direct current magnetic field generated in the sampling component acts on the magnetic sensor through electromagnetic induction; the magnetic sensor outputs two signals according to the different directions of the direct current: the first signal is amplified by the first amplifying component, and the obtained first drive signal is used to drive the first relay; the second amplified signal is amplified by the second amplifying component, and the obtained second drive signal is used to drive the second relay; the first relay outputs a first remote signal, and the second relay outputs a second remote signal; The first input end of the electromagnetic isolation sampling module is connected to the near tripping contact end of the pressure plate by electromagnetic isolation; The second and third input terminals of the electromagnetic isolation sampling module are respectively connected to the first current limiting resistor and the second current limiting resistor to form a sampling branch; The first output end of the electromagnetic isolation sampling module is connected to the input end of the first relay, and the second output end is connected to the input end of the second relay; The power protection fuse is connected in series with the power module to form a power branch circuit; After the sampling branch is connected in parallel with the power branch, it is connected in series between the positive and negative power supplies of the control bus.

2. The online monitoring device for a protection outlet circuit according to claim 1 is characterized in that: In the sampling branch, one end of the first current limiting resistor is connected to the positive power supply of the control bus, and the other end is connected to the second input end of the electromagnetic isolation sampling module; one end of the second current limiting resistor is connected to the negative power supply of the control bus, and the other end is connected to the third input end of the electromagnetic isolation sampling module; the housing of the electromagnetic isolation sampling module is provided with a shielded ground terminal directly grounded; In the power branch, one end of the power protection fuse is connected to the positive power supply of the control bus, and the other end is connected to one end of the power module; the other end of the power module is connected to the negative power supply of the relay protection control bus.

3. A method for online monitoring of a protection outlet circuit implemented by using the online monitoring device for the protection outlet circuit according to any one of claims 1 to 2, characterized in that: The steps of the online monitoring method are as follows: Step 1, in the current sampling period, using electromagnetic isolation to collect the potential and potential polarity of the contact end of the pressure plate near the tripping switch; collecting external auxiliary state information; wherein the potential and potential polarity of the contact end of the pressure plate near the tripping switch are collected using an electromagnetic isolation sampling module; Step 2, when the potential of the contact end near the pressure plate tripping is not zero, the electromagnetic isolation sampling module sends a drive signal to the first relay and the second relay respectively according to the potential polarity of the contact end near the pressure plate tripping; according to the drive signal, the first relay outputs a first remote signaling signal, and the second relay outputs a second remote signaling signal; Step 3, based on the first remote signal, the second remote signal and the external auxiliary status information, in the current sampling period, the online monitoring results of the pressure plate input status, the protection outlet circuit status and the action behavior of the protection device can be obtained.

4. The method for online monitoring of a protection outlet circuit according to claim 3 is characterized in that: In step 1, the external auxiliary status information is obtained through field observation or monitoring system, and the external auxiliary status information includes: circuit breaker opening and closing status, manual observation results of pressure plate status, protection device action message, device remote signal change time and circuit breaker opening time.

5. The method for online monitoring of a protection outlet circuit according to claim 4, characterized in that: Step 2 includes: When the potential of the pressure plate near the tripping contact is not zero and is positive, the electromagnetic isolation sampling module sends a first drive signal to the first relay; When the potential of the pressure plate near the tripping contact is not zero and is negative, the electromagnetic isolation sampling module sends a second drive signal to the second relay.

6. A method for online monitoring of a protection outlet circuit according to claim 5, characterized in that: In step 3, when the potential of the pressure plate near the tripping contact is not zero, the online monitoring results of the pressure plate input state, the protection output circuit state and the protection device action behavior in the current sampling period are as follows: (1) When the first remote signal is 1 and the second remote signal is 0, and the circuit breaker is in the closed state, it is determined that the pressure plate is in a reliable on-state and the protection output circuit is in a normal state; (2) When the first remote signal is 0 and the second remote signal is 1, and the circuit breaker is in the open state, it is determined that the pressure plate is in a reliable on-state and the protection output circuit is in a normal state; (3) When the first remote signal is 0 and the second remote signal is 1, and the circuit breaker is in the closed state and the manual observation result of the pressure plate state is reliable, it is determined that the pressure plate rear-stage output circuit is abnormal; (4) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, and the circuit breaker changes from the closed state to the open state, and the protection device has an action message, the monitoring device telesignal change time is earlier than the circuit breaker opening time, then it is determined that the pressure plate has been reliably put into operation, the protection output circuit is intact, and the protection device action behavior is normal; (5) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, and the circuit breaker changes from the closed state to the open state, and there is no action message from the protection device, the monitoring device telesignal change time is later than the circuit breaker tripping time, then it can be determined that the pressure plate has been reliably put into operation, the protection output circuit is intact, and there is a problem with the circuit breaker body and / or the circuit breaker related circuit that causes the circuit breaker to trip incorrectly, but the protection device action behavior is normal; (6) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, and the circuit breaker changes from the closed state to the open state, and the protection device has no action output message, the monitoring device telesignal change time is earlier than the circuit breaker tripping time, then it can be determined that the pressure plate has been reliably put into operation, the protection output circuit is intact, the circuit breaker is opened under the drive of the protection device, but the action behavior of the protection device is abnormal; (7) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, and the circuit breaker does not trip and the protection device has an action message, it can be determined that the pressure plate has been reliably put into operation, the protection device operates normally, and there is a problem with the subsequent output circuit of the pressure plate and / or the circuit breaker body, causing the circuit breaker to refuse to operate.

7. The method for online monitoring of a protection outlet circuit according to claim 4, characterized in that: In step 3, the potential of the pressure plate near the tripping contact is zero. In the current sampling period, when the first telesignal signal and the second telesignal signal are both 0 and the circuit breaker is in the closed state, the pressure plate operation instruction is obtained, and the online monitoring results of the pressure plate input state, the protection output circuit state and the action behavior of the relay protection device are as follows: (1) When the pressure plate operation instruction is to be put into operation, it is determined that the pressure plate is in an unreliable conduction state and / or there is an abnormality in the pressure plate's downstream output circuit; (2) When the pressure plate operation instruction requires exiting operation, the pressure plate is judged to be in the normal exit open state.

8. The method for online monitoring of a protection outlet circuit according to claim 3 is characterized in that: Step 3 also includes: indicating the online monitoring result of the protection outlet circuit status by the signal light status and color: (1) When both the first telesignal signal and the second telesignal signal are 0, the signal light goes out; (2) When the first remote signal is 1 and the second remote signal is 0, the signal light is on and turns red, indicating that the circuit breaker is in the closed state; (3) When the first remote signal is 0 and the second remote signal is 1, the signal light is on and turns green, indicating that the circuit breaker is in the open state; (4) When the first telesignal signal changes from 1 to 0 and the second telesignal signal changes from 0 to 1, the signal light changes from red to green, indicating that the circuit breaker changes from the closed state to the open state.

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