CN111628480A - Protection device and method for circuit breaker excitation coil - Google Patents
Protection device and method for circuit breaker excitation coil Download PDFInfo
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- CN111628480A CN111628480A CN202010381381.8A CN202010381381A CN111628480A CN 111628480 A CN111628480 A CN 111628480A CN 202010381381 A CN202010381381 A CN 202010381381A CN 111628480 A CN111628480 A CN 111628480A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/008—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for protective arrangements according to this subclass
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/327—Testing of circuit interrupters, switches or circuit-breakers
- G01R31/333—Testing of the switching capacity of high-voltage circuit-breakers ; Testing of breaking capacity or related variables, e.g. post arc current or transient recovery voltage
- G01R31/3333—Apparatus, systems or circuits therefor
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/22—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for distribution gear, e.g. bus-bar systems; for switching devices
- H02H7/222—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for distribution gear, e.g. bus-bar systems; for switching devices for switches
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- Emergency Protection Circuit Devices (AREA)
Abstract
The invention discloses a protection device and a protection method for a circuit breaker magnet exciting coil. The protection device includes: the circuit breaker comprises a circuit breaker control loop, an excitation coil closing protection unit and an excitation coil monitoring unit; the excitation coil closing protection unit comprises: the protection circuit comprises a first relay, a first protection switch and a first freewheeling diode; the exciting coil monitoring unit includes: the protection circuit comprises a first voltage division circuit, a first current transformer, a relay drive circuit, a first protection switch drive circuit and a microprocessor. The invention can protect the exciting coil of the circuit breaker to the maximum extent by monitoring the exciting current waveform and time in the opening and closing process of the circuit breaker in real time, thereby analyzing and early warning the fault problem of the circuit breaker or potential fault hidden danger and protecting and controlling the exciting coil in real time.
Description
Technical Field
The invention relates to the technical field of circuit breakers, in particular to a protection device and a protection method for an excitation coil of a circuit breaker.
Background
Circuit breakers are the core protection and control devices in power transmission lines. Whether the circuit breaker can normally operate is related to the safety of the whole power transmission system. However, in actual operation, the switch-on/off excitation coil of the circuit breaker is often burnt during the switch-on/off operation process, and even the mechanism box of the circuit breaker is burnt, so that the switch-on/off operation cannot be normally performed. The operating personnel carry out a large amount of analyses to the reason that the coil burns out, to different trouble problems, operating personnel have also proposed many preventive maintenance measures, but these measures are mostly to specific fault reason to need to adopt artifical method of regularly patrolling, and have many measures to maintain afterwards, can't in time protect according to the online state of excitation coil.
Disclosure of Invention
The embodiment of the invention provides a protection device and a protection method for a circuit breaker magnet exciting coil, and aims to solve the problem that the circuit breaker magnet exciting coil cannot be protected in time according to the online state of the circuit breaker magnet exciting coil in the prior art.
In a first aspect, there is provided a protection apparatus for a circuit breaker exciting coil, the circuit breaker exciting coil including: closing coil and first separating brake coil, protection device includes: the circuit breaker comprises a circuit breaker control loop, an excitation coil closing protection unit and an excitation coil monitoring unit;
the excitation coil closing protection unit comprises: the circuit breaker comprises a first relay, a first protection switch and a first freewheeling diode, wherein the anode of a circuit breaker control loop is connected with one end of a closing coil through the first relay and the first protection switch, the cathode of the circuit breaker control loop is connected with the other end of the closing coil, and the first freewheeling diode is connected with the two ends of the closing coil in parallel;
the exciting coil monitoring unit includes: a first voltage division circuit, a first current transformer, a relay drive circuit, a first protection switch drive circuit and a microprocessor, two ends of the first voltage division circuit are respectively connected with the output end of the first relay and the negative electrode of the circuit breaker control circuit, the first voltage division circuit is formed by connecting two first resistors in series, the first current transformer is connected with the input end of the microprocessor through a first isolation detection circuit, the middle of the two first resistors is connected with the input end of the microprocessor through the first isolation detection circuit, the output end of the microprocessor is connected with the first relay through the relay driving circuit, the output end of the microprocessor is connected with the first protection switch through the first protection switch driving circuit, and the circuit breaker control loop is connected with the input end of the microprocessor through a signal isolation detection circuit.
In a second aspect, a protection method for a field coil of a circuit breaker is provided, where the protection method employs the protection device in the embodiment of the first aspect, and the protection method includes:
the microprocessor receives a closing signal sent by the circuit breaker through the signal isolation detection circuit;
the microprocessor receives a first voltage value sent by the first voltage dividing circuit through the first isolation detection circuit according to the closing signal;
the microprocessor judges whether the first voltage value is abnormal or not;
if the first voltage value is not abnormal, the microprocessor sends a first closing signal to the relay driving circuit according to the closing signal, so that the relay driving circuit drives the first relay to be closed;
the microprocessor sends a first conduction signal to the first protection switch driving circuit according to the closing signal, so that the first protection switch driving circuit drives the first protection switch to be conducted, and the closing coil is electrified;
the microprocessor receives a first current value sent by the first current transformer, calculates an integral value of the first current value, and judges whether the integral value of the first current value reaches a preset first safety threshold value;
if the integral value of the first current value reaches a preset first safety threshold, the microprocessor sends a first turn-off signal to the first protection switch driving circuit, so that the first protection switch driving circuit drives the first protection switch to be turned off;
and the microprocessor sends a first disconnection signal to the relay driving circuit, so that the relay driving circuit drives the first relay to be disconnected.
Therefore, the excitation coil of the circuit breaker can be protected to the greatest extent by monitoring the waveform and time of the excitation current in the opening and closing processes of the circuit breaker in real time, so that the fault problem or potential fault hidden danger of the circuit breaker can be analyzed and early warned, and the excitation coil can be protected and controlled in real time; the isolation detection circuit divides the working circuit into a weak current control circuit and a strong current power circuit, so that the weak current control part and the strong current power part are effectively electrically isolated, and the reliability of the device can be effectively improved; and the real-time reporting of the information can be realized based on the technology of the Internet of things.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.
Fig. 1 is a schematic structural diagram of a protection device for a circuit breaker excitation coil according to an embodiment of the invention;
fig. 2 is a first flowchart of a protection method for a circuit breaker excitation coil according to an embodiment of the invention;
fig. 3 is a second flowchart of a protection method for a circuit breaker field coil according to an embodiment of the present invention;
fig. 4 is a flowchart three of a protection method for a circuit breaker exciting coil according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention discloses a protection device for a circuit breaker magnet exciting coil. As shown in fig. 1, the circuit breaker exciting coil includes: the closing coil 1 and the first opening coil 2 are both excitation coils. The action time and the current waveform of the coil are often closely related to the body fault of the circuit breaker, so that the excitation current waveform and the time are monitored in the opening and closing processes of the circuit breaker, the fault problem of the circuit breaker or potential fault hidden danger can be analyzed and early warned, and the protection device provided by the embodiment of the invention is designed based on the principle.
Specifically, the protection device includes: the circuit breaker comprises a circuit breaker control loop 3, an excitation coil closing protection unit and an excitation coil monitoring unit.
The circuit breaker control loop 3 can be used for receiving remote control commands of switching on or switching off of the circuit breaker.
The excitation coil closing protection unit comprises: a first relay K1, a first protection switch M1, and a first freewheeling diode D1. The first protection switch M1 is a MOSFET switch. The positive pole of the circuit breaker control circuit 3 is connected to one end of the closing coil 1 through a first relay K1 and a first protection switch M1. Specifically, the input end of the first relay K1 is connected to the positive electrode of the circuit breaker control circuit 3, the output end of the first relay K1 is connected to the source of the first protection switch M1, and the drain of the first protection switch M1 is connected to one end of the closing coil 1. And the negative electrode of the circuit breaker control loop 3 is connected with the other end of the closing coil 1. The first freewheeling diode D1 is connected in parallel across the closing coil 1. Specifically, the anode of the first freewheeling diode D1 is connected to the other end of the closing coil 1, and the cathode of the first freewheeling diode D1 is connected to one end of the closing coil 1. The first freewheeling diode D1 functions as a freewheel to avoid arcing problems.
The exciting coil monitoring unit includes: the relay protection circuit comprises a first voltage division circuit, a first current transformer L1, a relay driving circuit 4, a first protection switch driving circuit 5 and a microprocessor 6. The two ends of the first voltage division circuit are respectively connected with the output end of the first relay K1 and the negative electrode of the circuit breaker control circuit 3. The first voltage divider circuit is formed by two first resistors R1 connected in series. The first current transformer L1 is connected to the input of the microprocessor 6 via a first isolation detection circuit 7. The middle of the two first resistors R1 is connected to the input of the microprocessor 6 via a first isolation detection circuit 7. The output end of the microprocessor 6 is connected with a first relay K1 through the relay drive circuit 4. The output terminal of the microprocessor 6 is connected to the first protection switch M1 through the first protection switch driving circuit 5. The circuit breaker control loop 3 is connected with the input end of the microprocessor 6 through a signal isolation detection circuit 8.
The circuit breaker control circuit 3 receives a remote control command from a circuit breaker to perform a closing operation, sends a closing signal to the microprocessor 6 through the signal isolation detection circuit 8, the microprocessor 6 detects the amplitude u1 of input voltage through the first voltage division circuit and the first isolation detection circuit 7, closes the first relay K1 under the condition of no abnormal condition, and then applies a control signal d1 to the first protection switch M1 through the first protection switch driving circuit 5 to enable the closing coil 1 to be powered on. Meanwhile, the microprocessor 6 samples the closed loop current waveform i1 through the first current transformer L1, starts a judgment strategy, and turns off the first protection switch M1 when the integral value of the coil current (the duration and the integral of the current, which reflects the work and heat of the coil) reaches a first safety threshold. At this time, the coil current will freewheel through the first freewheel diode D1, no arcing problem will occur, and finally the first relay K1 is opened. Once the first protection switch M1 is turned off, if it is detected that the current does not drop, which reflects that the first protection switch M1 has a breakdown fault, the coil can be protected by turning off the first relay K1, which is the same as the effect of the conventional time delay relay.
Therefore, through the above structural design, the exciting coil monitoring unit can control the action of the exciting coil closing protection unit by monitoring the voltage and the current so as to protect the closing coil 1.
Furthermore, the protection device further comprises: the first excitation coil opening protection circuit. The first excitation coil opening protection circuit includes: a second relay K2, a second protection switch M2, and a second freewheeling diode D2. The second protection switch M2 is a MOSFET switch. The positive pole of the circuit breaker control circuit 3 is connected to one end of the first opening coil 2 via a second relay K2 and a second protection switch M2. Specifically, the input end of the second relay K2 is connected to the positive electrode of the circuit breaker control circuit 3, the output end of the second relay K2 is connected to the source of the second protection switch M2, and the drain of the second protection switch M2 is connected to one end of the first switching coil 2. The negative pole of the circuit breaker control circuit 3 is connected with the other end of the first opening coil 2. A second freewheeling diode D2 is connected in parallel across the first switching coil 2. Specifically, the anode of the second freewheeling diode D2 is connected to the other end of the first switching coil 2, and the cathode of the second freewheeling diode D2 is connected to one end of the first switching coil 2. The second freewheeling diode D2 functions as a freewheel to avoid arcing problems.
The exciting coil monitoring unit further includes: a second voltage division circuit, a second current transformer L2, and a second protection switch drive circuit 9. And two ends of the second voltage division circuit are respectively connected with the output end of the second relay K2 and the negative electrode of the circuit breaker control circuit 3. The second voltage divider circuit is formed by two second resistors R2 connected in series. The second current transformer L2 is connected to the input of the microprocessor 6 through a second isolation detection circuit 10. The middle of the two second resistors R2 is connected to the input of the microprocessor 6 through the second isolation detection circuit 10. The output end of the microprocessor 6 is connected with a second relay K2 through the relay drive circuit 4. The output of the microprocessor 6 is connected to a second protection switch M2 via a second protection switch driver circuit 9.
The circuit breaker control circuit 3 receives a remote control command from the circuit breaker to perform opening operation, sends an opening signal to the microprocessor 6 through the signal isolation detection circuit 8, the microprocessor 6 detects the amplitude u2 of input voltage through the second voltage division circuit and the second isolation detection circuit 10, closes the second relay K2 under the condition of no abnormal condition, and then applies a control signal d2 to the second protection switch M2 through the second protection switch driving circuit 9 to enable the first opening coil 2 to be powered up. Meanwhile, the microprocessor 6 samples the closed loop current waveform i2 through a second current transformer L2, starts a judgment strategy, and turns off a second protection switch M2 when the integral value of the coil current (the duration and the integral of the current, which reflects the work and heat of the coil) reaches a second safety threshold. At this time, the coil current will freewheel through the second freewheeling diode D2, no arcing problem will occur, and finally the second relay K2 is turned off. Once the second protection switch M2 is turned off, if it is detected that the current does not drop, which reflects that the second protection switch M2 has a breakdown fault, the coil can be protected by turning off the second relay K2, which is the same as the effect of the conventional time delay relay.
Therefore, with the above-described structural design, the exciting coil monitoring unit can protect the first switching coil 2 by monitoring the voltage and the current so as to control the operation of the first exciting coil switching-off protection circuit.
In addition, in order to avoid the danger caused by the failure of the first switching coil 2, which leads to the failure of switching, a spare switching coil can be added. Therefore, the circuit breaker field coil further includes: and a second switching coil 11 as an excitation coil.
The protection device further comprises: and the second excitation coil opening protection circuit. The second excitation coil tripping protection circuit comprises: a third relay K3, a third protection switch M3, and a third freewheeling diode D3. The third protection switch M3 is a MOSFET switch. The positive electrode of the breaker control circuit 3 is connected to one end of the second opening coil 11 via a third relay K3 and a third protection switch M3. Specifically, the input end of the third relay K3 is connected to the positive electrode of the circuit breaker control circuit 3, the output end of the third relay K3 is connected to the source of the third protection switch M3, and the drain of the third protection switch M3 is connected to one end of the second switching coil 11. The negative pole of the breaker control circuit 3 is connected to the other end of the second switching coil 11. The third freewheeling diode D3 is connected in parallel across the second shunt coil 11. Specifically, the anode of the third freewheeling diode D3 is connected to the other end of the second shunt coil 11, and the cathode of the third freewheeling diode D3 is connected to one end of the second shunt coil 11. The third freewheeling diode D3 functions as a freewheel to avoid arcing problems.
The exciting coil monitoring unit further includes: a third voltage division circuit, a third current transformer L3, and a third protection switch driving circuit 12. And two ends of the third voltage division circuit are respectively connected with the output end of the third relay K3 and the negative electrode of the circuit breaker control circuit 3. The third voltage divider is formed by two third resistors R3 connected in series. The third current transformer L3 is connected to the input of the microprocessor 6 via a third isolation detection circuit 13. The middle of the two third resistors R3 is connected to the input of the microprocessor 6 through a third isolation detection circuit 13. The output end of the microprocessor 6 is connected with a third relay K3 through the relay drive circuit 4. The output of the microprocessor 6 is connected to a third protection switch M3 via a third protection switch driver circuit 12.
If u2 is abnormal, or the integral value of i2 reaches a preset second safety threshold, or i2 does not drop after the second protection switch M2 is turned off, it indicates that the first brake coil 2 and/or the first excitation coil brake-separating protection circuit has a fault, and the second brake coil 11 and the second excitation coil brake-separating protection circuit need to be started. Specifically, the circuit breaker control circuit 3 receives a remote control command from the circuit breaker to perform a switching-off operation, sends a switching-off signal to the microprocessor 6 through the signal isolation detection circuit 8, the microprocessor 6 detects the amplitude u3 of the input voltage through the third voltage division circuit and the third isolation detection circuit 13, closes the third relay K3 under the condition of no abnormal condition, and then applies a control signal d3 to the third protection switch M3 through the third protection switch driving circuit 12 to power up the second switching-off coil 11. Meanwhile, the microprocessor 6 samples the closed loop current waveform i3 through a third current transformer L3, starts a judgment strategy, and turns off a third protection switch M3 when an integral value of the coil current (duration and integral of the current, which reflects coil work and heat) reaches a second safety threshold. At this time, the coil current will freewheel through the third freewheeling diode D3, no arcing problem will occur, and finally the third relay K3 is turned off. Once the third protection switch M3 is turned off, if it is detected that the current does not drop, which reflects that the third protection switch M3 has a breakdown fault, the coil can be protected by turning off the third relay K3, which is the same as the effect of the conventional time delay relay.
Therefore, with the above-described structural design, the exciting coil monitoring unit can protect the second switching coil 11 by monitoring the voltage and the current so as to control the operation of the second exciting coil switching-off protection circuit.
Specifically, the input end of the microprocessor 6 is connected to the first isolation detection circuit 7, the second isolation detection circuit 10 and the third isolation detection circuit 13 through the analog-to-digital converter 14. The analog-to-digital converter 14 may convert the received analog signal into a digital signal that may be processed by the microprocessor 6.
Preferably, the protection device further comprises: a communication unit 15 for accessing a communication network. The communication unit 15 is electrically connected to the microprocessor 6. The communication unit 15 may be ZigBee wireless communication technology. The communication unit 15 may be used for wireless networking. The ZigBee wireless communication technology has the main characteristics of supporting the ad hoc network function and having strong self-recovery capability. When the circuit breaker control circuit 3 energizes the closing coil 1, the first opening coil 2 or the second opening coil 11, the communication unit 15 starts to work and is connected to the ZigBee network, the microprocessor 6 is connected with the Internet of things through the communication unit 15 to conduct wireless networking, relevant information is uploaded to the background server, and once the power is cut off, the communication unit 15 exits from the network.
Preferably, the protection device further comprises: an AC-DC power supply 16 for converting alternating current into direct current and a voltage stabilizing unit 17 for adjusting the voltage of the direct current. The AC-DC power supply 16 is used to supply power to the protection device so that the corresponding elements of the protection device are operable. The voltage stabilizing unit 17 is connected with the AC-DC power supply 16, and can adjust the voltage of the direct current to match the working voltage of the corresponding element, so that the danger of burning the element due to overlarge voltage is avoided. The voltage stabilizing unit 17 may be a Low drop out regulator (LDO) regulator.
In addition, the circuit breaker excitation coil protection device provided by the embodiment of the invention can also monitor other signals. Specifically, the microprocessor 6 intelligently monitors the state return signal of the circuit breaker control loop 3 and the logic process of circuit breaker control through the signal isolation detection circuit 8, wherein the switching value return signal to be monitored may include, but is not limited to: an operating supply voltage, a closing signal, an opening signal, a breaker auxiliary switch state, a closing coil state, an opening coil state, a tripping relay state, a closing hold relay state, an opening hold relay state, and an anti-tripping relay state. The microprocessor 6 checks the correctness of the logic sequence of the switch action, measures the switch action time, and detects different switching value state signals from the circuit breaker control circuit 3, thereby analyzing and recording the possible faults and abnormity of the circuit breaker control circuit 3, and simultaneously completing the fault identification of the excitation coil and the transmission of wireless data.
In summary, the protection device for the circuit breaker excitation coil of the embodiment of the invention can protect the circuit breaker excitation coil to the maximum extent by monitoring the excitation current waveform and time in the opening and closing processes of the circuit breaker in real time, so that the circuit breaker fault problem or potential fault hidden danger can be analyzed and early warned, and the excitation coil can be protected and controlled in real time; the isolation detection circuit divides the working circuit into a weak current control circuit and a strong current power circuit, so that the weak current control part and the strong current power part are effectively electrically isolated, and the reliability of the device can be effectively improved; and the real-time reporting of the information can be realized based on the technology of the Internet of things.
The embodiment of the invention also discloses a method for protecting the exciting coil of the circuit breaker. The protection method adopts the protection device described in the above embodiment. The protection method can be used for a closing process, and as shown in fig. 2, the protection method comprises the following steps:
step S201: and the microprocessor receives a closing signal sent by the circuit breaker through the signal isolation detection circuit.
Step S202: and the microprocessor receives a first voltage value sent by the first voltage division circuit through the first isolation detection circuit according to the closing signal.
Step S203: the microprocessor judges whether the first voltage value is abnormal.
Step S204: if the first voltage value is not abnormal, the microprocessor sends a first closing signal to the relay driving circuit according to the closing signal, so that the relay driving circuit drives the first relay to close.
Step S205: the microprocessor sends a first conduction signal to the first protection switch driving circuit according to the closing signal, so that the first protection switch driving circuit drives the first protection switch to be conducted, and the closing coil is powered on.
Step S206: the microprocessor receives a first current value sent by the first current transformer, calculates an integral value of the first current value, and judges whether the integral value of the first current value reaches a preset first safety threshold value.
Step S207: and if the integral value of the first current value reaches a preset first safety threshold, the microprocessor sends a first turn-off signal to the first protection switch driving circuit, so that the first protection switch driving circuit drives the first protection switch to turn off.
Step S208: and the microprocessor sends a first disconnection signal to the relay driving circuit to enable the relay driving circuit to drive the first relay to be disconnected.
Through the steps, the closing can be controlled, and the closing coil is protected.
Preferably, the protection method can also be used for a switching-off process, as shown in fig. 3, the protection method further includes:
step S301: and the microprocessor receives a first switching-off signal sent by the circuit breaker through the signal isolation detection circuit.
Step S302: and the microprocessor receives a second voltage value sent by the second voltage division circuit through the second isolation detection circuit according to the first switching signal.
Step S303: the microprocessor judges whether the second voltage value is abnormal.
Step S304: and if the second voltage value is not abnormal, the microprocessor sends a second closing signal to the relay driving circuit according to the first switching signal, so that the relay driving circuit drives the second relay to close.
Step S305: and the microprocessor sends a second conduction signal to the second protection switch driving circuit according to the first brake separating signal, so that the second protection switch driving circuit drives the second protection switch to be conducted, and the first brake separating coil is electrified.
Step S306: and the microprocessor receives a second current value sent by the second current transformer, calculates an integral value of the second current value, and judges whether the integral value of the second current value reaches a preset second safety threshold value.
Step S307: and if the integral value of the second current value reaches a preset second safety threshold value, the microprocessor sends a second turn-off signal to the second protection switch driving circuit, so that the second protection switch driving circuit drives the second protection switch to turn off.
Step S308: and the microprocessor sends a second disconnection signal to the relay driving circuit to enable the relay driving circuit to drive the second relay to be disconnected.
Through the steps, the opening can be controlled, and the first opening coil is protected.
Preferably, as shown in fig. 4, when the first opening coil and/or the first excitation coil opening protection circuit fails, the protection method further includes:
step S401: and if the second voltage value is abnormal, or the integral value of the second current value reaches a preset second safety threshold value, or the second current value does not decrease after the second protection switch is switched off, the microprocessor receives a second switching-off signal sent by the circuit breaker through the signal isolation detection circuit.
Step S402: and the microprocessor receives a third voltage value sent by the third voltage dividing circuit through a third isolation detection circuit according to the second switching signal.
Step S403: the microprocessor judges whether the third voltage value is abnormal.
Step S404: and if the third voltage value is not abnormal, the microprocessor sends a third closing signal to the relay driving circuit according to the second switching signal, so that the relay driving circuit drives the third relay to close.
Step S405: and the microprocessor sends a third conduction signal to the third protection switch driving circuit according to the second shunt signal, so that the third protection switch driving circuit drives the third protection switch to be conducted, and the second shunt coil is electrified.
Step S406: and the microprocessor receives a third current value sent by the third current transformer, calculates an integral value of the third current value and judges whether the integral value of the third current value reaches a preset second safety threshold value.
Step S407: and if the integral value of the third current value reaches a preset second safety threshold value, the microprocessor sends a third turn-off signal to the third protection switch driving circuit, so that the third protection switch driving circuit drives the third protection switch to turn off.
Step S408: and the microprocessor sends a third disconnection signal to the relay driving circuit to enable the relay driving circuit to drive the third relay to be disconnected.
Through the steps, the opening can be controlled, and the second opening coil is protected.
In summary, the method for protecting the field coil of the circuit breaker according to the embodiment of the present invention can protect the field coil of the circuit breaker to the maximum extent by monitoring the field current waveform and time in the opening and closing processes of the circuit breaker in real time, so as to analyze and early warn the fault problem of the circuit breaker or potential fault hidden danger, and protect and control the field coil in real time.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (9)
1. A protection apparatus of a circuit breaker exciting coil, characterized in that the circuit breaker exciting coil comprises: closing coil and first separating brake coil, protection device includes: the circuit breaker comprises a circuit breaker control loop, an excitation coil closing protection unit and an excitation coil monitoring unit;
the excitation coil closing protection unit comprises: the circuit breaker comprises a first relay, a first protection switch and a first freewheeling diode, wherein the anode of a circuit breaker control loop is connected with one end of a closing coil through the first relay and the first protection switch, the cathode of the circuit breaker control loop is connected with the other end of the closing coil, and the first freewheeling diode is connected with the two ends of the closing coil in parallel;
the exciting coil monitoring unit includes: a first voltage division circuit, a first current transformer, a relay drive circuit, a first protection switch drive circuit and a microprocessor, two ends of the first voltage division circuit are respectively connected with the output end of the first relay and the negative electrode of the circuit breaker control circuit, the first voltage division circuit is formed by connecting two first resistors in series, the first current transformer is connected with the input end of the microprocessor through a first isolation detection circuit, the middle of the two first resistors is connected with the input end of the microprocessor through the first isolation detection circuit, the output end of the microprocessor is connected with the first relay through the relay driving circuit, the output end of the microprocessor is connected with the first protection switch through the first protection switch driving circuit, and the circuit breaker control loop is connected with the input end of the microprocessor through a signal isolation detection circuit.
2. The circuit breaker field coil protection device of claim 1, further comprising: a first field coil opening protection circuit, the first field coil opening protection circuit comprising: the positive pole of the circuit breaker control circuit is connected with one end of the first opening coil through the second relay and the second protection switch, the negative pole of the circuit breaker control circuit is connected with the other end of the first opening coil, and the second freewheeling diode is connected at two ends of the first opening coil in parallel;
the exciting coil monitoring unit further includes: second divider circuit, second current transformer and second protection switch drive circuit, the both ends of second divider circuit are connected respectively the output of second relay with circuit breaker control circuit's negative pole, the second divider circuit is established ties by two second resistance and is constituteed, second current transformer keeps apart detection circuitry through the second and connects microprocessor's input, two the centre of second resistance is passed through detection circuitry is kept apart to the second connects microprocessor's input, microprocessor's output passes through relay drive circuit connects the second relay, microprocessor's output passes through second protection switch drive circuit connects the second protection switch.
3. The circuit breaker field coil protection device of claim 2, wherein the circuit breaker field coil further comprises: a second opening coil;
the protection device further comprises: a second field coil opening protection circuit, the second field coil opening protection circuit comprising: the anode of the circuit breaker control circuit is connected with one end of the second opening coil through the third relay and the third protection switch, the cathode of the circuit breaker control circuit is connected with the other end of the second opening coil, and the third freewheeling diode is connected at two ends of the second opening coil in parallel;
the exciting coil monitoring unit further includes: third voltage division circuit, third current transformer and third protection switch drive circuit, the both ends of third voltage division circuit are connected respectively the output of third relay with circuit breaker control circuit's negative pole, the third voltage division circuit is established ties by two third resistances and is constituteed, third current transformer passes through the third and keeps apart detection circuitry and connect microprocessor's input, two the centre of third resistance is passed through the third keeps apart detection circuitry and connects microprocessor's input, microprocessor's output passes through relay drive circuit connects the third relay, microprocessor's output passes through third protection switch drive circuit connects third protection switch.
4. The apparatus for protecting an exciting coil of a circuit breaker according to claim 3, wherein: the input end of the microprocessor is respectively connected with the first isolation detection circuit, the second isolation detection circuit and the third isolation detection circuit through an analog-to-digital converter.
5. The apparatus for protecting an exciting coil of a circuit breaker according to claim 1, further comprising: and the communication unit is used for accessing a communication network and is electrically connected with the microprocessor.
6. The apparatus for protecting an exciting coil of a circuit breaker according to claim 1, further comprising: an AC-DC power supply for converting an alternating current into a direct current and a voltage stabilizing unit for adjusting a voltage of the direct current.
7. A method for protecting an exciting coil of a circuit breaker, wherein the protection method is implemented by using the protection device according to any one of claims 1 to 6, and the method comprises the following steps:
the microprocessor receives a closing signal sent by the circuit breaker through the signal isolation detection circuit;
the microprocessor receives a first voltage value sent by the first voltage dividing circuit through the first isolation detection circuit according to the closing signal;
the microprocessor judges whether the first voltage value is abnormal or not;
if the first voltage value is not abnormal, the microprocessor sends a first closing signal to the relay driving circuit according to the closing signal, so that the relay driving circuit drives the first relay to be closed;
the microprocessor sends a first conduction signal to the first protection switch driving circuit according to the closing signal, so that the first protection switch driving circuit drives the first protection switch to be conducted, and the closing coil is electrified;
the microprocessor receives a first current value sent by the first current transformer, calculates an integral value of the first current value, and judges whether the integral value of the first current value reaches a preset first safety threshold value;
if the integral value of the first current value reaches a preset first safety threshold, the microprocessor sends a first turn-off signal to the first protection switch driving circuit, so that the first protection switch driving circuit drives the first protection switch to be turned off;
and the microprocessor sends a first disconnection signal to the relay driving circuit, so that the relay driving circuit drives the first relay to be disconnected.
8. The circuit breaker excitation coil protection method according to claim 7, further comprising:
the microprocessor receives a first switching-off signal sent by the circuit breaker through the signal isolation detection circuit;
the microprocessor receives a second voltage value sent by the second voltage division circuit through the second isolation detection circuit according to the first switching signal;
the microprocessor judges whether the second voltage value is abnormal or not;
if the second voltage value is not abnormal, the microprocessor sends a second closing signal to the relay driving circuit according to the first switching-off signal, so that the relay driving circuit drives the second relay to be closed;
the microprocessor sends a second conducting signal to the second protection switch driving circuit according to the first switching signal, so that the second protection switch driving circuit drives the second protection switch to be conducted, and the first switching coil is powered up;
the microprocessor receives a second current value sent by the second current transformer, calculates an integral value of the second current value, and judges whether the integral value of the second current value reaches a preset second safety threshold value;
if the integral value of the second current value reaches a preset second safety threshold value, the microprocessor sends a second turn-off signal to the second protection switch driving circuit, so that the second protection switch driving circuit drives the second protection switch to be turned off;
and the microprocessor sends a second disconnection signal to the relay driving circuit, so that the relay driving circuit drives the second relay to be disconnected.
9. The circuit breaker field coil protection method of claim 8, further comprising:
if the second voltage value is abnormal, or the integral value of the second current value reaches a preset second safety threshold value, or the second current value does not drop after the second protection switch is switched off, the microprocessor receives a second switching-off signal sent by the circuit breaker through the signal isolation detection circuit;
the microprocessor receives a third voltage value sent by the third voltage dividing circuit through the third isolation detection circuit according to the second switching signal;
the microprocessor judges whether the third voltage value is abnormal or not;
if the third voltage value is not abnormal, the microprocessor sends a third closing signal to the relay driving circuit according to the second switching-off signal, so that the relay driving circuit drives the third relay to be closed;
the microprocessor sends a third conducting signal to the third protection switch driving circuit according to the second switching-off signal, so that the third protection switch driving circuit drives the third protection switch to be conducted, and the second switching-off coil is powered up;
the microprocessor receives a third current value sent by the third current transformer, calculates an integral value of the third current value, and judges whether the integral value of the third current value reaches a preset second safety threshold value;
if the integral value of the third current value reaches a preset second safety threshold value, the microprocessor sends a third turn-off signal to the third protection switch driving circuit, so that the third protection switch driving circuit drives the third protection switch to be turned off;
and the microprocessor sends a third disconnection signal to the relay driving circuit, so that the relay driving circuit drives the third relay to be disconnected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010381381.8A CN111628480A (en) | 2020-05-06 | 2020-05-06 | Protection device and method for circuit breaker excitation coil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010381381.8A CN111628480A (en) | 2020-05-06 | 2020-05-06 | Protection device and method for circuit breaker excitation coil |
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| Publication Number | Publication Date |
|---|---|
| CN111628480A true CN111628480A (en) | 2020-09-04 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010381381.8A Pending CN111628480A (en) | 2020-05-06 | 2020-05-06 | Protection device and method for circuit breaker excitation coil |
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| Country | Link |
|---|---|
| CN (1) | CN111628480A (en) |
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2020
- 2020-05-06 CN CN202010381381.8A patent/CN111628480A/en active Pending
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