CN115932513A - Exciter insulation monitoring system - Google Patents
Exciter insulation monitoring system Download PDFInfo
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- CN115932513A CN115932513A CN202211655690.5A CN202211655690A CN115932513A CN 115932513 A CN115932513 A CN 115932513A CN 202211655690 A CN202211655690 A CN 202211655690A CN 115932513 A CN115932513 A CN 115932513A
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
- Y04S10/52—Outage or fault management, e.g. fault detection or location
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Abstract
The application relates to an exciter insulation monitoring system, the exciter insulation monitoring system includes: the control system comprises an insulation monitoring device, an exciter exciting winding and a silicon controlled rectifier bridge, wherein the output end of the insulation monitoring device and the negative electrode output end of the silicon controlled rectifier bridge are connected with the negative electrode of the exciter exciting winding; the thyristor rectifier bridge is used for providing direct-current voltage for the exciter excitation winding; and the insulation monitoring device is used for monitoring whether the exciter exciting winding has a ground fault or not. The method can avoid interphase short circuit faults.
Description
Technical Field
The application relates to the technical field of exciter insulation monitoring, in particular to an exciter insulation monitoring system.
Background
The excitation system of the nuclear power station provides an excitation power supply for the turbo generator unit through the excitation winding of the exciter, so the safety and the stable operation of the turbo generator unit are directly influenced by the working condition of the excitation winding. However, in the using process, if the exciting winding has a ground fault, the short circuit of the exciting winding can be caused, so that the exciting machine equipment is burnt, the equipment vibration is intensified, even the shafting and the steam turbine are magnetized, the unit is difficult to repair, and the downtime is long. Therefore, it is necessary to monitor whether the field winding has insulation resistance to ground.
In the traditional technology, the insulation resistance value to the ground of the excitation winding is monitored by adopting a double-end injection type exciter insulation monitoring device. However, when the monitoring device is used to monitor the insulation resistance to ground of the field winding, a fault of an inter-phase short circuit may occur.
Disclosure of Invention
In view of the above, it is necessary to provide an exciter insulation monitoring system capable of avoiding an inter-phase short circuit fault in view of the above technical problems.
The application provides an exciter insulation monitoring system. The system comprises:
the control system comprises an insulation monitoring device, an exciter exciting winding and a silicon controlled rectifier bridge, wherein the output end of the insulation monitoring device and the negative electrode output end of the silicon controlled rectifier bridge are connected with the negative electrode of the exciter exciting winding;
the thyristor rectifier bridge is used for providing direct-current voltage for the exciter excitation winding;
and the insulation monitoring device is used for monitoring whether the exciter exciting winding has a ground fault or not.
In one embodiment, the insulation monitoring device further comprises:
the excitation circuit comprises a sensitive resistor, a first resistor and a second resistor, wherein the first end of the sensitive resistor is grounded, the second end of the sensitive resistor is respectively connected with the first end of the first resistor and the first end of the second resistor, and the second end of the first resistor and the second end of the second resistor are both connected with the negative pole of the exciter excitation winding;
and the insulation monitoring device is used for monitoring whether the exciter exciting winding has a ground fault according to the current value flowing through the sensitive resistor and a preset current threshold value.
In one embodiment, the insulation monitoring device is configured to determine that a ground fault exists in the exciter field winding when the current value flowing through the sensitive resistor is greater than the current threshold value.
In one embodiment, the insulation monitoring device further comprises an oscilloscope connected with the sensitive resistor, and the oscilloscope is used for monitoring the current value flowing through the sensitive resistor.
In one embodiment, the exciter insulation monitoring system further comprises an alarm device;
the insulation monitoring device is also used for sending a control instruction to the alarm device when the exciter exciting winding is monitored to have the ground fault;
and the alarm device is used for generating alarm prompt information according to the control instruction.
In one embodiment, the insulation monitoring device further comprises a square wave power supply connected with the sensitive resistor;
the square wave power supply is used for supplying voltage to the insulation monitoring device.
In one embodiment, the current threshold is determined according to a voltage value provided by the square wave power supply, a resistance value of the first resistor and a resistance value of the second resistor.
In one embodiment, the resistance value of the first resistor is the same as the resistance value of the second resistor.
In one embodiment, the resistance value of the first resistor and the resistance value of the second resistor are both greater than 100K Ω.
In one embodiment, the positive output terminal of the thyristor rectifier bridge is connected to the positive pole of the exciter field winding.
The exciter insulation monitoring system comprises an insulation monitoring device, an exciter exciting winding and a silicon controlled rectifier bridge, wherein the output end of the insulation monitoring device and the negative electrode output end of the silicon controlled rectifier bridge are connected with the negative electrode of the exciter exciting winding; the thyristor rectifier bridge is used for providing direct-current voltage for the exciter exciting winding; and the insulation monitoring device is used for monitoring whether the exciter exciting winding has a ground fault. Through with the output of insulation monitoring device, the negative output of SCR rectifier bridge all is connected with exciter field winding's negative pole, the alternate short circuit trouble has been avoided all being connected with exciter field winding with two outputs of insulation monitoring device to the formed route, and in addition, when exciter field winding takes place ground fault, this route and exciter field winding's insulating resistance to ground can form the measurement return circuit, can monitor fast that exciter winding has taken place ground fault, thereby avoided exciter field winding to take place ground fault and caused the damage to exciter field winding.
Drawings
FIG. 1 is a schematic diagram of the connection of a double-ended injection exciter insulation detection system in one embodiment;
FIG. 2 is a schematic diagram of exciter field current of an exciter insulation monitoring system in one embodiment;
FIG. 3 is a schematic diagram of an exciter insulation monitoring system measuring loop current and ground potential in another embodiment;
FIG. 4 is a schematic diagram of an exciter insulation monitoring system in one embodiment;
FIG. 5 is a schematic diagram of an exciter insulation monitoring system in another embodiment;
FIG. 6 is a schematic diagram of exciter field current of an exciter isolation monitoring system in another embodiment;
FIG. 7 is a schematic diagram of an exciter insulation monitoring system measuring loop current and ground potential in another embodiment;
FIG. 8 is a schematic diagram of exciter field current and field winding positive and negative to ground potential of an exciter insulation monitoring system in another embodiment;
FIG. 9 is a schematic diagram of an exciter insulation monitoring system measuring loop current and ground potential in another embodiment;
FIG. 10 is a schematic diagram of exciter field current and field winding positive and negative to ground potential of an exciter insulation monitoring system in another embodiment;
FIG. 11 is a schematic diagram of an exciter insulation monitoring system in another embodiment;
FIG. 12 is a schematic diagram of an exciter insulation monitoring system in another embodiment;
FIG. 13 is a schematic diagram of an exciter insulation monitoring system in another embodiment;
FIG. 14 is a schematic diagram of the connection of a single ended injection exciter insulation monitoring system in one embodiment;
FIG. 15 is a simulation of an exciter insulation monitoring system according to one embodiment;
description of reference numerals:
insulating monitoring devices: 10; sensitive resistance: 101, a first electrode and a second electrode; a first resistance: 102, and (b);
a second resistance: 103; an oscilloscope: 104; square wave power supply: 105;
exciter field winding: 20; thyristor rectifier bridge: 30, of a nitrogen-containing gas; an alarm device: 40.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
At present, an excitation loop mainly comprises a generator, an excitation transformer, a multiphase brushless exciter, an excitation regulator (AVR), a thyristor rectifier bridge and the like, wherein the generator and the multiphase brushless exciter are positioned on a conventional island 16-meter platform; the excitation transformer, excitation regulator (AVR) and thyristor rectifier bridge are located on a conventional island 6-meter platform. The general technical conditions of the turbonator stipulate that the cold insulation resistance of an exciter excitation winding is not less than 100 megaohms (M omega), and the cold insulation resistance of a direct water-cooled excitation winding is not less than 2 kiloohms (K omega); the specifications of the hydro generator dictate that the insulation resistance of the windings should not be below 0.5M omega in any case. If one point of insulation damage, such as grounding fault, occurs to the excitation winding and the loop connected with the excitation winding, no serious result is generated, but if a second point of grounding fault occurs, part of the rotor winding is short-circuited, the rotor body can be burned, and even the magnetization of the steam turbine occurs. For the safe operation of a large-scale generator set, after a point of ground fault occurs in an excitation circuit, the load should be immediately transferred, and the stable shutdown detection is realized. The safe and stable operation of the turbo generator set is directly influenced by the working condition of the exciter. Therefore, an insulation monitoring device is required to be added to the pole winding of the nuclear power plant exciter to monitor whether the ground fault exists in the field winding.
In the prior art, whether a ground fault exists in an excitation winding is monitored by adopting a double-end injection type insulation monitoring device shown in fig. 1, however, an interphase short circuit is generated in a double-end injection type insulation monitoring device, so that an excitation system is demagnetized, and a unit is shut down. As shown in fig. 2, the excitation current of the exciter in normal operation is about 76 amperes (a), and when a double-end injection insulation monitoring device is adopted, the excitation current rapidly drops from 76A to 24A when the operation time t =2.5s of the excitation system; as shown in fig. 3, the positive pole of the excitation winding is lowered to 16 volts (V) from a normal value, the negative pole of the excitation winding is changed to 8V from-30V, and the current of the measurement loop cable is instantly increased to 240A from 0.1mA, that is, an interphase short-circuit fault is generated between the positive pole and the negative pole of the measurement loop cable, which causes the excitation system to lose magnetism, and finally causes the unit to stop. Therefore, the exciter insulation monitoring system for avoiding generating the interphase short-circuit fault monitors whether the excitation winding has the ground fault or not.
In one embodiment, as shown in fig. 4, there is provided an exciter insulation monitoring system comprising: the excitation control system comprises an insulation monitoring device 10, an exciter excitation winding 20 and a thyristor rectifier bridge 30, wherein the output end of the insulation monitoring device 10 and the negative electrode output end of the thyristor rectifier bridge 30 are connected with the negative electrode of the exciter excitation winding 20; a thyristor rectifier bridge 30 for providing dc voltage to the exciter field winding 20; and the insulation monitoring device 10 is used for monitoring whether the exciter excitation winding 20 has a ground fault.
The insulation monitoring refers to the steps that voltage is injected into the tested equipment, the insulation resistance value of the tested equipment is calculated according to ohm's law, and insulation monitoring is conducted on the tested equipment according to the insulation resistance value; exciter field winding refers to the coil winding inside the exciter that can generate a magnetic field. A thyristor bridge is a commonly used power semiconductor electronic device and in this embodiment is used to convert the ac power generated by the exciter transformer to dc power.
In the present embodiment, the output terminal of the insulation monitoring device 10 is connected to the negative electrode of the exciter field winding 20, and the negative output terminal of the thyristor bridge 30 is connected to the negative electrode of the exciter field winding 20, thereby forming a path composed of the thyristor bridge 30, the insulation detection device 10, and the exciter field winding 20. It should be noted that, if the exciter field winding 20 has a ground fault, the above-mentioned path may form a measurement loop together with the insulation resistance of the exciter field winding 20 to the ground, and the current value of the insulation resistance of the exciter field winding to the ground flows through the measurement loop, so that the corresponding insulation resistance value can be obtained by the detected current change in the measurement loop.
The exciter insulation monitoring system comprises an insulation monitoring device, an exciter exciting winding and a silicon controlled rectifier bridge, wherein the output end of the insulation monitoring device and the negative electrode output end of the silicon controlled rectifier bridge are connected with the negative electrode of the exciter exciting winding; the thyristor rectifier bridge is used for providing direct-current voltage for the exciter exciting winding; and the insulation monitoring device is used for monitoring whether the exciter exciting winding has a ground fault. Through with the output of insulation monitoring device, the negative output of SCR rectifier bridge all is connected with exciter field winding's negative pole, the alternate short circuit trouble has been avoided all being connected with exciter field winding with two outputs of insulation monitoring device to the formed route, and in addition, when exciter field winding takes place ground fault, this route and exciter field winding's insulating resistance to ground can form the measurement return circuit, can monitor fast that exciter winding has taken place ground fault, thereby avoided exciter field winding to take place ground fault and caused the damage to exciter field winding.
In the above scenario of monitoring the exciter field winding for a ground fault, it is possible to determine whether a ground fault has occurred by monitoring the current change in the measurement loop. In one embodiment, as shown in fig. 5, the insulation monitoring device 10 further comprises: the exciter comprises a sensitive resistor 101, a first resistor 102 and a second resistor 103, wherein the first end of the sensitive resistor 101 is grounded, the second end of the sensitive resistor 101 is respectively connected with the first end of the first resistor 102 and the first end of the second resistor 103, and the second end of the first resistor 102 and the second end of the second resistor 103 are both connected with the negative electrode of an exciter exciting winding 20; and the insulation monitoring device 10 is used for monitoring whether the exciter field winding 20 has a ground fault according to the current value flowing through the sensitive resistor 101 and a preset current threshold value.
The sensitive resistor 101 is a high-precision resistor, has a small resistance error, and can monitor a small current change in a loop. It should be noted that, in order that the voltage injected into the measurement loop by the insulation monitoring device 10 does not interfere with or affect the operation of the exciter, the first resistor 102 and the second resistor 103 are large resistors. Optionally, the resistance value of the first resistor 102 and the resistance value of the second resistor 103 may be the same, and both the resistance value of the first resistor 102 and the resistance value of the second resistor 103 are greater than 100K Ω, for example, both the resistance value of the first resistor 102 and the resistance value of the second resistor 103 may be 180K Ω. The preset current threshold in this embodiment may be a maximum current value flowing through the measurement loop when no ground fault occurs, and optionally, the current threshold in this embodiment may be determined according to the voltage of the measurement loop, the resistance value of the first resistor 102, and the resistance value of the second resistor 103.
In this embodiment, the first resistor 102 and the second resistor 103 may be connected in parallel, one end of the parallel circuit may be connected to the sensitive resistor 101, and the other end of the parallel circuit may be connected to the negative electrode of the exciter field winding 20. When the exciter field winding 20 has a ground fault, a measurement loop consisting of the sensitive resistor 101, the parallel loop of the first resistor 102 and the second resistor 103, the thyristor rectifier bridge 30, the negative electrode of the exciter field winding 20 and the insulation resistance of the exciter field winding 20 to the ground is formed, and the insulation detection device 10 injects voltage into the measurement loop through the other end of the parallel loop of the first resistor 102 and the second resistor 103 to provide power for the measurement loop, so that the insulation resistance of the exciter field winding 20 to the ground can be obtained by detecting the current value flowing through the sensitive resistor 101. Illustratively, when the exciter operates normally, the change relationship of the exciter exciting current with time is shown in fig. 6, the exciting current of the exciter is about 76A, when the exciter operates to t =2.5s, a ground fault occurs at the negative pole of the exciter exciting winding, as shown in fig. 7, the measurement loop current changes by only a few mA, the measurement loop current is basically unchanged, the amplitude of the change of the measurement loop to the ground potential is less than 200V, at this time, as shown in fig. 8, the positive pole and the negative pole of the exciter exciting winding slightly change to the ground potential, but no oscillation (overvoltage) phenomenon occurs, and the exciting current of the exciter winding slightly changes and floats. Or, when the exciter runs to t =2.5s, a ground fault occurs at the positive pole of the exciter field winding, as shown in fig. 9, the change amplitude of the measurement loop current is smaller than 2mA, and the change amplitude of the measurement loop to the ground potential is smaller than 200V, at this time, as shown in fig. 10, although the positive pole and the negative pole of the exciter field winding change to the ground potential, an oscillation (overvoltage) phenomenon does not occur, and the current change of the exciter field winding is in the milliampere level, so that it can be known that, when the exciter insulation monitoring system provided by the present application has a ground fault, the current and the ground potential of the measurement loop, the current and the ground potential of the exciter field winding do not change to a relatively large extent, that is, in the monitoring of whether the exciter field winding has a ground fault, the excitation system loss problem caused by an inter-phase short circuit fault can be avoided.
In this embodiment, the insulation monitoring device further includes a sensitive resistor, a first resistor and a second resistor, a first end of the sensitive resistor is grounded, a second end of the sensitive resistor is connected to a first end of the first resistor and a first end of the second resistor, and a second end of the first resistor and a second end of the second resistor are both connected to a negative electrode of the exciter field winding to form a measurement loop.
In the scenario that the insulation monitoring device monitors whether the ground fault exists in the exciter field winding according to the current value flowing through the sensitive resistor and the preset current threshold, on the basis of the above embodiment, in an embodiment, the insulation monitoring device 10 is configured to determine that the ground fault exists in the exciter field winding 20 when the current value flowing through the sensitive resistor 101 is greater than the current threshold.
Optionally, the current value flowing through the sensing resistor 101 and the current threshold may be determined by calculating a difference between the current value flowing through the sensing resistor 101 and the current threshold, or may be determined by calculating a ratio between the current value flowing through the sensing resistor 101 and the current threshold, which is not limited herein. For example, if the difference between the current value flowing through the sense resistor 101 and the current threshold is positive, it indicates that the current value flowing through the sense resistor 101 is greater than the current threshold, and it can be determined that the exciter field winding 20 has a ground fault.
In this embodiment, the insulation monitoring device can quickly determine whether the current value flowing through the sensitive resistor is greater than the current threshold value by comparing the current value flowing through the sensitive resistor with the current threshold value, so that it can be determined that the ground fault exists in the exciter field winding when the current value flowing through the sensitive resistor is greater than the current threshold value.
In the above scenario where the ground fault of the exciter field winding is determined according to the current flowing through the sensitive resistor, the current value flowing through the sensitive resistor can be monitored according to an oscilloscope. In one embodiment, as shown in fig. 11, the insulation monitoring device 10 further includes an oscilloscope 104 connected to the sensitive resistor 101, and the oscilloscope 104 is used for monitoring the current value flowing through the sensitive resistor 101.
The oscilloscope 104 can draw a change curve of an instantaneous value of the measured signal on the screen of the oscilloscope 104 under the action of the measured signal, that is, a waveform curve of the amplitude of the current flowing through the sensitive resistor 101 changing with time can be observed by the oscilloscope 104.
Specifically, in this embodiment, two ends of the oscilloscope 104 are respectively connected to two ends of the sensitive resistor 101, and a graph on a display screen of the oscilloscope 104 can represent a change of a current value flowing through the sensitive resistor 101 with time. It can be understood that if there is a ground fault in the exciter field winding 20, the ground insulation resistance of the exciter field winding 20 will generate a corresponding current, and the current will flow through the measurement loop formed by the above-mentioned sensitive resistor 101, the parallel loop of the first resistor 102 and the second resistor 103, the thyristor rectifier bridge 30, the negative electrode of the exciter field winding 20, and the ground insulation resistance of the exciter field winding 20, and the change of the current value in the measurement loop can be monitored by the oscilloscope 104, that is, it can be determined whether there is a ground fault in the exciter field winding 20 by observing the change of the graph on the display screen of the oscilloscope 104.
In this embodiment, the insulation monitoring device further includes an oscilloscope connected to the sensitive resistor, and the oscilloscope is used to monitor the current value flowing through the sensitive resistor, so that it can be quickly determined whether the ground fault exists in the exciter field winding according to the change of the current value monitored by the oscilloscope.
On the basis of the above embodiment, if the exciter field winding has a ground fault, the insulation monitoring device may also give an alarm. In one embodiment, as shown in fig. 12, the exciter insulation monitoring system further comprises an alarm device 40; the insulation monitoring device 10 is further used for sending a control command to the alarm device 40 when the exciter field winding 20 is monitored to have the ground fault; the alarm device 40 is used for generating alarm prompt information according to the control instruction.
Optionally, in this embodiment, the alarm device 40 and the insulation detection device 10 may be in communication connection, and when the insulation monitoring device 10 monitors that the exciter field winding 20 has a ground fault, the insulation detection device may send a control command to the alarm device 40 through the communication connection with the alarm device, and instruct the alarm device 40 to generate an alarm prompt message through the control command. Alternatively, the alarm device 40 may be a separate alarm device independent of the insulation detection device 10, or may be integrated into the insulation monitoring device 10. Optionally, in this embodiment, the alarm device 40 may include a display screen, and the alarm prompt information may be text information, or the alarm device 40 may include an indicator light, and the alarm prompt information may also be indicator light information. For example, in the present embodiment, the alarm prompt information is taken as text information, when there is a ground fault in the exciter field winding 20, the insulation monitoring device 10 sends a control command to the alarm device 40, and after receiving the control command, the alarm device 40 may display a text of "insulation fault" on the display screen of the alarm device 40 based on the control command.
In this embodiment, the exciter insulation monitoring system further includes an alarm device, and the insulation monitoring device may send a control command to the alarm device when monitoring that the exciter field winding has a ground fault, instruct the alarm device to generate alarm prompt information through the control command, and use the alarm prompt information to prompt an operation and maintenance worker that the exciter field winding has a ground fault in time, so that the maintenance worker can repair the exciter field winding in time.
In the above scenario where the insulation monitoring device determines whether the exciter field winding has a ground fault, it is necessary to provide an operating voltage to the insulation monitoring device. In one embodiment, as shown in fig. 13, the insulation monitoring device 10 further comprises a square wave power supply 105 connected to the sensitive resistor 101; the square wave power supply 105 is used to provide a voltage to the insulation monitoring device 10.
It will be appreciated that the insulation monitoring device 10 requires an operating power source for operation. Optionally, in this embodiment, the insulation monitoring device 10 may further include a square wave power supply 105 connected to the sensitive resistor 101, and the operating power supply of the insulation monitoring device 10 may be provided by its own square wave power supply 105. In addition, it should be noted that, in order that the voltage injected into the measurement loop by the insulation monitoring device 10 does not interfere and affect the operation of the exciter, it is necessary to ensure that the operating voltage of the insulation monitoring device 10 is less than a certain voltage value, for example, the voltage value of the square wave power supply 105 may be 10V, so as to ensure that the operation of the exciter is not interfered and affected when the operating voltage is supplied to the insulation monitoring device 10 by using the 10V voltage supplied by the square wave power supply 105. Further, as an alternative embodiment, since the current threshold may be the maximum current value flowing through the measurement loop when the exciter field winding 20 has no ground fault, the current threshold may be determined according to the voltage value provided by the square wave power supply 105, the resistance value of the first resistor 102, and the resistance value of the second resistor 103.
In this embodiment, the insulation monitoring device further includes a square wave power supply connected to the sensitive resistor, and the square wave power supply can provide voltage to the insulation monitoring device to ensure that the insulation monitoring device can have a working voltage to enter an operating state, and monitor whether a ground fault exists in the excitation winding of the exciter.
Based on the above embodiment, in one embodiment, the positive output terminal of the thyristor rectifier bridge 30 is connected to the positive pole of the exciter field winding 20.
Optionally, in this embodiment, the silicon controlled rectifier bridge 30 further includes an anode output end, and the exciter field winding further includes an anode end, as shown in fig. 14, the anode output end of the silicon controlled rectifier bridge 30 may be connected to the anode of the exciter field winding 20 to form a loop, so that the two ends of the insulation monitoring device 10 may be connected to the cathode output end of the silicon controlled rectifier bridge 30, the cathode output end of the silicon controlled rectifier bridge 30 is connected to the cathode of the exciter field winding 20, and the anode of the exciter field winding 20 is connected to the anode output end of the silicon controlled rectifier bridge 30, so as to form a complete loop.
In this embodiment, the positive output end of the thyristor rectifier bridge is connected to the positive pole of the exciter field winding, so as to form a path between the thyristor rectifier bridge and the exciter field winding, thereby forming a complete loop for the entire excitation system.
It should be noted that the exciter insulation detection system simulation model proposed in the present application may be as shown in fig. 15, and the exciter insulation monitoring system simulation model includes a generator 1501, a thyristor rectifier bridge 1502, a switch 1503, a square wave power supply 1504, a sensitive resistor 1505, a low-pass filter 1506, a first resistor 1507, a second resistor 1508, an oscilloscope 1509, and an exciter winding 1510. The square wave power supply 1504, the sensitive resistor 1505, the low-pass filter 1506, the first resistor 1507, the second resistor 1508 and the oscilloscope 1509 form an insulation monitoring device; the insulation monitoring device, the thyristor rectifier bridge 1502 and the exciter field winding 1510 form a passage; the square wave power supply 1504 provides an operating voltage for the insulation monitoring device. Optionally, the insulation monitoring device may determine whether the ground fault exists in the exciter field winding 1510 according to a change in a current value flowing through the sensitive resistor 1505, when the ground fault exists in the exciter field winding 1510, the path and a ground insulation resistor of the exciter field winding 1510 may form a measurement loop, a corresponding current may be generated in the measurement loop, a change condition of the current in the measurement loop may be visually observed through the oscilloscope 1504, and according to a change curve graph of the current, it may be determined whether the ground fault exists in the exciter field winding 1510, for example, if the current has a large amplitude change at a certain time, it may be determined that the ground fault exists in the exciter field winding 1510.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.
Claims (10)
1. An exciter insulation monitoring system, comprising: the control system comprises an insulation monitoring device, an exciter exciting winding and a silicon controlled rectifier bridge, wherein the output end of the insulation monitoring device and the negative electrode output end of the silicon controlled rectifier bridge are connected with the negative electrode of the exciter exciting winding;
the thyristor rectifier bridge is used for providing direct-current voltage for the exciter exciting winding;
and the insulation monitoring device is used for monitoring whether the exciter exciting winding has a ground fault or not.
2. An exciter insulation monitoring system according to claim 1, wherein the insulation monitoring device further comprises: the excitation circuit comprises a sensitive resistor, a first resistor and a second resistor, wherein the first end of the sensitive resistor is grounded, the second end of the sensitive resistor is respectively connected with the first end of the first resistor and the first end of the second resistor, and the second end of the first resistor and the second end of the second resistor are both connected with the negative pole of the exciter excitation winding;
and the insulation monitoring device is used for monitoring whether the exciter exciting winding has a ground fault according to the current value flowing through the sensitive resistor and a preset current threshold value.
3. An exciter insulation monitoring system according to claim 2, wherein the insulation monitoring means is configured to determine that a ground fault exists in the exciter field winding when the value of the current flowing through the sensitive resistor is greater than the current threshold.
4. An exciter insulation monitoring system according to any of claims 1 to 3, wherein the insulation monitoring means further comprises an oscilloscope connected to the sensitive resistor for monitoring the value of current flowing through the sensitive resistor.
5. Exciter insulation monitoring system according to any of claims 1-3, characterized in that the exciter insulation monitoring system further comprises an alarm device;
the insulation monitoring device is also used for sending a control instruction to the alarm device when the exciter exciting winding is monitored to have the ground fault;
and the alarm device is used for generating alarm prompt information according to the control instruction.
6. Exciter insulation monitoring system according to claim 2, characterized in that the insulation monitoring device further comprises a square wave power supply connected to the sensitive resistor;
the square wave power supply is used for supplying voltage to the insulation monitoring device.
7. Exciter insulation monitoring system according to claim 6, characterized in that the current threshold is determined from the voltage value provided by the square wave power supply, the resistance value of the first resistance and the resistance value of the second resistance.
8. Exciter insulation monitoring system according to claim 7, characterized in that the resistance value of the first resistor and the resistance value of the second resistor are the same.
9. Exciter insulation monitoring system according to claim 8, characterized in that the resistance value of the first resistor and the resistance value of the second resistor are both larger than 100K Ω.
10. The exciter insulation monitoring system of claim 1, wherein the positive output of the thyristor rectifier bridge is connected to the positive pole of the exciter field winding.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211655690.5A CN115932513A (en) | 2022-12-22 | 2022-12-22 | Exciter insulation monitoring system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211655690.5A CN115932513A (en) | 2022-12-22 | 2022-12-22 | Exciter insulation monitoring system |
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| CN115932513A true CN115932513A (en) | 2023-04-07 |
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| CN202211655690.5A Pending CN115932513A (en) | 2022-12-22 | 2022-12-22 | Exciter insulation monitoring system |
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- 2022-12-22 CN CN202211655690.5A patent/CN115932513A/en active Pending
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