CN212012125U - Neutral point grounding resistor protection circuit - Google Patents
Neutral point grounding resistor protection circuit Download PDFInfo
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- CN212012125U CN212012125U CN202020986971.9U CN202020986971U CN212012125U CN 212012125 U CN212012125 U CN 212012125U CN 202020986971 U CN202020986971 U CN 202020986971U CN 212012125 U CN212012125 U CN 212012125U
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- 230000009286 beneficial effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
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Abstract
The utility model discloses a neutral point ground resistance protection circuit, including control switch KIN, auxiliary relay KA1, time relay KT1 and high-pressure vacuum switch KM1, whole circuit structure neutral point unbalanced voltage signal makes control switch KIN closed when taking place system ground connection, form drive circuit with auxiliary relay KA 1's normally closed contact after control switch KIN is closed, make high-pressure vacuum switch KM1 drop into high-power ground resistance R and prevent ground connection excessive pressure, auxiliary relay KA1 and time relay KT1 constitute delay control circuit, once relay protection equipment refuses the time out and can not amputate ground resistance, when reaching delay control circuit delay upper limit, delay circuit just initiatively amputates high-power ground resistance R, avoid high-power ground resistance R to drop into the overheat burnout for a long time, whole circuit structure realizes through pure hardware, moreover, the steam generator is simple in structure, the protection delay can be set, Is stable and reliable.
Description
Technical Field
The utility model relates to an electric power protection and neutral point grounding system technical field specifically are a neutral point ground resistance protection circuit.
Background
In a 6-35KV AC power network, the grounding capacitance current is large in a cable power supply system, and when the current is larger than a specified value, arc grounding overvoltage is generated. If a neutral point resistance grounding mode is adopted, resistive current can be injected into a fault point, so that the grounding fault current has resistance-capacitance property, the phase difference with voltage is reduced, the reignition rate of the fault point current after zero crossing and arc extinguishing is reduced, the overvoltage is limited within 2.6 times of phase voltage, the sensitivity of relay protection equipment is improved, and the tripping operation is acted, so that the normal operation of a system is effectively protected.
From the above, it can be seen that: the core device of the resistor cabinet is a grounding resistor. When the system is grounded, the current can reach hundreds of amperes, the temperature of the resistor rises to about 800 ℃ within a few seconds, and the relay protection equipment can cut off the fault line under normal conditions; if the relay protection equipment is failed or other reasons cause that a fault line is not cut off within a specified time, the resistor burns out due to long-time overheating, and in order to prevent the situation, an overtime quit circuit is added to the ground resistor to serve as backup protection.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a neutral point grounding resistance protection circuit realizes, simple structure, protection delay can be set, reliable and stable through pure hardware to solve the problem of proposing among the above-mentioned background art.
In order to achieve the above object, the utility model provides a following technical scheme: a neutral point ground resistance protection circuit comprises a control switch KIN, an intermediate relay KA1, a time relay KT1 and a high-voltage vacuum switch KM1, wherein the input end of the control switch KIN is connected with a live wire L, and the live wire L is connected with the time relay KT1 in parallel through a lead; the output end of the control switch KIN is connected with the intermediate relay KA1 and the time relay KT1 in parallel; the intermediate relay KA1 is further connected with a time relay KT1 and a high-voltage vacuum switch KM1, the input end of the high-voltage vacuum switch KM1 is connected with a zero line N, and the zero line N is connected with the intermediate relay KA1 and the time relay KT1 in parallel through conducting wires.
Preferably, the inlet ends of the live wire L and the neutral wire N are provided with a normally closed power supply air switch QF 1.
Preferably, the intermediate relay KA1 is a normally closed contact, and the intermediate relay KA1 comprises a KA1_1 control coil and a KA1_2 contact.
Preferably, the time relay KT1 is a normally open contact, and the time relay KT1 comprises a KT1_1 control coil and a KT1_2 time delay contact.
Preferably, one end of the KT1_2 delay contact is connected to the live wire L, the other end of the KT1_2 delay contact is connected to the KA1_1 control coil, and the other end of the KA1_1 control coil is connected to the neutral wire N.
Preferably, the high-voltage vacuum switch KM1 is a normally open contact, and the high-voltage vacuum switch KM1 comprises a KM1_1 control coil and a KM1_2 contact.
Preferably, a high-power grounding resistor R is connected in series with the KM1_2 contact.
Preferably, the control switch KIN is a normally open contact, the control switch KIN is connected in parallel with a KT1_1 control coil in the time relay KT1 and a KA1_2 contact in the intermediate relay KA1, the other end of the KA1_2 contact is connected in series with a KM1_1 control coil in the high-voltage vacuum switch KM1, and the other ends of the KM1_1 control coil and the KT1_1 control coil are connected in parallel with a neutral line N.
Compared with the prior art, the beneficial effects of the utility model are as follows:
the neutral point grounding resistance protection circuit has the advantages that when system grounding occurs, a neutral point unbalanced voltage signal enables a control switch KIN to be closed, the control switch KIN and a normally closed contact of an intermediate relay KA1 form a driving loop after being closed, a high-power grounding resistance R is switched into a high-voltage vacuum switch KM1 to prevent grounding overvoltage, the intermediate relay KA1 and a time relay KT1 form a delay control circuit, once a relay protection device fails to cut off the grounding resistance due to overtime, when the delay upper limit of the delay control circuit is reached, the delay circuit actively cuts off the high-power grounding resistance R, the high-power grounding resistance R is prevented from being switched into an overheat mode for a long time to be burnt, the whole circuit structure is realized through pure hardware, the structure is simple, the protection delay can be set, and the.
Drawings
FIG. 1 is a circuit hardware wiring diagram of the present invention;
fig. 2 is a logic diagram of the circuit protection of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
Referring to fig. 1, a neutral point ground resistance protection circuit includes a control switch KIN, an intermediate relay KA1, a time relay KT1 and a high-voltage vacuum switch KM1, wherein an input end of the control switch KIN is connected with a live wire L, and the live wire L is connected in parallel with the time relay KT1 through a wire; the output end of the control switch KIN is connected in parallel with the intermediate relay KA1 and the time relay KT 1; the intermediate relay KA1 is also connected with a time relay KT1 and a high-voltage vacuum switch KM1, the input end of the high-voltage vacuum switch KM1 is connected with a zero line N, and the zero line N is connected with the intermediate relay KA1 and the time relay KT1 in parallel through conducting wires.
In the above embodiment, the model number of the intermediate relay KA1 is: 3RH6122-1AN 20; the model of the time relay KT1 is: h3 BA-N8H; the model of the high-voltage vacuum switch KM1 is EVS 160-160A.
Referring to fig. 2, the inlet terminals of the live line L and the neutral line N are provided with a normally closed power supply air switch QF 1; the intermediate relay KA1 is a normally closed contact, and the intermediate relay KA1 comprises a KA1_1 control coil and a KA1_2 contact; the time relay KT1 is a normally open contact, and the time relay KT1 comprises a KT1_1 control coil and a KT1_2 delay contact; one end of a KT1_2 delay contact is connected to a live wire L, the other end of the KT1_2 delay contact is connected with a KA1_1 control coil, and the other end of the KA1_1 control coil is connected to a zero line N; the high-voltage vacuum switch KM1 is a normally open contact, and the high-voltage vacuum switch KM1 comprises a KM1_1 control coil and a KM1_2 contact; a KM1_2 contact is connected with a high-power grounding resistor R in series; the control switch KIN is a normally open contact, the control switch KIN is connected with a KT1_1 control coil in the time relay KT1 and a KA1_2 contact in the intermediate relay KA1 in parallel, the other end of the KA1_2 contact is connected with a KM1_1 control coil in the high-voltage vacuum switch KM1 in series, and the other ends of the KM1_1 control coil and the KT1_1 control coil are connected on the zero line N in parallel.
In the above embodiment, when system grounding occurs, a neutral point unbalanced voltage signal closes a normally open contact of a control switch KIN, at this time, the control switch KIN, a KA1_2 contact (normally closed contact) and a KM1_1 control coil form a conducting loop, so that a KM1_2 contact is closed and a high-power grounding resistor R is put into the conducting loop, meanwhile, the control switches KIN and a KT1_1 control coil form a conducting loop, and a time relay KT1 starts timing (a setting range is 0-12S, the system is set to 10S); if the relay protection equipment does not cut off the fault line within 10 seconds after the high-power grounding resistor R is put into operation for more than 10S, KT1_2 is closed to form a conducting loop with KA1_1 so that the normally closed contact KA1_2 is disconnected, KA1_2 is disconnected so that the KM1_1 coil is powered off, and the KM1_1 coil is powered off so that the KM1_2 contact is disconnected so that the high-power grounding resistor R is cut off, so that the high-power grounding resistor R is prevented from being burnt out due to overtime input.
In summary, the following steps: the neutral point grounding resistance protection circuit has the advantages that when system grounding occurs, a neutral point unbalanced voltage signal enables a control switch KIN to be closed, the control switch KIN and a normally closed contact of an intermediate relay KA1 form a driving loop after being closed, a high-power grounding resistance R is switched into a high-voltage vacuum switch KM1 to prevent grounding overvoltage, the intermediate relay KA1 and a time relay KT1 form a delay control circuit, once a relay protection device fails to cut off the grounding resistance due to overtime, when the delay upper limit of the delay control circuit is reached, the delay circuit actively cuts off the high-power grounding resistance R, the high-power grounding resistance R is prevented from being switched into an overheat mode for a long time to be burnt, the whole circuit structure is realized through pure hardware, the structure is simple, the protection delay can be set, and the.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (8)
1. The utility model provides a neutral point ground resistance protection circuit, includes control switch KIN, auxiliary relay KA1, time relay KT1 and high-pressure vacuum switch KM1, its characterized in that: the input end of the control switch KIN is connected with a live wire L, and the live wire L is connected with a time relay KT1 in parallel through a lead; the output end of the control switch KIN is connected with the intermediate relay KA1 and the time relay KT1 in parallel; the intermediate relay KA1 is further connected with a time relay KT1 and a high-voltage vacuum switch KM1, the input end of the high-voltage vacuum switch KM1 is connected with a zero line N, and the zero line N is connected with the intermediate relay KA1 and the time relay KT1 in parallel through conducting wires.
2. A neutral grounding resistor protection circuit according to claim 1, wherein: and the inlet wire ends of the live wire L and the zero wire N are provided with normally closed power supply air switches QF 1.
3. A neutral grounding resistor protection circuit according to claim 1, wherein: the intermediate relay KA1 is a normally closed contact, and the intermediate relay KA1 comprises a KA1_1 control coil and a KA1_2 contact.
4. A neutral grounding resistor protection circuit according to claim 1, wherein: the time relay KT1 is a normally open contact, and the time relay KT1 comprises a KT1_1 control coil and a KT1_2 delay contact.
5. A neutral grounding resistor protection circuit according to claim 4, wherein: one end of the KT1_2 delay contact is connected on the live wire L, the other end is connected with the KA1_1 control coil, and the other end of the KA1_1 control coil is connected on the zero line N.
6. A neutral grounding resistor protection circuit according to claim 1, wherein: the high-voltage vacuum switch KM1 is a normally open contact, and the high-voltage vacuum switch KM1 comprises a KM1_1 control coil and a KM1_2 contact.
7. A neutral grounding resistor protection circuit according to claim 6, wherein: and a high-power grounding resistor R is connected in series on the KM1_2 contact.
8. A neutral grounding resistor protection circuit according to claim 1, wherein: the control switch KIN is normally open contact, and the control switch KIN goes up and is parallelly connected with KT1_1 control coil in the time relay KT1 and the KA1_2 contact in the auxiliary relay KA1, and the other end of KA1_2 contact is established ties KM1_1 control coil in the high-pressure vacuum switch KM1, and the other end of KM1_1 control coil and KT1_1 control coil is parallelly connected on zero line N.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020986971.9U CN212012125U (en) | 2020-06-02 | 2020-06-02 | Neutral point grounding resistor protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020986971.9U CN212012125U (en) | 2020-06-02 | 2020-06-02 | Neutral point grounding resistor protection circuit |
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| Publication Number | Publication Date |
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| CN212012125U true CN212012125U (en) | 2020-11-24 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202020986971.9U Active CN212012125U (en) | 2020-06-02 | 2020-06-02 | Neutral point grounding resistor protection circuit |
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| Country | Link |
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| CN (1) | CN212012125U (en) |
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2020
- 2020-06-02 CN CN202020986971.9U patent/CN212012125U/en active Active
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| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20211115 Address after: 071000 No. 18, second floor, R & D building, No. 2999, Xiangyang North Street, Baoding City, Hebei Province Patentee after: Bowei Electric Co.,Ltd. Address before: No. 2999 Xiangyang North Street, Baoding City, Hebei Province, 071000 Patentee before: HEBEI BOWEI ELECTRIC CO.,LTD. |
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| EE01 | Entry into force of recordation of patent licensing contract | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Assignee: Hebei Bowei Electric Power Technology Co.,Ltd. Assignor: Bowei Electric Co.,Ltd. Contract record no.: X2024990000133 Denomination of utility model: A Neutral Grounding Resistance Protection Circuit Granted publication date: 20201124 License type: Common License Record date: 20240410 |