CN202535062U - System for grounding combination of neutral point and resistor via controllable reactance in electric power grid - Google Patents
System for grounding combination of neutral point and resistor via controllable reactance in electric power grid Download PDFInfo
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- CN202535062U CN202535062U CN2012201157957U CN201220115795U CN202535062U CN 202535062 U CN202535062 U CN 202535062U CN 2012201157957 U CN2012201157957 U CN 2012201157957U CN 201220115795 U CN201220115795 U CN 201220115795U CN 202535062 U CN202535062 U CN 202535062U
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- neutral point
- bus
- reactance
- control switch
- controller
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Abstract
The utility model discloses a system for grounding a combination of a neutral point and a resistor via a controllable reactance in an electric power grid, comprising a Z-type grounding transformer T connected with a bus and providing a neutral point, a controller; a reactance coil L, a neutral point voltage transformer PT0 and a neutral point current transformer CT0 which are respectively connected with the neutral point; a bus voltage measuring apparatus PT and n zero sequence current transformers CT1-CTn which are both connected with the bus and the controller respectively, wherein n is a positive integer, the voltage limiting resistor Rxy is connected with the neutral point through a control switch K1, and the line selection resistor Rxx is connected with the neutral point through a control switch K2. The system can enable the voltage limiting resistor to fully play an effect of limiting high power overvoltage and enables the line selection resistor to fully play an effect of increasing a fault current and also play an effect of resonance grounding compensation, through the flexible change of a neutral point grounding mode, thereby increasing power supply reliability and circuit equipment safety.
Description
Technical field
The utility model relates to the system of the interior neutral point of a kind of power network through controllable reactance and resistor group splice grafting ground.
Background technology
At present, the neutral grounding in distribution power network of low-voltage grade mainly contains following several kinds in the electric power system: 1. isolated neutral; 2. neutral point resistance grounded; 3. resonance grounding mode.
In isolated neutral system, when a phase fault took place, the power supply that is connected on the current collector on the voltage between phases was not destroyed; They can continue operation; Weak spot maybe be breakdown but at this moment non-fault phase voltage raises insulation, thereby cause the phase ground short circuit, damages electric equipment.At present; In order to solve the problem that isolated neutral brings, generally adopt two kinds of grounding through arc mode or low resistance grounding modes, wherein: the grounding through arc mode can realize extinguish arcs; Isolate the ground path difficulty but exist, search the bigger shortcoming of ground path difficulty.Though shortcomings such as the low resistance grounding mode is the tripping earth fault line accurately, and existence does not have differentiation to instantaneity ground connection and permanent earth fault, and trip-out rate is high, and earth fault current is big.Therefore, existing earth neutral system can not effectively be got rid of electrical network earth fault, can not guarantee the safe operation of electric power system.
Summary of the invention
The purpose of the utility model is to overcome the defective of prior art and provides in a kind of power network neutral point through the system on controllable reactance and resistor group splice grafting ground; Flexible variation through neutral grounding mode; Give full play to the effect that pressure limiting resistance limits high power overvoltage and route selection resistance increase fault current; Add the resonance grounding compensating action, improved the power supply reliability of power distribution network and the device security of circuit.
The technical scheme that realizes above-mentioned purpose is:
Neutral point comprises Z type grounding transformer T, reactance coil L, bus voltage measurement device PT, pressure limiting resistance R through the system on controllable reactance and resistor group splice grafting ground in a kind of power network
Xy, the route selection resistance R
Xx, control switch K
1, control switch K
2, neutral point voltage instrument transformer PT
0, neutral point current instrument transformer CT
0, controller and n zero sequence current mutual inductor CT
1-CT
n, n is a positive integer, wherein:
Z type grounding transformer T is connected to bus, and its neutral point is through neutral point voltage instrument transformer PT
0With neutral point current instrument transformer CT
0Connect controller respectively;
The pressure limiting resistance R
XyAn end through control switch K
1Connect described neutral point, other end ground connection;
The route selection resistance R
XxAn end through control switch K
2Connect described neutral point, other end ground connection;
The end of reactance coil L connects said neutral point, other end ground connection;
Bus voltage measurement device PT connection bus and said controller;
Each zero sequence current mutual inductor CT
1-CT
nConnection bus and said controller;
Said controller is controlled said control switch K respectively
1With control switch K
2Break-make, and the reactance of regulating said reactance coil L.
Neutral point is through the system on controllable reactance and resistor group splice grafting ground in the above-mentioned power network, and wherein, said bus is the 10KV bus.
The beneficial effect of the utility model is: the utility model excises series damping resistor when system's generation single phase ground fault, the neutral ground reactance is given full play to the compensating action of reactance by regulating the compensate for failed electric current in advance, reaches the purpose of blow-out; When system occurred presetting overvoltage, neutral point became reactance parallel connection pressure limiting resistance earthing; When the earth fault duration surpassed preset value, neutral point became reactance parallel connection route selection resistance earthing; Therefore; The utility model is through the flexible variation of neutral grounding mode; Give full play to the effect that pressure limiting resistance limits high power overvoltage and route selection resistance increase fault current, realize going after profit or gain fraud, add the resonance grounding compensating action through the size of controlling making time and parallel resistance resistance; The combination earthing mode makes and compensation, pressure limiting, the route selection Trinity has improved the power supply reliability of power distribution network and the device security of circuit.
Description of drawings
Fig. 1 is the structural representation of the interior neutral point of the power network of the utility model through the system on controllable reactance and resistor group splice grafting ground.
Embodiment
Below in conjunction with accompanying drawing the utility model is described further.
See also Fig. 1, neutral point comprises Z type grounding transformer T, reactance coil L, bus voltage measurement device PT, pressure limiting resistance R through the system on controllable reactance and resistor group splice grafting ground in the power network of the utility model
Xy, the route selection resistance R
Xx, control switch K
1, control switch K
2, neutral point voltage instrument transformer PT
0, neutral point current instrument transformer CT
0, controller 1 and n zero sequence current mutual inductor CT
1-CT
n, n is a positive integer, wherein:
Z type grounding transformer T be used to provide system neutral, is connected to bus, and its neutral point is through neutral point voltage instrument transformer PT
0With neutral point current instrument transformer CT
0Connect controller 1 respectively;
The pressure limiting resistance R
XyBe used to suppress the amplitude overvoltage, an end is through control switch K
1Connect said neutral point, other end ground connection;
The route selection resistance R
XxBe used for single-phase earth fault line selection, an end is through control switch K
2Connect said neutral point, other end ground connection;
Reactance coil L is used for the compensation network capacitance current, and an end connects said neutral point, other end ground connection;
Bus voltage measurement device PT is used to obtain busbar voltage and open delta voltage, connection bus and controller 1;
Each zero sequence current mutual inductor CT
1-CT
nConnection bus and controller 1;
Said controller 1 is controlled control switch K respectively
1With control switch K
2Break-make, and the reactance of regulating reactance coil L.
In the present embodiment, bus is the 10KV bus.Controller 1 is to be the micro control device of kernel with the PC104 industrial computer.
When electrical network normally moves; The reactance coil L of presetting system puts into operation; Controller 1 real-time measurement system capacitance current; Corresponding adjustment reactance gear guarantees reactance coil L all the time near the resonance point operation, and the long-time displacement voltage of series damping resistor restriction neutral point should not surpass 15% of electrical network phase voltage.
When system's generation single phase ground fault, the excision series damping resistor, reactance coil L gives full play to the compensating action of reactance by regulating the compensate for failed electric current in advance, makes the fault point residual flow less than 10A, reaches the purpose of blow-out.If overvoltage more than 2.5 times appears in system, drop into the pressure limiting resistance R
Xy, neutral point becomes reactance coil L parallel connection pressure limiting resistance R
XyEarthing mode, pressure limiting resistance R behind the certain hour
XyWithdraw from; The earth fault duration surpasses preset value, or continuous three times are dropped into the pressure limiting resistance R
XyAfter, drop into the route selection resistance R
Xx, neutral point becomes reactance coil L parallel connection route selection resistance R
XxEarthing mode is through the route selection resistance R
XxChange the zero sequence loop parameter, utilize zero-sequenceprotection or line selection apparatus to carry out failure line selection, excise permanent earth fault fast; If route selection unsuccessful (be mostly earth fault transition resistance big due to), or switch is failure to actuate, and time-delay earth fault does not disappear, and still excises the route selection resistance R
Xx, neutral point resonance grounding mode is got back to by system.This moment, transition resistance was bigger, and the overvoltage amplitude can be very not high; The simultaneous ground fault electric current is less, has reduced the threat to personal safety.
The utility model is through the flexible variation of neutral grounding mode; Give full play to the effect that pressure limiting resistance limits high power overvoltage and route selection resistance increase fault current; Size through control making time and parallel resistance resistance realizes going after profit or gain fraud; Add the resonance grounding compensating action, the combination earthing mode makes and compensation, pressure limiting, the route selection Trinity has improved the power supply reliability of power distribution network and the device security of circuit.
Above embodiment only supplies to explain the usefulness of the utility model; But not to the restriction of the utility model; The technical staff in relevant technologies field under the situation of spirit that does not break away from the utility model and scope, can also make various conversion or modification; Therefore all technical schemes that are equal to also should belong to the category of the utility model, should be limited each claim.
Claims (2)
1. neutral point is characterized in that through the system on controllable reactance and resistor group splice grafting ground in the power network, comprises Z type grounding transformer T, reactance coil L, bus voltage measurement device PT, pressure limiting resistance R
Xy, the route selection resistance R
Xx, control switch K
1, control switch K
2, neutral point voltage instrument transformer PT
0, neutral point current instrument transformer CT
0, controller and n zero sequence current mutual inductor CT
1-CT
n, n is a positive integer, wherein:
Z type grounding transformer T is connected to bus, and its neutral point is through neutral point voltage instrument transformer PT
0With neutral point current instrument transformer CT
0Connect controller respectively;
The pressure limiting resistance R
XyAn end through control switch K
1Connect described neutral point, other end ground connection;
The route selection resistance R
XxAn end through control switch K
2Connect described neutral point, other end ground connection;
The end of reactance coil L connects said neutral point, other end ground connection;
Bus voltage measurement device PT connection bus and said controller;
Each zero sequence current mutual inductor CT
1-CT
nConnection bus and said controller;
Said controller is controlled said control switch K respectively
1With control switch K
2Break-make, and the reactance of regulating said reactance coil L.
2. neutral point is characterized in that through the system on controllable reactance and resistor group splice grafting ground said bus is the 10KV bus in the power network according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012201157957U CN202535062U (en) | 2012-03-23 | 2012-03-23 | System for grounding combination of neutral point and resistor via controllable reactance in electric power grid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012201157957U CN202535062U (en) | 2012-03-23 | 2012-03-23 | System for grounding combination of neutral point and resistor via controllable reactance in electric power grid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202535062U true CN202535062U (en) | 2012-11-14 |
Family
ID=47136219
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2012201157957U Expired - Fee Related CN202535062U (en) | 2012-03-23 | 2012-03-23 | System for grounding combination of neutral point and resistor via controllable reactance in electric power grid |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202535062U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102623984A (en) * | 2012-03-23 | 2012-08-01 | 上海市电力公司 | System for grounding neutral point in power grid through controllable reactor and resistor in combined manner |
| CN103368167A (en) * | 2013-06-27 | 2013-10-23 | 刘宝稳 | Single-phase earth fault fundamental current full compensation device and method |
| CN103595029A (en) * | 2013-10-24 | 2014-02-19 | 杭州智光一创科技有限公司 | Fault self-adaptive ground connecting processing system and method for distribution network power grid |
| CN110416990A (en) * | 2019-06-17 | 2019-11-05 | 赵子云 | Medium voltage network neutral ground controls equipment |
-
2012
- 2012-03-23 CN CN2012201157957U patent/CN202535062U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102623984A (en) * | 2012-03-23 | 2012-08-01 | 上海市电力公司 | System for grounding neutral point in power grid through controllable reactor and resistor in combined manner |
| CN103368167A (en) * | 2013-06-27 | 2013-10-23 | 刘宝稳 | Single-phase earth fault fundamental current full compensation device and method |
| CN103595029A (en) * | 2013-10-24 | 2014-02-19 | 杭州智光一创科技有限公司 | Fault self-adaptive ground connecting processing system and method for distribution network power grid |
| CN110416990A (en) * | 2019-06-17 | 2019-11-05 | 赵子云 | Medium voltage network neutral ground controls equipment |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20121114 Termination date: 20200323 |