CN106374449B - Arc Suppression Coil Control method and system - Google Patents
Arc Suppression Coil Control method and system Download PDFInfo
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- CN106374449B CN106374449B CN201610890280.7A CN201610890280A CN106374449B CN 106374449 B CN106374449 B CN 106374449B CN 201610890280 A CN201610890280 A CN 201610890280A CN 106374449 B CN106374449 B CN 106374449B
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- neutral point
- point voltage
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- voltage
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/08—Limitation or suppression of earth fault currents, e.g. Petersen coil
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- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The present invention relates to a kind of Arc Suppression Coil Control method and system, method includes the following steps：The neutral point voltage of arc suppression coil is sampled with certain frequency, obtains neutral point voltage；If the neutral point voltage meets preset numerical value constraints, and the duration for meeting preset numerical value constraints reaches preset time threshold, and earth fault occurs for judgement；Wherein, the preset numerical value constraints is set according to the maximum value of ground start voltage and neutral point voltage；When earth fault occurs, outputs control signals to silicon controlled control circuit startup arc suppression coil and compensate.
Description
Technical field
The present invention relates to technical field of power systems, more particularly to a kind of Arc Suppression Coil Control method and system.
Background technology
With urban development, the capacity of power grid increases, and a large amount of uses of cable, system capacitive current drastically increase in distribution
Adding, the electric arc that earthing capacitance current is formed in fault point when singlephase earth fault occurring in this case is unable to self-extinguish,
The overvoltage that indirect arc generates often makes fault spread, significantly reduces Operation of Electric Systems reliability, is transported to power grid security
Row constitutes a latent danger.
China often uses earthing mode of the neutral point through arc suppression coil, arc suppression coil in mesolow distribution network systems at present
Capacity should be able to smoothly change, and automatic tracing and measuring capacitance current should act and adequately compensate for immediately work in single-phase earthing
Frequency earthing capacitance current, promotes electric arc to extinguish rapidly.Phase-control type arc suppression coil is a kind of novel transformer type controlled reactor,
It is a kind of post-set arc suppression coils controlled by thyristor, it is short in secondary winding to adjust by the angle of flow for adjusting thyristor
Road electric current, to realize the controllable adjustment of reactance value.
Since it is that a kind of post-set arc suppression coils need when traditional control device judges ground connection according to ground start
Voltage judges and starts control device, needs multiple cycles that could judge to be grounded and start compensation output, is grounded the response time
Long, response speed is slow, is difficult the compensating action for playing arc suppression coil in intermittent grounding fault.
Invention content
Based on this, it is necessary to for the problem that response speed is slow, provide a kind of Arc Suppression Coil Control method and system.
A kind of Arc Suppression Coil Control method, includes the following steps：
The neutral point voltage of arc suppression coil is sampled with certain frequency, obtains neutral point voltage；
If the neutral point voltage meets preset numerical value constraints, and meets continuing for preset numerical value constraints
Time reaches preset time threshold, and earth fault occurs for judgement；Wherein, the preset numerical value constraints is opened according to ground connection
The maximum value setting of dynamic voltage and neutral point voltage；
When earth fault occurs, outputs control signals to silicon controlled control circuit startup arc suppression coil and compensate.
A kind of Arc Suppression Coil Control System, including：
Voltage collection circuit, processing circuit and control circuit；
The control circuit control voltage collection circuit adopts the neutral point voltage of arc suppression coil with certain frequency
Sample obtains neutral point voltage；
Collected neutral voltage is sent to the processing circuit by the voltage collection circuit；
The processing circuit meets preset numerical value constraints in the neutral voltage, and meets preset numerical value constraint
When the duration of condition reaches preset time threshold, earth fault occurs for judgement, and when earth fault occurs, output control
Signal processed to silicon controlled control circuit starts arc suppression coil and compensates.
Above-mentioned Arc Suppression Coil Control method and system, is sampled by the neutral point voltage to arc suppression coil, in acquisition
Property point voltage, the neutral point voltage is analyzed according to preset numerical value constraints, judge whether occur earth fault,
And when earth fault occurs, outputs control signals to silicon controlled control circuit startup arc suppression coil and compensate, at half week
It can judge whether earth fault occurs within wave, when earth fault occurs, processor circuit is output control signals to controllably
Silicon control circuit starts arc suppression coil and compensates, and improves extinguishing arc efficiency.
Description of the drawings
Fig. 1 is the Arc Suppression Coil Control method flow diagram of one embodiment；
Fig. 2 is the neutral point voltage oscillogram of the acquisition of embodiment 1；
Fig. 3 is the neutral point voltage oscillogram of the acquisition of embodiment 2；
Fig. 4 is the neutral point voltage oscillogram of the acquisition of embodiment 3；
Fig. 5 is the structural schematic diagram of the Arc Suppression Coil Control System of one embodiment.
Specific implementation mode
The present invention provides the phased Arc Suppression Coil Control device that a kind of earth fault judges quick self-adapting start.The dress
Earth fault can be judged within the time of half of cycle (10ms) and start compensation output and grounding alarm by setting.
Technical scheme of the present invention is illustrated below in conjunction with the accompanying drawings.
As shown in Figure 1, the present invention provides a kind of Arc Suppression Coil Control method, it may include following steps：
S1 samples the neutral point voltage of arc suppression coil with certain frequency, obtains neutral point voltage；
Wherein, certain frequency is typically no less than 64 points/cycle.
S2 if the neutral point voltage meets preset numerical value constraints, and meets preset numerical value constraints
Duration reaches preset time threshold, and earth fault occurs for judgement；Wherein, the preset numerical value constraints is according to connecing
Ground starts the maximum value setting of voltage and neutral point voltage；
Judge whether that earth fault, which occurs, can take two ways, solve different moments ground connection, be grounded quick response.
Mode one：It obtains absolute value in the neutral point voltage and is more than U0upLinAnd it is less than or equal to U0MaxOut-of-limit neutrality
Point voltage；Accumulated counts are carried out to the out-of-limit neutral point voltage, obtain accumulated value Cnt；When the sampled point of the neutral point voltage
Absolute value be less than U0upLinContinuous time be less than the time threshold, and CntWhen more than 1/4 sample frequency, judgement occurs
Earth fault；Wherein, U0upLinFor the upper limit value of ground start voltage, U0MaxFor the maximum value of the neutral point voltage, U0upFor
Ground start limit value.
Mode two：It obtains absolute value in the neutral point voltage and is more than U0upLinAnd it is less than or equal to U0MaxOut-of-limit neutrality
Point voltage；It adds up to the absolute value of the out-of-limit neutral point voltage, obtains accumulated value U0Sum；When the neutral point voltage
Absolute value is more than U0upLinContinuous time be more than or equal to the time threshold or the accumulated value U0SumMore than U0upWhen, judgement
Earth fault occurs；Wherein, U0upLinFor the upper limit value of ground start voltage, U0MaxFor the maximum value of the neutral point voltage,
U0upFor ground start limit value.
Wherein, the time threshold described in above two mode generally takes when closing on ground voltage value, preferred real at one
It applies in example, the time threshold described in above two mode generally takes 5ms.Time between two neighboring more point of accumulation, the threshold value
The data being arranged before and after making the zero crossing of neutral point voltage are effective simultaneously, ensure ground connection quick response；If single-phase earthing is high resistant
Ground connection or fault moment are happened at neutral point voltage close to before zero crossing within 45 °, and sampled value is relatively low, as long as in mode one
More than U0upLinWith regard to accumulated counts, it is ensured that quick response；It is happened at if single-phase earthing is metallic earthing or fault moment
After property point voltage over zero near 45 °, sampled value is relatively high, adds up to sampled value absolute value in mode two, Ke Yijia
Fast-response speed.
S3 when earth fault occurs, outputs control signals to silicon controlled control circuit startup arc suppression coil and compensates.
After earth fault occurs for judgement, alarm signal can be sent out.The alarm signal can be sound-light alarm
Signal.
For the clearer deterministic process for illustrating the present invention, illustrated with concrete numerical value.
Embodiment 1
Wherein sample frequency is set as each 128 points of cycle sampling, more limit value upper limit U0upLin=Uq is set as 25V, U0Max
It is set as 141.4V (upper limit case), then U0upIt is computed and is set as 993V.
As shown in Fig. 2, when ground connection is happened at the 29th sampled point, and when touchdown time U0 virtual value is 100V, from sampling
The 29th point of point starts to add up, when to the 36th, cumulative and U0SumIt is 1123.7, U0SumMore than U0up, it is judged as earth fault,
Judge time time for 20/128* (36-29)=1.09375ms, about 1.1ms.
Embodiment 2
Wherein sample frequency is set as 6400, i.e., each cycle samples at 128 points, more limit value upper limit U0upLin=Uq is set as
25V, U0MaxIt is set as 35.4V (lower limit situation), then U0upIt is computed and is set as 993V.
As shown in figure 3, when ground connection is happened at the 48th sampled point, and when touchdown time U0 virtual value is 25V, from sampled point
48th point starts to judge, since 48 points to 80 points of sampled point absolute values are less than U0upLinAnd continuous time be equal to 5ms, 48 points
It is not involved in cumulative, therefore adds up since 80 points to 80 points of sampled point absolute values, when to the 112nd, add up and U0SumFor
993.24V, U0SumMore than U0up, it is judged as earth fault, judges time time for 20/128* (112-48)=10ms.
Embodiment 3
Wherein sample frequency is set as 6400, i.e., each cycle samples at 128 points, more limit value upper limit U0upLin=Uq is set as
25V, U0MaxIt is set as 35.4V (lower limit situation), then U0upIt is computed and is set as 993V.
As shown in figure 4, when ground connection is happened at the 32nd sampled point, and when touchdown time U0 virtual value is 25V, from sampled point
32nd point starts to judge, because 32 points to 48 points of sampled point absolute value is more than U0upLin, add up since 32 points, to the 48th
When point, cumulative and U0SumFor 496.62V, since 48 points to 80 points of sampled point absolute values are less than U0upLinAnd continuous time is equal to
5ms, 48 points to 80 points of sampled point absolute value be not involved in it is cumulative because the sampled point absolute value from 80 points to the 96th point is more than
U0upLin, continue to add up since 80 points, when to the 96th, add up and U0SumFor 993.24V, U0SumMore than U0up, it is judged as connecing
Earth fault judges time time for 20/128* (96-32)=10ms.
Above 3 embodiments are the earth fault judgment methods of the cumulative sampled point absolute value being greater than the set value used.
Using to the sampled point being greater than the set value judge principle based on the earth fault judgment method of accumulated counts and add up
The earth fault judgment method for the sampled point absolute value being greater than the set value is identical, only by accumulated samples point absolute value convert in order to
Sampled point counts, and no longer carries out illustrated in greater detail herein.
As shown in figure 4, the present invention provides a kind of Arc Suppression Coil Control System, it may include：
Voltage collection circuit 11, processing circuit 12 and control circuit 13；
The control circuit 11 control voltage collection circuit 12 with certain frequency to the neutral point voltage of arc suppression coil into
Row sampling, obtains neutral point voltage；
Collected neutral voltage is sent to the processing circuit 13 by the voltage collection circuit 12；
The processing circuit 13 meets preset numerical value constraints in the neutral voltage, and meets preset numerical value about
When the duration of beam condition reaches preset time threshold, earth fault occurs for judgement, and when earth fault occurs, output
Control signal to silicon controlled control circuit starts arc suppression coil and compensates.
Judge whether that earth fault, which occurs, can take two ways.
Mode one：
It obtains absolute value in the neutral point voltage and is more than U0upLinAnd it is less than or equal to U0MaxOut-of-limit neutral point voltage；
Accumulated counts are carried out to the out-of-limit neutral point voltage, obtain accumulated value Cnt；When the neutral point voltage sampled point it is absolute
Value is less than U0upLinContinuous time be less than the time threshold, and CntWhen more than 1/4 sample frequency, ground connection event occurs for judgement
Barrier；Wherein, U0upLinFor the upper limit value of ground start voltage, U0MaxFor the maximum value of the neutral point voltage, U0upIt is opened for ground connection
Dynamic limit value.
Mode two：
It obtains absolute value in the neutral point voltage and is more than U0upLinAnd it is less than or equal to U0MaxOut-of-limit neutral point voltage；
It adds up to the absolute value of the out-of-limit neutral point voltage, obtains accumulated value U0Sum；When the absolute value of the neutral point voltage
More than U0upLinContinuous time be more than or equal to the time threshold or the accumulated value U0SumMore than U0upWhen, judgement connects
Earth fault；Wherein, U0upLinFor the upper limit value of ground start voltage, U0MaxFor the maximum value of the neutral point voltage, U0upTo connect
Ground starts limit value.
Wherein, the time threshold described in above two mode generally takes when closing on ground voltage value, preferred real at one
It applies in example, the time threshold described in above two mode generally takes 5ms.Time between two neighboring more point of accumulation, the threshold value
The data being arranged before and after making the zero crossing of neutral point voltage are effective simultaneously, ensure ground connection quick response；If single-phase earthing is high resistant
Ground connection or fault moment are happened at neutral point voltage close to before zero crossing within 45 °, and sampled value is relatively low, as long as in mode one
More than U0upLinWith regard to accumulated counts, it is ensured that quick response；It is happened at if single-phase earthing is metallic earthing or fault moment
After property point voltage over zero near 45 °, sampled value is relatively high, adds up to sampled value absolute value in mode two, Ke Yijia
Fast-response speed.
The Arc Suppression Coil Control System can also include warning device 14, and the warning device can send out alarm signal
Number.The warning device can be acoustic-optic alarm.
In one embodiment, the control circuit is silicon controlled control circuit.
It is tested by Practical Project, the present invention is grounded in any time of power frequency period, can after the grounding 1.0938
Judge to be grounded and start compensation output in~10ms, including entirely judge the case where neutral point voltage is across zero in the period,
Compared with traditional earth fault judgment method, judge that speed is fast, it can be with rapid arc extinction.
Each technical characteristic of embodiment described above can be combined arbitrarily, to keep description succinct, not to above-mentioned reality
It applies all possible combination of each technical characteristic in example to be all described, as long as however, the combination of these technical characteristics is not deposited
In contradiction, it is all considered to be the range of this specification record.
Several embodiments of the invention above described embodiment only expresses, the description thereof is more specific and detailed, but simultaneously
It cannot therefore be construed as limiting the scope of the patent.It should be pointed out that coming for those of ordinary skill in the art
It says, without departing from the inventive concept of the premise, various modifications and improvements can be made, these belong to the protection of the present invention
Range.Therefore, the protection domain of patent of the present invention should be determined by the appended claims.
Claims (8)
1. a kind of Arc Suppression Coil Control method, which is characterized in that include the following steps：
The neutral point voltage of arc suppression coil is sampled with certain frequency, obtains neutral point voltage；
If the neutral point voltage meets preset numerical value constraints, and meets the duration of preset numerical value constraints
Reach preset time threshold, earth fault occurs for judgement；Wherein, the preset numerical value constraints is according to ground start electricity
Pressure and the maximum value of neutral point voltage are set；
When earth fault occurs, outputs control signals to silicon controlled control circuit startup arc suppression coil and compensate；
If the neutral point voltage meets preset numerical value constraints, and meets the duration of preset numerical value constraints
Reach preset time threshold, judges that the step of earth fault occurs includes：
It obtains absolute value in the neutral point voltage and is more than U0upLinAnd it is less than or equal to U0MaxOut-of-limit neutral point voltage；
It adds up to the absolute value of the sampled point of the out-of-limit neutral point voltage, obtains accumulated value U0Sum；
When the absolute value of the neutral point voltage is more than U0upLinContinuous time be more than or equal to the time threshold or described tired
Value added U0SumMore than U0upWhen, earth fault occurs for judgement；
Wherein, U0upLinFor the upper limit value of ground start voltage, U0MaxFor the maximum value of the neutral point voltage, U0upIt is opened for ground connection
Dynamic limit value；
Or
It obtains absolute value in the neutral point voltage and is more than U0upLinAnd it is less than or equal to U0MaxOut-of-limit neutral point voltage；
Accumulated counts are carried out to the out-of-limit neutral point voltage, obtain accumulated value Cnt；
When the absolute value of the sampled point of the neutral point voltage is less than U0upLinContinuous time be less than the time threshold, and
CntWhen more than 1/4 sample frequency, earth fault occurs for judgement；
Wherein, U0upLinFor the upper limit value of ground start voltage, U0MaxFor the maximum value of the neutral point voltage, U0upIt is opened for ground connection
Dynamic limit value.
2. Arc Suppression Coil Control method according to claim 1, which is characterized in that further comprising the steps of：
When the absolute value of the neutral point voltage is less than U0upLinContinuous time be more than the time threshold when, judgement do not connect
Earth fault；
When earth fault not occurring, the step of being sampled to the neutral point voltage of arc suppression coil with certain frequency is returned, and
By U0SumIt resets.
3. Arc Suppression Coil Control method according to claim 1, which is characterized in that further comprising the steps of：
When the absolute value of the neutral point voltage is less than U0upLinContinuous time be more than the time threshold when, judgement do not connect
Earth fault；
When earth fault not occurring, the step of being sampled to the neutral point voltage of arc suppression coil with certain frequency is returned, and
By CntIt resets.
4. the Arc Suppression Coil Control method according to claims 1 to 3 any one, which is characterized in that further include following step
Suddenly：
When earth fault occurs for judgement, alarm signal is sent out.
5. the Arc Suppression Coil Control method according to claims 1 to 3 any one, which is characterized in that certain frequency
Rate is directly proportional to ground start voltage.
6. the Arc Suppression Coil Control method according to claims 1 to 3 any one, which is characterized in that the time threshold
For 5ms.
7. a kind of Arc Suppression Coil Control System, which is characterized in that including：
Voltage collection circuit, processing circuit and control circuit；
The control circuit control voltage collection circuit samples the neutral point voltage of arc suppression coil with certain frequency, obtains
Take neutral point voltage；
Collected neutral point voltage is sent to the processing circuit by the voltage collection circuit；
The processing circuit meets preset numerical value constraints in the neutral point voltage, and meets preset numerical value constraint item
When the duration of part reaches preset time threshold, earth fault occurs for judgement, and when earth fault occurs, output control
Signal to silicon controlled control circuit starts arc suppression coil and compensates；
The processing circuit meets preset numerical value constraints in the neutral point voltage, and meets preset numerical value constraint item
The duration of part reaches preset time threshold, judges that the step of earth fault occurs includes：
It obtains absolute value in the neutral point voltage and is more than U0upLinAnd it is less than or equal to U0MaxOut-of-limit neutral point voltage；
It adds up to the absolute value of the sampled point of the out-of-limit neutral point voltage, obtains accumulated value U0Sum；
When the absolute value of the neutral point voltage is more than U0upLinContinuous time be more than or equal to the time threshold or described tired
Value added U0SumMore than U0upWhen, earth fault occurs for judgement；
Wherein, U0upLinFor the upper limit value of ground start voltage, U0MaxFor the maximum value of the neutral point voltage, U0upIt is opened for ground connection
Dynamic limit value；
Or
It obtains absolute value in the neutral point voltage and is more than U0upLinAnd it is less than or equal to U0MaxOut-of-limit neutral point voltage；
Accumulated counts are carried out to the out-of-limit neutral point voltage, obtain accumulated value Cnt；
When the absolute value of the sampled point of the neutral point voltage is less than U0upLinContinuous time be less than the time threshold, and
CntWhen more than 1/4 sample frequency, earth fault occurs for judgement；
Wherein, U0upLinFor the upper limit value of ground start voltage, U0MaxFor the maximum value of the neutral point voltage, U0upIt is opened for ground connection
Dynamic limit value.
8. Arc Suppression Coil Control System according to claim 7, which is characterized in that the control circuit is SCR control
Circuit.
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|---|---|---|---|
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