CN209313424U - A kind of zero-sequence current protection circuit - Google Patents
A kind of zero-sequence current protection circuit Download PDFInfo
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- CN209313424U CN209313424U CN201920349182.1U CN201920349182U CN209313424U CN 209313424 U CN209313424 U CN 209313424U CN 201920349182 U CN201920349182 U CN 201920349182U CN 209313424 U CN209313424 U CN 209313424U
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Abstract
The utility model discloses a kind of zero-sequence current protection circuits; including the high-voltage switch gear tripping contactor for protection; the high-voltage switch gear tripping contactor connects to form the first control loop with the normally opened contact of the time relay, and the both ends of first control loop are separately connected the positive and negative anodes of power supply；The coil of the time relay successively connects to form the second control loop with the normally opened contact of the normally opened contact of residual voltage relay, residual current relay, and the both ends of second control loop are separately connected the positive and negative anodes of power supply；The voltage input contact of the residual voltage relay is connect with zero sequential potential transformer, and the residual current relay is connect with zero sequence current mutual inductor.Utility model has the advantages that by two residual voltage, zero-sequence current parameters to determine whether the trip operation in turn that is out of order more accurately is judged in single-phase earthing there are ground fault, to avoid malfunctioning, raising accuracy of action.
Description
Technical field
The utility model relates to network system field, in particular to the zero-sequence current protection device of a kind of distribution line.
Background technique
10KV system neutral is using low resistance grounding, and zero-sequence current protection is directly dynamic when line cord single-phase earthing
Make in tripping.When the two-way power supply A of electric substation, route B cyclization, zero-sequence current protection II section movement mistrip is switched, protects and fills
It sets recording and shows that three-phase voltage is normal, three-phase current waveform stabilization, zero-sequence current amplitude is secondary to be more than up to 2A (40A or more)
II sections of zero-sequenceprotection of movement setting valve, three phase unbalance current is excessive when being judged as cyclization causes.Then, to switchgear
Contact of breaker, contact resistance etc. are checked, line electricity cable end is handled and polished, still can not eliminate 2
The out-of-balance current generated when route cyclization.If further increasing protection act setting valve, out-of-balance current can be escaped
It influences；But when cable single-phase earthing really occurs, the amplitude of zero-sequence current may be unable to reach protection act setting valve,
Protection can be failure to actuate, and can not cut off failure.Therefore, how on the basis of not improving zero-sequence current protection movement setting valve, prevent
Only zero-sequence current protection error action of device is made when the cyclization of duplex feeding route, is our problem to be addressed by invention.
Summary of the invention
It is an object of the invention to overcome the deficiencies of the prior art and provide a kind of zero-sequence current protection circuits, can be improved
The accuracy of zero-sequence current trip protection.
To achieve the goals above, the technical solution adopted by the present invention are as follows: a kind of zero-sequence current protection circuit, including be used for
The high-voltage switch gear tripping contactor of protection, the high-voltage switch gear tripping contactor connect to be formed with the normally opened contact of the time relay
The both ends of first control loop, first control loop are separately connected the positive and negative anodes of power supply；The coil of the time relay
Successively connect to form the second control loop with the normally opened contact of the normally opened contact of residual voltage relay, residual current relay,
The both ends of second control loop are separately connected the positive and negative anodes of power supply；The voltage input contact of the residual voltage relay
It is connect with zero sequential potential transformer, the residual current relay is connect with zero sequence current mutual inductor.
Switching pressing plate in tripping outlet is arranged in series in second control loop.
The present invention has the advantages that by two residual voltage, zero-sequence current parameters to determine whether there are ground fault,
The trip operation in turn that is out of order more accurately is judged in single-phase earthing, to avoid malfunctioning, improves accuracy of action,
Structure is simple simultaneously, it is convenient to realize, can be thus achieved using the normally-open normally-close contact of most common relay.
Detailed description of the invention
Below to each width attached drawing of description of the invention expression content and figure in label be briefly described:
Fig. 1 is the first control loop of the utility model schematic diagram
Fig. 2 is the second control loop of the utility model schematic diagram；
Fig. 3 is residual voltage of the present invention, electric current relay schematic diagram.
Specific embodiment
A specific embodiment of the invention is made further detailed below against attached drawing by the description to optimum embodiment
Thin explanation.
In 10KV neutral grounding by small resistance power supply system, when phase ground connection, residual voltage reaches as high as 100V (gold
Attribute ground connection).Technical solution of the present invention is exactly to utilize residual voltage criterion, as compound zero-sequence current protection device action
Assistant criteria realize the correct trip avoidance function of zero-sequence current protection.The protection act of this compound zero-sequence current protection device
Logic uses two criterions of zero-sequence current and residual voltage: when zero-sequence current is greater than " single-phase earthing definite value ", residual voltage is greater than
When " residual voltage definite value ", protective device movement tripping；When zero-sequence current is greater than " single-phase earthing definite value ", residual voltage is less than
When " residual voltage definite value ", it is latched zero-sequence current protection.To realize that compound zero-sequence current protection device list occurs in route
Action message is protected when being mutually grounded；And route does not occur single-phase earthing, 2 route cyclizations occur out-of-balance current it is larger when protection
Device will not malfunction.
As shown in Figure 1-3, a kind of zero-sequence current protection circuit, trip contactor TC including the high-voltage switch gear for protection,
The coil of high-voltage switch gear tripping contactor TC connects to form the first control loop with the normally opened contact of the time relay, the first control
The both ends in circuit are separately connected the positive and negative anodes of power supply；The coil of the time relay successively with the normally opened touching of residual voltage relay
Point, residual current relay normally opened contact connect to form the second control loop, the both ends of the second control loop are separately connected electricity
The positive and negative anodes in source；The voltage input contact of residual voltage relay is connect with zero sequential potential transformer, residual current relay with
Zero sequence current mutual inductor connection.
Residual voltage relay, residual current relay are according to preset voltage and current come turn-on action.It is preset with voltage
Threshold value, current threshold, when the residual voltage that mutual inductor detects is greater than the set value, the residual voltage actuating of relay, coil leads to
Electricity, normally opened contact closure；When mutual inductor detects that zero-sequence current is greater than the set value, residual current relay movement, line
Circle drives normally opened contact closure after being powered.When the normally opened contact of residual current relay, residual voltage relay is closed, this
When the first control loop be connected, the coil of time relay TJ is powered, the time relay in such the second control loop of position
Normally opened contact closure, high-voltage switch gear trip contactor TC coil energization movement, contactor disconnect faulty line, to reach guarantor
The effect of shield.
It is arranged in series switching pressing plate QT in tripping outlet in the second control loop, is used to start or close the zero-sequence current
Whether protecting the starting of circuit.
A kind of compound zero-sequence current protection device includes: that IJO is residual current relay, and YJo is residual voltage relay
Device, QT are that tripping exports switching pressing plate, and TJ is tripping Outlet time relay, and TC is high-voltage switch gear tripping contactor coil.
When single-phase earthing does not occur for neutral point small resistance grounding system Voltage Cable Lines Construction, it is fixed that residual voltage is less than setting
Value, even if at this moment the out-of-balance current as caused by the factors such as cyclization (zero-sequence current) is greater than the current threshold of setting, protective device
Contactor TC will not export tripping；If single-phase earthing occurs for route, residual voltage is greater than setting definite value, and zero-sequence current is big
In definite value current threshold, two conditions are met the requirements simultaneously, and the time relay could be powered movement at this time, the contact of protective device
Device TC, which could be powered, trips outlet.
One, the connection relationship of circuit:
(1) residual current relay IJO is connected to the zero-sequence current output end of zero sequence current mutual inductor, residual voltage relay
Two ends of YJo are connected to the both ends of zero sequential potential transformer.Residual current relay when the zero-sequence current of input is greater than the set value,
Coil is just powered conducting, and normally opened contact is just closed；Residual voltage relay is when the residual voltage of input is greater than the set value, coil
It is just connected, normally opened contact is just closed.Its residual voltage relay, residual current relay can choose conducting according to actual needs
Voltage, conducting electric current meet the relay of condition to realize or select to can be set the electronic relay of turn-on parameter, pass through
Manual setting conducting voltage, conducting electric current.
(2) this programme is there are two control loop, the circuit of a conducting for controlling the time relay, the other is high
The cabinet that compresses switch trip control loop, the time relay conducting whether control loop in, positive supply K+ be connected to zero-sequence current after
The first end of electric appliance IJO normally opened contact, the second end of IJO normally opened contact are connected to the of residual voltage relay YJo normally opened contact
One end, the second end of residual voltage relay YJo normally opened contact are connected to one end of tripping outlet switching pressing plate QT, and tripping outlet is cut
Another one end for being connected to tripping Outlet time relay TJ of pressing plate QT is changed, trip the another of Outlet time relay TJ coil
End is respectively connected to the negative supply K- of control loop.
(3) the positive supply KT+ of high-tension switch cabinet tripping control loop is connected to tripping Outlet time relay TJ normally opened contact
One end, tripping Outlet time relay TJ normally opened contact it is another be connected to high-voltage switch gear tripping contactor coil TC one
End, another positive supply KT- for being connected to high-tension switch cabinet tripping control loop of high-voltage switch gear tripping contactor coil TC.
Two, the course of work of protective device
(1) when single-phase earthing occurs for power supply line, zero-sequence current is greater than the action current of residual current relay, zero sequence
The normally opened contact of electric current relay IJO is closed, residual voltage relay YJo normally opened contact closure, when protection puts into tripping outlet
Switch pressing plate QT when, tripping Outlet time relay TJ obtain it is electric, tripping Outlet time relay TJ normally opened contact closure, make height
The contactor coil TC that trips of compressing switch obtains electric, high-voltage switch gear starting tripping circuit, and switch trip cuts off the fault wire of single-phase earthing
Road.
(2) when 2 power supply line's cyclizations, and when single-phase earthing does not occur for route, residual voltage relay is due to being unsatisfactory for
Operation condition and be in an off state, residual voltage relay YJo normally opened contact open, even if at this moment out-of-balance current (zero sequence
Electric current) big, residual current relay IJO normally opened contact closure, tripping Outlet time relay TJ will not obtain electric, switch
It will not trip, it is therefore prevented that zero-sequenceprotection is malfunctioned in 2 route cyclizations.
Obviously present invention specific implementation is not subject to the restrictions described above, as long as using method concept and skill of the invention
The improvement for the various unsubstantialities that art scheme carries out, it is within the scope of the present invention.
Claims (2)
1. a kind of zero-sequence current protection circuit, including high-voltage switch gear tripping contactor, it is characterised in that: the high-voltage switch gear tripping
Contactor connects to form the first control loop with the normally opened contact of the time relay, and the both ends of first control loop connect respectively
Connect the positive and negative anodes of power supply；The coil of the time relay successively with the normally opened contact of residual voltage relay, zero-sequence current after
The normally opened contact of electric appliance connects to form the second control loop, and the both ends of second control loop are separately connected the positive and negative of power supply
Pole；The voltage input contact of the residual voltage relay is connect with zero sequential potential transformer, the residual current relay with
Zero sequence current mutual inductor connection.
2. a kind of zero-sequence current protection circuit as described in claim 1, it is characterised in that: in second control loop
It is arranged in series tripping outlet switching pressing plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920349182.1U CN209313424U (en) | 2019-03-19 | 2019-03-19 | A kind of zero-sequence current protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920349182.1U CN209313424U (en) | 2019-03-19 | 2019-03-19 | A kind of zero-sequence current protection circuit |
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| Publication Number | Publication Date |
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| CN209313424U true CN209313424U (en) | 2019-08-27 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201920349182.1U Active CN209313424U (en) | 2019-03-19 | 2019-03-19 | A kind of zero-sequence current protection circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113300338A (en) * | 2021-05-26 | 2021-08-24 | 中铁十六局集团电气化工程有限公司 | Method, device, medium and equipment for inhibiting power supply system relay protection misoperation |
-
2019
- 2019-03-19 CN CN201920349182.1U patent/CN209313424U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113300338A (en) * | 2021-05-26 | 2021-08-24 | 中铁十六局集团电气化工程有限公司 | Method, device, medium and equipment for inhibiting power supply system relay protection misoperation |
| CN113300338B (en) * | 2021-05-26 | 2023-11-07 | 中铁十六局集团电气化工程有限公司 | Method, device, medium and equipment for suppressing relay protection misoperation of power supply system |
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