CN103490373B - A kind of method preventing breaker misoperation and a kind of breaker - Google Patents

Abstract

The invention discloses a kind of method preventing breaker misoperation, belong to electrical safety technical field.The duty of current transformer is detected in real time by the present invention by transformer detection module, and when operation of current transformers abnormal state being detected, the fault monitored for now current transformer is only reported to the police, and does not threads off；When detecting that operation of current transformers state is normal, then the fault monitored for now breaker controller is normally protected.The invention also discloses a kind of breaker.The present invention can effectively prevent the misoperation of the breaker caused because operation of current transformers is abnormal, thus improves the global reliability of breaker, and realizes simple.

Description

A kind of method preventing breaker misoperation and a kind of breaker

Technical field

The present invention relates to a kind of method preventing breaker misoperation, belong to electrical safety technical field.

Background technology

Breaker is the critical elements in low-voltage distribution system, and its functional reliability is self-evident.Intelligent controller is as disconnected The central component of road device, is to realize the intelligentized core of breaker.Current transformer (Current Transformer) is called for short CT, it act as the heavy current (the primary current value of current transformer) in power system is for conversion into suitable relay The weak current (the secondary current value of current transformer) that device uses.Current transformer is long in current measurement and relay protection There is since phase irreplaceable status.In low-voltage intelligent circuit breaker, generally by measuring coil and energy coil two parts Composition.Whole current transformer is enclosed within breaker major loop bus, measuring coil sensing output voltage numerically with Primary current is linear, and the on-line parameter as intelligent controller is measured and protection signal input.Energy is coil-induced Go out self electromotive force as one of intelligent controller working power.After current transformer circuit supervision fail, particularly measuring coil broken string, Not only can affect the intelligent breaker measurement to the parameters of electric power such as electric current, power, also result in time serious have ground protection, The breaker misoperation of the functions such as current imbalance protection, open-phase protection.

In the prior art, most of intelligent breakers the most do not have the detection function to current transformer state；And minority With the breaker of current transformer status detection function, also simply send corresponding report when current transformer circuit supervision fail being detected Alert signal, it is impossible to effectively prevent from causing breaker misoperation because of current transformer circuit supervision fail.

Summary of the invention

The technical problem to be solved is to overcome existing breaker can not effectively prevent because of current transformer originally Die and hinder and cause the deficiency of breaker misoperation, it is provided that a kind of method preventing breaker misoperation and a kind of open circuit Device, can effectively prevent the breaker misoperation that the fault of current transformer own is caused.

The present invention solves above-mentioned technical problem the most by the following technical solutions:

A kind of method preventing breaker misoperation, described breaker includes intelligent controller, current transformer, dropout Device, current transformer is for monitoring in real time bus current and by monitoring result transmission to intelligent controller, intelligence According to the monitoring result that current transformer exports, controller judges whether that controlling trip gear carries out trip action；Described open circuit Device also includes the transformer detection module for detecting the duty of described current transformer in real time；When intelligence control When the monitoring result that device processed receives is beyond the normal range (NR) preset, the inspection that intelligent controller exports according to transformer detection module Survey result and judge that the duty of current transformer is the most normal, as operation of current transformers state is normal, then Based Intelligent Control Device sends alarm signal and controls trip gear and carry out trip action；Such as operation of current transformers abnormal state, then intelligence control Device processed only sends alarm signal.

A kind of breaker, including intelligent controller, current transformer, trip gear, current transformer is for bus Electric current is monitored in real time and is transmitted monitoring result to intelligent controller, and intelligent controller exports according to current transformer Monitoring result judges whether that controlling trip gear carries out trip action；Described breaker also includes for described Current Mutual Inductance The transformer detection module that the duty of device detects in real time；When intelligent controller receive monitoring result beyond pre- If normal range (NR) time, intelligent controller judges the work of current transformer according to the testing result that transformer detection module exports Making state the most normal, as operation of current transformers state is normal, then intelligent controller sends alarm signal and controls to thread off Device carries out trip action；Such as operation of current transformers abnormal state, then intelligent controller only sends alarm signal.

Compared to existing technology, technical solution of the present invention has the advantages that

One, can effectively prevent from causing the misoperation of breaker because operation of current transformers is abnormal, thus improve the entirety of breaker Reliability；

Two, technical solution of the present invention is without increasing the hardware circuit of intelligent controller, it is achieved simple, can effectively save cost.

Accompanying drawing explanation

Fig. 1 is the principle schematic of the inventive method；

Fig. 2 is the controller part-structure block diagram of breaker of the present invention；

Fig. 3 is the breaker of the present invention control flow when the monitoring result exception that current transformer exports；

Fig. 4 is the breaker of the present invention control flow when the monitoring result display earth fault that current transformer exports；

Fig. 5 is the breaker of the present invention control when the monitoring result display current imbalance fault that current transformer exports Flow process；

Fig. 6 is the breaker of the present invention control flow when the monitoring result display open phase fault that current transformer exports.

Detailed description of the invention

Below in conjunction with the accompanying drawings technical scheme is described in detail:

The thinking of the present invention is to utilize transformer detection module to the duty of the current transformer in breaker the most just Detect the most in real time, and judge whether that needs carry out corresponding protection act according to testing result.

The present invention prevents breaker misoperation Method And Principle as it is shown in figure 1, intelligent controller is to transformer detection module Signal is sampled, it is judged that operation of current transformers state is the most normal: if abnormal, then for now Current Mutual Inductance The fault (such as earth fault, open phase fault, current imbalance fault etc.) that device is monitored only is reported to the police, and is failure to actuate； If normal, then (such as earth fault, open phase fault, electric current are or not the fault monitored for now current transformer Balancing fault etc.) protect according to normal condition.

Transformer detection module in technical solution of the present invention can use various prior art to realize, such as, and Application No. One Chinese invention patent application of 20111005974.8 describes a kind of electric current for monitoring current transformer state Diagnostic device and diagnostic method thereof, add an earth resistance between current transformer and current signal Acquisition Circuit, logical Cross the output voltage of sensed current signal modulate circuit to differentiate whether current transformer breaks.Another Application No. 20101056781.4 Chinese invention patent application describe a kind of current transformer disconnection detection method, by software pair Current sampling signal carries out calculating and compare to differentiate whether current transformer breaks.

Fig. 2 shows the structure of the breaker controller part of the present invention, and microprocessor receives and is connected with current transformer Voltage collection circuit, the system power information that collected of current collection circuit, control de-according to the Protection parameters set Button circuit, thus realize the defencive function of breaker；Display circuit for show the measured values such as the electric current of breaker, voltage, Protection seting value, safeguard data etc..As it can be seen, this breaker also includes the transformer inspection being connected with microprocessor signals Survey module, the duty of transformer can be detected in real time, and the data detected are transferred to microprocessor.

Fig. 3 shows the breaker of the present invention control flow when the monitoring result exception that current transformer exports, such as figure institute Show: first initialize；Then operation of current transformers state is sampled by controller by transformer detection module； If sampled result is that state is abnormal, then the fault judged for the monitoring signal exported according to current transformer is only reported Alert, do not thread off, be then back to transformer detection module signals step of sampling；If it is normal that sampled result is state, then perform Normal error protection program, is then back to transformer detection module signals step of sampling.

In order to just be further appreciated by technical scheme with the public, separately below with breaker of the present invention at Current Mutual Inductance As a example by monitoring result display earth fault, current imbalance fault and the open phase fault situation of device output, describe this in detail Bright specific implementation.

Fig. 4 shows the breaker of the present invention control stream when the monitoring result display earth fault that current transformer exports Journey, judges as it can be seen, controller carries out sampling according to the signal of transformer detection module to operation of current transformers state. When actual motion current balance type in system, if the current transformer state now detecting certain phase current is abnormal, then should There is deviation in phase current mutual inductor secondary, it is impossible to truly reflect actual current, according to earth currentController can monitor the earth current of certain numerical value, if the earth current monitored surpasses Having crossed the setting valve of the landing operation preset, the earth fault indicator lamp of controller then sends warning flicker.Simultaneously as Current transformer state is abnormal, and corresponding mulual inductor malfunction indicator lamp also can send warning flicker.Preset at controller In the middle of program, when monitoring earth current more than the landing operation setting valve preset, the landing operation time starts to add up, The most cumulative numerical value is an electric current cycle period.Owing to this earth current is not truly to produce in the middle of circuit, and It is to cause owing to current transformer is abnormal, so user is not intended to now breaker and carries out protection of threading off, say, that as Fruit now breaker actuation then can be classified as the category of misoperation.In order to avoid the generation of this type of misoperation, controller is in inspection In the case of measuring current transformer abnormal state, corresponding numerical value will be deducted actuation time on every cycle period docking ground, So so that the landing operation time cumulative setting valve less than the landing operation time, dropout instruction also would not be sent. Such as, rated current In of this breaker is 1600A, and real work electric current is 1600A, and operating frequency is 50Hz, Landing operation current setting is 800A, and landing operation time setting value is 400ms.If now A phase current mutual inductance Device breaks, and due to three-phase imbalance, system will monitor the earth-fault current of 1600A.Due to earth fault Electric current be more than landing operation current setting, earth fault indicator lamp start flicker, the simultaneous ground fault time start with 20ms is the cycle to start to add up.But owing to this earth-fault current is to be caused by transformer disconnection, so pre-set programs To deduct 20ms in each cycle, such earth fault time will be unable to be added to landing operation time setting value simultaneously. It is to say, when current transformer is abnormal, breaker will only be reported to the police, and be failure to actuate, thus reach to prevent The purpose of breaker misoperation.

Fig. 5 shows that breaker of the present invention is when monitoring result that current transformer exports display current imbalance fault Control flow, as it can be seen, operation of current transformers state is sampled by controller according to transformer detection module signal Judge.When actual motion current balance type in system, if the current transformer state now detecting certain phase current is abnormal, Then there is deviation in this phase current mutual inductor secondary output voltage, it is impossible to truly reflect actual current, according to three-phase current the most not The degree of balance:

$I_{\mathrm{unbal}}=\frac{\underset{i=1}{\overset{n}{\mathrm{Max}}}|I_i-I_{\mathrm{avg}}|}{I_{\mathrm{avg}}}\×100\%,$

Wherein,

$I_{\mathrm{avg}}=\frac{{\mathrm{\Σ}}_{i=1}^n{I}_i}{n},$

N is the number of phases, I_iBeing the electric current (i.e. A, B, C phase) of each phase, controller can monitor the electric current of certain numerical value Degree of unbalancedness.If be detected that current unbalance factor exceeded the threshold value of adjusting preset, the current imbalance of controller therefore Barrier indicator lamp can send warning flicker.Simultaneously as current transformer state is abnormal, corresponding malfunction indicator lamp also can Send warning flicker.In the middle of the program that controller is preset, when monitoring current unbalance factor more than the threshold value of adjusting preset Time, current imbalance starts to add up actuation time, and the most cumulative numerical value is an electric current cycle period.Due to this electricity Stream imbalance is not truly to produce in the middle of circuit, but causes, so user is not intended to owing to current transformer is abnormal Now breaker carries out protection of threading off, say, that if now breaker actuation, can be classified as the category of misoperation.For Avoiding the generation of this type of misoperation, controller, will in every cycle period in the case of detecting that current transformer is abnormal Is deducted corresponding numerical value, so so that current imbalance is cumulative less than actuation time for actuation time the landing operation time Threshold value of adjusting, also would not send dropout instruction.Such as, the rated current of this breaker is 1600A, real work Electric current is 1600A, and operating frequency is 50Hz, and current imbalance action threshold value of adjusting is 80%, threshold of adjusting actuation time Value is 40s.If now A phase current mutual inductor breaks, due to three-phase imbalance, system power degree of unbalancedness will It is 200%.Owing to current unbalance factor 200% is more than adjusting threshold value 80%, current imbalance malfunction indicator lamp starts to dodge Bright, current imbalance starts to start to add up with 20ms for the cycle fault time simultaneously.But due to this current imbalance event Barrier electric current is to be caused by mulual inductor malfunction, so pre-set programs will deduct 20ms, such electric current in each cycle simultaneously The imbalance fault time will be unable to be added to current imbalance and adjusts actuation time threshold value.It is to say, at current transformer Under abnormal state, breaker will only be reported to the police, and be failure to actuate, thus reach to prevent the purpose of breaker misoperation.

Fig. 6 shows the breaker of the present invention control stream when the monitoring result display open phase fault that current transformer exports Journey, owing to open phase fault is the extreme case of current imbalance, therefore operation principle is with preventing current imbalance fault malfunction Making, here is omitted.

Claims (2)

1. the method preventing breaker misoperation, described breaker includes intelligent controller, current transformer, trip gear, current transformer is for monitoring in real time bus current and by monitoring result transmission to intelligent controller, according to the monitoring result that current transformer exports, intelligent controller judges whether that controlling trip gear carries out trip action；It is characterized in that, described breaker also includes the transformer detection module for detecting the duty of described current transformer in real time；When the monitoring result that intelligent controller receives is beyond the normal range (NR) preset, according to the testing result that transformer detection module exports, intelligent controller judges that the duty of current transformer is the most normal, if operation of current transformers state is normal, then intelligent controller sends alarm signal and controls trip gear and carry out trip action；If operation of current transformers abnormal state, then intelligent controller only sends alarm signal.

2. a breaker, including intelligent controller, current transformer, trip gear, current transformer is for monitoring in real time bus current and by monitoring result transmission to intelligent controller, according to the monitoring result that current transformer exports, intelligent controller judges whether that controlling trip gear carries out trip action；It is characterized in that, described breaker also includes the transformer detection module for detecting the duty of described current transformer in real time；When intelligent controller receive monitoring result beyond preset normal range (NR) time, according to the testing result that transformer detection module exports, intelligent controller judges that the duty of current transformer is the most normal, if operation of current transformers state is normal, then intelligent controller sends alarm signal and controls trip gear and carry out trip action；If operation of current transformers abnormal state, then intelligent controller only sends alarm signal.