CN102981101A - Detection method for misoperation prevention of power transmission line - Google Patents

Abstract

The invention discloses a detection method for misoperation prevention of a power transmission line. The method comprises the steps of sleeving an induction coil in equipment on an earthing knife-switch, sleeving two coils containing iron cores on the knife-switch, one coil as a source coil and with alternating current and the other coil as a measuring coil for measuring the magnitude of induced current in a down conductor loop, analyzing and calculating source coil voltage and current measured by the measuring coil, obtaining loop impedance of the whole line, informing a transformer substation at the opposite end of turning on an earthing knife-switch at the opposite end, allowing the equipment to detect the earthing condition and the interphase short circuit condition of the line phase by phase, informing a dispatching department of powering on if a detection result shows no interphase short circuit or earthing other than the earthing of the local earthing knife-switch, and informing the earthing knife-switch at the opposite end to switch on and debug if the line status is abnormal. The method has the advantages that the earthing condition of the line after overhaul and before switching-on can be detected, and the line can be directly judged whether an earthing point exists according to the detection result.

Description

A kind of transmission line of electricity is taken precautions against operation error detection method

Technical field

The invention belongs to electric line strick precaution maloperation method, the method and technology field that is applicable to take precautions against the rear combined floodgate maloperation under the short circuit condition of electric line maintenance of taking precautions against.

Background technology

When the electric line interruption maintenance, for guaranteeing the person and device security, can carry out grounding to circuit, after maintenance is finished, need to untie first ground connection, close a floodgate again.Yet because a variety of causes, the situation that ground connection is just closed a floodgate may appear not untiing, the failure of must closing a floodgate like this, and gently cause power off time to lengthen, and heavy then threaten equipment even personal safety.Some places adopt certain means of communication now, such as power carrier communication, note, GPRS, adjacent (opposite end) the grounding switch status information of standing is reached our station, if the distance station grounding switch closes a floodgate, automatic blocking our station closing operation then, thus our station band contact of earth maloperation avoided.This class anti-misoperation apparatus has certain effect, but has the problem of two aspects: the one, only can identify grounding switch, and helpless to the ground wire of interim overlap joint; The 2nd, this class device relies on the unimpeded of the correct detection of disconnecting link device state and communications conduit, and system architecture is comparatively complicated, and reliability is difficult to guarantee.Also have in addition the researcher to propose a kind of ferroresonance voltage stabilized transformer and detect the method that ground connection prevents switching on earth wire.This equipment is to become a distant place in the resonance voltage stabilizing to apply voltage, detects transformer pair side voltage swing, if think that ground connection existence is arranged, near short circuit, voltage is very little in transformer pair side, thereby " pilot lamp " extinguishes No switching on.This apparatus structure is simple, and stronger practicality is arranged, but because different electric pressures, the line parameter circuit value difference of obstructed length is large, only relies on " pilot lamp " whether to extinguish and indicates whether to have the ground connection difficulty larger.

Summary of the invention

Above-mentioned existing method wastes time and energy, the shortcoming of poor operability in order to overcome just in the present invention, and the method that provides a kind of new rear ground wire of detection line maintenance whether to disconnect, the method can judge effectively easily whether the line-to-ground line disconnects, save a large amount of manpower and materials, improve the safe operation of power system level.

Technical solution of the present invention is: a kind of transmission line of electricity is taken precautions against operation error detection method, and step of the present invention is:

1) finishes at line maintenance, after all artificial ground wires are removed, the inductive coil in the equipment is enclosed within on the grounding switch; Two coils that comprise iron core of suit are made power coil for one on the disconnecting link, pass to alternating current, by electromagnetic induction, produce induction current in loop, down conductor place; Another coil is made measuring coil, measures faradic size in the down conductor loop; The electric current that analytical calculation power coil voltage and measuring coil record obtains the impedance loop of whole piece circuit;

2) notice opposite end transformer station opens the opposite end grounding switch, and equipment detects by relative line-to-ground situation and alternate short circuit situation;

3) if the testing result demonstration without alternate short circuit and the ground connection except local grounding switch, is then withdrawed from checkout equipment, open local grounding switch, notice traffic department: " line maintenance is complete, possesses the electric condition of sending "; If line status is undesired, then notify the opposite end grounding switch to close a floodgate, and according to the testing result line inspection, the rear repetition preceding step of fixing a breakdown is until line status is normal.

The present invention is based on electromagnetic induction principle whole transmission line of electricity impedance loop is carried out non-cpntact measurement; Control section is collected measurement result, compares with the criterion of formulating, and whether the line-to-ground line is disconnected judge, the corresponding pilot lamp of Different Results is bright.

The invention has the beneficial effects as follows:

(1) the line-to-ground situation is detected before behind line maintenance, closing a floodgate, avoid the circuit switching on earth wire, cause closing a floodgate unsuccessfully.

(2) can judge directly whether circuit has earth point according to testing result.

Below in conjunction with the drawings and specific embodiments the present invention is done further explanation.

Description of drawings

Fig. 1 is work structuring synoptic diagram of the present invention.

Embodiment

See Fig. 1, the equipment place to use is mainly substation grounding disconnecting link place, and concrete operation step is as follows:

1. finish at line maintenance, after all artificial ground wires are removed, the inductive coil in the equipment is enclosed within on the grounding switch.Two coils that comprise iron core of suit are made power coil for one on the disconnecting link, pass to alternating current, by electromagnetic induction, produce induction current in loop, down conductor place; Another coil is made measuring coil, measures faradic size in the down conductor loop; The electric current that analytical calculation power coil voltage and measuring coil record obtains the impedance loop of whole piece circuit.

2. notice opposite end transformer station opens the opposite end grounding switch, and equipment detects by relative line-to-ground situation and alternate short circuit situation.

3. if testing result shows without alternate short circuit and the ground connection except local grounding switch, then withdraw from checkout equipment, open local grounding switch, notice traffic department: " line maintenance is complete, possesses the electric condition of sending ".If line status is undesired, then notify the opposite end grounding switch to close a floodgate, and according to the testing result line inspection, the rear repetition preceding step of fixing a breakdown is until line status is normal.

Claims (1)

1. a transmission line of electricity is taken precautions against operation error detection method, it is characterized in that the method step is:

1) finishes at line maintenance, after all artificial ground wires are removed, the inductive coil in the equipment is enclosed within on the grounding switch; Two coils that comprise iron core of suit are made power coil for one on the disconnecting link, pass to alternating current, by electromagnetic induction, produce induction current in loop, down conductor place; Another coil is made measuring coil, measures faradic size in the down conductor loop; The electric current that analytical calculation power coil voltage and measuring coil record obtains the impedance loop of whole piece circuit;

2) notice opposite end transformer station opens the opposite end grounding switch, and equipment detects by relative line-to-ground situation and alternate short circuit situation;

3) if the testing result demonstration without alternate short circuit and the ground connection except local grounding switch, is then withdrawed from checkout equipment, open local grounding switch, notice traffic department: " line maintenance is complete, possesses the electric condition of sending "; If line status is undesired, then notify the opposite end grounding switch to close a floodgate, and according to the testing result line inspection, the rear repetition preceding step of fixing a breakdown is until line status is normal.