CN104362587B - A kind of secondary current mutual inductor interstar connection loop high-voltage protects system - Google Patents

Abstract

System is protected the present invention relates to a kind of secondary current mutual inductor interstar connection loop high-voltage; the system short circuit protection location, sampling unit, comparator, control terminal unit, time-delay reset unit and power supply unit over the ground; the signal of collection is passed to comparator by the sampling unit; comparator is connected with short circuit protection location over the ground and control control terminal unit respectively, and power supply unit is that controlling of sampling unit and time-delay reset circuit are powered.The sampling unit is provided with plus DM EMI protection circuit; electric leakage or broken string high pressure CTAI signals are connected to short circuit protection location over the ground all the way; another road is connected to after commutation diode V1 by resistance R1, the decompression of resistance R2 current limlitings; again by resistance R3, resistance R4 partial pressures to comparator, neutral point COM is connected between resistance R1, resistance R2 by DM EMI protection filtering high-voltage capacitance CV1.

Description

A kind of secondary current mutual inductor interstar connection loop high-voltage protects system

Technical field

It is to be related to a kind of secondary current mutual inductance specifically the invention belongs to the technical field of power systems such as industrial, civilian Device connection circuit leaks electricity or broken string high voltage protective technology.

Background technology

During current transformer normal work, secondary circuit is bordering on short-circuit condition.At this moment produced by secondary current it is secondary around Group magnetomotive force F2 has demagnetizing effect to first winding magnetomotive force F1, therefore composite magnetic power F0=F1-F2 is less, resultant flux φ 0 Also less, induced electromotive force E2 numerical value is no more than tens volts in secondary winding.Therefore, in order to reduce current transformer Size and cost, transformer section unshakable in one's determination be close the very littles of magnetic magnetic flux φ 0 in normal operation according to current transformer and Design.Current transformer in use is opened a way in the event of secondary circuit, and secondary winding magnetomotive force F2 is equal to zero, first winding Magnetomotive force F1 still keeps constant, and is completely used for excitatory, composite magnetic power F0=F1, composite magnetic power when F0 at this moment is more normal (F1-F2) manyfold is increased so that the magnetic flux in unshakable in one's determination sharp increases and reaches saturation state.Because saturation unshakable in one's determination is caused Flux waveformses are changed into flat-topped wave, because induced electromotive force is proportional to rate of change d φ/dt of magnetic flux, at this moment in secondary winding Very high induced electromotive force e2 will be induced.The induced electromotive force e2 of secondary winding is the non-sine on pinnacle when secondary winding is opened a way Ripple, its peak value is up to the height of thousands of volts, and this insulation to staff and secondary device and secondary cable is all murther. Another influence is, because of the sharp increase of magnetic flux in iron core, to cause core loss to increase, and causes serious heating also to burn current transformer Ruin.3rd influence is that the error for making current transformer because remanent magnetism unshakable in one's determination is excessive increases powered secondary winding in current transformer Forbid open running.This has strict regulation in national standard electrical safe working order.

The content of the invention

In order to solve technical problem and defect, present invention aims at provide a kind of secondary current mutual inductor interstar connection to return Road is leaked electricity or broken string high voltage protective technology, the safety of detection in real time, short-circuit delay protection personnel and device components.

In order to solve the above-mentioned technical problem, the technical solution adopted in the present invention is：A kind of secondary current mutual inductor interstar connection Return high voltage protective system, the system short circuit protection location, sampling unit, comparator, control terminal unit, time-delay reset list over the ground The signal of collection is passed to comparator by member and power supply unit, the sampling unit, and comparator protects single with short circuit over the ground respectively Member and the unit connection of control control terminal, power supply unit is that controlling of sampling unit and time-delay reset circuit are powered.The sampling is single Member is provided with DM EMI protection circuit is added, and electric leakage or broken string high pressure CTAI signals are connected to short circuit protection location over the ground all the way, separately Be connected to all the way after commutation diode V1 by resistance R1, resistance R2 current limlitings decompression, then by resistance R3, resistance R4 partial pressures give than Compared with device, neutral point COM is connected between resistance R1, resistance R2 by DM EMI protection filtering high-voltage capacitance CV1.The comparison Device IC1 is when 3 pin sampled signals are higher than the reference voltage V ref of 2 pin, the pin of comparator 1 output trigger signal.The control terminal Unit drives Q1, Q2, control relay K1, relay K2 action respectively by resistance R5, resistance R6.Leaked after relay K1 actions Electricity or broken string high pressure are protected by short circuit over the ground, while lighting alarm lamp LED1；Control alarm buzzing after relay K2 actions Device sends alarm.Relay K2 is additionally operable to remote controlled normally opened, normally closed dry contact.The time-delay reset circuit is included after drive Dynamic loop and peripheral circuit, for when failure is not excluded, delay circuit provide relay K1, relay K2 operating voltages after It is continuous to be alarmed.

The present invention uses above-mentioned technical proposal, compared with prior art, and the present invention is connect using single-phase, multiphase current transformer Line loop is inputted, and any loop generation open fault is alarmed, indicated immediately, remote control.Simple circuit is reliable simultaneously, in real time prison Survey, act.Low in energy consumption, in the case where circuit is not acted, only comparator and delay chip is powered holding state, static work( Consume very little, only circuit operation moment actuating of relay power consumption 1W or so.

Brief description of the drawings

The system framework figure of Fig. 1 specific embodiment of the invention；

The sampling unit circuit diagram of Fig. 2 specific embodiment of the invention；

The comparator circuit figure of Fig. 3 specific embodiment of the invention；

The control terminal element circuit protective grounding of Fig. 4 specific embodiment of the invention and indicating fault schematic diagram；

The control terminal element circuit alarm of Fig. 5 specific embodiment of the invention and remote control normally-open normally-close dry contact signal Figure；

The time-delay reset potential circuit figure of Fig. 6 specific embodiment of the invention；

The electrical schematic of Fig. 7 specific embodiment of the invention.

Embodiment

Below against accompanying drawing, by the description to embodiment, embodiment of the invention such as involved each component Shape, construction, the mutual alignment between each several part and annexation, the effect of each several part and operation principle, manufacturing process and Operate with method etc., is described in further detail, to help those skilled in the art to inventive concept of the invention, technology Scheme has more complete, accurate and deep understanding.

As shown in figure 1, a kind of secondary current mutual inductor interstar connection returns high voltage protective system, short circuit protection is single over the ground for the system Member, sampling unit, comparator, control terminal unit, time-delay reset unit and power supply unit, the sampling unit is by the letter of collection Comparator number is passed to, comparator is connected with short circuit protection location over the ground and control control terminal unit respectively, and power supply unit is Controlling of sampling unit and time-delay reset circuit are powered.The sampling unit leaks electricity or broken provided with DM EMI protection circuit is added High pressure CTAI signals are connected to short circuit protection location over the ground all the way, another road be connected to after commutation diode V1 by resistance R1, Resistance R2 current limlitings are depressured, then by resistance R3, resistance R4 partial pressures to comparator, neutral point COM is protected by DM EMI and filtered High-voltage capacitance CV1 is connected between resistance R1, resistance R2.The comparator IC1 is when benchmark electricity of the 3 pin sampled signals higher than 2 pin When pressing Vref, the pin of comparator 1 output trigger signal.The control terminal unit by resistance R5, resistance R6 drive respectively Q1, Q2, control relay K1, relay K2 actions.Electric leakage or broken string high pressure are protected by short circuit over the ground after relay K1 actions, simultaneously Light alarm lamp LED1；Control alarm buzzer sends alarm after relay K2 actions.Relay K2 is additionally operable to can be long-range Normally opened, the normally closed dry contact of control.The time-delay reset circuit is included after driving circuit and peripheral circuit, for working as failure When not excluding, delay circuit provides relay K1, relay K2 operating voltages and proceeds alarm, holding state, power supply Delay protection circuit chip power supply is provided.

Fig. 2 sampling unit circuits.COM is neutral point, and CTAI is high pressure of leaking electricity or break, and directly arrives relay over the ground all the way Protection, enters V1 rectifications all the way, is depressured by R1, R2 current limliting, then by R3, R4 partial pressure to comparator.CV1 is that DM EMI protects filtering High-voltage capacitance.

Fig. 3 is that, compared with device circuit, sampled data compares and controls output.Comparator IC1 is higher than 2 pin when 3 pin sampled signals Reference voltage V ref when, the pin of comparator 1 output trigger signal, control relay K1, K2.

Fig. 4,5 are control terminal element circuit, for terminal control protection, instruction, warning circuit.When the pin of comparator 1 is defeated Go out trigger signal and Q1, Q2 are driven by R5, R6 respectively, then relay K1, K2 is acted.Electric leakage or broken string high pressure quilt after K1 actions Short circuit is protected over the ground, while alarm lamp LED1 is lighted, visually informs the position of trouble point；Control alarm honeybee after K2 actions Ring device sends alarm, the faulty generation of acoustically sense.Relay K2 additionally provides remote controlled normally opened, normally closed stem grafting Point, facilitates the functions such as remote control operation or instruction.Input terminal：There is device working power terminal, electric current is all the way or more Road sampling input terminal, normally opened, the normally closed dry contact terminal for remote control of alarming.Also SR on the spot.

Fig. 6 is time-delay reset circuit.When failture evacuation, reset switch SW is pressed, then protection circuit is stopped, located again In monitoring guard mode in real time.If failure is not excluded, delay circuit works on, and alarm is still present.Delay short circuit with Protective current transformer and personal security.Relay K1, K2 operating voltage are to drive supply by delay protection circuit chip IC 2 , IC2 driving circuits are just being for setting up, are being because IC2 and its peripheral circuit constitute delay circuit.When failture evacuation, press multiple Bit switch SW, then protection circuit be stopped, again in real time monitoring guard mode.If failure is not excluded, delay circuit Work on, alarm is still present.

Fig. 7 is the power supply that whole invention protection circuit be able to need not be lacked.The Power Management Design is reliable and stable, Width funtion, height Efficiency, the Switching Power Supply of low-power consumption are provided, it is ensured that the reliability of whole protection circuit.And small volume, small, price of generating heat are low It is honest and clean.

The present invention is exemplarily described above in conjunction with accompanying drawing, it is clear that the present invention is implemented not by aforesaid way Limitation, as long as the improvement of the various unsubstantialities of inventive concept and technical scheme of the present invention progress is employed, or without changing Enter and the design of the present invention and technical scheme are directly applied into other occasions, within protection scope of the present invention.

Claims (4)

1. a kind of secondary current mutual inductor interstar connection loop high-voltage protects system, it is characterised in that：Short circuit protection is single over the ground for the system Member, sampling unit, comparator, control terminal unit, time-delay reset unit and power supply unit, the sampling unit is by the letter of collection Comparator number is passed to, comparator is connected with short circuit protection location over the ground and control control terminal unit respectively, and power supply unit is Controlling of sampling unit and time-delay reset circuit are powered；The sampling unit is provided with DM EMI protection circuit, and electric leakage or broken string are high Pressure CTAI signals are connected to short circuit protection location over the ground all the way, and another road is connected to after commutation diode V1 by resistance R1, electricity The decompression of R2 current limlitings is hindered, then by resistance R3, resistance R4 partial pressures to comparator, neutral point COM is high by DM EMI protection filtering Voltage capacitance CV1 is connected between resistance R1, resistance R2；The comparator IC1 is higher than the reference voltage of 2 pin when 3 pin sampled signals During Vref, the pin of comparator 1 output trigger signal；The control terminal unit includes protection indicating circuit, warning circuit, and control is eventually End unit drives Q1, Q2, control relay K1, relay K2 action respectively by resistance R5, resistance R6.

2. secondary current mutual inductor interstar connection loop high-voltage according to claim 1 protects system, it is characterised in that：Relay Electric leakage or broken string high pressure are protected by short circuit over the ground after K1 actions, while lighting alarm lamp LED1；Controlled after relay K2 actions Alarm buzzer processed sends alarm.

3. secondary current mutual inductor interstar connection loop high-voltage according to claim 2 protects system, it is characterised in that：Relay K2 is additionally operable to remote controlled normally opened, normally closed dry contact.

4. secondary current mutual inductor interstar connection loop high-voltage according to claim 1 protects system, it is characterised in that：It is described to prolong When reset circuit include after driving circuit and peripheral circuit, for when failure is not excluded, delay circuit provide relay K1, Relay K2 operating voltages proceed alarm.