CN201378738Y

CN201378738Y - Two-control-three pre-charge phase-control switching circuit of switched capacitor set

Info

Publication number: CN201378738Y
Application number: CN200920105307U
Authority: CN
Inventors: 杨建宁
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-01-21
Filing date: 2009-01-21
Publication date: 2010-01-06
Anticipated expiration: 2019-01-21

Abstract

The utility model relates to a two-control-three pre-charge phase-control switching circuit of a switched capacitor set, which comprises two phase-control switches for pre-charging the capacitor set to form a three-phase zero-point switch. The input end of the switch is connected with an LC series filter circuit which is in star connection of two-phase. Output ends of the two switches are connected together to be connected with the LC filter circuit of a third phrase. The LC filter circuit which is in star connection is connected with a three-phase network source. A phase control device independently controls the two phase-control switches to be on or off at peak point of voltage. Beside each phase-control switch, a series circuit of a high-voltage silicon stack diode and a high-voltage current limiting resistance is in parallel connection so as to achieve the action of pre-charging the capacitor set, and at the same time a RC series absorbing circuit is in parallel connection. Measurement waveforms show that: the switched effect image TSC (thyristor switched capacitor set) of the utility model can switch once without impact in one second, has no energy consumption, and can utilize the normal switch as the phase-control switch so as to have low cost.

Description

A kind of 2 controls, 3 precharge phased switch circuit of opening-closing capacitor bank

The present invention relates to a kind of 2 controls, 3 precharge phased switch circuit of opening-closing capacitor bank, be used for electrical network power quality controlling engineering, excise in the time of can realizing the quick non-impact current input of capacitor group and current over-zero, belong to the reactive power compensation and the harmonic wave technical field of filtering of electric power system.

Background technology

The opening-closing capacitor bank custom circuit is: mechanical contact fling-cut switch, thyristor switchable capacitor (TSC), vacuum switch synchronously.

The mechanical contact fling-cut switch, threephase switch is at uncertain line voltage point switched capacitor at random, and rush of current is big, and the rated current of minimum several times causes the line voltage distortion.Also have combined floodgate mechanical contact spring, open the dangerous probability of restriking in the contact, spring is restriked and is made capacitor group overvoltage, damages capacitor, causes the accident easily.

Thyristor switchable capacitor (TSC) circuit can accurately drop into capacitor, does not have rush of current.The problem of do not have spring, restriking.But, the middle TSC circuit of pressing, thyristor will bear about 3 times electrical network effective value voltage, thyristor withstand voltage has only several KV, needs many thyristors series connection, and there is the tube voltage drop about 2V in the thyristor conducting, the electric current of hundreds of ampere flows through thyristor, the loss heating is big, produces the heat of several KW when pressing the TSC circuit turn-on in the cover, and power consumption is big.So big caloric requirement is waited by air-cooled, water-cooled, heat pipe dispels the heat.The TSC technical difficulty is big, the cost height.

The phased switch of using on the engineering is also referred to as synchronous vacuum switch or synchro switch now, as patent document " synchro switch ", the patent No.: ZL98808789.8, patent document " phase control switch device ", the patent No.: ZL99118416.5, patent document: " phase controlling switch device ", application number: 00137229.7 tells about, and 3 deficiencies are also arranged: the synchro switch element is many, just reduced closed impulse current, operate time is with standard machinery formula contact fling-cut switch identical too slow.The phased switch of described opening-closing capacitor bank or be called synchronous vacuum switch three switches are all arranged, switch element is many; The operation principle of phased switch opening-closing capacitor bank, switch are all in the zero crossing closure of sine voltage.When on capacitor, not having voltage, have only the effective of this switched capacitor.At the zero crossing of sine wave, the voltage change ratio maximum, the precision of this step switch of will seeking common ground must be high.Say for 15/19 page of patent document " synchro switch " specification: the precision of switch be zero crossing ± during 1ms, the impact-level of generation is half of standard machinery formula contact switch, is equivalent to the level of series resistance switched capacitor, precision is high more, impacts more little.This shows that no small impact is still arranged; After the switch opens, need to wait for that the charging voltage on the capacitor drops to zero, just can be closed again, a few minutes time of wait, the throwing of switch, cut and be minute rank, non-impact current opening-closing capacitor bank fast operate time.

The appearance of thyristor switchable capacitor group and phased switch technology all has nearly 30 years history, and application is arranged on the engineering, but application quantity is all little.

In press in attitude reactive power compensation and the harmonic wave technical field of filtering, domestic and international recognized techniques means, a large amount of schemes that adopt are filter circuits (FC) that thyristor-controlled reactor (TCR)+capacitor and reactor are formed.But TCR has shortcoming: TCR+FC finishes power network compensation, need do a cover and the onesize reactive power device of reactive power that needs filtering again, with the idle size of thyristor control.Like this, customer investment is big, and TCR itself needs about 120 yuan/KVAR., takes up an area of greatly, and power consumption is big, is known as 3%.The TCR of 100MVAR has the energy consumption of 3MAW, really is many.Produce harmonic current during TCR work, by the FC filtering.Though TCR has shortcoming, just there are not a kind of better scheme or means to replace TCR at present.

Summary of the invention

The invention a kind of novel switched circuit, its location: press the situation that attitude compensation field TCR+FC rules all the land in reversing; Overcome the price height of thyristor switchable capacitor group (TSC), big shortcoming consumes energy; Break through the slow-footed restriction of conventional phased switch, will shorten operate time, finish once action by being opened to closure, the time, closure did not produce rush of current in 1 second, and opening electric current is zero; Reduce the structure that traditional three-phase phased switch adopts three independent switches, only adopt two independently switch just finished the three-phase on-off action, be called 2 controls 3; To the precharge of capacitor group, at the peak dot fling-cut switch of voltage, switch ratio of precision tradition phased switch is low, and effect is better than traditional phased switch, this means that cost is low, the quality height, and the user accepts well.Energy-conserving and environment-protective do not have energy consumption, meet requirements of the times.The name of novel switched circuit of the present invention is called: a kind of 2 controls, 3 precharge phased switch circuit of opening-closing capacitor bank.

The present invention realizes by following scheme: form 3 phase Zero-point switches to the precharge phased switch of capacitor group for two, the input of switch is connected with the reactor L of two-phase star connection and the series filtering circuit of capacitor C, the output of two switches links together and is connected with the LC filter circuit of third phase, the LC filter circuit of Y-connection is connected with the three phase network power supply by high-tension fuse, and phase control device is independently controlled two phased switch in the peak dot place of voltage break-make.Zero-point switch is in the time of closure, and current potential is zero, circuit working safety; The short circuit current of Zero-point switch is little when phase fault takes place device, safety.

Described to the precharge phased switch of capacitor group, on every phased switch next door, the series circuit of be connected in parallel high voltage silicon stack diode and high-voltage and current-limitation resistance reaches the precharge effect of capacitor group; The capacitor C that is being connected in parallel simultaneously absorbs circuit with connecting of resistor R, absorbs fast-changing voltage on the switch.

The negative electrode of described two high voltage silicon stack diodes to the precharge phased switch of capacitor group all is connected on the mains side of switch, and perhaps the anode of two high voltage silicon stack diodes all is connected on the mains side of switch.

Described phased switch is generally permanent magnetism vacuum contactor or permanent magnetism vacuum switch, also can be the vacuum contactor of electromagnetic type or the vacuum switch of electromagnetic type.

Described phase control device is by the line voltage synchronizing indicator, and single-chip microcomputer selects the phase controller, and the permanent magnetism coil actuator is formed.Coil power is by the power supply of direct current 220V stabilized voltage power supply, and the circuit of phase control device is similar to the control circuit of the conventional phased switch that scientific and technological magazine publishes, for those skilled in the art is understood, so not tired stating.

2 controls, the 3 precharge phased switch circuit of this opening-closing capacitor bank, application is to capacitor group precharge technology, peak point switched capacitor at line voltage, it is the perfect condition that does not have impulse current, require the precision of switch not high, use regular tap just can reach the function of high-precision phased switch, make cost reduce with regular tap, the user can accept.According to the circuit opening-closing capacitor bank of above-mentioned requirements assembling, test data shows and reached expected result: closure does not have switching overvoltage and does not have impulse current, opens switch during current over-zero; Reached the effect of approximate thyristor switchable capacitor group simultaneously, realized quick acting, closed in 1 second execution once by being opened to; Switch opens, the long-term placement stopped action at tens days, and when moving once more, the action numerical value of measuring current voltage does not change, and has reached safe and reliable requirement.Neoteric switch can be at low pressure (below the 1KV), the middle pressure (1KV＜middle pressure＜=35KV), high pressure (＞35KV) use in the wide range of voltages, TCR is not applied in the electrical network of 110KV, using for a plurality of fields such as distrbution network system, controlled series compensation, metallurgy industry, mine, electric railway, the re-set target that presses attitude compensation TCR+FC dominance in reversing has been seen dawn.

Description of drawings:

Fig. 1: 2 control precharge at 3 zero points phased switch circuit figure of opening-closing capacitor bank

Fig. 2: 1 second open closed once, K switch 1 electric current, K switch 2 voltage power supply oscillograms

Fig. 3: waveform launches: K switch 1 electric current, K switch 2 voltage power supply oscillograms in the time of closed

Fig. 4: waveform launches: K switch 1 electric current, K switch 2 voltage power supply oscillograms when opening

Fig. 5: 1 second open closed once, K switch 2 electric currents, K switch 1 voltage power supply oscillogram

Fig. 6: waveform launches: K switch 2 electric currents, K switch 1 voltage power supply oscillogram in the time of closed

Fig. 7: waveform launches: K switch 2 electric currents, K switch 1 voltage power supply oscillogram when opening

Specific implementation method:

Lead to and see Fig. 1-7.

Form 3 Zero-point switches mutually to the precharge phased switch K1 of capacitor group and K switch 2 for two, the series circuit of K switch 1 other be connected in parallel high voltage silicon stack diode D1 and high-voltage and current-limitation resistance R 1 reaches the precharge effect of capacitor group; The capacitor C4 that is being connected in parallel simultaneously absorbs circuit with connecting of resistor R 2, absorbs fast-changing voltage on the K switch 1.The series circuit of K switch 2 other be connected in parallel high voltage silicon stack diode D2 and high-voltage and current-limitation resistance R 3 reaches the precharge effect of capacitor group; The capacitor C5 that is being connected in parallel simultaneously absorbs circuit with connecting of resistor R 4, absorbs fast-changing voltage on the K switch 2.The input of K switch 1 is connected with the series filtering circuit of reactor L1 and capacitor C1, L1, C1 filter circuit are connected with three phase network power supply U by high-tension fuse F1, the input of K switch 2 is connected with the series filtering circuit of reactor L2 and capacitor C2, L2, C2 filter circuit are connected with three phase network power supply V by high-tension fuse F2, the output of K switch 1, K switch 2 in succession together, be connected with the series filtering circuit of reactor L3 and capacitor C3, L3, C3 filter circuit are connected with three phase network power supply V by high-tension fuse F3.The negative electrode of high voltage silicon stack diode D1 is received capacitor C1, and the anode of high voltage silicon stack diode D1 is received high-tension resistive R1; The negative electrode of high voltage silicon stack diode D2 is received capacitor C2, and the anode of high voltage silicon stack diode D2 is received high-tension resistive R2.There are a lot of benefits at the place at zero point that is connected to the capacitor group of star connection to the precharge phased switch of capacitor group: Zero-point switch is in the time of closure, and current potential is zero, circuit working safety; The short circuit current of Zero-point switch is little when phase fault takes place device, safety.

Phased switch is generally permanent magnetism vacuum contactor or permanent magnetism vacuum switch, also can be the vacuum contactor of electromagnetic type or the vacuum switch of electromagnetic type.

Phase control device is by line voltage synchronizing indicator 1, and single-chip microcomputer selects phase controller 2, and permanent magnetism coil actuator 5 is formed.Coil power is by 4 power supplies of direct current 220V stabilized voltage power supply.The circuit of phase control device is similar to the control circuit of the conventional phased switch that scientific and technological magazine publishes, for those skilled in the art is understood, so not tired stating.

The voltage and current waveform of Test Switchboard K1, K switch 2 such as Fig. 2-Fig. 7.The abscissa of Fig. 2 is that every lattice 500ms and Fig. 5 abscissa are 200ms, Fig. 2, what Fig. 5 showed is continuous 1 open closed in second oscillogram once, Fig. 3, Fig. 4, Fig. 6, the abscissa of Fig. 7 is 20ms, the switching waveform is amplified, observation K switch 1, the input of K switch 2 and the voltage of excision, current waveform, switch is at the peak point of line voltage as can be seen, closure when switching voltage is zero, non-impact current, open switch when electric current is zero, phased switch and reactor and capacitor filtering circuit are connected in series, and electric current is same, the electric current of each phased switch does not impact and the reactor and the capacitor filtering circuit of phased switch series connection do not have rush of current yet.The effect of 2 controls, the 3 precharge phased switch circuit switchings of opening-closing capacitor bank is similar with the thyristor switchable capacitor group, than the phased switch of routine or be called the good of phase-selecting switch.

The main element type selecting of a specific embodiment: 2 control precharge at the 3 zero points phased switch circuit that are applied to the opening-closing capacitor bank of line voltage 10KV electric current 200A, phased switch K1, phased switch K2 adopt common single-phase permanent contactor, model C KG4-250/12-DY, the high voltage silicon stack diode voltage is 60KV, electric current 1A, the high-voltage and current-limitation resistance of connecting with the high voltage silicon stack diode is 12KV, 10K ohm, the 500W high-tension resistive, the capacitor C that is connected in parallel with phased switch and the series circuit of resistor R are the RC absorber that is connected on the common electric network source line.High-tension fuse is voltage 12KV, electric current 300A.

Described phase control device is independently controlled two phased switch in the peak dot place of voltage break-make, when line voltage during with the positive sequence wiring, the negative electrode of two high voltage silicon stack diodes is received the invariant position of the mains side of switch, two phased switch can be connected on any two-phase of 3 circuitry phases, K switch 1, K switch 2 are received on the different phase places, as long as synchronous voltage signal is done corresponding the adjustment, control program is constant, closed and open K switch 1, K switch 2, when being zero, non-impact current when obtaining Closing Switch equally, electric current open the effect of switch.

Specific embodiment of the present invention has been made detailed explanation to content of the present invention, for persons skilled in the art, the any conspicuous change that it is done without departing from the premise in the spirit of the present invention, all constitute to infringement of patent right of the present invention, with corresponding legal responsibilities.

Claims

1. 2 of an opening-closing capacitor bank control 3 precharge phased switch circuit, it is characterized in that: form 3 phase Zero-point switches to the precharge phased switch of capacitor group for two, the input of switch is connected with the reactor L of two-phase star connection and the series filtering circuit of capacitor C, the output of two switches links together and is connected with the LC filter circuit of third phase, the LC filter circuit of Y-connection is connected with the three phase network power supply by high-tension fuse, and phase control device is independently controlled two phased switch in the peak dot place of voltage break-make.

2. control 3 precharge phased switch circuit according to 2 of right 1 described a kind of opening-closing capacitor bank, it is characterized in that: on every phased switch next door, the be connected in parallel series circuit of high voltage silicon stack diode and high-voltage and current-limitation resistance reaches the precharge effect of capacitor group; The capacitor C that is being connected in parallel simultaneously absorbs circuit with connecting of resistor R, absorbs fast-changing voltage on the switch.

3. control 3 precharge phased switch circuit according to 2 of right 1 described a kind of opening-closing capacitor bank, it is characterized in that: the negative electrode of two high voltage silicon stack diodes that phased switch is other all is connected on the mains side of switch, and perhaps the anode of two high voltage silicon stack diodes all is connected on the mains side of switch.

4. control 3 precharge phased switch circuit according to 2 of right 1 described a kind of opening-closing capacitor bank, it is characterized in that: described phased switch is generally permanent magnetism vacuum contactor or permanent magnetism vacuum switch, also can be the vacuum contactor of electromagnetic type or the vacuum switch of electromagnetic type.