CN206076914U

CN206076914U - A kind of combined mass circuit breaker system

Info

Publication number: CN206076914U
Application number: CN201620958475.6U
Authority: CN
Inventors: 张健; 张京伦
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-08-26
Filing date: 2016-08-26
Publication date: 2017-04-05
Anticipated expiration: 2026-08-26

Abstract

This utility model is related to a kind of combined mass circuit breaker system.The purpose of this utility model is to provide a kind of combined mass circuit breaker system of economic and reliable, to solve the problems, such as that existing breaking capacity of breaker is inadequate, expensive, poor stability.The technical solution of the utility model is：Combined mass circuit breaker system, it is characterised in that：The open-circuit system cut-offs component by the main circuit breaker on major loop and short circuit chopper, current-limiting transformer, secondary side and relay protection and control unit is constituted, wherein：It is connected with main circuit breaker at generator power supply side outlet, short circuit chopper is connected in series with main circuit breaker, the two ends of the two ends parallel connection current-limiting transformer first side winding of short circuit chopper, two ends and the secondary side of current-limiting transformer secondary side winding cut-off modules in parallel and be connected；The relay protection and control unit is used for tripping operation and the feed motion for automatically controlling each chopper.This utility model is applied to electrical engineering field.

Description

A kind of combined mass circuit breaker system

Technical field

This utility model is related to electrical engineering field, especially the combined mass chopper in high-rating generator exit System.

Background technology

Generator Circuit Breaker of Large Capacity be arranged between electromotor and main transformer, can to improve power plant's operational efficiency and Reliability plays vital effect to protecting electromotor.At present, capacity is more than 600,000 kilowatts of generating set outlet dress If chopper is gradually into trend.However, Generator Circuit Breaker of Large Capacity to cut-off more than short circuit current 100kA expensive, at present Only there is complete ability (opening electric etc. including ABB, Alstom, Rhizoma Sparganii, west) in only a few enterprise both at home and abroad.

At present, the capacity of high-rating generator has reached the maximum short circuit current of interregional grid in gigawatt level, electrical network Already close to the maximum rupturing capacity value of chopper, thus it is very urgent to the demand of big connecting-disconnecting function chopper.Chopper is given birth to Produce the chopper in the generator outlet loop of the current gigawatt unit of producer, up to 10,000,000 yuan～15,000,000 yuan of price (RMB) or more.The economy of power plant is invested in serious restriction, and moment cut-offs breaker actuation and still has generation runaway accident Possibility, and in high pressure 500kV electrical networks, as the current maximum connecting-disconnecting function of 500kV choppers is 80KA, more than the electric current Not yet have the ability at present to manufacture.Therefore, the either Breaking capacity of high-rating generator outlet side chopper, or to big in electrical network The requirement of capacity chopper, all in the urgent need to having：1) more than 250kA is reached for 30kV voltages cut-off short circuit current ability, for 500kV electric pressures, the requirement of more than connecting-disconnecting function 80kA.

The content of the invention

The technical problems to be solved in the utility model is：For the problems referred to above, this utility model provides a kind of economic and reliable Combined mass circuit breaker system, it is inadequate, expensive, poor stability to solve existing breaking capacity of breaker Problem.

The technical scheme adopted by this utility model is：Combined mass circuit breaker system, it is characterised in that described disconnected Road system cut-offs component and relay protection control by the main circuit breaker on major loop and short circuit chopper, current-limiting transformer, secondary side Unit composition processed, wherein：

It is connected with main circuit breaker at generator power supply side outlet, short circuit chopper is connected in series with main circuit breaker, short circuit breaks The two ends of the two ends parallel connection current-limiting transformer first side winding of road device, two ends and the secondary side of current-limiting transformer secondary side winding are opened Disconnected modules in parallel connection；

The relay protection and control unit is used for tripping operation and the feed motion for automatically controlling each chopper.

The secondary side cut-offs component for secondary side chopper, preferred SF 6 high-voltage AC circuit breaker.

The secondary side cut-offs component and cut-offs component for power electronics, by rectifier bridge stack DZ, capacitor C₁With capacitor C₂、 Electric discharge permutator DK₁～DK₄And electric discharge electric magnet DCT compositions, wherein capacitor C₁With capacitor C₂After parallel connection again with rectifier bridge Two DC output end parallel connections of heap DZ, the electric magnet DCT that discharges are connected in parallel on the centre of two capacitors, and capacitor C₁, put Electrical switch DK₁With electric discharge permutator DK₂With capacitor C₂, electric discharge permutator DK₃With electric discharge permutator DK₄Symmetrical cloth Put.

The preferred sulfur hexafluoride AC circuit breaker of the main circuit breaker, oil-break or vacuum circuit breaker.

The preferred sulfur hexafluoride AC circuit breaker of the short circuit chopper or vacuum circuit breaker, switch off time are 3～5ms.

The current-limiting transformer adopts three-phase two-simulation transformer, including first side winding, secondary side winding, hollow silicon steel Piece, insulating barrier and load ratio bridging switch, wherein, hollow stalloy is the iron-core workpiece with air gap delta.

The beneficial effects of the utility model are：This utility model by short circuit chopper two ends parallel connection current-limiting transformer, The method that secondary side chopper continuously cut-offs is set simultaneously so that short circuit current was transferred on current-limiting transformer in moment, and was made It is reduced by the short circuit current of main circuit breaker so that the chopper for commonly using at present there can be the situation of safety guarantee Under cut-off, so as to avoid occur security incident.This utility model is easily implemented, and manufacturing cost only has current power plant's input to send out The 2/3 or so of motor breaking device device fund, it is not only with significant economic benefit and also big to the dash current of electromotor Big to reduce, safety is improved.

Description of the drawings

Fig. 1 is the electrical schematic diagram of this utility model prior art.

Fig. 2 is electrical schematic diagram of the present utility model.

Fig. 3 is the circuit diagram of this utility model embodiment one.

Fig. 4 is the circuit diagram of this utility model embodiment two.

Fig. 5～Fig. 8 is the circuit diagram of two group capacitors discharge and recharge in turn in embodiment two.

Specific embodiment

As shown in Fig. 2 the knockdown Large Copacity open-circuit system of this utility model is by the main circuit breaker DL on major loop₁With it is short Meet chopper DL₂, current-limiting transformer BK, secondary side cut-off 4 (secondary side chopper DL of component₃Or power electronics cut-offs component) and Relay protection and control unit B H is constituted, wherein：Generator power supply side outlet and main circuit breaker DL₁Connection, short circuit chopper DL₂With Main circuit breaker DL₁It is connected in series, short circuit chopper DL₂Two ends parallel connection current-limiting transformer BK first side windings N₁Two ends, current limliting Transformator BK secondary side windings N₂Two ends cut-off component 4 with secondary side and be connected in parallel.The original peace of the electric substation or power plant Relay protection and control unit B H of dress is used for tripping operation and the feed motion for automatically controlling each chopper.

The current-limiting transformer BK typically adopts three-phase two-simulation transformer, including first side winding N₁, secondary side winding N₂, hollow stalloy 1, insulating barrier 2 and load ratio bridging switch 3, wherein, hollow stalloy is the iron-core workpiece with air gap delta, to increase Its safety.

When system is normally run, main circuit breaker DL₁, short circuit chopper DL₂With secondary side chopper DL₃(or power electronics is opened Disconnected component) closing position is respectively at, due to first side winding N of current-limiting transformer BK₁In short circuit chopper DL₂Short circuit Among state, therefore first side winding N₁Voltage will not be presented.When system is short-circuited, such as D point failures when, by relay protect Shield control unit BH (program being pre-designed) indicates short circuit chopper DL₂First trip, the short circuit chopper DL in the design₂For A kind of fast chopper, is customized improvement to its operating mechanism, it is desirable to break quick disjunction (conventional type within 5ms Chopper break is 15～25ms), and work as short circuit chopper DL₂After disjunction, short circuit current flows to current-limiting transformer BK First side winding N₁Coil, short circuit current I₁In N₁Electromotive force U is induced on the coil of winding₁, the electricity that now transformator is presented Anti- value X_L=U₁/I₁, in design, take reactance value X_LFor 0.5～1 Ω, performance number P=produced by current-limiting transformer is then flowed through U₁·I₁, in short circuit chopper DL₂After disjunction, work as secondary side chopper DL again₃By relay protection signal by current limliting transformation Device BK secondary side windings N₂Loop opening after, first side winding N can be caused₁Upper voltage U₁Increase sharply, in current-limiting transformer BK Power P=the U of upper consumption₁·I₁, such as work as U₁Increment when being 2.2 times, according to systemic transient energy conservation principle, now short circuit Electric current I_D2.2 times will be reduced, if secondary side chopper DL in design₃Break be also 3～5ms, then the system device More than half when initial short circuit current can be restricted to initial value in 10ms, or original 1/3rd, As long as by designing current-limiting transformer BK armature winding N₁The number of turn can just adjust the value of limiting short-circuit current.

Among the design of this device, for short circuit chopper DL₂Disconnected from for example general 35kV vacuum of plain type breaker During road device (ZN-35/1500 type choppers), because its opening time is usually 25～35ms, and due to the particularity of this device, Opening time is asked to foreshorten in 5ms, therefore, the present invention needs to be changed in the operating mechanism of former chopper with flash electromagnet Make (can customize on request), for example the Quick push/pull electric magnet using electromagnetic force in 100～300kg connects into ZN-35 types Sub-switching operation bar, from electric magnet model LX3-1000D, manufacturer is Suzhou Li Xun magnetoelectricities Science and Technology Ltd., Jing this After the transformation of sample separating brake operating mechanism, can be by short circuit chopper DL₂Opening time foreshorten in 5ms.

It is described further below by two specific embodiments as follows：

Embodiment one,

It is well known that be short-circuited failure when, system short-circuit electric current is effectively limited, it is necessary to instantaneous series connection Enter a resistor for having certain value number or reactor DK (shown in Fig. 1), such as scheme (the patent of Ningxia electric research institute Number for 201310007631.1), and Qiu family of Zhejiang University coltfoal, Wang Hongfu " improve wind-driven generator using tandem brake resistance The scheme of group low voltage ride-through capability ".It is not little that restrictor apparatus generally in 500kV systems require that the resistance value of series connection is required In 8～10 Ω, could be by short circuit current I_D500kV/10 Ω=50kA level below is dropped to by 70kA.But, due to disconnected Road device DL and reactor DK be it is in parallel in the case of cut-off, in shunt reactor, the size of resistance, directly affects open circuit The breaking capacity of device DL, when DK resistances are excessive, will result in breaker open operation failure of interruption, if such as reactor resistance Xc 7 During Ω, moment is U in the magnitude of voltage that breaker fracture is formed₁=70kA × 7 Ω=490kV, and this magnitude of voltage be multiplied by again it is short Road electric current, rupturing capacity S=I_D·U₁, illustrate that the performance number produced by the fracture may already exceed the rupturing capacity of chopper S, will cause chopper cannot disjunction short circuit current and explode or burn switch.Therefore, parallel reactance in the design The resistance value Xc of device is the smaller the better.

As shown in figure 3, this example main circuit breaker DL₁With short circuit chopper DL₂Sulfur hexafluoride AC circuit breaker is selected.It is secondary Component 4 is cut-off using secondary side chopper DL in side₃, and sulfur hexafluoride AC circuit breaker, it is desirable to design current-limiting transformer BK's Initial 0.5 Ω of reactance value (typically between 0.5～1 Ω), i.e., as secondary side chopper DL₃During closure, U in first side winding N₁ Voltage is very low, then the reactance X for being presented by current-limiting transformer BK_BK=U₁/I_DVery little.So short circuit chopper DL₂Produce in disjunction moment Raw fracture voltage value is：If short circuit current is 70kA, according to Ohm's law U=IR, U=70kA × 0.5 Ω=35kV, work( Rate S=70kA × 35kV=2450kVA, Breaking capacity S=70k A × 500kV=of this value than original mode 35000MVA reduces 500/35=14 times；And work as secondary side chopper DL₃After disconnection, the reactance value of current-limiting transformer BK is sent out again A big increment change is given birth to, this has accessed the reactor of a high impedance equivalent to series connection on major loop, and it can be by short circuit Electric current is down to below 50kA by 70kA, at this moment again by main circuit breaker DL₁Major loop is cut-off, now, due to short circuit current Within the safety of normal circuit breaker cut-offs scope, main circuit breaker DL₁Carry out sub-switching operation just fool proof.We Case is greatly reduced to short circuit chopper DL₂With main circuit breaker DL₁Breaking capacity require, and the low cost of plain type breaker It is honest and clean, so as to the cost to system and device is greatly reduced, and due to quickly sealing in reactor, short circuit current is reduced to generating electricity The impact of machine, substantially increases electrical equipment safety in fault conditions.

Embodiment two,

As shown in Fig. 4, Fig. 5～8, this example is applied to generator breaker system, main circuit breaker DL in system₁It is disconnected for vacuum Road device, short circuit chopper DL₂For sulfur hexafluoride AC circuit breaker, secondary side cut-offs component 4 by rectifier bridge stack DZ (high-voltage rectifyings two Pole pipe), capacitor C₁With capacitor C₂, electric discharge permutator DK₁～D K₄And electric discharge electric magnet DCT compositions, wherein capacitor C₁ With capacitor C₂It is in parallel with two DC output ends of rectifier bridge stack DZ again after parallel connection, electric discharge electric magnet DCT be connected in parallel on two it is electric The centre of container, and capacitor C₁, electric discharge permutator DK₁With electric discharge permutator DK₂With capacitor C₂, electric discharge conversion open Close DK₃With electric discharge permutator DK₄It is arranged symmetrically.

Under normal circumstances, short circuit chopper DL₂In "on" position, current-limiting transformer BK first side windings N₁In short circuit State, electric current is from DL₂Flow through, transformator N₁On winding, voltage is zero, in system without be lost, when be short-circuited failure when, by electricity Current transformer CT monitors and is uploaded to relay protection and control unit B H, when the control unit judges that the electric current is more than preset value Afterwards, the control unit is to short circuit chopper DL₂Send ON- and OFF- command, DL₂At once disconnect in 5ms, will transformator primary side Winding N₁In as reactor input current limliting operation, now, the short circuit current can be restricted to the 30% of desired value.It is same with this When, secondary side winding N of current-limiting transformer BK₂Power to rectifier bridge stack, the rectified bridge heap DZ of alternating current will be the short circuit for exchanging electric After stream is rectified into DC rectifier, immediately to capacitor C₁Charge, the design charging interval is 1.5～3ms, as capacitor C₁It is fully charged Afterwards, the electric current in loop becomes 0, now, secondary side winding N of transformator₂In because charging current cut-off, i.e., equivalent to secondary Side winding N₂Loop cutout open circuit, at this moment can cause transformator first side winding N at once₁Voltage U₁Steeply rise, by ohm Impedance on law I=U/R, i.e. transformator major loop is greatly increased, so as to be formed in 5～6ms moment equivalent to going here and there again Couple into the equivalent reactance device of a big reactance value and produce metering function, realize main circuit breaker DL₁In the model of rated current Enclose the purpose that interior safety is cut-off.

When requiring with reclosing, capacitor C can be passed through₁With capacitor C₂Exchange operation realizing charge and discharge process, It is described in detail below：

Such as Fig. 5, when normally running, discharge permutator DK₁Closure, discharge permutator DK₂、DK₃、DK₄Disconnect, due to First side winding N of transformator₁It is shorted chopper DL₂Institute's short circuit, therefore U₁=0, U_AH=0.It is when short trouble occurs, short Meet chopper DL₂Cut-off, U₁Produce voltage, and U₂＞＞ U₁, switch to DC voltage U after bridge heap D Z_AH, now,

1st, the short circuit current after rectified by the A points of bridge heap DZ, Jing A → B → D → H, and formed the mode in loop to I.e. via electric discharge permutator DK₁To capacitor bank C₁Charge, as capacitor C₁After fully charged, relay protection and control unit B H is By DK₁Disconnect, immediately DK₂Close a floodgate (such as Fig. 6), connect electric discharge electric magnet DC T, to capacitor C₁Discharged；At the same time, after Electric protection control unit BH close again electric discharge permutator DK₃, by standby capacitor C₂Put into operation, capacitor C₁Electric discharge knot DK is switched after beam₂Automatically disconnect again.

2nd, when second short circuit accident is met, short circuit current flows through the DC current after bridge heap DZ rectifications by A → B → E → H and form the mode (as shown in Figure 7) in loop, short circuit current is by the permutator DK that discharges₃Flow to capacitor C₂Charge, work as C₂ After fully charged, discharge permutator DK₃Automatically disconnect again, meanwhile, discharge permutator DK₁、DK₄Automatic closing, discharge electric magnet DCT short circuits are in capacitor C₂Two ends, make capacitor C₂Electric discharge, after electric discharge terminates, DK₄Automatically disconnect again, each element state is returned again To original state (as shown in Figure 8).

Above steps realizes control by the computer program of relay protection and control unit B H, in order is performed, always There is a group capacitor (C₁Or C₂) output terminals A, the H of bridge heap DZ are constantly coupled to, it is smooth to ensure rectifier bridge stack DZ output charge circuits It is logical.This example has the advantages that speed is fast, reliability is high.

The components and parts model and manufacturer that this utility model is related to is preferably as follows：

1st, for (such as embodiment one), main circuit breaker DL for 500kV electrical networks₁, short circuit chopper DL₂It is disconnected with secondary side Road device DL₃It is adapted to from sulfur hexafluoride AC circuit breaker, model LW-12-500/3000A, Xi'an High-tension Switch Factory production.

The secondary side of current-limiting transformer BK should meet the operation of long-time short-circuit condition, during using 500kV electrical networks, transformator choosing With Shenyang Transformer Factory, the product of model SFLG-300000/500.

2nd, for the electromotor that exit potential is 27kV (such as embodiment two), high-voltage rectifier bridge heap D Z-types number are QL- 150kV/5A, Anshan prosper together Electronics Co., Ltd. production.Using more than 200 parallel ways, to meet what short circuit current matched Require.

Capacitor C₁、C₂From the high-voltage capacitor of model TBB66kV/32064/334 of Xi'an Condenser Factory production Group.

Electric discharge permutator DK₁～DK₄From the 110kV sulfur hexafluoride (SF of Xi'an High-tension Switch Factory production₆) alternating current interruption Device, model LW6-110I/600A.

Electric discharge electric magnet DCT, from the model LEM-100A energy absorbing type of Ningbo Science and Technology Ltd. of Li Qu automatizatioies production Electric magnet.

When using 27kV generator breaker cases, current-limiting transformer BK, from the manufacture of Zhejiang San Men transformer factories High-impedance transformer, model SFP-200000/110.

Main circuit breaker DL₁, short circuit chopper DL₂From the 35kV vacuum circuit breakers of Xi'an electric equipment factory production, model ZN-35kV/15000A。

Claims

1. a kind of combined mass circuit breaker system, it is characterised in that：The open-circuit system is by the main circuit breaker on major loop (DL₁) and short circuit chopper (DL₂), current-limiting transformer (BK), secondary side cut-off component (4) and relay protection and control unit (BH) Composition, wherein：

With main circuit breaker (DL at generator power supply side outlet₁) connection, short circuit chopper (DL₂) and main circuit breaker (DL₁) series connection company Connect, short circuit chopper (DL₂) two ends parallel connection current-limiting transformer (BK) first side winding (N₁) two ends, current-limiting transformer (BK) Secondary side winding (N₂) two ends cut-off component (4) with secondary side and be connected in parallel；

The relay protection and control unit (BH) is for automatically controlling tripping operation and the feed motion of each chopper.

2. combined mass circuit breaker system according to claim 1, it is characterised in that：The secondary side cut-offs component (4) it is secondary side chopper (DL₃), preferred SF 6 high-voltage AC circuit breaker.

3. combined mass circuit breaker system according to claim 1, it is characterised in that：The secondary side cut-offs component (4) component is cut-off for power electronics, by rectifier bridge stack DZ, capacitor C₁With capacitor C₂, electric discharge permutator DK₁～DK₄And put Electric electric magnet DCT compositions, wherein capacitor C₁With capacitor C₂After parallel connection again with two DC output ends of rectifier bridge stack DZ simultaneously Connection, the electric magnet DCT that discharges are connected in parallel on the centre of two capacitors, and capacitor C₁, electric discharge permutator DK₁With electric discharge conversion Switch DK₂With capacitor C₂, electric discharge permutator DK₃With electric discharge permutator DK₄It is arranged symmetrically.

4. combined mass circuit breaker system according to claim 1, it is characterised in that：Main circuit breaker (the DL₁) excellent Select sulfur hexafluoride AC circuit breaker, oil-break or vacuum circuit breaker.

5. combined mass circuit breaker system according to claim 1, it is characterised in that：Short circuit chopper (the DL₂) It is preferred that sulfur hexafluoride AC circuit breaker or vacuum circuit breaker, switch off time is 3～5ms.

6. combined mass circuit breaker system according to claim 1, it is characterised in that：The current-limiting transformer (BK) Using three-phase two-simulation transformer, including first side winding (N₁), secondary side winding (N₂), hollow stalloy (1), insulating barrier (2) With load ratio bridging switch (3), wherein, hollow stalloy is the iron-core workpiece with air gap delta.