CN201163716Y

CN201163716Y - Short trouble current limiter with energy consumption resistor

Info

Publication number: CN201163716Y
Application number: CNU200720130986XU
Authority: CN
Inventors: 费万民; 张艳莉; 都小利
Original assignee: Nanjing Normal University
Current assignee: Nanjing Normal University
Priority date: 2007-12-14
Filing date: 2007-12-14
Publication date: 2008-12-10
Anticipated expiration: 2017-12-14

Abstract

The utility model discloses a short circuit failure current restrictor with an energy dissipative resistance. The current restrictor comprises a bypass inductance(L2), an uncontrolled rectifier bridge consisting of diodes, a direct current inductance(L1), a controllable switch(T1), a resistance(R) and a zinc oxide surge absorber ZnO, etc., wherein the bypass inductance(L2) is in parallel connection with the zinc oxide ZnO surge absorber and then in parallel connection with the AC end of a bridge circuit; the direct current inductance(L1) is in parallel connection with the resistance(R) and then in serial connection with the controllable switch(T1), and connected with the DC side of the bridge circuit. When the utility model is applied to an alternating voltage power supply system, the rectifying bridge circuit and the direct current inductance(L1) can not only limit the rise rate of short circuit current in the early stage of the short circuit failure but also contributes to an effective value of the short circuit current after the short circuit failure happens, thereby reducing the current ratings of bypass inductances(L2, L3 and L4) and lowering the cost of the whole current restrictor; moreover, by adjusting the frequency and the duty cycle of the driving signals of a self-cut switch tube(T1), the resistance content provided by the current restrictor during the short circuit current restricting period can also be adjusted, thereby the stability of the power system is improved.

Description

Short-circuit fault current limiter with power consumption resistance

Technical field

The utility model is a kind of alternating voltage electric power system that is applied to, and to the device that short-circuit current and climbing thereof limit, belongs to the technical field that exchanges the flexible transmission technology, is a kind of short-circuit fault current limiter with power consumption resistance specifically.

Background technology

Continuous expansion along with electric power system scale and capacity, the level of short circuit current increases fast, when short circuit current level surpasses the interrupting capacity of circuit breaker, short trouble may cause the badly damaged of main power equipment such as transformer, high voltage switchgear, power cable etc., cause system's instability, even cause the paralysis of system.Short-circuit fault current limiter by the impedance parameter of quick change faulty line, is limited in the level of permission with short circuit current after detecting short trouble and taking place, with the protection power equipment, become one of key element of flexible AC transmitting system.

Dotted portion in the accompanying drawing 1 is a kind of bridge-type short circuit current limiter with single self-turn-off device, and among the figure, L1 is a dc inductance, and L2 is a by-pass inductor, and D1-D4 etc. have formed one does not control rectifier bridge, and T1 is the self-on-off switching device, and D5 is a fly-wheel diode.Lx, Rx are line inductance and line resistance.Under the normal situation of system, control T1 conducting is finished after L1 magnetizes, and under stable situation, ignores the power loss of D1-D5, T1 and L1, and the flow restricter two ends do not have pressure drop.After short trouble took place, through the electric current meeting fast rise of T1 and L1, after this electric current was greater than a certain set point, T1 was turn-offed in control, and the L1 electric current is through the D5 afterflow, and bridge circuit and L1 log off, and short circuit current is subjected to the restriction of L2.

Because bridge circuit and dc inductance are only at the short trouble initial stage, the limiting short-circuit current rate of climb after short trouble is detected, logs off, and do not participate in limiting steady short, thereby utilance is lower.If with the sustained diode 5 in the resistance R replacement accompanying drawing 1 of suitable resistance; after short trouble takes place; adopt the signal of certain frequency and duty ratio to come control switch pipe T1; then diode bridge, L1, T1, R can bear a short circuit current of having modulated; this short circuit current and short circuit current sum among the by-pass inductor L2 of having modulated is to satisfy total short circuit current that selectivity of relay protection requires; therefore; can reduce the electric current quota of by-pass inductor L2; improve the utilance of each element, reduce installation cost generally.Simultaneously, power consumption resistance can also absorb the transient state component that short trouble causes, damped oscillation helps the stable of electric power system.For this reason, propose a kind of bridge type short circuit fault current limiter, can improve the utilance of bridge circuit and L1, reduce the current stress of by-pass inductor L2, reduce the flow restricter cost and improve the stability of system with power consumption resistance.

The utility model content

The purpose of this utility model is to overcome the defective that prior art exists, a kind of short-circuit fault current limiter with power consumption resistance is provided, in dc inductance two ends parallel resistance, after short trouble takes place, square-wave signal with certain frequency and duty ratio comes the control switch pipe, if switch periods is T, the service time of T1 is Ton in the one-period, and the turn-off time of T1 is Toff=T-Ton.During Ton, be added in the two ends of L1 and resistance R after the supply voltage rectification, thereby in inductance and resistance, produce electric current, the electric current of inductance L 1 initial value when one-period finishes in the past begins to increase; At the T1 blocking interval, inductive current is by resistance R, the magnetic energy consumption that inductance L 1 stores on resistance R, current attenuation; By regulating the frequency and the duty ratio of control signal, can regulate inductive current and periodically rise and attenuation law, promptly control is by the equivalent electric flow valuve of diode rectification bridge circuit.Because diode rectification bridge circuit and T1, L1, R have born the part electric current, can improve the utilance of bridge circuit and L1, reduce the electric current quota of by-pass inductor L2, L3, L4, reduce the cost of whole flow restricter, certain resistance load characteristics is provided in the time of can also be for system short-circuit, improves the stability of a system.Periodically turn on and off T1, can cause certain switching overvoltage, therefore,, can protect rectifier bridge and T1 at two ends (the interchange input side of rectification bridge circuit just) the zinc oxide ZnO surge absorber in parallel of by-pass inductor L2 etc. by line inductance Lx etc.

The utlity model has the short-circuit fault current limiter of power consumption resistance, do not control rectifier bridge, dc inductance L1, gate-controlled switch T1, resistance R, the zinc oxide surge absorber ZnO etc. that are made up of by-pass inductor L2, diode form.After by-pass inductor L2 and the parallel connection of zinc oxide ZnO surge absorber, be connected in parallel on bridge circuit again and exchange end; Dc inductance L1 and resistance R parallel connection after gate-controlled switch T1 connects, are connected on the DC side of bridge circuit.Under the normal situation of electric power system, control T1 is in normal open state, because inductance L 1 is born direct voltage, its both end voltage approaches zero, and also near zero, flow restricter presents the zero impedance state to the shunt inductance both end voltage.After short trouble takes place and is detected, square-wave signal with certain frequency and duty ratio removes control switch pipe T1 immediately, during the Ton of switching tube conducting, be added in the two ends of L1 and resistance R after the supply voltage rectification, thereby produce electric current in inductance and resistance, the electric current of inductance L 1 initial value when one-period finishes in the past begins to increase; During the Toff that T1 turn-offs, inductive current is by resistance R, the magnetic energy consumption that inductance L 1 stores on resistance R, current attenuation; By regulating the frequency and the duty ratio of control signal, can regulate inductive current and periodically rise and attenuation law, promptly control is by the equivalent electric flow valuve of diode rectification bridge circuit.Because diode rectification bridge circuit and T1, L1, R have born the part electric current, can improve the utilance of bridge circuit and L1, reduce the electric current quota of by-pass inductor L2, reduce the cost of whole flow restricter, certain resistance load characteristics is provided in the time of can also be for system short-circuit, improves the stability of a system.

The utlity model has the short-circuit fault current limiter of power consumption resistance, what comprise that by-pass inductor L2, diode form does not control rectifier bridge, dc inductance L1, gate-controlled switch T1, resistance R, zinc oxide surge absorber ZnO etc.Wherein, the collector electrode of the common cathode of diode D1, D2, self-on-off switching tube T1 in the rectifier bridge (or drain electrode), be connected together; One of one end of the emitter of self-on-off switching tube T1 (or source electrode), resistance R and direct current reactor L1 terminates at together; The other end of the public anode of diode D3, D4 and resistance R is connected together in the other end of direct current reactor L1 and the rectifier bridge; The anode of the end of the end of shunt reactor L2, zinc oxide surge absorber ZnO and the negative electrode of diode D3, diode D1 is connected together, and is an outlet terminal of flow restricter; The anode of the other end of the other end of shunt reactor L2, zinc oxide surge absorber ZnO and the negative electrode of diode D4, diode D2 is connected together, and is another outlet terminal of flow restricter.During use, this flow restricter passes through two outlet terminal series connections between power supply and load.

This flow restricter can also adopt following structure, is used for the three-phase isolated neutral system.The utlity model has the short-circuit fault current limiter of power consumption resistance, the diode rectifier bridge of being made up of diode D1～D6, self-on-off switching tube T1, resistance R, direct current reactor L1, shunt reactor L2～L4, zinc oxide surge absorber ZnO1～ZnO3 etc. constitute.Wherein, the collector electrode of the negative electrode of diode D1, D2, D3, self-on-off switching tube T1 (or drain electrode) is connected together; One of one end of the emitter of self-on-off switching tube T1 (or source electrode), resistance R and direct current reactor L1 terminates at together; The other end of the anode of D4, D5, D6, direct current reactor L1, the other end of resistance R are connected together; The negative electrode of the end of the end of shunt reactor L2, zinc oxide surge absorber ZnO1, the anode of diode D1, diode D4 is connected together, and constitutes the outlet terminal of flow restricter a phase; The negative electrode of the end of the end of shunt reactor L3, zinc oxide surge absorber ZnO2, the anode of diode D2, diode D5 is connected together, and constitutes the outlet terminal of flow restricter b phase; The negative electrode of the end of the end of shunt reactor L4, zinc oxide surge absorber ZnO3, the anode of diode D3, diode D6 is connected together, and constitutes the outlet terminal of flow restricter c phase; The other end of the other end of shunt reactor L2, L3, L4 and zinc oxide surge absorber ZnO1, ZnO2, ZnO3 is connected together.During use, a of flow restricter, b, c phase outlet terminal are connected together with a, b, the c reference edge mutually of three phase mains respectively, constitute the equivalent neutral point of three phase mains under the normal operation.

Reactor L1 can be for superconduct, also can be for conventional type.According to the economy requirement, L2, L3, L4 preferably adopt the inductance of conventional type.

The utility model is applied to the alternating voltage electric power system, make rectification bridge circuit and direct current reactor L1 can limit short trouble initial period short-circuit current climbing, also can contribute to short trouble back short circuit current effective value takes place, can reduce the electric current quota of by-pass inductor L2, L3, L4, reduce the cost of whole flow restricter, and, by regulating the frequency and the duty ratio of self-on-off switching tube T1 drive signal, can also adjust the resistive content that flow restricter is provided during short circuit current limitation, improve the stability of electric power system.

Description of drawings

Fig. 1 is the current limiter circuit figure of prior art;

Fig. 2 is the main circuit schematic diagram (phase structure) that the utlity model has the short-circuit fault current limiter of power consumption resistance;

Fig. 3 is the main circuit schematic diagram (three-phase structure that is used for isolated neutral system) that the utlity model has the short-circuit fault current limiter of power consumption resistance;

Embodiment

Followingly this utility model is described in further detail with reference to drawings and Examples.

Embodiment 1, as shown in Figure 2 the utlity model has the short-circuit fault current limiter of power consumption resistance, and do not control rectifier bridge, dc inductance L1, gate-controlled switch T1, resistance R, the zinc oxide surge absorber ZnO etc. that are made up of by-pass inductor L2, diode form.After by-pass inductor L2 and the parallel connection of zinc oxide ZnO surge absorber, be connected in parallel on bridge circuit again and exchange end; Dc inductance L1 and resistance R parallel connection after gate-controlled switch T1 connects, are connected on the DC side of bridge circuit.Under the normal situation of electric power system, control T1 is in normal open state, because inductance L 1 is born direct voltage, its both end voltage approaches zero, and also near zero, flow restricter presents the zero impedance state to the shunt inductance both end voltage.After short trouble takes place and is detected, square-wave signal with certain frequency and duty ratio removes control switch pipe T1 immediately, during the Ton of switching tube conducting, be added in the two ends of L1 and resistance R after the supply voltage rectification, thereby produce electric current in inductance and resistance, the electric current of inductance L 1 initial value when one-period finishes in the past begins to increase; During the Toff that T1 turn-offs, inductive current is by resistance R, the magnetic energy consumption that inductance L 1 stores on resistance R, current attenuation; By regulating the frequency and the duty ratio of control signal, can regulate inductive current and periodically rise and attenuation law, promptly control is by the equivalent electric flow valuve of diode rectification bridge circuit.Because diode rectification bridge circuit and T1, L1, R have born the part electric current, can improve the utilance of bridge circuit and L1, reduce the electric current quota of by-pass inductor L2, reduce the cost of whole flow restricter, certain resistance load characteristics is provided in the time of can also be for system short-circuit, improves the stability of a system.

Embodiment 2, as shown in Figure 3 is used for the three-phase isolated neutral system.The utlity model has the short-circuit fault current limiter of power consumption resistance, the diode rectifier bridge of being made up of diode D1～D6, self-on-off switching tube T1, resistance R, direct current reactor L1, shunt reactor L2～L4, zinc oxide surge absorber ZnO1～ZnO3 etc. constitute.Wherein, the collector electrode of the negative electrode of diode D1, D2, D3, self-on-off switching tube T1 (or drain electrode) is connected together; One of one end of the emitter of self-on-off switching tube T1 (or source electrode), resistance R and direct current reactor L1 terminates at together; The other end of the anode of D4, D5, D6, direct current reactor L1, the other end of resistance R are connected together; The negative electrode of the end of the end of shunt reactor L2, zinc oxide surge absorber ZnO1, the anode of diode D1, diode D4 is connected together, and constitutes the outlet terminal of flow restricter a phase; The negative electrode of the end of the end of shunt reactor L3, zinc oxide surge absorber ZnO2, the anode of diode D2, diode D5 is connected together, and constitutes the outlet terminal of flow restricter b phase; The negative electrode of the end of the end of shunt reactor L4, zinc oxide surge absorber ZnO3, the anode of diode D3, diode D6 is connected together, and constitutes the outlet terminal of flow restricter c phase; The other end of the other end of shunt reactor L2, L3, L4 and zinc oxide surge absorber ZnO1, ZnO2, ZnO3 is connected together.During use, a of flow restricter, b, c phase outlet terminal are connected together with a, b, the c reference edge mutually of three phase mains respectively, constitute the equivalent neutral point of three phase mains under the normal operation.Under normal circumstances, control switch pipe T1 is in normal open state, under stable situation, ignores the internal resistance of diode bridge and inductance L 1, and the dc inductance both end voltage is zero, and the flow restricter equivalence is a point on electric, and system is had no adverse effects.After short trouble takes place, supply voltage is after the diode bridge rectification, (because T1 also is in on-state) is added in the dc inductance two ends, cause the increase of dc inductance L1 electric current, after detecting short trouble, similar to the operation principle of phase structure flow restricter, square-wave signal with certain frequency and duty ratio removes control switch pipe T1, during the Ton of switching tube conducting, be added in the two ends of L1 and resistance R after the supply voltage rectification, thereby produce electric current in inductance and resistance, the electric current of inductance L 1 initial value when one-period finishes in the past begins to increase; During the Toff that T1 turn-offs, inductive current is by resistance R, the magnetic energy consumption that inductance L 1 stores on resistance R, current attenuation; By regulating the frequency and the duty ratio of control signal, can regulate inductive current and periodically rise and attenuation law, promptly control is by the equivalent electric flow valuve of diode rectification bridge circuit.Because diode rectification bridge circuit and T1, L1, R have born the part electric current, can improve the utilance of bridge circuit and L1, reduce the electric current quota of by-pass inductor L2, L3, L4, reduce the cost of whole flow restricter, certain resistance load characteristics is provided in the time of can also be for system short-circuit, improves the stability of a system.

Claims

1, a kind of short-circuit fault current limiter with power consumption resistance, the do not control rectifier bridge, dc inductance (L1), gate-controlled switch (T1), resistance (R), zinc oxide surge absorber (ZnO) that comprise that by-pass inductor (L2), diode form are formed; It is characterized in that: the common cathode of diode in the rectifier bridge (D1, D2), the collector electrode or the drain electrode of self-on-off switching tube (T1), be connected together; One of one end of the emitter of self-on-off switching tube (T1) or source electrode, resistance (R) and direct current reactor (L1) terminates at together; The public anode of diode in the other end of direct current reactor (L1) and the rectifier bridge (D3, D4) and the other end of resistance (R) are connected together; The anode of the negative electrode of one end of one end of shunt reactor (L2), zinc oxide surge absorber (ZnO) and diode (D3), diode (D1) is connected together, and is an outlet terminal of flow restricter; The anode of the negative electrode of the other end of the other end of shunt reactor (L2), zinc oxide surge absorber (ZnO) and diode (D4), diode (D2) is connected together, and is another outlet terminal of flow restricter.

2, a kind of short-circuit fault current limiter with power consumption resistance is by the diode (diode rectifier bridge of D1～D6) forms, self-on-off switching tube (T1), resistance (R), direct current reactor (L1), shunt reactor (L2～L4), the zinc oxide surge absorber (formation of ZnO1～ZnO3); It is characterized in that: the negative electrode of diode (D1, D2, D3), the collector electrode or the drain electrode of self-on-off switching tube (T1) are connected together; One of one end of the emitter of self-on-off switching tube (T1) or source electrode, resistance (R) and direct current reactor (L1) terminates at together; The other end of the anode of diode (D4, D5, D6), the other end of direct current reactor (L1), resistance (R) is connected together; The negative electrode of the anode of one end of one end of shunt reactor (L2), zinc oxide surge absorber (ZnO1), diode (D1), diode (D4) is connected together, and constitutes the outlet terminal of flow restricter a phase; The negative electrode of the anode of one end of one end of shunt reactor (L3), zinc oxide surge absorber (ZnO2), diode (D2), diode (D5) is connected together, and constitutes the outlet terminal of flow restricter b phase; The negative electrode of the anode of one end of one end of shunt reactor (L4), zinc oxide surge absorber (ZnO3), diode (D3), diode (D6) is connected together, and constitutes the outlet terminal of flow restricter c phase; The other end of the other end of shunt reactor (L2, L3, L4) and zinc oxide surge absorber (ZnO1, ZnO2, ZnO3) is connected together.