CN2488215Y

CN2488215Y - Reactive compensator

Info

Publication number: CN2488215Y
Application number: CN 01214571
Authority: CN
Inventors: 李群湛; 贺建闽
Original assignee: Southwest Jiaotong University
Current assignee: Southwest Jiaotong University; Xian Jiaotong University
Priority date: 2001-03-28
Filing date: 2001-03-28
Publication date: 2002-04-24
Anticipated expiration: 2011-03-28

Abstract

The utility model provides a reactive compensator which is characterized in that one end of a primary winding of a step-down transformer is connected with a high-voltage bus, and one end of a secondary winding is connected with a low-voltage bus; the low-voltage bus is connected with the thyristor switch, tapping switch and the primary winding of powerstat; the secondary winding of the powerstat is in series with the high-voltage shunt capacitor and series reactor, and also can be in series with the high-voltage shunt reactor. The thyristor switch is used for breaking off the load, and the tapping switch is to regulate voltage in the condition of unload. Applying the voltage regulation in low voltage to adjust the reactive power of the high-voltage branch can both absorbs the capacitive reactive power and the inductance reactive power with a power factor above 0.9; and the inductance reactive power or the capacitive reactive power can be applied in the inductance or capacitive reactive compensation.

Description

Reactive power compensator

The utility model relates to the Alternating Current Power Supply technical field, relates in particular to the electrified railway power supply technical field.

Power factor is generally in 0.8 (hysteresis) or big slightly under the AC-DC electric locomotive traction operating mode, for reaching the economic power factor, consider utilance and the locomotive car body space and the heavy restriction of axle of compensation arrangement, for the traction load of big ups and downs, how to implement compensation at traction substation (ground), mostly be nonadjustable at present, its effect depends on which kind of metering method electric power system adopts to reactive power.Before the eighties reaches, electric power system is to idle employing " the anti-counterplot of sending " mode, i.e. the counter-rotating of the wattless component watt-hour meter of traction substation absorbs capacitive reactive power from electric power system during overcompensation, inductive load nearby is benefited, and the metering result seem that the traction substation reactive power compensation is effective.Developed into idle " counter sending disregarded " afterwards, promptly install the idle anti-non-return measure of sending additional at traction substation, the reactive power of overcompensation is not counted in power factor, to this, electric railway strengthens compensation rate in right amount still can obtain satisfied effect, further, the nineties beginning, many power supply administrations carry out idle " counter just sending counted " energetically, be that overcompensation is considered as " undercompensation ", so electric locomotive adopts regeneration feedback " power factor " to decline to a great extent in addition, far below the 0.9 economic power factor requirement that lags behind, the traction substation power factor that has be low to moderate 0.6 and below, and annual therefore reached 2,000,000 yuan even more by fine.Need to prove that no matter adopt which kind of metering method, the capacitive reactive power that benefit is crossed in non-adjustable compensation all will be digested by electric power system, but the requirement that the result is non-adjustable compensation not competent idle " the anti-counterplot of sending ", unless adopt adjustable compensation.In recent years, in conjunction with advanced foreign technology, China administered the multiple scheme that also proposed with regard to reactive power compensation of electric railway electric substation and harmonic synthesis, which kind of scheme no matter, all be the lagging reactive power of making every effort to compensation traction load under the first-harmonic, improve power factor, and take into account filtering (or counteracting) harmonic wave.Major programme has: (1) vacuum circuit-breaker switched capacitor.Biggest advantage is simple, reduced investment; When shortcoming was combined floodgate, the switching filter branch had a transient process, can produce the overcurrent overvoltage, influences the reliability service of capacitor and series reactor; During the surgical filtering branch road, recovery voltage is higher on the contact, and the possibility that has switch to restrike when repeatedly repeating to puncture, produces very high overvoltage on the capacitor, cause device damage.The switching of capacitor group is impacted, and the IEC regulation is no more than 1000 times/year, and the restriction of switch life in addition can not frequent switching, thereby influences the dynamic compensation effect.(2) passive compensator+active compensation device.Adopt active filter produce with load in the opposite harmonic current of harmonic current phase place, make the requirement of its total harmonic current of satisfying power supply of cancelling out each other.Relatively success is passive, active compound filter, it can be maximized favourable factors and minimized unfavourable ones, and makes full use of flexibility, the controllability of Passively compensated big capacity and active compensation, but its complex structure, cost height, operating cost height, and this technology is in conceptual phase, and technology is prematurity still.(3) fixed capacitor (FC)+thyristor is regulated reactor (TCR).Fixed filters is pressed the harmonic requirement design, anti-parallel thyristor is connected with reactor, regulate the inductance current that flows into the loop by changing the thyristor angle of flow, make capacitive reactive power unnecessary in itself and the parallel filter be able to balance, satisfy the requirement of power factor.Advantage is that fixing filter branch in parallel drops into for a long time, does not need switching, whenever can both satisfy the harmonic wave designing requirement, need thyristor quantity few, the TCR response speed is fast, and adjusting function is good, shortcoming is that the fixed compensation filter capacity is very big, and TCR also produces harmonic wave, and is lossy.(4) fixed capacitor (FC)+controllable transducer.Automatically regulate saturable reactor magnetic saturation degree and change the inductance current that flows into the loop, make capacitive reactive power unnecessary in itself and the parallel filter be able to balance.Advantage is that fixing filter branch in parallel drops into for a long time, does not need switching, realizes smooth adjustable; But equally will produce harmonic wave with TCR, lossy, noise is big.(5) thyristor switchable capacitor (TSC).According to certain optimizing pattern, the many groups of design certain or certain is filter several times, and each branch road is capacitive under the first-harmonic, and classification changes the idle of compensation arrangement and exerts oneself; Offset is humorous under the filter subharmonic, this subharmonic of filter of holding concurrently.Advantage is that loss is little, and simple in structure, speed responsive is fast, do not produce harmonic wave, can realize operating passing zero, can not produce overvoltage serious as vacuum switch, shortcoming is can only classification adjustable, and filter effect is subjected to the influence of system performance and input group number, and one-time investment is big.(6) former Soviet Union has proposed a kind of adjustable reactive-load compensation equipment of passing through many groups thyristor switch pressure regulation of step-down transformer, and advantage is that response speed is fast, and lower than high pressure pressure regulation scheme cost, shortcoming is a complex structure, and maintenance is big.For adjustable, consider that again the frequent variations of electric railway load and various machinery (contact is arranged) switch are subjected to its electrical endurance (be lower than its mechanical endurance 1/10) restriction, some country's beginnings are abroad also adopted thyristors to exchange switches to change the idle of compensation arrangement and exert oneself in a large number.Wherein using maximum, foremost in electric power system is Static Var Compensator (SVC), it is by TSC (Thyristor-Switched Capacitor, thyristor switchable capacitor) and TCR (Thyristor-Controlled Reactor, thyristor-controlled reactor) forms, TSC realizes coarse adjustment, and TCR realizes fine tuning.Top (3), (4), (5) in fact all belong to the SVC category.The SVC of electric power system is used for voltage stabilizing more.South Africa, Australia, Japan have used SVC in electric railway, are mainly used in the compensation negative phase-sequence, and equipment is huge, invest huge, Britain's use be the reduced form TSC of SVC, purpose is pressure regulation.Obviously, propose a kind of simple in structurely, easy to operate, invest low (avoiding high-pressure thyristor), life-span long (utilizing the mechanical endurance of shunting switch and the electrical endurance of thyristor), the significant utility model technology of compensation effect is very necessary.

The purpose of this utility model provides a kind of reactive power compensator, and it can improve power factor or raising and burning voltage effectively, suppresses negative-sequence current, can cooperate with non-adjustable paralleling compensating device or filter, reduces the device installed capacity, strengthens filter function.

The purpose of this utility model can be realized by following technical scheme, it comprises voltage regulating transformer and connected shunting switch and thyristor switch, step-down transformer, the capacitor group, reactor, to be (1) adjust the reactive power of high pressure branch road by the low pressure pressure regulation to technical characterictic, can absorb capacitive reactive power from electrical network, also can absorb lagging reactive power; (2) thyristor switch cut-offs load, and shunting switch is realized No-load changer; (3) step-down transformer and voltage regulating transformer both can same iron core winding, also can divide iron core winding.Its basic mode of connection is that one of the former limit of step-down transformer winding is terminated at high voltage bus, other end ground connection; One termination low-voltage bus bar of inferior limit winding, other end ground connection.Low-voltage bus bar connects two groups of thyristor switchs, and thyristor switch respectively connects the end that a component connects switch, and the other end of shunting switch connects an end of the former limit winding of voltage regulating transformer, the other end ground connection of the former limit of voltage regulating transformer winding; The inferior limit winding of one group of voltage regulating transformer is connected with high-voltage parallel capacitor group and series reactor, connects with high-voltage shunt reactor in the inferior limit of another group voltage regulating transformer.Thyristor switch cut-offs load, and shunting switch is realized No-load changer.When two groups of voltage regulating transformers use simultaneously, adjust the reactive power of high pressure branch road, can from electrical network, absorb capacitive reactive power, also can absorb lagging reactive power by the low pressure pressure regulation.When two groups of voltage regulating transformers use separately, can from electrical network, absorb perception and capacitive reactive power respectively.

Effect that the utility model is compared with prior art had and advantage are simple in structure, easy to operate, use the low-voltage thyristor switch to reduce cost, use shunting switch to realize No-load changer, utilize the advantage of its of length mechanical endurance and overcome the shortcoming of its electrical endurance weak point, use thyristor to cut-off load, electrical endurance is long, can be applicable to the occasion of frequent adjusting, and transient process is little, relevant device is not impacted, simultaneously, can from electrical network, absorb capacitive reactive power, also can absorb lagging reactive power, can realize making power factor reach the target of economic power factor more than 0.9 under the strictest reactive measurement mode (counter just sending counted), have concurrently and suppress negative-sequence current and filter function, can also effectively utilize existing non-adjustable paralleling compensating device or filter, also can match, to strengthen filter function with the filter of special making and settlement.

Description of drawings of the present utility model.

Fig. 1 is a basic winding diagram of the present utility model;

Fig. 2 is the winding diagram that is used for only absorbing the capacitive reactive power occasion of the present utility model;

Fig. 3 is the winding diagram that is used for only absorbing the lagging reactive power occasion of the present utility model.

Embodiment

The utility model comprises

voltage regulating transformer

6a, 6b and connected

shunting switch

5a, 5b and

thyristor switch

4a, 4b, step-down transformer 2, capacitor group 7,

reactor

8,9, technical characterictic is (1) adjusts the high pressure branch road by the low pressure pressure regulation a reactive power, capacitive reactive power can be from electrical network, absorbed, also lagging reactive power can be absorbed; (2) thyristor switch cut-offs load, and shunting switch is realized No-load changer; (3) step-down transformer and voltage regulating transformer both can same iron core winding, also can divide iron core winding.

Its basic mode of connection is that one of step-down transformer 2 former limit windings are terminated at high voltage bus 1, other end ground connection; One termination low-voltage bus bar 3 of inferior limit winding, other end ground connection.Low-voltage bus bar 3 connects two groups of

thyristor switch

4a, 4b,

thyristor switch

4a, 4b respectively connect the end that a component meets

switch

5a, 5b, the other end of

shunting switch

5a, 5b connects the former limit winding of

voltage regulating transformer

6a, 6b, the other end ground connection of

voltage regulating transformer

6a, 6b respectively; The inferior limit winding of voltage regulating transformer 6a is connected with high-voltage parallel capacitor group 7 and series reactor 8, connects with high-voltage shunt reactor 9 in the inferior limit of another group voltage regulating transformer 6b.Thyristor switch cut-offs load, and shunting switch is realized No-load changer, thereby, adjust the reactive power of high pressure branch road by the low pressure pressure regulation, can from electrical network, absorb capacitive reactive power, also can absorb lagging reactive power.* organize the end of the same name of former limit winding of transformer for each.

Low-voltage bus bar 3 connects thyristor switch 4a and shunting switch 5a, and the other end of shunting switch 5a connects the former limit winding of voltage regulating transformer 6a, and the inferior limit winding of voltage regulating transformer 6a is connected with high-voltage parallel capacitor group 7 and series reactor 8.Thyristor switch cut-offs load, and shunting switch is realized No-load changer, thereby, adjust the capacitive reactive power that the high pressure branch road absorbs by the low pressure pressure regulation from electrical network.

Low-voltage bus bar 3 connects thyristor switch 4b and shunting switch 5b, the other end of shunting switch 5b connects the former limit winding of voltage regulating transformer 6b, connect with high-voltage shunt reactor 9 in the inferior limit of voltage regulating transformer 6b, thyristor switch cut-offs load, shunting switch is realized No-load changer, thereby, adjust the lagging reactive power that the high pressure branch road absorbs from electrical network by the low pressure pressure regulation.

Claims

1. reactive power compensator, comprise voltage regulating transformer (6a, 6b) and connected shunting switch (5a, 5b) and thyristor switch (4a, 4b), be provided with step-down transformer (2), capacitor group (7) and reactor (8,9) between high voltage bus (1) and the low-voltage bus bar (3), it is characterized in that:

A. one of the former limit of step-down transformer (2) winding be terminated at high voltage bus (1), other end ground connection, a termination low-voltage bus bar (3) of inferior limit winding, other end ground connection;

B. low-voltage bus bar (3) and connect two groups of thyristor switchs (4a, 4b), thyristor switch (4a, 4b) respectively connects the end that a component meets switch (5a, 5b), the other end of shunting switch (5a, 5b) connects the former limit winding of voltage regulating transformer (6a, 6b), the other end ground connection of voltage regulating transformer (6a, 6b);

C. the inferior limit winding of voltage regulating transformer (6a) is connected with high-voltage parallel capacitor group (7) and series reactor (8), connects with high-voltage shunt reactor (9) in the inferior limit of another group voltage regulating transformer (6b).

2. a kind of reactive power compensator according to claim 1 is characterized in that: the positive pole of thyristor switch (4a, 4b) is connected with low-voltage bus bar (3), and negative pole is connected with shunting switch (5a, 5b) respectively.

3. a kind of reactive power compensator according to claim 1 is characterized in that: step-down transformer and voltage regulating transformer both can same iron core winding, also can divide iron core winding.

4. a kind of reactive power compensator according to claim 1, it is characterized in that: low-voltage bus bar (3) serial connection thyristor switch (4a) and shunting switch (5a), the other end of shunting switch (5a) connects the former limit winding of voltage regulating transformer (6a), and the inferior limit winding of voltage regulating transformer (6a) is connected with high-voltage parallel capacitor group (7) and series reactor (8).

5. a kind of reactive power compensator according to claim 1, it is characterized in that: low-voltage bus bar (3) serial connection thyristor switch (4b) and shunting switch (5b), the other end of shunting switch (5b) connects the former limit winding of voltage regulating transformer (6b), connects with high-voltage shunt reactor (9) in the inferior limit of voltage regulating transformer (6b).