CN102638048A

CN102638048A - Automatic bypass processing method of H-bridge cascaded chain type static synchronous compensator (STATCOM)

Info

Publication number: CN102638048A
Application number: CN201210086979XA
Authority: CN
Inventors: 杨立军; 杨婷; 邹积勇; 杨志; 薛恒怀; 季石斌; 吴新兵
Original assignee: WEIFAN INTELLIGENT ELECTRICAL HI-TECH Co Ltd
Current assignee: WEIFAN INTELLIGENT ELECTRICAL HI-TECH Co Ltd
Priority date: 2012-03-29
Filing date: 2012-03-29
Publication date: 2012-08-15

Abstract

The invention relates to an automatic bypass processing method of an H-bridge cascaded chain type static synchronous compensator (STATCOM). The method is characterized in that when the number M of fault units of a certain phase is greater than the number K of redundant units, an upper machine judges a corresponding power tube which enters bypass work by reading the work state information of the fault unit, thus sending switching on or switching off information and enabling the fault unit to enter a bypass state; simultaneously, a carrier phase shifting angle of a corresponding fault phase and a given voltage value of a direct current-side unit bus are adjusted in real time in an on-line manner, the original operation state of a non-fault phase is remained unchanged, the given voltage value of the direct current-side bus of a unit in front of a bypass is set, an STATCOM system is set as a chain and a unit in need of bypass is set as a chain, then after bypass adjustment, the carrier phase shifting angle of a unit module is adjusted. By using the automatic bypass processing method disclosed by the invention, the cost can be saved, consumption can be reduced, the effective fault tolerance of the fault unit can be realized, and the control policy can be adjusted in real time in an on-line manner so as to maintain the system to be stable.

Description

The bypass automatic processing method of a kind of H bridge cascade chain type STATCOM

Technical field

The invention belongs to Electrical Power System Dynamic reactive power compensation field, be specifically related to the auto by pass processing method of a kind of H bridge chain type STATCOM.

Background technology

STATCOM (STATCOM) is a kind of novel static passive compensation device based on the power current inverter technology; Through control its output voltage amplitude and with respect to the phase place of system voltage be may command its send or absorb idle; Thereby the raising grid power factor is stablized line voltage.For increasing installed capacity, can adopt many level chain type cascade structure, its elementary cell is the H bridge inverter circuit, the unit module circuit topology is as shown in Figure 1; The cascade of a plurality of H bridge inversion unit module inserts electrical network through reactor, and the chain type STATCOM circuit system topology that is constituted is as shown in Figure 2, whenever is in series by individual independent H bridge unit module, and other is provided with a redundancy unit.

Cascade connection type STATCOM is because its special construction causes its unit module probability of malfunction bigger.Be to improve the reliability of STATCOM device, reduce the device frequent switching,, need the unit module of bypass fault, make device can continue operation when trouble unit number during greater than redundancy unit.Common bypass strategy is that extra bypass circuit is set, and normal conditions are for being the bypass structure of core with relay or thyristor.From reducing the plant area area, the angle of reduction device loss and saving manufacturing cost is set out, and needs more simple, the economic and reliable bypass strategy of design, for each unit module provides protection.

Summary of the invention

For overcoming the defective of prior art; The objective of the invention is to propose a kind of more simple; Economic and reliable auto by pass processing method makes trouble unit in effective bypass, through adjusting corresponding fault phase control strategy; Guarantee system side three-phase voltage balance, the stable operation of maximization holdout device.

The auto by pass processing method of a kind of H bridge cascade chain type STATCOM mainly comprises two steps: 1) that power tube under power tube or the left and right sides brachium pontis on the left and right sides brachium pontis of corresponding fault H bridge unit module is open-minded; 2) through revising fault phase phase-shifting carrier wave phase angle and DC side unit busbar voltage set-point, guarantee the three-phase output voltage symmetry.With H bridge topological structure shown in Figure 1 is example, and the T1 of corresponding fault H bridge unit module and T2 or T3 and T4 is open-minded simultaneously; Through revising fault phase phase-shifting carrier wave phase angle and DC side unit busbar voltage set-point, guarantee the three-phase output voltage symmetry.

According to auto by pass processing method of the present invention, be applicable to many level cascade chain type STATCOM H bridge unit module as shown in Figure 2, establishing the number that whenever is linked is that the redundancy unit number does in addition.

Auto by pass processing method of the present invention; On H bridge unit module structure shown in Figure 1; Do not need to establish in addition extra bypass circuit or by-pass switch, open signal through sending out simultaneously, thereby realize the trouble unit auto by pass to the T1 of H bridge unit module and T2 or T3 and T4.

Auto by pass processing method of the present invention, bypass operation also comprise adjusts corresponding fault phase phase-shifting carrier wave phase angle and DC side unit busbar voltage set-point simultaneously, and non-fault keeps normal operation mutually.If bypass front unit DC side busbar voltage set-point does, the STATCOM system is a chain, and needing by-pass unit be chain, and then bypass is adjusted; Unit module phase-shifting carrier wave phase angle is adjusted into.

Auto by pass processing method of the present invention, as shown in Figure 1, H bridge unit module comprises by T5, the common capacitance voltage leadage circuit of forming of R1 and R2.This leadage circuit divides two kinds of working methods: 1) R2 works independently; 2) form leadage circuit jointly by R1 and R2 after opening T5, can accelerate the speed of releasing this moment.

Auto by pass processing method of the present invention, power tube all has independently temperature in the H bridge unit module circuit, and Working Status Monitoring circuit and driver modules such as voltage are communicated by letter with host computer through optic module.

Description of drawings

Fig. 1 is the H bridge inverter circuit schematic diagram of individual module;

Fig. 2 is many level cascade chain type STATCOM main circuit schematic diagram.

Embodiment

Embodiment 1, if certain phase fault unit number M when counting K greater than redundancy unit, host computer is judged to get into the corresponding power tube of bypass work through read failure cell operation state information.Thereby send switching information, make trouble unit get into bypass condition.Online in real time is adjusted corresponding fault phase phase-shifting carrier wave phase angle and DC side unit busbar voltage set-point simultaneously, and non-fault keeps former running status constant mutually.If bypass front unit DC side busbar voltage set-point does, the STATCOM system is a chain, and needing by-pass unit be chain, and then bypass is adjusted; Unit module phase-shifting carrier wave phase angle is adjusted into.What deserves to be mentioned is,, insert voltage, components and parts voltage withstand class such as dc bus capacitor and power tube but the by-pass unit number depends primarily on the PCC point for the STATCOM system that confirms that chain number is.

After trouble unit got into bypass condition, the dc bus capacitor busbar voltage can be passed through T5, and R1 and R2 release, and be as shown in Figure 1.Host computer can determine whether needs are opened T5 according to the dc bus capacitor bus voltage value before the bypass simultaneously, to accelerate the speed of releasing, guarantees device safety.If when catastrophe failure took place for trouble unit the same side bridge wall power tube such as T1 and T3 or T2 and T4, then host computer sent the envelope pulse signal to all unit of three-phase.

The above is merely concrete example in real time of the present invention, does not limit protection scope of the present invention with this.Any based on equivalent control strategy of the present invention conversion, all belong to protection scope of the present invention.

Claims

1. the auto by pass processing method of a H bridge cascade chain type STATCOM comprises two steps: 1) that power tube under power tube or the left and right sides brachium pontis on the left and right sides brachium pontis of corresponding fault H bridge unit module is open-minded; 2) through revising fault phase phase-shifting carrier wave phase angle and DC side unit busbar voltage set-point, guarantee the three-phase output voltage symmetry.

2. the auto by pass processing method of a kind of H bridge cascade chain type STATCOM according to claim 1; It is characterized in that: the computational methods of the corresponding fault phase of described adjustment phase-shifting carrier wave phase angle and DC side unit busbar voltage set-point do; If bypass front unit DC side busbar voltage set-point does; The STATCOM system is a chain, and needing by-pass unit is chain, and then bypass is adjusted; Unit module phase-shifting carrier wave phase angle is adjusted into.

3. the auto by pass processing method of a kind of H bridge cascade chain type STATCOM according to claim 1; It is characterized in that: said H bridge unit module comprises by T5; The common capacitance voltage leadage circuit of forming of R1 and R2, described leadage circuit divides two kinds of working methods: 1) R2 works independently; 2) form leadage circuit jointly by R1 and R2 after opening T5, can accelerate the speed of releasing this moment.

4. according to the auto by pass processing method of a kind of H bridge cascade chain type STATCOM shown in the claim 1, it is characterized in that: power tube all has independently temperature, Working Status Monitoring circuit and driver modules such as voltage in the H bridge unit module circuit.