CN102118032A - SVC reactive prediction and compensation method for rectifier load - Google Patents

Abstract

The invention relates to a static var compensator (SVC) reactive prediction and compensation method for a rectifier load. The method comprises the following steps of: 1) calculating a triggering angle and simultaneously calculating reactive power to be generated by a load by using a rectifier controller and transmitting the reactive power of the rectifier load to an SVC controller; 2) receiving prediction reactive power transmitted by the rectifier controller by using the SVC controller, acquiring the on-off state of a branch breaker of a filter, simultaneously acquiring a power grid current signal and a power grid voltage signal used for the calculation of a reactive compensation amount, and finally realizing trigger control compensation in a triggering angle manner; and 3) after predicting and compensating, compensating a deviation caused by the calculation of the reactive power through a proportion integration (PI) regulation link. The method has the advantages that: effective compensation of a large amount of rapid reactive power in the working process of the load can be realized by an SVC device; and the SVC device has short response time, can fulfill the aim of reactive power rapid compensation, can effectively inhibit the impact of the power grid caused by the reactive power, and eliminates a voltage flicker.

Description

A kind of idle predictive compensation method of SVC of rectifier load

Technical field

The present invention relates to high pressure SVC and high-current rectifier equipment, be applied to rectifier as the load power supply and need the field of reactive power compensation.

Background technology

SVC silent oscillation reactive-load compensation equipment be most widely used at present, reactive-load compensation equipment that technology is the most ripe, regulate the resistance value of branch road by the thyristor trigger angle of control compensation reactor branch road, and cooperate with filter, reach the idle support in power system power supply zone or large-scale power user's reactive power compensation.SVC is applied to electric power system can the enhanced system ability to transmit electricity, improves stability of power system, has power oscillation damping and suppresses the functions such as compensation of sub-synchronous oscillation, power factor; SVC is applied to the power factor that the large-scale power user can improve the user, cuts down expenses, and stable busbar voltage, suppress harmonic wave and inject electric power system.

Under the traditional approach, SVC is applied to the large-scale metallurgical load of rectifier as power supply, also adopts detection of grid electric current and voltage operational factor or direct detection load voltage and current parameter to calculate required compensation rate, with the idle output of control SVC equipment.Calculate compensation way in traditional sampling, retrained by the intrinsic triggering mode of sampling filter time-delay and SVC equipment, its response time is the fastest to be about 10ms.

Big and frequent and fast the time, wish that then reactive-load compensation equipment can compensate more apace when the customer charge buckles, to suppress voltage flicker, reach best compensation effect.SVG equipment can be met consumers' demand, but the SVG equipment price is far above SVC equipment at present, so seek the new compensation way of SVC equipment improving its response time, with the application of widening SVC equipment, effectively prolong service time of SVC equipment, become the urgent task of SVC production firm.

In order to make nuclear reactor obtain ultra-high temperature, use tokamak device (Т о к а М а к) now the most widely: ring-type electromagnetism plasma device.To finish this project jointly in France by some industrial countries in the recent period.The name of this project is called international thermonuclear fusion experimental reactor (ITER).

Tokamak device is to guarantee the generation (it has additional heat-generating system) of heat by the temperature of the short-circuited winding in the electromagnetic system and it and the electric current that flows through it, and guarantees the realization of plasma under the help of powerful electromagnetic field.

The tokamak electromagnetic system is to guarantee the generation of plasma and proofread and correct its polarity that with DC power supply utilize the silicon controlled rectifier of three-phase bridge connection type to finish, rectifier is connected under the power 66kV busbar transformer.

Electromagnetic power system and heated by plasma system have the rectification characteristic under pulse condition.The i.e. storage in electromagnetic system of energy is the final tache in this process, and offers electrical network with rectification form under the state of inversion.Reactive power impact fast can appear in a large number in this course of work.

At present, SVC equipment does not appear in the newspapers at the idle predictive compensation mode of rectifier load.

Summary of the invention

The idle predictive compensation method of SVC that the purpose of this invention is to provide a kind of rectifier load, this method is based on international thermonuclear fusion experimental reactor (ITER) project, by DC power supply prediction reactive load, effective compensation of a large amount of fast reactive that occur in the load tokamak device course of work being impacted by the realization of SVC device fully, the SVC device response time is short, can reach the reactive power purpose of compensation fast, can effectively suppress idle impact, eliminate the generation of voltage flicker electrical network.

For achieving the above object, the present invention is achieved through the following technical solutions:

A kind of idle predictive compensation method of SVC of rectifier load, this method may further comprise the steps:

1) rectifier controller calculates the reactive power that load be about to produce when calculating trigger angle, and is the standard signal of 4mA～20mA with this rectifier reactive load power transfer, transfers to the SVC controller;

2) the SVC controller receives the prediction reactive power that rectifier controller sends, gather the on off state of filter branches circuit breaker, gather power network current and mains voltage signal simultaneously, be used for the calculating of reactive power compensation amount, finally realize triggering control compensation in the trigger angle mode;

3) the idle predictive compensation mode of SVC control strategy: the SVC controller judges by the on off state of detection filter device branch breaker whether filter branches devotes oneself to work, and behind the filter branches breaker closing, the Sfcn state is designated as 1; Behind the breaker open operation of filter outlet, the Sfcn state value is 0; After the reactive power fixed compensation amount that multiply by this branch road with each filter branches quantity of state is sued for peace then, obtain the idle amount of each filter branch;

4) behind predictive compensation, deviation appears stablizing in system's reactive power, then calculates the deviation that causes by PI governing loop compensating power.

The computing formula of described each six arteries and veins rectifier reactive load power is:

$\mathrm{Qyc}=[\sqrt{2}\mathrm{Vpcc}\×\sin (\mathrm{\μ}+\mathrm{\α})-\frac{\mathrm{Iref}\×600}{K}\×\mathrm{Ls}]\×\frac{3}{\mathrm{\π}\×K}\×\mathrm{Iref}$

Wherein:

Qyc is the reactive load power of one six arteries and veins rectifier

Vpcc is a rectifier transformer primary side busbar voltage rated value

μ is the commutation overlap angle of rectifier under trigger angle α

α is the rectifier trigger angle

Iref is the direct current reference value, i.e. rectifier control direct current desired value

K is the rectifier transformer no-load voltage ratio

Ls is a rectifier transformer primary side system inductance value

The reactive power of the rectifier connection in series-parallel group of many six pulse wave rectifier device compositions is each rectifier reactive power sum, and computing formula is:

Qyc＝Qyc1+Qyc2+…+Qycn

1,2 wherein: ... n is the 1st, the 2nd, n platform six pulse wave rectifier devices.

Compared with prior art, the invention has the beneficial effects as follows:

Rectifier controller calculates the reactive power that load is about to generation when calculating trigger angle, and this reactive power is transferred to the SVC controller; SVC equipment just can accurately trigger in advance and carry out reactive power compensation under the situation that need not the calculated load reactive power, has effectively reduced the response time of SVC, reaches the reactive power purpose of compensation fast.On rectifier equipment, use and show that the reactive power compensation response time of the present invention can foreshorten to about 3ms, effectively suppressed idle impact, eliminated the generation of voltage flicker electrical network.

Description of drawings

Fig. 1 is the structured flowchart of the idle predictive compensation method of SVC of rectifier load;

Fig. 2 is the control block diagram of the idle predictive compensation method of SVC of rectifier load;

Fig. 3 is many three-phase controlled bridge rectifier connection in series-parallel basic block diagram;

Fig. 4 is the control strategy block diagram of the idle predictive compensation method of SVC of rectifier load.

Embodiment

See Fig. 1-Fig. 4, the idle predictive compensation method of SVC of rectifier load, the key problem in technology of this method is, the one, how accurately rectifier controller prediction and calculation dc load is reflected at the reactive power value of grid side; The 2nd, the SVC control system is to the supervision of filter branch state; The 3rd, the correction of SVC compensation precision.Four, to send reactive power be 3ms～4ms with the reactive power time difference constantly that rectifier produces constantly to SVC equipment, and the response time is short.

If the rectifier varmeter is not calculated accurately really, then can directly influence the inhibition effect of flickering.The influence of the voltage landing that change of current impedance causes so rectifier controller when the calculated load reactive power, has taken into full account rectifier is simultaneously to existing the account form under the SVC reactive-load compensation equipment situation to do corresponding adjustment.

The computational methods of rectifier reactive load power are as follows:

The computing formula of each six arteries and veins rectifier reactive load power is:

$\mathrm{Qyc}=[\sqrt{2}\mathrm{Vpcc}\×\sin (\mathrm{\μ}+\mathrm{\α})-\frac{\mathrm{Iref}\×600}{K}\×\mathrm{Ls}]\×\frac{3}{\mathrm{\π}\×K}\×\mathrm{Iref}$

Wherein:

Qyc is the reactive load power of one six arteries and veins rectifier

Vpcc is a rectifier transformer primary side busbar voltage rated value

μ is the commutation overlap angle of rectifier under trigger angle α

α is the rectifier trigger angle

Iref is the direct current reference value, i.e. rectifier control direct current desired value

K is the rectifier transformer no-load voltage ratio

Ls is a rectifier transformer primary side system inductance value

The reactive power of the rectifier connection in series-parallel group of many six pulse wave rectifier device compositions is each rectifier reactive power sum, and computing formula is:

Qyc＝Qyc1+Qyc2+…+Qycn

1,2 wherein: ... n is the 1st, the 2nd, n platform six pulse wave rectifier devices.

Because the idle predictive compensation method of SVC of rectifier load of the present invention does not directly rely on the detection system electric current and voltage to carry out idle adjusting, so when carrying out reactive power compensation except needs are considered the reactive load compensation of rectifier, also will be according to the adjustment of the input and the excision situation amount of compensating of filter branch, avoid dropping into and withdrawing from causing reactive power impact in the process at SVC.

As shown in Figure 4, the SVC controller judges by the on off state of detection filter device branch road whether filter branches devotes oneself to work, and behind the filter branches breaker closing, the Sfcn state is designated as 1; Behind the breaker open operation of filter outlet, the Sfcn state value is 0.After the reactive power fixed compensation amount that multiply by this branch road with each filter branches quantity of state is sued for peace then, obtain the idle amount of each filter branch.The idle amount of filter branch is a capacitive reactive power.Under the idle predictive compensation mode of SVC, capacitive reactive power just is defined as, and lagging reactive power is defined as negative.

SVC is idle, and the predictive compensation mode control strategy course of work is as follows: when filter branches dropped into, the idle amount that SVC need compensate increased, and the TCR trigger angle diminishes, and exports corresponding lagging reactive power; After the filter branch excision, the idle amount that SVC need compensate reduces on the contrary, and it is big that the TCR trigger angle becomes, and exports corresponding lagging reactive power and reduce.When the idle increase of load perception, the idle total amount that SVC need compensate reduces, and it is big that the TCR trigger angle becomes, and exports corresponding lagging reactive power and reduce.If behind predictive compensation, deviation appears stablizing in system's reactive power, and then the PI governing loop starts, and eliminates the steady state error of compensation.

Among Fig. 4: Qfcn is the compensating power per unit value of each filtering channel

Sfcn is the on off state of each filtering channel

Qyc is that rectifier controller calculates reactive power output, is per unit value

Qsr is the inlet wire SVC of a system reactive power compensation target reactive power value

Qs is system's inlet wire reactive power detected value

Us is a system busbar voltage

Is is system's inlet wire current value

The synthetic load of SVC equipment replacement removes and comprises filter FC, holder gram mark device that rectifier is powered, also comprise other accessory power supply load that is under the same bussed supply, if do not consider the load except that the rectifier main power source, certain deviation can appear in SVC equipment effect.So SVC equipment self has added the integration adjusting when receiving rectifier prediction reactive power,, also proofreaied and correct simultaneously because the reactive power of rectifier controller is calculated the compensate that error causes to guarantee the stable state compensation effect of SVC compensator.

If SVC equipment sends reactive power and constantly do not work good with the reactive power that rectifier produces constantly, lead compensation or lag compensation all do not reach desirable flickering and suppress effect.For guaranteeing that capacitive reactive power do not occur impacts, and will obtain enough the response time fast, the last response time is determined at 3ms～4ms, has reached the compensation effect that prevents reactive power impact and suppress flickering fully.

Compensation effect under the idle predictive compensation mode of SVC of compensation effect under the SVC device tradition compensation way of rectifier load and rectifier of the present invention load has been done the contrast experiment, and the result is as follows:

Test condition: rectifier AC side voltage is 113V, and direct current is reduced to the SVC compensation effect of zero process with 1000kA/s speed by 40kA.

Under the SVC device tradition compensation way, the response time is about 10ms, and the full remuneration time is about 60ms.

SVC is under idle predictive compensation mode, and the response time only is 3ms～4ms, and the full remuneration time is about 20ms.

Experimental results show that: this compensation way is compared with traditional SVC compensation way has fast notable feature of response time, is applied in to have under the quick jumbo reactive power impact load operating mode, can effectively suppress system voltage flickering problem.

Claims (3)

1. the idle predictive compensation method of SVC of rectifier load is characterized in that this method may further comprise the steps:

1) rectifier controller calculates the reactive power that load be about to produce when calculating trigger angle, and is the standard signal of 4mA～20mA with this rectifier reactive load power transfer, transfers to the SVC controller;

2) the SVC controller receives the prediction reactive power that rectifier controller sends, gather the on off state of filter branches circuit breaker, gather power network current and mains voltage signal simultaneously, be used for the calculating of reactive power compensation amount, finally realize triggering control compensation in the trigger angle mode;

3) the idle predictive compensation mode of SVC control strategy: the SVC controller judges by the on off state of detection filter device branch breaker whether filter branches devotes oneself to work, and behind the filter branches breaker closing, the Sfcn state is designated as 1; Behind the breaker open operation of filter outlet, the Sfcn state value is 0; After the reactive power fixed compensation amount that multiply by this branch road with each filter branches quantity of state is sued for peace then, obtain the idle amount of each filter branch;

4) behind predictive compensation, deviation appears stablizing in system's reactive power, then calculates the deviation that causes by PI governing loop compensating power.

2. the idle predictive compensation method of SVC of a kind of rectifier load according to claim 1 is characterized in that the computing formula of described each six arteries and veins rectifier reactive load power is:

$\mathrm{Qyc}=[\sqrt{2}\mathrm{Vpcc}\×\sin (\mathrm{\μ}+\mathrm{\α})-\frac{\mathrm{Iref}\×600}{K}\×\mathrm{Ls}]\×\frac{3}{\mathrm{\π}\×K}\×\mathrm{Iref}$

Wherein:

Qyc is the reactive load power of one six arteries and veins rectifier

Vpcc is a rectifier transformer primary side busbar voltage rated value

μ is the commutation overlap angle of rectifier under trigger angle α

α is the rectifier trigger angle

Iref is the direct current reference value, i.e. rectifier control direct current desired value

K is the rectifier transformer no-load voltage ratio

Ls is a rectifier transformer primary side system inductance value

The reactive power of the rectifier connection in series-parallel group of many six pulse wave rectifier device compositions is each rectifier reactive power sum, and computing formula is:

Qyc＝Qyc1+Qyc2+…+Qycn

1,2 wherein: ... n is the 1st, the 2nd, n platform six pulse wave rectifier devices.

3. the idle predictive compensation method of SVC of a kind of rectifier load according to claim 1 is characterized in that, it is 3ms～4ms with the reactive power time difference constantly that rectifier produces constantly that SVC equipment sends reactive power, and the response time is short.

Images