CN103532149A - Multi-side voltage reactive coordination optimization control method for high-voltage distribution network transformer substation - Google Patents

Abstract

The invention relates to a multi-side voltage reactive coordination optimization control method for a high-voltage distribution network transformer substation. The method comprises the steps that an all-side voltage reactive coordination optimization impedance model set of the transformer substation is built; the all-side short circuit impedance at the medium-low voltage side is calculated, the coordination optimization model set of the transformer substation is modified, and in addition, models are typed into a coordination controller; a corresponding coordination optimization impedance model is selected; the operation data of an MCR (magnetically controlled reactor) at the medium voltage side, an MSVC (MCR static var compensator) at the low voltage side and three-side buses of a main transformer are measured in real time, and the input capacity of the SVC (static var compensator) at the low voltage side, the MCR at the medium voltage side and the tapping point gear of the main transformer are optimized and calculated; according to optimization results, the tapping point gear of the main transformer is regulated, var compensators at two sides adopt the double closed-loop control, and are regulated in a way of following the outer ring control of the coordination optimization impedance model, and on the premise of enabling parameters at the medium voltage side not to exceed the limit, the MSVC at the low voltage side adopts the self closed loop control.

Description

A kind of high pressure distribution transformer station many sides voltage power-less coordinating and optimizing control method

Technical field

The present invention relates to a kind of high pressure distribution transformer station many sides voltage power-less coordinating and optimizing control method, be particularly related to and a kind ofly take senior middle school of transformer station low-pressure side voltage power-less as Comprehensive Control target, control mesolow both sides magnet controlled reactor MCR type static passive compensation device SVC, realize the voltage power-less comprehensive coordination optimal control method of each side of transformer station.

Background technology

Along with socioeconomic development, a large amount of utilizations of the high-power perception such as high-power rectifying equipment, arc furnace and electric locomotive and non-linear equipment, the voltage power-less problem of bringing is thus more and more serious.In electric power system, the safe and economical operation of quality of voltage to electric power system, on guaranteeing that there is important impact in safety and the life-span of user security production and product quality and power consumption equipment.Idle work optimization is the main points that realize systematic economy operation, and the adjusting of voltage and reactive power has contact closely.The operation voltage level of electric power system depends on the balance of reactive power, idle deficiency can cause low voltage, otherwise can make voltage higher, therefore effectively voltage control and reasonably reactive power compensation, can not only guarantee quality of voltage, stability and the fail safe that can also improve power system operation, obtain good economic benefit.

It is that the reactive power compensator of one-sided (mostly being low-pressure side) is carried out that traditional transforming plant voltage reactive is controlled, and control method mainly contains: nine district Tu Huo five district figure controls, voltage/power control and inverse regulation voltage control etc.Wherein, the most basic mode is that transforming plant voltage reactive is controlled, and which generally adopts adjusting load tap changer, opening-closing capacitor bank etc.In recent years, the application of static passive compensation device SVC has realized idle continuously smooth and has regulated, and the dynamic auto compensation that has reached voltage power-less is controlled.

According to pertinent literature, static passive compensation device SVC is comprised of capacitor group and controlled reactor, applies wider thyristor-controlled reactor TCR and limit by power electronic device characteristic, only for 35kV and following electric pressure.At present the many TCR type SVC of application are only usingd power factor or the voltage of certain grade or power factor mostly as target, and control target is relatively single, fail the complexity of the system that takes into full account, and are difficult to realize good multiobjective optimal control.

When static passive compensation device SVC controls for the voltage power-less of certain each electric pressure of transformer station, static passive compensation device SVC is often via the low-voltage bus bar connecting system of transformer, under different system operation modes and different load level, static passive compensation device SVC is not necessarily synchronous for the voltage-regulation of each side, may occur that high-pressure side is on the low side and low-pressure side is higher or high-pressure side normal and low-pressure side is on the low side etc. complex situations.Now, static passive compensation device SVC may cause the higher or on the low side of other sides for the adjusting of low-pressure side, is difficult to take into account the supply power voltage of each side bus of transformer.

In high voltage distribution network Zhong， 220kV transformer station, adopt three-winding transformer more, as 220kV/110kV/10kV or 220kV/110kV/35kV, have the circuit of a plurality of electric pressures.Existing capacitor group and static passive compensation device SVC mostly are 35kV and following electric pressure, and the adjusting of the voltage power-less of medium voltage side bus mainly coordinates adjusting to realize by high voltage side of transformer tap and low-voltage reactive compensator capable.Adopting the major defect existing is in this way: on the one hand, be difficult to each side voltage power-less of reply and regulate inconsistent complex situations, be more difficult to take into account the accurate control of each side voltage power-less simultaneously; On the other hand, by the reactive power compensator of low-pressure side, compensate the idle idle transformers that pass through in a large number that cause of medium voltage side, cause a large amount of electric energy losses, affect economical operation and the useful life of transformer.

Summary of the invention

For the deficiencies in the prior art, the invention provides a kind of many sides of high pressure distribution three-winding transformer voltage power-less coordinating and optimizing control method, the method adopts the magnet controlled reactor MCR of medium voltage side and the MCR type static passive compensation device MSVC of low-pressure side to carry out coordination optimization control.Coordination optimizing control system comprises medium voltage side MCR, low-pressure side MSVC, middle voltage bus bar and respectively installs voltage current transformer, monitors three side bus voltages, electric current and reactive power, and control a plurality of devices by coordination optimization controller.The control method of native system comprises: build model, Real-Time Monitoring, coordination optimization and control, concrete steps are as follows:

1) by the installed capacity typing tuning controller of the installed capacity of the MCR type SVC of the low-pressure side of main transformer (MCR capacity, capacitor group total capacity and the configuration of each pool-size) and medium voltage side direct screening MCR;

2) press nameplate calculation of parameter main transformer operation equivalent model, under different running method, the running status (apportion/paired running) of high-pressure side system short-circuit impedance and transformer, obtain each side voltage power-less coordination optimization impedance model collection of transformer station under different running method, hereinafter to be referred as " Coordination and Optimization Model collection ";

3) utilize power system simulation software, calculate each side short-circuit impedance of the lower low-pressure side of different running method ，Dui transformer station Coordination and Optimization Model collection and revise, make more realistic running status, to realize more accurately coordination optimization, control, and by model typing tuning controller;

4) according to main transformer tap gear switching information, transformer substation system and main transformer operational mode, the coordination optimization impedance model that real-time selection is corresponding.

5) measure in real time the service data that main transformer three side bus, low-pressure side MSVC and middle pressure are surveyed MCR, optimize the input capacity that calculates main transformer tap gear, medium voltage side MCR and low-pressure side SVC;

Above-mentioned optimal conditions comprises: senior middle school's low pressure three side bus voltage levvls, mesolow side power factor and active power.Follow medium voltage side power factor and the preferential principle of low-pressure side bus voltage levvl, then consider each side voltage levvl and power factor.

6) according to optimum results, regulate main transformer tap gear, both sides reactive power compensator is adopted to two closed-loop controls, follow the reactive power compensator of the outer shroud regulating and controlling both sides of coordination optimization impedance model, guaranteeing that, under the not out-of-limit prerequisite of medium voltage side parameter, low-pressure side MSVC adopts from closed-loop control.

The present invention adopts the New Virtual air gap controlled reactor based on multistage virtual air gap optimisation technique, and its total harmonic distortion is no more than 2.5% rated current; Fast response time, is not more than 20ms～60ms settling time; Loss reduces, and the active loss under rated output capacity is about 0.8%, and average loss is about 0.5%.Therefore, can meet preferably system and control requirement, have good operational efficiency of the economy.

Accompanying drawing explanation

Fig. 1 is many sides voltage power-less coordination optimizing control system block diagram of the present invention.

Fig. 2 is the equivalent circuit diagram of three-winding transformer.

Each side voltage power-less coordination optimization impedance model figure of Tu3Wei transformer station.

Fig. 4 is the coordination optimization impedance model figure based on each side short-circuit impedance of transformer station.

Fig. 5 is control method flow chart of the present invention.

Specific implementation method

As shown in Figure 1, many sides voltage power-less coordination optimizing control system of the present invention, as shown in Figure 2, Figure 3 and Figure 4, Real-Time Monitoring, coordination optimization and control flow are as shown in Figure 5 for Coordination and Optimization Model.Specific implementation method is as follows:

1, according to main transformer nameplate parameter, transformer parameter is calculated and convert on high-tension side equivalence value, draw the equivalent circuit diagram of three-winding transformer as shown in Figure 2.Concrete computational process is as follows:

(1) first, the relevant short circuit loss of the less winding of capacity is converted to Δ P _s1-3=n ²Δ P' _s1-3, Δ P _s2-3=n ²Δ P' _s2-3, the short circuit loss Δ P of each winding _snand resistance R _nfor:

$\left\{\begin{array}{c}{\mathrm{\&Delta;P}}_{S1}=\frac{1}{2}({\mathrm{\&Delta;P}}_{S1-2}+{\mathrm{\&Delta;P}}_{S1-3}-{\mathrm{\&Delta;P}}_{S2-3})\\ {\mathrm{\&Delta;P}}_{S2}=\frac{1}{2}({\mathrm{\&Delta;P}}_{S1-2}+{\mathrm{\&Delta;P}}_{S2-3}-{\mathrm{\&Delta;P}}_{S1-3})\\ {\mathrm{\&Delta;P}}_{\mathrm{<figure-callout\; id="3"\; label="S"\; filenames="HDA0000390926790000012.png"\; state="\{\{state\}\}">S</figure-callout>}3}=\frac{1}{2}({\mathrm{\&Delta;P}}_{S1-3}+{\mathrm{\&Delta;P}}_{S2-3}-{\mathrm{\&Delta;P}}_{S1-2})\end{array}\right.\&DoubleRightArrow;\begin{array}{c}\left\{\begin{array}{c}{R}_1=\frac{{\mathrm{\&Delta;P}}_{S1}{U}_N^2}{S_N^2}\\ R_2=\frac{{\mathrm{\&Delta;P}}_{S2}{U}_N^2}{S_N^2}\\ {\mathrm{<figure-callout\; id="3"\; label="R"\; filenames="HDA0000390926790000012.png"\; state="\{\{state\}\}">R</figure-callout>}}_3=\frac{{\mathrm{\&Delta;P}}_{S3}{U}_N^2}{S_N^2}\end{array}\right..---\left(1\right)\end{array}$

(2) calculate the short-circuit voltage U of each winding _sn% and reactance X _nfor:

$\left\{\begin{array}{c}{U}_{S1}\%=\frac{1}{2}(U_{S1-2}\%+U_{S1-3}\%-U_{S2-3}\%)\\ U_{S2}\%=\frac{1}{2}(U_{S1-2}\%+U_{S2-3}\%-U_{S1-3}\%)\\ U_{\mathrm{<figure-callout\; id="3"\; label="S"\; filenames="HDA0000390926790000012.png"\; state="\{\{state\}\}">S</figure-callout>}3}\%=\frac{1}{2}(U_{S1-3}\%+U_{S2-3}\%-U_{S1-2}\%)\end{array}\right.\&DoubleRightArrow;\begin{array}{c}\left\{\begin{array}{c}{X}_1=\frac{U_{S1}\%U_N^2}{S_N}\\ X_2=\frac{U_{S2}\%U_N^2}{{\mathrm{<figure-callout\; id="3"\; label="S\; N\; X"\; filenames="HDA0000390926790000012.png"\; state="\{\{state\}\}">S</figure-callout>}}_N}& \\ X_{}{}_3=\frac{{\mathrm{<figure-callout\; id="3"\; label="U\; S"\; filenames="HDA0000390926790000012.png"\; state="\{\{state\}\}">U</figure-callout>}}_S\%U_N^2}{S_N}\end{array}\right.---\left(2\right)\end{array}$

(3) the excitation resistance R of calculating transformer _m, excitation reactance X _mand power loss Δ P _o+ j Δ Q _ofor:

$\left\{\begin{array}{c}{G}_T=\frac{{\mathrm{\&Delta;P}}_o}{U_N^2}\&DoubleRightArrow;R_m=\frac{1}{G_T}\\ B_T=\frac{I_o\%S_N}{U_N^2}\&DoubleRightArrow;X_m=\frac{1}{B_T}\end{array}\right.---\left(3\right)$ ${\mathrm{\&Delta;P}}_o+{\mathrm{j\&Delta;Q}}_o={\mathrm{\&Delta;P}}_o+j\frac{I_o\%}{100}{S}_N---\left(4\right)$

Wherein, U _nfor transformer rated voltage, S _nfor transformer rated capacity, Δ P' _s1-2, Δ P' _s1-3, Δ P' _s2-3for short circuit loss, U _s1-2%, U _s1-3%, U _s2-3% is impedance voltage percentage, Δ P _ofor no-load loss, I _o% is no-load current percentage.

2, under different running method, high-pressure side system short-circuit impedance X _swith the running status (apportion/paired running) of transformer, obtain each side voltage power-less coordination optimization impedance model collection of transformer station.

If medium voltage side MCR installed capacity is for being Q<sub TranNum="155">110kV</sub>with low-pressure side MSVC installed capacity be Q<sub TranNum="156">10kV</sub>, consider in transformer Type Equivalent Circuit Model that field excitation branch line impedance parameter is much larger than load branch, therefore omit field excitation branch line; In addition due to R<sub TranNum="157">n</sub><<X<sub TranNum="158">n</sub>so, resistance is also ignored.After simplifying, each side voltage power-less coordination optimization impedance model of transformer station is as formula 5, and its illustraton of model as shown in Figure 3.The idle input capacity of each side Δ in formula 5<sub TranNum="159">q</sub>cause voltage variety Δ<sub TranNum="160">u</sub>functional relation, can calculate the required reactive compensation capacity of regulation voltage.

$\left\{\begin{array}{c}{\mathrm{\&Delta;U}}_{220\mathrm{kV}}=-\frac{({\mathrm{\&Delta;Q}}_{110\mathrm{kV}}+{\mathrm{\&Delta;Q}}_{10\mathrm{kV}})X_S}{U_n}\\ {\mathrm{\&Delta;U}}_{110\mathrm{kV}}=-\frac{{\mathrm{\&Delta;Q}}_{110\mathrm{kV}}(X_S+X_1+X_2)+{\mathrm{\&Delta;Q}}_{10\mathrm{kV}}(X_S+X_1)}{U_n}\\ {\mathrm{\&Delta;U}}_{10\mathrm{kV}}=-\frac{{\mathrm{\&Delta;Q}}_{110\mathrm{kV}}(X_S+X_1)+{\mathrm{\&Delta;Q}}_{10\mathrm{kV}}(X_S+X_1+X_3)}{U_n}\end{array}\right.---\left(5\right)$

Wherein, X _sfor high-pressure side system short-circuit impedance, X ₁, X ₂, X ₃be respectively transformer senior middle school low-pressure side winding equivalent impedance, Δ U _220kV, Δ U _110kV, Δ U _10kVbe respectively transformer senior middle school low-pressure side voltage variety, Δ Q _110kV, Δ Q _10kVbe respectively the idle input capacity of mesolow side, U _nfor high-voltage side bus voltage.

3, according to electric power system, calculate and the simulation software that is correlated with, under known different running method, the short-circuit impedance ，Dui transformer station Coordination and Optimization Model of three sides is revised, and can better reflect practical operation situation.

Senior middle school's low-pressure side short-circuit impedance is X _sC220, X _sC110, X _sC10, by formula 6, can obtain system side impedance X _sC-S, the low-pressure side winding impedance X of senior middle school _sC-1, X _sC-2, X _sC-3.

$\left\{\begin{array}{c}{X}_{\mathrm{SC}220}\&DoubleRightArrow;X_{\mathrm{SC}-S}\\ X_{\mathrm{SC}110}\&DoubleRightArrow;X_{\mathrm{SC}-S}+X_{\mathrm{SC}-1}+X_{\mathrm{SC}-2}\\ X_{\mathrm{SC}10}\&DoubleRightArrow;X_{\mathrm{SC}-S}+X_{\mathrm{SC}-1}+X_{\mathrm{SC}-3}\end{array}\right.---\left(6\right)$

By short-circuit impedance, obtain coordination optimization impedance model figure based on each side short-circuit impedance of transformer station as shown in Figure 4, similar to the transformer station shown in Fig. 3 each side voltage power-less coordination optimization impedance model.Therefore, the different relations of voltage being adjusted according to the reactive power compensation under different running method, revise Coordination and Optimization Model, obtain revised Coordination and Optimization Model as shown in Equation 7.

$\left\{\begin{array}{c}{\mathrm{\&Delta;U}}_{220\mathrm{kV}}=-\frac{({\mathrm{\&Delta;Q}}_{110\mathrm{kV}}+{\mathrm{\&Delta;Q}}_{10\mathrm{kV}})X_S^{\&prime;}}{U_n}+\mathrm{\&alpha;}\\ {\mathrm{\&Delta;U}}_{110\mathrm{kV}}=-\frac{{\mathrm{\&Delta;Q}}_{110\mathrm{kV}}(X_S^{\&prime;}+X_1^{\&prime;}+X_2^{\&prime;})+{\mathrm{\&Delta;Q}}_{10\mathrm{kV}}(X_S^{\&prime;}+X_1^{\&prime;})}{U_n}+\mathrm{\&beta;}\\ {\mathrm{\&Delta;U}}_{10\mathrm{kV}}=-\frac{{\mathrm{\&Delta;Q}}_{110\mathrm{kV}}(X_S^{\&prime;}+X_1^{\&prime;})+{\mathrm{\&Delta;Q}}_{10\mathrm{kV}}(X_S^{\&prime;}+X_1^{\&prime;}+{\mathrm{<figure-callout\; id="3"\; label="X"\; filenames="HDA0000390926790000012.png"\; state="\{\{state\}\}">X</figure-callout>}}_3^{\&prime;})}{U_n}+\mathrm{\&gamma;}\end{array}\right.---\left(7\right)$

Wherein, X' _sfor high-pressure side system short-circuit impedance, X' ₁, X' ₂, X' ₃be respectively transformer senior middle school low-pressure side winding equivalent impedance.Constant term α, the β, the γ that increase can obtain when reality is debugged, and for proofreading and correct reactive voltage, regulate the fixed voltage deviation existing.

Repeat above-mentioned steps, can obtain a plurality of coordination optimization impedance models under different running method, composition model collection, is convenient to implement optimal control for operational mode.

As shown in Figure 5, coordination optimization control flow of the present invention comprises: parameter model typing, Real-Time Monitoring, coordination optimization and control flow.Crucial implementation step is as follows:

1) parameter model typing: typing main transformer parameter, reactive power compensator parameter and voltage power-less coordination optimization impedance model collection.According to main transformer tap gear switching information, transformer substation system and main transformer operational mode, the coordination optimization impedance model that real-time selection is corresponding.

2) Real-Time Monitoring: measure in real time the service data that main transformer three side bus, low-pressure side MSVC and middle pressure are surveyed MCR, optimize the input capacity that calculates main transformer tap gear, medium voltage side MCR and low-pressure side SVC.

3) coordination optimization and control: both sides reactive power compensator is adopted to two closed-loop controls, follow coordination optimization impedance model and come regulating and controlling both sides reactive power compensator to drop into capacity.

Take power factor as the optimization aim relation between required power factor and compensation capacity, with short time load active-power P, do not become prerequisite, the power-factor cos α before and after compensation and the relation between cos β and required reactive compensation capacity Δ Q are as shown in Equation 7.

$\mathrm{\&Delta;Q}=P[\sqrt{\frac{1}{{\left(\cos \mathrm{\&alpha;}\right)}^2}-1}-\sqrt{\frac{1}{{\left(\cos \mathrm{\&beta;}\right)}^2}-1}]---\left(7\right)$

Claims (4)

1. high pressure distribution transformer station many sides voltage power-less coordinating and optimizing control method, is characterized in that, comprises the steps:

(1) set up transformer station's Coordination and Optimization Model collection under different running method;

(2) calculate each side short-circuit impedance of the lower low-pressure side of different running method ，Dui transformer station Coordination and Optimization Model collection and revise, make more realistic running status, and by model typing tuning controller;

(3) according to main transformer tap gear switching information, transformer substation system and main transformer operational mode, select corresponding coordination optimization impedance model;

(4) measure in real time the service data of static passive compensation device MSVC and the controlled reactor MCR that middle pressure is surveyed of main transformer three side bus, low-pressure side, optimize the input capacity that calculates main transformer tap gear, the controlled reactor MCR of medium voltage side and the static passive compensation device SVC of low-pressure side;

(5) according to optimum results, regulate main transformer tap gear, both sides reactive power compensator is adopted to two closed-loop controls, follow the reactive power compensator of the outer shroud regulating and controlling both sides of coordination optimization impedance model, guaranteeing under the not out-of-limit prerequisite of medium voltage side parameter, low-pressure side static passive compensation device MSVC adopts from closed-loop control.

2. high pressure distribution according to claim 1 transformer station many sides voltage power-less coordinating and optimizing control method, is characterized in that, described impedance model collection comprises under all different running method, the running status of high-pressure side system short-circuit impedance and transformer.

3. high pressure distribution according to claim 2 transformer station many sides voltage power-less coordinating and optimizing control method, it is characterized in that, described transformer station Coordination and Optimization Model collection comprises: press nameplate calculation of parameter main transformer operation equivalent model, under different running method, the apportion of high-pressure side system short-circuit impedance and transformer, paired running state, obtain each side voltage power-less coordination optimization impedance model collection of transformer station under different running method.

4. high pressure distribution according to claim 1 transformer station many sides voltage power-less coordinating and optimizing control method, it is characterized in that, the model of described typing tuning controller comprises and utilizes power system simulation software, calculate each side short-circuit impedance of the lower low-pressure side of different running method, step (1) is set up to transformer station's Coordination and Optimization Model collection under different running method and revise, obtain each side voltage power-less coordination optimization impedance model of transformer station of more realistic running status.

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