CN102983576A - Single-phase equivalent circuit of power module for reactive compensation system - Google Patents

Abstract

The invention discloses a single-phase equivalent circuit for a power module of a reactive power compensation system, which is characterized in that the single-phase equivalent circuit includes a power supply, a single-phase transformer, and the original A main switch and an auxiliary switch that are connected to each other and form a loop, a reactor and a capacitor that are sequentially connected to the secondary side of the single-phase transformer and form a loop, wherein: the main switch and the primary side of the single-phase transformer The power supply is connected between them; the power supply is connected between the capacitor and the secondary side of the single-phase transformer. The invention enables the power module in the reactive power compensation system to be realized based on the single-phase equivalent circuit, thereby laying a foundation for further realizing the reactive power compensation system.

Description

A kind of one phase equivalent circuit of the power model for reactive compensation system

Technical field

The present invention relates to the reactive power compensation field, relate in particular to a kind of one phase equivalent circuit of the power model for reactive compensation system.

Background technology

The standard configuration reactive-load compensation equipment of present each transformer station, be the capacitor group switching mode that power factor controller adds contactor or capacitor control, and being frequent switching, the deficiency of this kind equipment maximum cause the life-span of capacitor not long, and can not accomplish continuous reactive power compensation, because of on-the-spot harmonic wave reason, the capacitor group also is easy to damage simultaneously.For this reason, the applicant is devoted to research and develop a kind of novel intelligent reactive power compensation system, and it can be according to the setting of the factor is lead to consumer's meritorous service, automatic power ratio control module, regulate continuously idle parameter, quick, high accuracy is carried out reactive power compensation, the power factor that the system that reaches is set.Therefore, the power model in the above-mentioned reactive power compensation system becomes for this reason that can system research and develop successful key.

But in view of never having corresponding equivalent electric circuit, research is absorbed in bottleneck.Therefore, provide as early as possible a kind of equivalent electric circuit of above-mentioned power model to become a problem demanding prompt solution.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art and a kind of one phase equivalent circuit of the power model for reactive compensation system is provided, so that the power model in the reactive compensation system is achieved according to this one phase equivalent circuit.

The technical scheme that realizes above-mentioned purpose is:

A kind of one phase equivalent circuit of the power model for reactive compensation system, described one phase equivalent circuit comprise a power supply, a single-phase transformer, respectively be connected with the former limit of this single-phase transformer and the main switch that consists of the loop with is connected auxiliary switch, be connected successively and consist of a reactor and an electric capacity in loop with the secondary of this single-phase transformer, wherein:

Be connected described power supply between the former limit of described main switch and described single-phase transformer;

Be connected described power supply between the secondary of described electric capacity and described single-phase transformer.

The one phase equivalent circuit of the above-mentioned power model that is used for reactive compensation system, wherein, the positive pole of described power supply connects respectively described main switch and described electric capacity, and negative pole connects respectively former limit and the secondary of described single-phase transformer.

The one phase equivalent circuit of the above-mentioned power model that is used for reactive compensation system, wherein, the voltage of described power supply is line voltage.

The invention has the beneficial effects as follows: the one phase equivalent circuit of the power model for reactive compensation system provided by the invention, so that the power model in the reactive compensation system is achieved according to this one phase equivalent circuit, thereby further for realizing that reactive compensation system lays the first stone.Simultaneously, the present invention also has simple in structure, the characteristics that are easy to realize.

Description of drawings

Fig. 1 is the circuit theory diagrams of the one phase equivalent circuit of the power model for reactive compensation system of the present invention.

Embodiment

The invention will be further described below in conjunction with accompanying drawing.

See also Fig. 1, the one phase equivalent circuit of the power model for reactive compensation system of the present invention, comprise power supply Ua, single-phase transformer T, be connected with the former limit of this single-phase transformer T respectively and the main switch S1 that consists of the loop is connected reactor Xt and the electric capacity Xc that is connected successively and consists of the loop with the secondary of this single-phase transformer T with auxiliary switch S4, wherein:

Be connected power supply Ua between the former limit of main switch S1 and single-phase transformer T;

Be connected power supply Ua between the secondary of electric capacity Xc and single-phase transformer T.

The positive pole of power supply Ua connects respectively main switch S1 and electric capacity Xc, and negative pole connects respectively former limit and the secondary of single-phase transformer T.

The voltage of power supply Ua is line voltage.

When main switch S1 opened, the voltage of power supply Ua was added in the former limit of single-phase transformer T by main switch S1, when auxiliary switch S4 opens, the former limit of single-phase transformer T and power supply Ua disconnect, its original edge voltage is 0, and this moment, the primary current of single-phase transformer T passed through auxiliary current, supposed w _s=2 π f _s, f _sBe switching frequency, D is duty ratio, 0≤D≤1, and t is the time, then switch function is:

$F(w_s,t)=D+\underset{n-1}{\overset{\∞}{\mathrm{\Σ}}}\frac{2\sin \left(\mathrm{nD\π}\right)}{\mathrm{n\π}}\cos n{w}_{s}t$

So suppose k _s=w _s/ w, w are angular speed, and then the original edge voltage of single-phase transformer T is:

$u_p=u_{a}F(w_s,t)=V_s\sin \mathrm{wtF}(w_s,t)={\mathrm{DV}}_s\sin \mathrm{wt}+\underset{n-1}{\overset{\∞}{\mathrm{\Σ}}}\frac{V_s\sin \left(\mathrm{nD\π}\right)}{\mathrm{n\π}}\sin (n{k}_s\±1)\mathrm{wt}$

Therefore regulate original edge voltage Up, then secondary voltage Us changes, and then regulates the voltage that is added on the electric capacity Xc, changes the electric current of electric capacity Xc, obtains continuous reactive power compensation amount, and the reactive power compensation amount of final reactive compensation system is:

$Q_c={(1-D)}^2\frac{V_s^2}{(X_{\mathrm{cf}}-X_{\mathrm{tf}})}$

Wherein: V _sBe the supply voltage of reactive compensation system, X _Cf=1/wc is that first-harmonic capacitive reactance and the c wherein of capacitor is capacitance, X _TfFirst-harmonic leakage reactance for transformer.

In sum, the one phase equivalent circuit of the power model for reactive compensation system provided by the invention, so that the power model in the reactive compensation system is achieved according to this one phase equivalent circuit, thereby further for realizing that reactive compensation system lays the first stone.

Above embodiment is only for explanation the present invention's, but not limitation of the present invention, person skilled in the relevant technique, in the situation that does not break away from the spirit and scope of the present invention, can also make various conversion or modification, therefore all technical schemes that are equal to also should belong to category of the present invention, should be limited by each claim.

Claims (3)

1. A single-phase equivalent circuit for a power module of a reactive power compensation system, characterized in that, said single-phase equivalent circuit comprises a power supply, a single-phase transformer, respectively connected to the primary side of the single-phase transformer A main switch and an auxiliary switch forming a loop, a reactor and a capacitor connected in turn to the secondary side of the single-phase transformer and forming a loop, wherein: The power supply is connected between the main switch and the primary side of the single-phase transformer; The power supply is connected between the capacitor and the secondary side of the single-phase transformer. 2. The single-phase equivalent circuit for a power module of a reactive power compensation system according to claim 1, wherein the positive poles of the power supply are respectively connected to the main switch and the capacitor, and the negative poles are respectively connected to the The primary and secondary sides of a single-phase transformer. 3. The single-phase equivalent circuit of a power module used in a reactive power compensation system according to claim 1 or 2, wherein the voltage of the power supply is grid voltage.

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