CN104078989B - A kind of reactive power generator device and without communication parallel method - Google Patents

Abstract

The invention discloses a kind of reactive power generator device and without communication parallel method, belong to electric and electronic technical field.Reactive power generator device, comprising: CT, balance resistance and STATCOM; CT and STATCOM is connected in parallel in electrical network respectively, and the former limit windings in series of CT is in electrical network, and vice-side winding adopts the mode of n bar branch circuit parallel connection, 2 & lt; N & lt; 20; Each branch road is all by connecting STATCOM after wired in series balance resistance; Comprising without communication parallel method of reactive power generator: 1) opening is installed CT former limit winding; 2) n bar branch circuit parallel connection CT vice-side winding; 3) calculated equilibrium series impedance; 4) balance resistance of connecting enters each branch road, and connects each STATCOM; 5) n platform STATCOM in parallel.This device separate unit STATCOM equipment break down exit electrical network time, other equipment still can accurate compensation system reactive power; And by connecting balance resistance between CT with each STATCOM, the transmission between signal can not only be carried out, and the electric current that each STATCOM can be made to divide is impartial.

Description

A kind of reactive power generator device and without communication parallel method

Technical field

The present invention relates to electric and electronic technical field, particularly relate to a kind of reactive power generator device and without communication parallel method.

Background technology

In electrical network, the electrical power of power supply supply load has two kinds: one is active power, and another kind is reactive power (reactivepower).Active power keeps power consumption equipment normally to run required electrical power, namely converts electrical energy into other forms of energy, as electric energy is changed into mechanical energy, luminous energy, heat energy.Reactive power is the exchange for circuit internal electric field and magnetic field, and is used for setting up in the electrical apparatus and maintain the electrical power in magnetic field.It is externally work done not, but changes other forms of energy into.

From the reactive power that generator and high voltage transmission line supply, can not meet the needs of load far away, so will arrange some reactive power compensators to carry out supplementary reactive power in electrical network, to ensure the needs of user to reactive power, such power consumption equipment could work under rated voltage.

Reactive power generator (StaticSynchronousCompensator, be called for short STATCOM, also known as SVG) be a kind of FACTS device of parallel connection type reactive power compensation, it can send or absorbing reactive power, and its output can change the special parameter that controls in electric power system; STATCOM is parallel in electrical network, and be equivalent to a controlled reactive current source, its reactive current can be followed the change of reactive load electric current rapidly and change, reactive power needed for auto-compensation network system, realizes dynamic passive compensation to power system reactive power.

In prior art, Current Transmit and STATCOM are directly parallel in network system, the reactive power needed for network system is compensated by STATCOM.The function of CT is used to measure the reactive current needed for user, CT directly measures current signal and passes to STATCOM from electrical network, usual employing n platform STATCOM parallel running, wherein a STATCOM is as main frame, other STATCOM are as from machine, after STATCOM main frame collects current signal, the reactive current value needed for user is calculated by a series of process, then by reactive current value divided by n, be converted into referenced reactive current, uniform distribution gives each STATCOM from machine, thus n/mono-of every platform STATCOM compensation network reactive current, complete the compensation of reactive power, such operation not only needs STATCOM main frame and each STATCOM to communicate with one another between machine, but also will arrange the number of units of STATCOM in parallel.

The direct parallel running of STATCOM there will be each the unequal problem of STATCOM output current, even damages power supply and transmission facility.

Summary of the invention

Need the problem of communication and each STATCOM CURRENT DISTRIBUTION inequality for each STATCOM parallel running in prior art each other, the invention provides a kind of reactive power generator device and without communication parallel method.

The invention provides a kind of reactive power generator device, comprising: Current Transmit, balance resistance and reactive power generator STATCOM;

CT and STATCOM is connected in parallel in electrical network respectively, and the former limit windings in series of CT is in electrical network, and vice-side winding adopts the mode of n bar branch circuit parallel connection, 2<n<20; Each branch road is all by connecting STATCOM after wired in series balance resistance;

Concrete connection procedure is as follows: CT is divided into former limit winding and vice-side winding, and former limit windings in series is in electrical network, and vice-side winding adopts the mode of n bar branch circuit parallel connection, and each branch road is all connected after 1 balance resistance and connected STATCOM; Specifically, each branch road of CT vice-side winding is all by being connected with the former limit of the Hall current sensor of STATCOM inside after series connection balance resistance; STATCOM inside comprises Hall current sensor, AD converter and CPU; Hall current sensor collection after detecting the current signal on CT vice-side winding, send AD converter to, the current signal recorded is changed into digital current signal by AD converter, and the digital current signal of gained is through CPU process and calculate, and obtains the output current of STATCOM; After CT records current signal from electrical network, branch road through the parallel connection of n bar passes to n platform STATCOM respectively, every platform STATCOM collects n/mono-that CT exports total current, can obtain n/mono-of electric network reactive-load electric current, and compensate as the reactive power of referenced reactive current to electrical network.

The account form of balance resistance is as follows:

(1) calculate when the connection conductive line resistance values of branch road is minimum, the lowest high-current value of STATCOM;

$I_{\max }=\frac{U}{{\mathrm{RL}}_{\min }+R}$

U is CT output voltage; RL _minfor the connection conductive line resistance values minimum value of branch road, R is balance resistance value; I _maxfor the lowest high-current value of STATCOM;

(2) calculate when the connection conductive line resistance values of branch road is maximum, the minimum current value of STATCOM;

$I_{\min }=\frac{U}{{\mathrm{RL}}_{\max }+R}$

RL _maxfor the connection conductive line resistance values maximum of branch road; I _minfor the minimum current value of STATCOM;

(3) two current error rates are calculated;

$\mathrm{\&Delta;I}=\frac{I_{\max }-I_{\min }}{I_{\min }}$

(4) meet current error rate and be less than maximum current error rate;

ΔI≤ΔI _max

(5) resistance of series connection balance resistance is calculated:

$R\&GreaterEqual;\frac{{\mathrm{RL}}_{\max }-{\mathrm{RL}}_{\min }}{{\mathrm{\&Delta;I}}_{\max }}-{\mathrm{RL}}_{\min }$

By balance resistance of connecting between CT with each STATCOM, the transmission between signal can not only be carried out, and the electric current that each STATCOM can be made to divide is impartial.

A kind of reactive power generator of the present invention is without communication parallel method; Implementation step is specially:

Step one, former for open C T limit winding to be contained on electrical network.

Step 2, CT vice-side winding is adopted the mode of n bar branch circuit parallel connection;

Step 3, calculate in each branch road the value of balance resistance of connecting; Computational process is as follows:

(1) calculate when the connection conductive line resistance values of branch road is minimum, the lowest high-current value of STATCOM;

$I_{\max }=\frac{U}{{\mathrm{RL}}_{\min }+R}$

U is CT output voltage; RL _minfor the connection conductive line resistance values minimum value of branch road, R is balance resistance value; I _maxfor the lowest high-current value of STATCOM;

(2) calculate when the connection conductive line resistance values of branch road is maximum, the minimum current value of STATCOM;

$I_{\min }=\frac{U}{{\mathrm{RL}}_{\max }+R}$

RL _maxfor the connection conductive line resistance values maximum of branch road; I _minfor the minimum current value of STATCOM;

(3) two current error rates are calculated;

$\mathrm{\&Delta;I}=\frac{I_{\max }-I_{\min }}{I_{\min }}$

(4) meet current error rate and be less than maximum current error rate;

ΔI≤ΔI _max

(5) resistance of calculated equilibrium resistance:

$R\&GreaterEqual;\frac{{\mathrm{RL}}_{\max }-{\mathrm{RL}}_{\min }}{{\mathrm{\&Delta;I}}_{\max }}-{\mathrm{RL}}_{\min }$

Step 4, balance resistance to be connected into each branch road, and connect each STATCOM.

Step 5, links n platform STATCOM on electrical network.

After CT measures current signal from electrical network, uniform distribution is to n bar branch road; After balance resistance, n platform STATCOM can collect impartial current value, completes the compensation of reactive power; When network system needs to increase STATCOM, a CT secondary circuit can be increased newly, after series connection balance resistance, be connected into STATCOM module.

The invention has the advantages that:

(1) a kind of reactive power generator provided by the invention is without communication parallel method, without the need to communication between STATCOM in parallel, facilitates unified allocation of resources.

(2) a kind of reactive power generator of the present invention is without communication parallel method, during newly-increased STATCOM in parallel, without the need to carrying out optimum configurations or other changes to the STATCOM equipment installed.

(3) a kind of reactive power generator of the present invention is without communication parallel method, under the prerequisite not increasing Software for Design and hardware device, realizes torque equilibrium between STATCOM in parallel.

(4) a kind of reactive power generator device provided by the invention, separate unit STATCOM equipment breaks down and exits the normal operation that electrical network does not affect other STATCOM equipment.

(5) a kind of reactive power generator device provided by the invention, when separate unit STATCOM equipment breaks down and exits electrical network, other equipment still can accurate compensation system reactive power.

(6) a kind of reactive power generator provided by the invention is without communication parallel method, only need a set of CT can realize multiple stage STATCOM without communication parallel method.

Accompanying drawing explanation

Fig. 1 is the schematic diagram that a kind of reactive power generator device of the present invention is connected in electrical network;

Fig. 2 is the structural representation of a kind of reactive power generator device of the present invention;

Fig. 3 is the structural representation of reactive power generator STATCOM of the present invention;

Fig. 4 is the schematic flow sheet of a kind of reactive power generator of the present invention without communication parallel method.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described in further detail.Described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on embodiments of the invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to protection scope of the present invention.

A kind of reactive power generator device of the present invention, specifically comprises: 1 Current Transmit, 20 balance resistances and 20 STATCOM; As shown in Figure 1: CT and 20 STATCOM is all connected in parallel in electrical network, the former limit windings in series of CT is in electrical network, and CT vice-side winding adopts the mode of 20 branch circuit parallel connections, and each branch road is all connected with a STATCOM, carries out the measurement of current signal;

CT records the mode uniform distribution by 20 branch circuit parallel connections after current signal from electrical network, passes to 20 STATCOM respectively; The wire length of each branch road is different, or the difference of wire itself, the electric current that on each outlet line, STATCOM gathers can be caused different, the current unevenness of each branch road STATCOM, the reactive power compensation capacity of each STATCOM can be caused uneven, so in the loop of CT and 20 STATCOM, each branch road is all connected after 1 balance resistance and is connected STATCOM;

Concrete connection procedure is as follows: as shown in Figure 2: CT is divided into former limit winding and vice-side winding, the former limit windings in series of CT is in electrical network, vice-side winding adopts the mode of 20 branch circuit parallel connections, each branch road of CT vice-side winding all adopts wire to pass through balance resistance of connecting, then be connected with the former limit of the Hall current sensor of STATCOM inside, as shown in Figure 3, STATCOM inside comprises Hall current sensor, AD converter and CPU; Hall current sensor collection after detecting the current signal on CT vice-side winding, send AD converter to, AD converter passes to CPU after the current signal recorded is changed into digital current signal, and CPU is to digital current signal transacting and calculate, and obtains the output current of STATCOM;

The computational methods of balance resistance are as follows: be 20 Μ Ω with conductive line resistance values RL, and error ± 20% is example

(1) calculate when the connection conductive line resistance values of branch road is minimum, the lowest high-current value of STATCOM;

$I_{\max }=\frac{U}{{\mathrm{RL}}_{\min }+R}---\left(1\right)$

U is CT output voltage; RL _minfor the connection conductive line resistance values minimum value of branch road, R is balance resistance value; I _maxfor the lowest high-current value of STATCOM; RL is chosen in the present embodiment _minvalue is 16 Μ Ω;

(2) calculate when the connection conductive line resistance values of branch road is maximum, the minimum current value of STATCOM;

$I_{\min }=\frac{U}{{\mathrm{RL}}_{\max }+R}---\left(2\right)$

RL _maxfor the connection conductive line resistance values maximum of branch road; I _minfor the minimum current value of STATCOM; RL is chosen in the present embodiment _maxbe 24 Μ Ω;

(3) two current error rates are calculated;

(4) meet current error rate and be less than maximum current error rate;

ΔI≤ΔI _max(4)

Maximum current error rate Δ I _maxpreferably 5%;

(5) resistance of calculated equilibrium resistance:

$R\&GreaterEqual;\frac{{\mathrm{RL}}_{\max }-{\mathrm{RL}}_{\min }}{{\mathrm{\&Delta;I}}_{\max }}-{\mathrm{RL}}_{\min }---\left(5\right)$

R=144 Μ Ω in the present embodiment; Preferred R=150 Μ Ω.

After CT records current signal from electrical network, 20 STATCOM are passed to respectively through 20 of CT vice-side winding branch roads in parallel, the electric current that shunting due to balance resistance makes each STATCOM divide is impartial, every platform STATCOM can be made to collect 1/20th of CT output total current, namely obtain 1/20th of electric network reactive-load electric current, and compensate as the reactive power of referenced reactive current to electrical network.

As shown in Figure 4, a kind of reactive power generator of the present invention is without communication parallel method; Implementation step is specially:

Step one, former for open C T limit winding to be contained on electrical network.

Step 2, CT vice-side winding is adopted the mode of 20 branch circuit parallel connections;

Step 3, calculate the value of balance resistance in each branch road; Computational process is as follows:

(1) calculate when the connection conductive line resistance values of branch road is minimum, the lowest high-current value of STATCOM;

$I_{\max }=\frac{U}{{\mathrm{RL}}_{\min }+R}---\left(1\right)$

U is CT output voltage; RL _minfor the connection conductive line resistance values minimum value of branch road, R is balance resistance value; I _maxfor the lowest high-current value of STATCOM;

(2) calculate when the connection conductive line resistance values of branch road is maximum, the minimum current value of STATCOM;

$I_{\min }=\frac{U}{{\mathrm{RL}}_{\max }+R}---\left(2\right)$

RL _maxfor the connection conductive line resistance values maximum of branch road; I _minfor the minimum current value of STATCOM;

(3) two current error rates are calculated;

$\begin{array}{c}\mathrm{\&Delta;I}=\frac{I_{\max }-I_{\min }}{I_{\min }}\\ =\frac{{\mathrm{RL}}_{\max }-{\mathrm{RL}}_{\min }}{{\mathrm{RL}}_{\min }+R}\end{array}---\left(3\right)$

(4) meet current error rate and be less than maximum current error rate;

ΔI≤ΔI _max(4)

(5) resistance of calculated equilibrium resistance:

$R\&GreaterEqual;\frac{{\mathrm{RL}}_{\max }-{\mathrm{RL}}_{\min }}{{\mathrm{\&Delta;I}}_{\max }}-{\mathrm{RL}}_{\min }---\left(5\right)$

Step 4, balance resistance to be connected into each branch road, and connect each STATCOM.

20 STATCOM are linked on electrical network by step 5.

After CT measures current signal from electrical network, 20 branch roads are given in uniform distribution; After balance resistance, 20 STATCOM can collect impartial current value; Complete the compensation of reactive power; As new access STATCOM, a newly-increased CT secondary circuit, is connected into STATCOM module after series connection balance resistance.

The present invention devises a kind of STATCOM parallel method without the need to communication, when needing to expand STATCOM capacity, directly increases STATCOM number of devices, without the need to arranging mounted equipment or change.

Claims (3)

1. a reactive power generator device, is characterized in that: comprise CT, balance resistance and STATCOM;

CT and STATCOM is connected in parallel in electrical network respectively, and CT is divided into former limit winding and vice-side winding, and the former limit windings in series of CT is in electrical network, and vice-side winding adopts the mode of n bar branch circuit parallel connection, 2<n<20; Each branch road of the vice-side winding of CT is all by being connected with the former limit of the Hall current sensor of STATCOM inside after series connection balance resistance; Be specially: each branch road of the vice-side winding of CT is all connected after 1 balance resistance, connects the former limit of the Hall current sensor of STATCOM inside; Hall current sensor collection after detecting the current signal on CT vice-side winding, send STATCOM internal A/D converter to, the current signal recorded is changed into digital current signal by AD converter, the digital current signal of gained is through the process of STATCOM innernal CPU and calculate, and obtains the output current of STATCOM; After CT records current signal from electrical network, branch road through the parallel connection of n bar passes to n platform STATCOM respectively, every platform STATCOM collects n/mono-that CT exports total current, namely obtains n/mono-of electric network reactive-load electric current, and compensates as the reactive power of referenced reactive current to electrical network;

The account form of balance resistance is as follows:

(1) calculate when the connection conductive line resistance values of branch road is minimum, the lowest high-current value of STATCOM;

$I_{max}=\frac{U}{{\mathrm{RL}}_{\min }+R}$

U is CT output voltage; RL _minfor the connection conductive line resistance values minimum value of branch road, R is balance resistance value; I _maxfor the lowest high-current value of STATCOM;

(2) calculate when the connection conductive line resistance values of branch road is maximum, the minimum current value of STATCOM;

$I_{min}=\frac{U}{{\mathrm{RL}}_{max}+R}$

RL _maxfor the connection conductive line resistance values maximum of branch road; I _minfor the minimum current value of STATCOM;

(3) two current error rates are calculated;

$\mathrm{\&Delta;}I=\frac{I_{max}-I_{\min }}{I_{min}}$

(4) meet current error rate and be less than maximum current error rate;

ΔI≤ΔI _max

(5) resistance of series connection balance resistance is calculated:

$R\&GreaterEqual;\frac{{\mathrm{RL}}_{max}-{\mathrm{RL}}_{min}}{{\mathrm{\&Delta;I}}_{max}}-{\mathrm{RL}}_{\min }.$

2. the reactive power generator being applied to reactive power generator device according to claim 1, without communication parallel method, is characterized in that:

Specifically comprise the following steps:

Step one, former for open C T limit winding is contained on electrical network;

Step 2, CT vice-side winding is adopted the mode of n bar branch circuit parallel connection;

Step 3, calculate in each branch road the value of balance resistance of connecting; Computational process is as follows:

(1) calculate when the connection conductive line resistance values of branch road is minimum, the lowest high-current value of STATCOM;

$I_{max}=\frac{U}{{\mathrm{RL}}_{min}+R}$

U is CT output voltage; RL _minfor the connection conductive line resistance values minimum value of branch road, R is balance resistance value; I _maxfor the lowest high-current value of STATCOM;

(2) calculate when the connection conductive line resistance values of branch road is maximum, the minimum current value of STATCOM;

$I_{min}=\frac{U}{{\mathrm{RL}}_{max}+R}$

RL _maxfor the connection conductive line resistance values maximum of branch road; Imin is the minimum current value of STATCOM;

(3) two current error rates are calculated;

$\mathrm{\&Delta;}I=\frac{I_{max}-I_{min}}{I_{min}}$

(4) meet current error rate and be less than maximum current error rate;

ΔI≤ΔI _max

(5) resistance of series connection balance resistance is calculated:

$R\&GreaterEqual;\frac{{\mathrm{RL}}_{max}-{\mathrm{RL}}_{min}}{{\mathrm{\&Delta;I}}_{max}}-{\mathrm{RL}}_{\min }$

Step 4, balance resistance to be connected into each branch road, and connect each STATCOM;

Step 5, links n platform STATCOM on electrical network.

3. reactive power generator as claimed in claim 2 is without communication parallel method, it is characterized in that: when network system needs to increase STATCOM, can increase a CT secondary circuit newly, be connected into STATCOM module after series connection balance resistance.