CN102709892B - Generalized element-based protection control method - Google Patents

Abstract

The invention provides a generalized element-based protection control method, which comprises the following steps of: dividing a power grid or a part of the power grid into a plurality of enclosed domains according to a topological structure of the power grid, wherein each enclosed domain is connected with the power grid through a plurality of loops of transmission lines; considering one enclosed domain as a generalized element; processing voltage and current information reflecting self state of each generalized element on site by each generalized element according to a unified time section, applying a processing result to an on-site generalized element grade production device and reporting the processing result to a power grid scheduling automation system; and judging whether each generalized element has a fault according to the processing result and a protection setting value of the generalized element, and carrying out protection control on each generalized element according to the failure criterion. The generalized element-based protection control method is an effective method for carrying out layered processing on information and promoting information processing aging in wide area protection of the power grid and is beneficial to popularization and application of a wide area protection technology.

Description

A kind of protection control method based on broad sense element

Technical field

The invention belongs to electric power network technique field, be specifically related to a kind of electrical network wide area protection control method.

Background technology

Along with the construction of intelligent grid, by specialized high-speed communication network, collect electrical network wide area state information, in wide scope, realize the protection and control of electrical network, in theory become possibility.But in reality, because electric network element quantity is very huge, Real-time Collection, process the magnanimity electric network state information of section unified time, and meet the timeliness requirement of electric network protection and control, have very large difficulty, thereby limited the application of wide area protection control.The present invention proposes the concept of a broad sense element, broad sense element is a closed area of electrical network, it can be a part for transformer station, whole transformer station, some transformer stations, a partial electric grid even, broad sense element includes a plurality of electric network elements, when carrying out the control of electrical network wide area protection, broad sense element is regarded as to a single electric network element, according to the voltage and current information of the connection line of broad sense element and external power grid, judge whether broad sense element exists the fault that affects external electrical network safety, if the fault of existence, can whole broad sense element be isolated away from electrical network by broad sense element protection device or automation system for the power network dispatching on the spot, realize the object of protection electrical network.The benefit of doing is like this, the information of broad sense element is processed on the spot owing to having carried out, and the amount of information of whole electrical network has been greatly reduced, and for realizing wide area protection, controls and won timeliness, had exploitativeness.

Protection control method based on broad sense element is a kind of backup protection scheme, will be later than the operate time of main protection in broad sense element its operate time, is a kind of standby measure of protecting under special circumstances power grid security.

Summary of the invention

In order to overcome the above-mentioned defect of prior art, the object of the invention is to propose a kind of electrical network wide area protection control method that can improve safe operation of electric network stability.

The present invention is achieved through the following technical solutions:

A protection control method based on broad sense element, the method comprises the steps:

Step 1, according to topological structure of electric, is divided into some closed domain by electrical network or its part, and each closed domain is connected with other closed domain or external electrical network by some back transmission lines;

Step 2, is considered as a broad sense element by each described closed domain, is about to all elements in each closed domain and is reduced to a single element and treats;

Step 3, according to section unified time, each broad sense element is the voltage and current information of processing reaction oneself state on the spot, and result is used for to broad sense component-level protective device on the spot, reports and submits to automation system for the power network dispatching simultaneously;

Step 4; described broad sense component-level protective device is or/and automation system for the power network dispatching; according to the state processing result of broad sense element and relevant protection definite value, judge whether broad sense element exists the fault that affects external electrical network, and complete the protection of broad sense element is controlled according to failure criterion.

Further, in described step 1, the principle that electrical network or its part is divided into some closed domain is:

(1) closed domain can Shi Yige transformer station a part, or Yi Ge transformer station, or a partial electric grid, at least comprise an electric network element in each closed domain;

(2) to take automation system for the power network dispatching be principle to the balance between electric network influencing when the processing timeliness of the whole network information and closed domain are isolated to the size of closed domain.

Further, in described closed domain, can comprise power supply.

Further, in described step 3, each the broad sense element on the spot concrete grammar of the voltage and current information of processing reaction oneself state is:

Suppose that alternating current circuit, m that a certain broad sense element has k to return to move return the DC line of moving and be connected with external power grid, there is n power supply (containing energy storage) inside, to, according to section unified time, gather the voltage and current of described circuit and power supply, and be handled as follows:

When m=0, (without DC line, be connected with external power grid), by the electric current of each alternating current circuit of separate calculating and power supply and:

$I_{\mathrm{AS}}=|\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{\stackrel{\·}{I}}_{\mathrm{Ai}}-\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\·}{I}}_{S.\mathrm{Aj}}|,$ $I_{\mathrm{BS}}=|\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{\stackrel{\·}{I}}_{\mathrm{Bi}}-\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\·}{I}}_{S.\mathrm{Bj}}|,$ $I_{\mathrm{CS}}=|\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{\stackrel{\·}{I}}_{\mathrm{Ci}}-\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\·}{I}}_{S.\mathrm{Cj}}|$

In formula,

be respectively the backcross current value of Flow Line A, B, C phase of i, i=1 ~ k;

be the current value of j power supply A, B, C phase, j=1 ~ n; Described each electric current all wants reduction to same electric pressure.

Further, in described step 4, the failure criterion of broad sense element comprises:

A) when m=0, be without DC line and be connected with external power grid, the failure criterion of broad sense element can comprise: criterion 1:Max (I _aS, I _bS, I _cS)>=I _set, i.e. I _aS, I _bS, I _cSmiddle the maximum meets or exceeds set point I _set;

Criterion 2:

Criterion 3:

B) when m ≠ 0, there is DC line to be connected with external power grid, the failure criterion of broad sense element can comprise:

Criterion 2:

Criterion 3:

In above formula, I _set, I _i.set, U _i.setbe protection set point,

electric current and voltage in the i bar circuit being connected with external electrical network for broad sense element, i=1～M, is measured by comprehensive automation system of transformer substation.

Further, in the criterion 2 in described two kinds of situations and criterion 3, can further dispose direction component, as dispose direction component, when criterion 2 or criterion 3 establishments and fault direction sensing broad sense element, just be identified as broad sense element fault; As do not configure direction component, and only, when criterion 2 or criterion 3 establishment, represent that broad sense element may exist fault, now, increase protection operation time limit.

Beneficial effect of the present invention is:

The present invention is by being divided into some closed domain by electrical network or its part; and each closed domain is defined as to broad sense element; by the relevant voltage of broad sense element, electric current are judged according to certain rule; can fast and effeciently screen this broad sense element and whether have the internal fault that affects external electrical network; if any; isolate whole broad sense element, thereby reach the object of protection electrical network, raising electric power netting safe running level.Because information is processed by layering, increased the exploitativeness of wide area protection.

Accompanying drawing explanation

Fig. 1 is broad sense element schematic diagram of the present invention;

Fig. 2 is the workflow diagram that the present invention is based on the protection control method embodiment of broad sense element.

Embodiment

Below in conjunction with accompanying drawing, the protection control method based on broad sense element of the present invention is further described in detail.

As shown in Figure 2, the protection control method based on broad sense element in this example, comprises the steps:

Step 1, according to topological structure of electric, is divided into some closed domain by electrical network or its part, and as shown in Figure 1, each closed domain at least comprises an electric network element, and is connected with external electrical network by some feedback electric wires;

The principle that electrical network is divided into some closed domain is:

(1) part or all that closed domain can Shi Yige transformer station, can be also even regional power grids of several transformer stations, in closed domain, can have power supply;

(2) should to take automation system for the power network dispatching be principle to the balance between whole electric network influencing when the processing timeliness of the whole network information and closed domain are isolated to the size of closed domain.

Step 2, is considered as a broad sense element by each described closed domain, the visual angle of controlling from electrical network wide area protection, described broad sense element is looked as a whole, as treated the common components of electrical network;

Step 3, first according to section unified time, each broad sense element is the information such as voltage, electric current of processing reaction oneself state on the spot, and concrete steps are:

Suppose that alternating current circuit, m that a certain broad sense element has k to return to move return the DC line of moving and be connected with external power grid, there is n power supply (containing energy storage) inside, to, according to section unified time, gather the voltage and current of described circuit and power supply, and be handled as follows:

When m=0, (without DC line, be connected with external power grid), calculate the separate electric current in each alternating current circuit and:

$I_{\mathrm{AS}}=|\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{\stackrel{\·}{I}}_{\mathrm{Ai}}-\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\·}{I}}_{S.\mathrm{Aj}}|,$ $I_{\mathrm{BS}}=|\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{\stackrel{\·}{I}}_{\mathrm{Bi}}-\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\·}{I}}_{S.\mathrm{Bj}}|,$ $I_{\mathrm{CS}}=|\underset{i=1}{\overset{k}{\mathrm{\Σ}}}{\stackrel{\·}{I}}_{\mathrm{Ci}}-\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\·}{I}}_{S.\mathrm{Cj}}|$

In formula,

be the backcross electric current of Flow Line A, B, C phase of i, i=1 ~ k; be the electric current of j power supply A, B, C phase, j=1 ~ n; Above-mentioned each voltage and current data are that the complex automatic system by transformer station measures; Described each electric current all wants reduction to same electric pressure (Reduction can with reference to < < power system fault analysis method > >, Liu Wanshun, electric power publishing house);

Then; by result, for broad sense component-level protective device on the spot, this protective device is being controlled all circuit breakers with external power grid interconnector of broad sense element, during protection action; can disconnect these circuit breakers simultaneously, and result is reported and submitted to automation system for the power network dispatching.

Step 4, broad sense component-level protective device or/with automation system for the power network dispatching, according to state analysis result and the set point of broad sense element, judge whether broad sense element exists fault, and complete the protection of broad sense element is controlled according to failure criterion;

The failure criterion of broad sense element is as follows:

A) when m=0, (without DC line, be connected with external power grid), when meeting following any one criterion, be all considered as broad sense element and break down, broad sense element protection device action:

Criterion 1:Max (I _aS, I _bS, I _cS)>=I _set(1)

Criterion 2: $1-\underset{i=1}{\overset{M}{\mathrm{\&Pi;}}}(1-L_{I.i})=1---\left(2\right)$

Criterion 3: $1-\underset{i=1}{\overset{M}{\mathrm{\&Pi;}}}(1-L_{U.i})=1---\left(3\right)$

In formula (1), I _setfor protection set point;

In formula (2), formula (3),

i _i.setand U _i.setbe protection set point;

for electric current and the magnitude of voltage of broad sense element and external power grid interconnector (dividing separate), by comprehensive automation system of transformer substation, measured; I=1～M, M=3 * (k+n);

B) when m ≠ 0, (there is DC line to be connected with external power grid), when meeting following any one criterion, be all considered as broad sense element and break down:

Criterion 2: $1-\underset{i=1}{\overset{M}{\mathrm{\&Pi;}}}(1-L_{I.i})=1$

Criterion 3: $1-\underset{i=1}{\overset{M}{\mathrm{\&Pi;}}}(1-L_{U.i})=1$

Now, M=3 * (k+n)+2 * m, other cotype (2) and formula (3).

In above-mentioned A, two kinds of situations of B, in criterion 2 and criterion 3, can coordinate direction component application, if any direction component, only when criterion 2 or criterion 3 are set up, and fault direction is while pointing to broad sense element, is just identified as broad sense element fault; As directionless element, criterion 2 or criterion 3 are set up, and represent that broad sense element may exist fault, but should suitably increase protection operation time limit.

Finally should be noted that: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit; in conjunction with above-described embodiment, the present invention is had been described in detail; those of ordinary skill in the field are to be understood that: those skilled in the art still can modify or be equal to replacement the specific embodiment of the present invention, but among the claim protection range that these modifications or change are all awaited the reply in application.

Claims (4)

1. the protection control method based on broad sense element, is characterized in that, the method comprises the steps:

Step 1, according to topological structure of electric, is divided into some closed domain by electrical network or its part, and each closed domain is connected with other closed domain or external electrical network by some back transmission lines;

Step 2, is considered as a broad sense element by each described closed domain, is about to each closed domain and is used as a single element and protects control;

Step 3, according to section unified time, each broad sense element is the voltage and current information of processing reaction oneself state on the spot, and result is used for to broad sense component-level protective device on the spot, reports and submits to automation system for the power network dispatching simultaneously;

Step 4, described broad sense component-level protective device is or/and automation system for the power network dispatching, according to the state processing result of broad sense element and relevant protection set point, judge whether broad sense element exists the fault that affects external electrical network, and complete the protection of broad sense element is controlled according to failure criterion;

In described step 3, each the broad sense element on the spot concrete grammar of the voltage and current information of processing reaction oneself state is:

Suppose that alternating current circuit, m that a certain broad sense element has k to return to move return the DC line of moving and be connected with external power grid, there is n power supply inside,, according to section unified time, gather the voltage and current of described circuit and power supply, and be handled as follows:

When m=0, without DC line, be connected with external power grid, by the electric current of each alternating current circuit of separate calculating and power supply and:

$I_{\mathrm{AS}}=|\underset{i=1}{\overset{k}{\mathrm{\&Sigma;}}}{\stackrel{\&CenterDot;}{I}}_{\mathrm{Ai}}-\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{\stackrel{\&CenterDot;}{I}}_{S.\mathrm{Aj}}|,I_{\mathrm{BS}}=|\underset{i=1}{\overset{k}{\mathrm{\&Sigma;}}}{\stackrel{\&CenterDot;}{I}}_{\mathrm{Bi}}-\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{\stackrel{\&CenterDot;}{I}}_{S.\mathrm{Bj}}|,I_{\mathrm{CS}}=|\underset{i=1}{\overset{k}{\mathrm{\&Sigma;}}}{\stackrel{\&CenterDot;}{I}}_{\mathrm{Ci}}-\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{\stackrel{\&CenterDot;}{I}}_{S.\mathrm{Cj}}|$

In formula, represent the backcross current value of Flow Line A, B, C phase of i, i=1～k;

be the current value of j power supply A, B, C phase, j=1～n; Described each electric current all wants reduction to same electric pressure;

In described step 4, the failure criterion of broad sense element comprises:

A) when m=0, be without DC line and be connected with external power grid, when meeting following any one criterion, be all considered as broad sense element and break down, the failure criterion of broad sense element comprises:

Criterion 1:Max (I _aS, I _bS, I _cS)>=I _set, i.e. I _aS, I _bS, I _cSmiddle the maximum meets or exceeds set point I _set;

Criterion 2:

Criterion 3:

B) when m ≠ 0, there is DC line to be connected with external power grid, when meeting following any one criterion, be all considered as broad sense element and break down, the failure criterion of broad sense element comprises:

Criterion 2:

Criterion 3:

In above formula, I _set, I _i.set, U _i.setbe protection set point, electric current and voltage in the i bar circuit being connected with external electrical network for broad sense element, i=1～M.

2. the method for claim 1, is characterized in that, in described step 1, the principle that electrical network or its part is divided into some closed domain is:

A part for (1) closed domain Shi Yige transformer station, or Yi Ge transformer station, or a partial electric grid, at least comprise an electric network element in each closed domain;

(2) should to take automation system for the power network dispatching be principle to the balance between electric network influencing when the processing timeliness of the whole network real time information and closed domain are isolated to the size of closed domain.

3. method as claimed in claim 2, is characterized in that, in described closed domain, comprises power supply.

4. the method for claim 1, it is characterized in that, in the criterion 2 in described A, two kinds of situations of B and criterion 3, can further configure direction component, as dispose direction component, when criterion 2 or criterion 3 establishments and fault direction sensing broad sense element, be just identified as broad sense element fault; As do not configure direction component, and only, when criterion 2 or criterion 3 establishment, represent that broad sense element may exist fault, now, increase protection operation time limit.

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