CN102709892A - 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 the broad sense element

Technical field

The invention belongs to the 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, through the specialized high-speed communication network, compile electrical network wide area state information, in wide scope, realize the protection and the control of electrical network, become possibility in theory.But in the reality, because electric network element quantity is very huge, gather in real time, handle the magnanimity electric network state information of section unified time, and satisfy the timeliness requirement of electric network protection and control, very big difficulty is arranged, thereby limited the application of wide area protection control.The present invention proposes the notion of a broad sense element; The broad sense element is a closed area of electrical network; Can be the part of transformer station, whole transformer station, some transformer stations even a partial electric grid, the broad sense element includes a plurality of electric network elements, when carrying out the control of electrical network wide area protection; Regard the broad sense element as 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 the fault that whether the broad sense element exists influences external electrical network safety, if there is fault; Can from electrical network, isolate away whole broad sense element by on the spot broad sense element protection device or automation system for the power network dispatching, realize the purpose of protection electrical network.The benefit of doing like this is that the information of broad sense element is owing to carried out handling on the spot, and the amount of information of whole electrical network has been greatly reduced, and has won timeliness for realizing wide area protection control, and exploitativeness has been arranged.

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

Summary of the invention

In order to overcome the above-mentioned defective of prior art, the objective 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 realizes through following technical scheme:

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

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

Step 2 is regarded as a broad sense element with described each closed domain, is about to all elements in each closed domain and is reduced to a unitary 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 broad sense component-level protective device on the spot, reports and submits simultaneously to automation system for the power network dispatching;

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

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

(1) closed domain can be the part of a transformer station, or a transformer station, or a partial electric grid, comprises an electric network element in each closed domain at least;

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

Further, can comprise power supply in the said closed domain.

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

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

When m=0 (not having DC line is connected with external power grid), by the electric current of each alternating current circuit of separate calculating and power supply with:

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

In the formula;

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

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

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

A) when m=0, be no 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, promptly have DC line to be connected with external power grid, the failure criterion of broad sense element can comprise:

Criterion 2:

Criterion 3:

In the following formula, I _Set, I _I.set, U _I.setBe the protection set point,

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

Further, can further dispose direction component in criterion 2 under said two kinds of situation and the criterion 3, as dispose direction component, when criterion 2 or criterion 3 establishments and fault direction sensing broad sense element, just be identified as the broad sense element fault; As do not dispose direction component, and only when criterion 2 or criterion 3 establishments, represent that promptly possibly there is fault in the broad sense element, at this moment, increase the protection operation time limit.

Beneficial effect of the present invention is:

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

Description of drawings

Fig. 1 is a broad sense element sketch map 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 the broad sense element of the present invention is done further detailed explanation.

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

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

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

(1) closed domain can be a part of or whole of a transformer station, also can be several transformer stations even a regional power grid, in the closed domain power supply can be arranged;

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

Step 2 is regarded as a broad sense element with described each closed domain, and is promptly from the visual angle of electrical network wide area protection control, that said broad sense element is as a whole, general as the common components of treating electrical network;

Step 3, earlier 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 that is moving and be connected with external power grid; There is n power supply (containing energy storage) inside; To gather said circuit and power source voltage and electric current according to section unified time, and handle as follows:

When m=0 (not having DC line is connected with external power grid), calculate the separate electric current in each alternating current circuit with:

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

In the formula; is the i electric current of Flow Line A, B, C phase of backcrossing, i=1 ~ k;

is 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 through transformer station measures; Said each electric current all wants reduction to same electric pressure (reduction method can with reference to " power system fault analysis method ", Liu Wanshun, electric power publishing house);

Then; Result is used for broad sense component-level protective device on the spot, and this protective device is being controlled the circuit breaker of broad sense element all and external power grid interconnector, during the protection action; Can break off these circuit breakers simultaneously, and the 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 the state analysis result and the set point of broad sense element, judge whether the broad sense element exists fault, and accomplish protection control the broad sense element according to failure criterion;

The failure criterion of broad sense element is following:

A) when m=0 (not having DC line is connected with external power grid), when satisfying following any criterion, all is regarded as the broad sense element and breaks down, broad sense element protection device action:

Criterion 1:Max (I _AS, I _BS, I _CS)>=I _Set(1)

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

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

In the formula (1), I _SetBe the protection set point;

In formula (2), the formula (3),

I _I.setAnd U _I.setBe the protection set point; For the electric current and the magnitude of voltage of broad sense element and external power grid interconnector (dividing separate), measure by comprehensive automation system of transformer substation; I=1～M, M=3 * (k+n);

B) when m ≠ 0 (having DC line to be connected), when satisfying following any criterion, all be regarded as the broad sense element and break down with external power grid:

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

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

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

Can cooperate direction component to use under above-mentioned A, two kinds of situation of B in criterion 2 and the criterion 3,, only set up when criterion 2 or criterion 3, and fault direction just is identified as the broad sense element fault when pointing to the broad sense element if any direction component; Like directionless element, criterion 2 or criterion 3 are set up, and represent that promptly possibly there is fault in the broad sense element, but the suitable protection operation time limit that suitably increases.

Should be noted that at last: above embodiment is only in order to technical scheme of the present invention to be described but not to its restriction; In conjunction with the foregoing description the present invention is specified; Under the those of ordinary skill in field be to be understood that: those skilled in the art still can specific embodiments of the invention make amendment or are equal to replacement, but these modifications or change are all among the claim protection range that application is awaited the reply.

Claims (6)

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

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

Step 2 is regarded as a broad sense element with described each 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 broad sense component-level protective device on the spot, reports and submits simultaneously to automation system for the power network dispatching;

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

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

(1) closed domain can be the part of a transformer station, or a transformer station, or a partial electric grid, comprises an electric network element in each closed domain at least;

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

3. method as claimed in claim 2 is characterized in that, can comprise power supply in the said closed domain.

4. the method for claim 1 is characterized in that, in the said step 3, each broad sense element concrete grammar of the voltage and current information of processing reaction oneself state on the spot is:

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

When m=0 (not having DC line is connected with external power grid), by the electric current of each alternating current circuit of separate calculating and power supply with:

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

In the formula;

expression i current value of Flow Line A, B, C phase of backcrossing, i=1 ~ k;

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

5. the method for claim 1 is characterized in that, in the said step 4, the failure criterion of broad sense element comprises:

A) when m=0, be no 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, promptly have DC line to be connected with external power grid, the failure criterion of broad sense element can comprise:

Criterion 2:

Criterion 3:

In the following formula, I _Set, I _I.set, U _I.setBe the protection set point,

Electric current and voltage in the i bar circuit that is connected with external electrical network for the broad sense element, i=1～M.

6. method as claimed in claim 5; It is characterized in that, can further dispose direction component in criterion 2 under said two kinds of situation and the criterion 3, as dispose direction component; When criterion 2 or criterion 3 establishments and fault direction sensing broad sense element, just be identified as the broad sense element fault; As do not dispose direction component, and only when criterion 2 or criterion 3 establishments, represent that promptly possibly there is fault in the broad sense element, at this moment, increase the protection operation time limit.

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