阅读说明：本技术 一种适用于企业电网异常情况下的电网稳定控制方法 (Power grid stability control method suitable for abnormal condition of enterprise power grid ) 是由 赵洪山 戚天忠 王亚东 毕童辉 于 2021-07-20 设计创作，主要内容包括：本发明涉及电网稳定控制技术领域,具体涉及一种适用于企业电网异常情况下的电网稳定控制方法。根据元件故障跳闸类别建立电网稳定控制逻辑,包括以下步骤,S1：元件故障跳闸判定；S2：元件故障跳闸类别判定；S3：依据S2中确定的故障跳闸类别,确定故障跳闸前后各项功率参数；S4：将S3中所得功率参数建立数学模型进行逻辑分析,从而实现电网异常情况下的稳定控制。(The invention relates to the technical field of power grid stability control, in particular to a power grid stability control method suitable for abnormal conditions of an enterprise power grid. Establishing a grid stability control logic according to the element fault trip category, comprising the following steps, S1: element fault trip determination; s2: judging the type of element fault tripping; s3: determining power parameters before and after the fault trip according to the fault trip type determined in the S2; s4: and (4) establishing a mathematical model for the power parameters obtained in the step (S3) to carry out logic analysis, so that stable control under the abnormal condition of the power grid is realized.)

1. A power grid stability control method suitable for an abnormal condition of an enterprise power grid is characterized by comprising the following steps: establishing a grid stability control logic according to the element fault trip category, comprising the following steps,

s1: element fault trip determination;

s2: judging the type of element fault tripping;

s3: determining power parameters before and after the fault trip according to the fault trip type determined in the S2;

s4: and (4) establishing a mathematical model for the power parameters obtained in the step (S3) to carry out logic analysis, so that stable control under the abnormal condition of the power grid is realized.

2. The power grid stability control method applicable to the abnormal situation of the enterprise power grid according to claim 1, wherein: the elements comprise the unit itself, a unit sending-out line, a load itself and a load power supply line.

3. The power grid stability control method applicable to the abnormal situation of the enterprise power grid according to claim 1, wherein: the component fault trip judgment is carried out by judging whether the operation component in the power grid is started or not, and judging the two-phase current I and the set current constant value I when the fault occurs_s1The absolute value of the active power P of the element and the active power P of the element_s2And the three establish a' logic relation for judgment.

4. The power grid stability control method applicable to the abnormal situation of the enterprise power grid according to claim 1, wherein: the power parameters in S3 include,

P_{machine for working}: the method comprises the steps that active power of a unit sending line is collected and calculated 20 milliseconds before fault tripping when the unit or the unit sending line is generated by each unit in the enterprise power grid in the same calculation period;

P_{and are}: the active power of the grid-connected tie line when a unit trip or load loss fault occurs in the enterprise power grid;

P_into: determining maximum input power limit power according to the overhead line model of a grid-connected tie line connected with the enterprise power grid and the external grid, the ambient temperature and the maximum power which can be provided by the external grid for the enterprise power grid;

P_{lotus leaf}: the active power value of the load power supply line 20 milliseconds before the fault tripping of the load power supply line or the self fault of the load occurs in the enterprise power grid;

P_{go out}: and determining the maximum output power limit power according to the overhead line model of the grid-connected tie line connected between the enterprise power grid and the external grid, the ambient temperature and the maximum power provided by the enterprise power grid and accepted by the external grid.

5. The power grid stability control method applicable to the abnormal situation of the enterprise power grid according to claim 1, wherein: the S4 mathematical model is:

|P_{and are}+P_{Machine for working}|-P_Into≥0

|P_{And are}-P_{Lotus leaf}|-P_{Go out}≥0

If P when tripping for a unit and its outgoing line fault_{And are}+P_{Machine for working}|-P_IntoAnd if the load is more than or equal to 0, cutting off the load in the network, wherein the load needing to be cut off is as follows: p_{Cutting machine}=|P_{And are}+P_{Machine for working}|-P_Into(ii) a Otherwise, the logic is ended;

if P when tripping in case of a fault in the load and its supply line_{And are}-P_{Lotus leaf}|-P_{Go out}And (3) cutting off the internal unit of the net if the number of the units is more than or equal to 0, wherein the required unit cutting amount is as follows: p_{Cutting machine}=|P_{And are}-P_{Lotus leaf}|-P_{Go out}(ii) a Otherwise, the logic ends.

Technical Field

The invention relates to the technical field of power grid stability control, in particular to a power grid stability control method suitable for abnormal conditions of an enterprise power grid.

Background

In order to meet the requirement of on-site consumption of new energy, the grid-connected operating enterprise power grid utilizes the peak regulation capability of the enterprise coal-fired unit to increase and consume the new energy as much as possible. However, in the early construction process of the coal-fired generator set in the enterprise power grid, the deep peak regulation of the set is not considered, and the power generation working condition of stable operation can be ensured only by the set participating in the deep peak regulation through technical methods such as flexible modification, operation parameter optimization and the like. And in the face of the increase of new energy consumption, new challenges are provided for the stable operation of the coal-fired generating set of the enterprise.

According to the operation experience of a conventional power system, line tripping events caused by line ground faults and short-circuit faults occur when a line sending out of a line and a load power supply line of a unit in a network are influenced by natural environment. For unstable factors caused by participation of the enterprise power grid in new energy consumption and fault tripping of the power transmission line under the normal operation condition of the enterprise power grid, the enterprise needs to consider that the economic loss is reduced as much as possible under the condition of fault tripping.

In view of the above situation, in order to reduce economic loss under the condition of load loss caused by unit or unit outgoing line fault tripping, load power supply line fault tripping or load self fault during normal operation or participation in new energy consumption of the enterprise power grid, a safety and stability control strategy configured in the enterprise power grid needs to be further optimized, and the load amount or the unit amount in the network which is removed stably under abnormal conditions is reduced as much as possible.

Disclosure of Invention

The invention provides a power grid stability control method under the abnormal condition of a power grid by utilizing a safety and stability control strategy, aiming at reducing the operation risk caused by fault tripping of a unit and a sending-out line thereof, self-fault of a load and fault tripping of a power supply line thereof in an enterprise power grid and reducing the economic loss of an enterprise.

In order to achieve the purpose, the invention adopts the following technical scheme:

a power grid stability control method suitable for the abnormal condition of an enterprise power grid, which establishes power grid stability control logic according to the element fault tripping category, comprises the following steps,

s1: element fault trip determination;

s2: judging the type of element fault tripping;

s3: determining power parameters before and after the fault trip according to the fault trip type determined in the S2;

s4: and (4) establishing a mathematical model for the power parameters obtained in the step (S3) to carry out logic analysis, so that stable control under the abnormal condition of the power grid is realized.

Further, the element faults include a fault of the unit, a fault of a sending line of the unit, a fault of a load and a fault of a load power supply line.

Further, the component fault tripping judgment is carried out by judging whether the operation component in the power grid is started or not, and the two-phase current I and the set current constant value I when the fault occurs_s1The absolute value of the active power P of the element and the active power P of the element_s2And the three establish a' logic relation for judgment.

Further, the power parameters in S3 include,

P_{machine for working}: the method comprises the steps that active power of a unit sending line is collected and calculated 20 milliseconds before fault tripping when the unit or the unit sending line is generated by each unit in the enterprise power grid in the same calculation period;

P_{and are}: the active power of the grid-connected tie line when a unit trip or load loss fault occurs in the enterprise power grid;

P_into: determining maximum input power limit power according to the overhead line model of a grid-connected tie line connected with the enterprise power grid and the external grid, the ambient temperature and the maximum power which can be provided by the external grid for the enterprise power grid;

P_{lotus leaf}: the active power value of the load power supply line 20 milliseconds before the fault tripping of the load power supply line or the self fault of the load occurs in the enterprise power grid;

P_{go out}: and determining the maximum output power limit power according to the overhead line model of the grid-connected tie line connected between the enterprise power grid and the external grid, the ambient temperature and the maximum power provided by the enterprise power grid and accepted by the external grid.

Further, the mathematical model in S4 is:

|P_{and are}+P_{Machine for working}|-P_Into≥0

|P_{And are}-P_{Lotus leaf}|-P_{Go out}≥0

If P when tripping for a unit and its outgoing line fault_{And are}+P_{Machine for working}|-P_IntoAnd if the load is more than or equal to 0, cutting off the load in the network, wherein the load needing to be cut off is as follows: p_{Cutting machine}=|P_{And are}+P_{Machine for working}|-P_Into(ii) a Otherwise, the logic is ended;

if P when tripping in case of a fault in the load and its supply line_{And are}-P_{Lotus leaf}|-P_{Go out}And (3) cutting off the internal unit of the net if the number of the units is more than or equal to 0, wherein the required unit cutting amount is as follows: p_{Cutting machine}=|P_{And are}-P_{Lotus leaf}|-P_{Go out}(ii) a Otherwise, the logic ends.

Compared with the prior art, the invention has the following beneficial effects:

by establishing a power grid stability control logic, when a load loss is caused by a fault trip of a unit or a unit sending-out line, a fault trip of a load power supply line or a self fault of a load in an enterprise power grid, if the input and output power of a grid-connected tie line is still in a limit range, the logic control output is reliable and does not act; when the grid-connected tie line is out of the range of input and output electric power, the logic control output is reliable, so that greater economic benefit is created for enterprises on the premise of ensuring stable operation of the power grid.

Drawings

Fig. 1 is a logic flow diagram of a component fault trip determination.

Detailed Description

The invention is further described with reference to the following figures and detailed description.

A power grid stability control method suitable for the abnormal condition of an enterprise power grid is used for establishing a power grid stability control logic according to element fault categories and comprises the following steps:

s1: element fault trip determination;

as shown in fig. 1, the two-phase current I and the set current constant value I are determined by whether the operation element in the power grid is started or not and the two-phase current I and the set current when the fault occurs_s1The absolute value of the active power P of the element and the active power P of the element_s2And the three establish a' logic relation for judgment.

S2: judging the type of element fault tripping;

the element faults comprise the faults of the unit, the faults of a sending line of the unit, the faults of a load and the faults of a load power supply line.

Specifically, the fault set of the line fault trip sent by the unit or the unit comprises: the unit is out of line fault, unit step-up transformer fault and unit self fault exit.

Specifically, the load loss fault set caused by the fault trip of the load power supply line or the fault of the load per se comprises: the first series of electrolytic aluminum load power supply lines are disconnected or the load is rapidly lost, the second series of electrolytic aluminum load power supply lines are disconnected or the load is rapidly lost, and the third series of electrolytic aluminum load power supply lines are disconnected or the load is rapidly lost.

S3: determining power parameters before and after the fault trip according to the fault type determined in the S2;

specifically, the power parameters include, for example,

P_{machine for working}: the method comprises the steps that active power of a unit sending line is collected and calculated 20 milliseconds before fault tripping when the unit or the unit sending line is generated by each unit in the enterprise power grid in the same calculation period;

P_{and are}: the active power of the grid-connected tie line when a unit trip or load loss fault occurs in the enterprise power grid;

P_into: determining maximum input power limit power according to the overhead line model of a grid-connected tie line connected with the enterprise power grid and the external grid, the ambient temperature and the maximum power which can be provided by the external grid for the enterprise power grid;

P_{lotus leaf}: the active power value of the load power supply line 20 milliseconds before the fault tripping of the load power supply line or the self fault of the load occurs in the enterprise power grid;

P_{go out}: and determining the maximum output power limit power according to the overhead line model of the grid-connected tie line connected between the enterprise power grid and the external grid, the ambient temperature and the maximum power provided by the enterprise power grid and accepted by the external grid.

S4: and (4) establishing a mathematical model for the power parameters obtained in the step (S3) to carry out logic analysis, so that stable control under the abnormal condition of the power grid is realized.

(1) The control means of line fault tripping is sent out by the unit or the unit:

when the unit or the sending-out line is tripped due to faults, the out-of-limit degree of the power possibly applied to the grid-connected tie line section is calculated according to the power before the grid-connected tie line section accident, and the load switching/pressure switching is carried out according to the over-switching principle.

If P is positive in the direction of national grid power transmission enterprise grid power_{And are}+P_{Machine for working}|-P_IntoAnd if the load is more than or equal to 0, cutting off the load in the network, wherein the load needing to be cut off is as follows: p_{Cutting machine}=|P_{And are}+P_{Machine for working}|-P_Into(ii) a If P_{And are}+P_{Machine for working}|-P_Into<0, the logic ends.

(2) The safety and stability control means for load loss caused by fault tripping of a load power supply line or self fault of the load:

when the load is lost due to the fault tripping of a load power supply line or the self fault of the load, the out-of-limit degree of the power transmitted by the section of the grid-connected tie line possibly caused by the fault of the load loss is calculated according to the power before the fault of the grid-connected tie section, and the tripping is executed according to the over-tripping principle.

If P_{And are}-P_{Lotus leaf}|-P_{Go out}And (3) cutting off the internal unit of the net if the number of the units is more than or equal to 0, wherein the required unit cutting amount is as follows: p_{Cutting machine}=|P_{And are}-P_{Lotus leaf}|-P_{Go out}(ii) a If P_{And are}-P_{Lotus leaf}|-P_{Go out}<0, the logic ends.

The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.