阅读说明：本技术 一种配网动态无功补偿方法、装置、设备及计算机介质 (Distribution network dynamic reactive power compensation method, device, equipment and computer medium ) 是由 招景明 杨雨瑶 潘峰 党三磊 张永旺 吴敏 于 2021-09-18 设计创作，主要内容包括：本发明公开了一种配网动态无功补偿方法、装置、设备及计算机介质,其中,所述方法包括：构建无功补偿装置所对应的无功补偿网络；利用对称分量法得到所述无功补偿网络的电流各分量以及配网负荷电流各分量；根据所述无功补偿网络的电流各分量和所述配网负荷电流各分量,确定配网三相平衡的条件集,所述条件集合包括正序电流平衡条件、负序电流平衡条件以及零序电流平衡条件；基于所述条件集求解所述无功补偿装置的无功容量优化函数,得到无功补偿量；根据所述无功补偿量对配网进行无功补偿。上述方法能够有效消除零序电流分量对三相不平衡电力系统带来的隐患,确保电力系统配网安全稳定运行。(The invention discloses a distribution network dynamic reactive power compensation method, a distribution network dynamic reactive power compensation device, distribution network dynamic reactive power compensation equipment and a computer medium, wherein the method comprises the following steps: constructing a reactive compensation network corresponding to the reactive compensation device; obtaining components of the current of the reactive compensation network and components of the load current of the distribution network by using a symmetric component method; determining a condition set of distribution network three-phase balance according to the current components of the reactive compensation network and the distribution network load current components, wherein the condition set comprises a positive sequence current balance condition, a negative sequence current balance condition and a zero sequence current balance condition; solving a reactive power capacity optimization function of the reactive power compensation device based on the condition set to obtain a reactive power compensation amount; and performing reactive compensation on the distribution network according to the reactive compensation quantity. The method can effectively eliminate the hidden trouble of the zero-sequence current component on the three-phase unbalanced power system, and ensure the safe and stable operation of the power distribution network of the power system.)

1. A distribution network dynamic reactive power compensation method is characterized by comprising the following steps:

constructing a reactive compensation network corresponding to the reactive compensation device;

obtaining components of the current of the reactive compensation network and components of the load current of the distribution network by using a symmetric component method;

determining a condition set of distribution network three-phase balance according to the current components of the reactive compensation network and the distribution network load current components, wherein the condition set comprises a positive sequence current balance condition, a negative sequence current balance condition and a zero sequence current balance condition;

solving a reactive power capacity optimization function of the reactive power compensation device based on the condition set to obtain a reactive power compensation amount; and performing reactive compensation on the distribution network according to the reactive compensation quantity.

2. The method for dynamic reactive compensation of distribution networks according to claim 1, wherein the reactive compensation network comprises:

a zero sequence current compensation network and a negative sequence current compensation network.

3. The method for dynamic reactive power compensation of the distribution network according to claim 2, wherein the obtaining of the components of the current of the reactive power compensation network and the components of the load current of the distribution network by using a symmetric component method specifically comprises:

and respectively decomposing the currents of the distribution network load current, the zero sequence current compensation network and the negative sequence current compensation network into a positive sequence current component, a negative sequence current component and a zero sequence current component by using a symmetrical component method.

4. The method for dynamic reactive power compensation of the distribution network according to claim 3, wherein the determining a condition set for distribution network three-phase balance according to the components of the reactive power compensation network current and the components of the distribution network load current specifically comprises:

determining a zero-sequence current balance condition of three-phase balance of the distribution network according to the distribution network load current and a zero-sequence current component corresponding to the zero-sequence current compensation network;

determining a negative sequence current balance condition of the three-phase balance of the distribution network according to the load current of the distribution network, the zero sequence current compensation network and the negative sequence current component corresponding to the negative sequence current compensation network;

and determining a positive sequence current balance condition of the three-phase balance of the distribution network according to the positive sequence current components corresponding to the distribution network load current, the zero sequence current compensation network and the negative sequence current compensation network.

5. The method for dynamic reactive power compensation of a distribution network according to claim 1, wherein the reactive power optimization function of the reactive power compensation device specifically comprises:

minimizing the reactive capacity of the reactive compensation device.

6. A distribution network dynamic reactive power compensation device is characterized by comprising:

the building module is used for building a reactive compensation network corresponding to the reactive compensation device;

the decomposition module is used for obtaining each component of the current of the reactive compensation network and each component of the load current of the distribution network by using a symmetric component method;

the first calculation module is used for determining a condition set of distribution network three-phase balance according to each component of the current of the reactive compensation network and each component of the distribution network load current, wherein the condition set comprises a positive sequence current balance condition, a negative sequence current balance condition and a zero sequence current balance condition;

the second calculation module is used for solving a reactive power capacity optimization function of the reactive power compensation device based on the condition set to obtain a reactive power compensation amount; and performing reactive compensation on the distribution network according to the reactive compensation quantity.

7. The distribution network dynamic reactive compensation device of claim 6, wherein the reactive compensation network comprises:

a zero sequence current compensation network and a negative sequence current compensation network.

8. The distribution network dynamic reactive compensation device according to claim 7, wherein the reactive capacity optimization function of the reactive compensation device specifically comprises:

minimizing the reactive capacity of the reactive compensation device.

9. A data processing apparatus, characterized by comprising:

a processor coupled to a memory, the memory storing a program for execution by the processor to cause the data processing apparatus to perform the method for distribution network dynamic reactive compensation of any of claims 1-5.

10. A computer storage medium, characterized in that the computer storage medium stores computer instructions for executing the distribution network dynamic reactive power compensation method according to any one of the above claims 1 to 5.

Technical Field

The invention relates to the technical field of computers, in particular to a distribution network dynamic reactive power compensation method, a distribution network dynamic reactive power compensation device, a distribution network dynamic reactive power compensation equipment and a computer medium.

Background

An ideal power system is expected to be established in a three-phase balanced condition, and a plurality of three-phase unbalanced loads exist in an actual power system, so that the generated unbalanced current seriously harms the power system, such as causing additional heating and vibration of the rotating motor, and endangering the safe operation and normal output of the rotating motor; or the copper loss and eddy current loss of the transformer are increased, the winding is overheated, and the service life is reduced.

At present, most of research on three-phase unbalance suppression is developed for a three-phase three-wire system power system, and dynamic reactive compensation is usually performed based on negative sequence current; however, in the compensation process, the line loss and the variable loss of part of the power equipment are increased under the influence of the zero sequence component, so that the service life is reduced, and the safe and stable operation of the power system is not facilitated.

Disclosure of Invention

Aiming at the technical problems, the invention provides a distribution network dynamic reactive power compensation method, a distribution network dynamic reactive power compensation device, a distribution network dynamic reactive power compensation equipment and a computer medium, which can effectively eliminate the hidden trouble of zero-sequence current components on a three-phase unbalanced power system and ensure the safe and stable operation of the system.

In view of the above, in a first aspect, the present invention provides a distribution network dynamic reactive power compensation method, including:

constructing a reactive compensation network corresponding to the reactive compensation device;

obtaining components of the current of the reactive compensation network and components of the load current of the distribution network by using a symmetric component method;

determining a condition set of distribution network three-phase balance according to the current components of the reactive compensation network and the distribution network load current components, wherein the condition set comprises a positive sequence current balance condition, a negative sequence current balance condition and a zero sequence current balance condition;

solving a reactive power capacity optimization function of the reactive power compensation device based on the condition set to obtain a reactive power compensation amount; and performing reactive compensation on the distribution network according to the reactive compensation quantity.

Optionally, the reactive compensation network includes: a zero sequence current compensation network and a negative sequence current compensation network.

Optionally, the obtaining of the components of the current of the reactive compensation network and the components of the load current of the distribution network by using a symmetric component method specifically includes:

and respectively decomposing the currents of the distribution network load current, the zero sequence current compensation network and the negative sequence current compensation network into a positive sequence current component, a negative sequence current component and a zero sequence current component by using a symmetrical component method.

Optionally, the determining a condition set of distribution network three-phase balance according to the components of the current of the reactive compensation network and the components of the distribution network load current specifically includes:

determining a zero-sequence current balance condition of three-phase balance of the distribution network according to the distribution network load current and a zero-sequence current component corresponding to the zero-sequence current compensation network;

determining a negative sequence current balance condition of the three-phase balance of the distribution network according to the load current of the distribution network, the zero sequence current compensation network and the negative sequence current component corresponding to the negative sequence current compensation network;

and determining a positive sequence current balance condition of the three-phase balance of the distribution network according to the positive sequence current components corresponding to the distribution network load current, the zero sequence current compensation network and the negative sequence current compensation network.

Optionally, the reactive capacity optimization function of the reactive power compensation device specifically includes: minimizing the reactive capacity of the reactive compensation device.

In a second aspect, the present invention provides a distribution network dynamic reactive power compensation apparatus, including:

the building module is used for building a reactive compensation network corresponding to the reactive compensation device;

the decomposition module is used for obtaining each component of the current of the reactive compensation network and each component of the load current of the distribution network by using a symmetric component method;

the first calculation module is used for determining a condition set of distribution network three-phase balance according to each component of the current of the reactive compensation network and each component of the distribution network load current, wherein the condition set comprises a positive sequence current balance condition, a negative sequence current balance condition and a zero sequence current balance condition;

the second calculation module is used for solving a reactive power capacity optimization function of the reactive power compensation device based on the condition set to obtain a reactive power compensation amount; and performing reactive compensation on the distribution network according to the reactive compensation quantity.

Optionally, the reactive compensation network includes: a zero sequence current compensation network and a negative sequence current compensation network.

Optionally, the reactive capacity optimization function of the reactive power compensation device specifically includes: minimizing the reactive capacity of the reactive compensation device.

In a third aspect, the present invention provides a data processing apparatus, including a processor, coupled with a memory, where the memory stores a program, and the program is executed by the processor, so that the data processing apparatus executes the distribution network dynamic reactive power compensation method according to the first aspect.

In a fourth aspect, the present invention further provides a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the distribution network dynamic reactive power compensation method according to the first aspect.

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

according to the distribution network dynamic reactive power compensation method provided by the invention, the reactive power compensation network corresponding to the reactive power compensation device is accessed into the distribution network to perform zero sequence current compensation and negative sequence current compensation, so that the rapid regulation of the reactive power of the system is realized; compared with the prior art, the invention fully considers the compensation of the zero-sequence current, effectively eliminates the adverse effect of the zero-sequence current on the distribution network equipment and ensures the safe and stable operation of the system.

Correspondingly, the invention also provides a distribution network dynamic reactive power compensation device, data processing equipment and a computer medium.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic flow chart of a distribution network dynamic reactive power compensation method provided in an embodiment of the present invention;

fig. 2 is a schematic diagram of a zero-sequence current compensation network provided in an embodiment of the present invention;

FIG. 3 is a schematic diagram of a negative-sequence current compensation network provided by an embodiment of the present invention;

fig. 4 is a block diagram of a configuration network dynamic reactive power compensation device provided in the embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In a distribution network, in order to compensate unbalance of dynamic loads, eliminate harmful current caused by the unbalanced loads in a power system, and quickly compensate reactive power required by the loads to improve a system power factor, the embodiment of the invention provides a dynamic reactive power compensation method for the distribution network.

Specifically, as shown in fig. 1, the method for dynamic reactive compensation of a distribution network provided by this embodiment includes the following steps:

s1: and constructing a reactive compensation network corresponding to the reactive compensation device.

The reactive power compensation device specifically comprises a zero sequence current compensation network and a negative sequence current compensation network, and is used for carrying out reactive power compensation on three-phase unbalanced loads under three-phase four-wire system and star connection, wherein each compensation network corresponds to one reactive power compensation device.

S2: and obtaining each component of the current of the reactive compensation network and each component of the load current of the distribution network by using a symmetric component method.

The symmetrical component method is widely applied to the asymmetry degree analysis of three-phase alternating current parameters, is a basic method for calculating the short-circuit current of a power system, and aims to convert a group of asymmetrical ABC three-phase quantities into three groups of symmetrical three-phase quantities respectively called positive sequence, negative sequence and zero sequence quantities.

In this embodiment, the currents of the distribution network load current, the zero-sequence current compensation network and the negative-sequence current compensation network can be decomposed into a positive-sequence current component, a negative-sequence current component and a zero-sequence current component by using a symmetric component method.

In particular, zero sequence current compensation network referring to fig. 2, in the zero sequence current compensation network, the three-phase voltages of the power system are completely symmetrical, so there areWherein the content of the first and second substances,therefore, the three-phase current of the distribution network load can be expressed as follows:

furthermore, the distribution network load three-phase current can be converted into the current based on the positive sequence component I according to the symmetrical component method₁Negative sequence component I₂And zero sequence component I₀The expression of (a):

the positive sequence component of the load current of the distribution network can be obtained by the formulaNegative sequence componentAnd zero sequence componentRespectively expressed as:

similarly, the positive sequence component of the current of the zero sequence current compensation network can be obtained based on the derivation modeNegative sequence componentAnd zero sequence componentThe concrete expression is as follows:

negative sequence current compensation network referring to fig. 3, for a negative sequence current compensation network, the two phase currents therein are represented as:

because zero sequence current does not exist in the negative sequence current compensation network adopting the delta connection method, the components of the negative sequence current can be deduced to be:

s3: and determining a condition set of distribution network three-phase balance according to the current components of the reactive compensation network and the distribution network load current components, wherein the condition set comprises a positive sequence current balance condition, a negative sequence current balance condition and a zero sequence current balance condition.

When the power system normally operates, the power system can be considered to be three-phase symmetrical, namely, the three-phase voltage and the current of each element are equal in magnitude, the phase difference between phases is also equal, and the power system has a sine waveform and a normal phase sequence; when three-phase imbalance occurs in a distribution network of a power system, the generated asymmetric current magnitude can be decomposed into three components through a symmetric component method, and analysis is performed based on the principle of current symmetry when the three phases of the distribution network are balanced, so that a condition set of distribution network three-phase balance is obtained.

Specifically, the zero-sequence current balance condition of the three-phase balance of the distribution network can be determined according to the load current of the distribution network and the zero-sequence current component corresponding to the zero-sequence current compensation network.

It can be understood that, since the negative sequence current compensation network line current of the delta connection does not generate zero sequence component, the zero sequence current compensation network of the star connection can meet the requirement as long as the zero sequence current compensation network of the star connection and the positive sequence network are offsetThe zero-sequence current of the power system distribution network can be balanced, and specifically, zero-sequence current balance conditions are derived as follows:

for the negative sequence current balance condition with concentrated distribution network three-phase balance condition, the negative sequence current balance condition can be determined according to the distribution network load current, the zero sequence current compensation network and the negative sequence current component corresponding to the negative sequence current compensation network.

In particular, when the negative-sequence current compensation network, the zero-sequence current compensation network and the negative-sequence current of the system cancel each other out (i.e. the negative-sequence currents of the system cancel each other out)Time), the negative-sequence current of the power system is balanced, and therefore, the negative-sequence current balance condition is expressed as:

in order to improve the power factor of the power system, the embodiment needs to compensate the reactive power to ensure that the positive sequence current of the system is pure active power, and the sum of imaginary parts of the positive sequence current of the system is zero at this time; therefore, the positive sequence current balance condition of the three-phase balance of the distribution network can be determined according to the positive sequence current components corresponding to the distribution network load current, the zero sequence current compensation network and the negative sequence current compensation network, which can be specifically expressed as:

the positive sequence current balance condition, the negative sequence current balance condition and the zero sequence current balance condition can be further simplified to obtain the following condition set equation set for distribution network three-phase balance:

there are five equations in the above equation set, but there are commonAndsix unknown variables, and thus there are infinite sets of solutions, namely: under the compensation scheme, various conditions exist in each phase of compensation network to meet the compensation requirement.

It can be understood that in the zero sequence compensation network, there is a total ofThree unknown variables, and only two equations are in the zero sequence current balance condition and are not related to the parameters corresponding to the negative sequence current compensation network; therefore, when the variable isWhen all are determined, there is a negative sequence compensation networkAndthree unknown variables, and three equations in the positive sequence current balance condition and the negative sequence current balance condition, thusAndcan be uniquely determined.

Based on the above analysis, in one embodiment, the variables are setFor known variables, the other five parameters can be determined as:

it can be understood that when the condition sets of the three-phase balance of the distribution network are all met, the reactive current of the unbalanced load can be completely compensated.

S4: solving a reactive power capacity optimization function of the reactive power compensation device based on the condition set to obtain a reactive power compensation amount; and performing reactive compensation on the distribution network according to the reactive compensation quantity.

In this embodiment, the reactive power optimization function of the reactive power compensation device specifically includes: the reactive capacity of the reactive power compensation device is minimized.

Considering that most compensation occasions have great requirements on the reactive capacity of the reactive power compensation device, the design difficulty and the economic cost of the reactive power compensation device are increased, and the compensation effect is reduced; in contrast, in the embodiment of the present invention, the reactive capacity of the reactive power compensation device is used as an optimization target, and the capacity of the reactive power compensation device is minimized on the premise of achieving the target compensation effect.

Specifically, the minimum total reactive capacity may be set as an optimization target, and a reactive capacity optimization function F of the reactive power compensation device may be defined:

in particular, F represents six unknown variables in two compensation networks(s) ((s)) And) Bisection of vector sums.

In one embodiment, to minimize F, it may be assumedWhen F is aboutThe derivative result is zero, and other unknown variables in F can be usedIs known as a gaugeShow, therefore, orderThe following can be obtained:

further, the variables are adjustedSubstituting into the function F, the reactive compensation amount under the condition of optimal reactive capacity can be obtained, and the reactive compensation amount is specifically expressed as a compensation susceptance formula:

to simplify the calculation, the above formula can be converted into a power representation:

in the distribution network dynamic reactive power compensation method provided by the embodiment, the reactive power compensation network corresponding to the reactive power compensation device is connected into the distribution network to perform zero sequence current compensation and negative sequence current compensation, so that the adverse effect of zero sequence current on system equipment can be effectively eliminated, and the rapid regulation of reactive power of the power system is realized.

Referring to fig. 4, in a second aspect, an embodiment of the present invention further provides a distribution network dynamic reactive power compensation apparatus, which includes a building module 101, a decomposing module 102, a first calculating module 103, and a second calculating module 104.

The building module 101 is configured to build a reactive compensation network corresponding to the reactive compensation device.

The decomposition module 102 is configured to obtain components of the current of the reactive compensation network and components of the load current of the distribution network by using a symmetric component method.

The first calculation module 103 is configured to determine a condition set of distribution network three-phase balance according to the current components of the reactive compensation network and the load current components of the distribution network, where the condition set includes a positive sequence current balance condition, a negative sequence current balance condition, and a zero sequence current balance condition.

The second calculation module 104 is configured to solve a reactive power capacity optimization function of the reactive power compensation device based on the condition set to obtain a reactive power compensation amount; and performing reactive compensation on the distribution network according to the reactive compensation quantity.

For the information interaction, execution process and other contents between the modules in the device, the specific contents may refer to the description in the embodiment of the method of the present invention because the embodiment of the method for dynamic reactive compensation of distribution network provided by the first aspect of the present invention is based on the same concept, and are not described herein again.

The above-described embodiments of the apparatus are merely illustrative, and the modules described as separate components may or may not be physically separate, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the units can be selected according to actual needs to achieve the purpose of the method of the embodiment.

In a third aspect, the present invention provides a data processing apparatus, including a processor, coupled with a memory, where the memory stores a program, and the program is executed by the processor, so that the data processing apparatus executes the distribution network dynamic reactive power compensation method according to the first aspect.

In a fourth aspect, the present invention further provides a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the distribution network dynamic reactive power compensation method according to the first aspect.

It will be understood by those skilled in the art that all or part of the processes of the methods of the above embodiments may be implemented by a computer program, which may be stored in a computer-readable storage medium, and may include the processes of the embodiments of the methods when executed. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), or the like.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.