CN107947140B - Control method and device for power fluctuation overvoltage of half-wavelength power transmission line - Google Patents

Abstract

The invention provides a method and a device for controlling power fluctuation overvoltage of a half-wavelength power transmission line, wherein a differential configuration strategy of an arrester along the half-wavelength power transmission line is obtained through the maximum absorption energy of the arrester under the action of the power fluctuation overvoltage in a uniform configuration strategy, and whether the power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the maximum absorption energy of the arrester under the action of the power fluctuation overvoltage in the differential configuration strategy meet the power fluctuation limiting requirement or not is judged, if yes, the differential configuration strategy is optimized, and otherwise, the differential configuration strategy is corrected. The invention defines the power fluctuation overvoltage and the characteristics of the half-wavelength power transmission line for the first time and provides a basis for the research of the half-wavelength power transmission line; the invention can effectively solve the problem of power fluctuation overvoltage of the half-wavelength power transmission system, and provides basis and foundation for inhibiting the power fluctuation overvoltage of the half-wavelength power transmission line.

Description

A method and device for controlling power fluctuation overvoltage of half-wavelength transmission line

technical field

The invention relates to the technical field of power systems, in particular to a method and a device for controlling power fluctuation overvoltage of a half-wavelength transmission line.

Background technique

Half-wave-length AC transmission (HWACT) refers to a three-phase AC transmission technology whose electrical distance is close to a power frequency half-wavelength, that is, about 3000km (50Hz) or about 2600km (60Hz) over long distances. Reactive power is self-balancing, no need to install reactive power compensation equipment, and no need to set up an intermediate switch station. It has strong power transmission capacity, good economy and reliability, and can realize long-distance synchronous networking. With the advancement of the global energy Internet, half-wave power transmission has received extensive attention as a scheme suitable for large-scale intercontinental power transmission.

However, the engineering application of half-wavelength power transmission still needs to solve some technical problems such as safety and stability control, overvoltage and submerged supply current suppression, relay protection configuration, etc. Among them, the suppression of overvoltage is one of the key problems restricting the application of half-wavelength power transmission. . Due to the special line structure of half-wavelength transmission lines, its overvoltage characteristics are very different from those of conventional transmission lines. Under fault conditions such as single-phase-to-ground, two-phase-to-ground short-circuit, three-phase ground-to-ground short-circuit, and interphase short-circuit, the half-wavelength characteristics of half-wavelength transmission lines are destroyed. The problem of transient overvoltage caused by phase excitation is extremely prominent, and the serious fault point can reach several times. It is the focus of overvoltage suppression of half-wavelength transmission lines.

The overvoltage of the half-wavelength transmission line will cause the half-wavelength transmission system to fail to operate safely. At present, the overvoltage of the half-wavelength transmission line is suppressed by installing a surge arrester on the half-wavelength transmission line. However, due to the voltage along the half-wavelength transmission line Due to the special relationship with its own transmission power, there is another overvoltage phenomenon. The installation of lightning arresters on the half-wavelength transmission line cannot solve this kind of overvoltage problem on the half-wavelength transmission line. This kind of overvoltage will lead to half-wavelength transmission. The system cannot operate safely.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned deficiency in the prior art that the half-wavelength transmission line cannot operate safely due to the overvoltage of the half-wavelength transmission line due to a fault, the present invention provides a method and device for controlling the power fluctuation overvoltage of the half-wavelength transmission line. The uniform configuration strategy of the arrester along the wavelength transmission line and the maximum absorbed energy of the arrester under the action of power fluctuation overvoltage in the uniform configuration strategy, and then determine the arrester along the half-wavelength transmission line according to the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage in the uniform configuration strategy and determine the power fluctuation overvoltage of the half-wavelength transmission line in the differential configuration strategy, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage, and then judge the differential configuration strategy. Whether the power fluctuation overvoltage of the half-wavelength transmission line, the duration of the power fluctuation overvoltage, and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage meet the power fluctuation limit requirements at the same time. The differentiated configuration strategy is revised to obtain the final differentiated configuration strategy.

In order to realize the above-mentioned purpose of the invention, the present invention adopts the following technical solutions:

The present invention provides a method for controlling power fluctuation overvoltage of a half-wavelength transmission line, comprising:

Determine the uniform arrangement strategy of arresters along half-wavelength transmission lines and the maximum absorbed energy of arresters under the action of power fluctuation and overvoltage in the uniform arrangement strategy;

According to the maximum absorbed energy of the arrester under the action of power fluctuation overvoltage in the uniform configuration strategy, the differentiated configuration strategy of the arrester along the half-wavelength transmission line is determined, and the power fluctuation overvoltage and power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy are determined. The maximum absorbed energy of the arrester under the action of the duration and power fluctuation overvoltage;

Determine whether the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy, the duration of the power fluctuation overvoltage, and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage simultaneously meet the power fluctuation limit requirements. The configuration strategy is optimized, otherwise, the differentiated configuration strategy is corrected.

The power fluctuation overvoltage of the half-wavelength transmission line includes the overvoltage that occurs on the half-wavelength transmission line when the power fluctuation generated in the case of a fault on the half-wavelength transmission line exceeds the natural power;

The amplitude of the power fluctuation overvoltage is proportional to the ratio of the power fluctuation to the natural power of the half-wavelength transmission line;

The duration of the power fluctuation overvoltage is consistent with the power fluctuation time of the half-wavelength transmission line;

If the fault is a single-phase instantaneous ground fault, the fault process of the single-phase instantaneous ground fault includes a fault period process, a reclosing process and a swing process.

The uniform configuration strategy of the arrester along the half-wavelength transmission line is determined according to the following process:

The half-wavelength transmission line is evenly divided into multiple line units with a fixed length, and the same number of arresters are installed at the end of each line unit.

In the uniform configuration strategy, the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage is determined according to the following process:

Under the condition of the maximum transmission capacity of the half-wavelength transmission line, the maximum absorbed energy of the arrester under the action of power fluctuation overvoltage in the uniform configuration strategy is determined by the electromagnetic transient simulation model of the half-wavelength transmission system.

The differential configuration strategy for determining the arrester along the half-wavelength transmission line according to the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform configuration strategy includes:

Based on the principle that the maximum absorbed energy of a single group of arresters does not exceed 80% of the energy absorption capacity of the arrester, that each arrester installation position can be installed with at most two groups of arresters, and that the arrester should be installed at the end of the line unit first, at the end of each line unit Terminals and internally mounted surge arresters.

The end point of the line unit and the lightning arrester installed inside include:

Determine the end points of the line unit and the installed number of internal arresters, including:

Assume that m groups of arresters are installed at the end terminals and inside of the line unit, and the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform configuration strategy is E _U , when E _U <0.8EM, _m =1; when E _U ≥ When 0.8E _M , m=[E _U /0.8E _M ], [] means rounding off, where E _M is the energy absorption capability of the arrester;

Determine the end point of the line unit and the installation location of the internal arrester, including:

When m=1, install a group of arresters at the end of the line unit;

When m=2, install two sets of arresters at the end of the line unit;

When m ≥ 3, two sets of arresters are installed at the end points of the line unit, and the remaining arresters are arranged inside the line unit as follows:

m为奇数时，

The remaining arresters are arranged at positions with distances d, 2d, ..., kd from the end point of the line unit, where k is a natural number, d represents the span of the half-wavelength transmission line, and when m is an even number,

When m is odd,

The determination of the power fluctuation overvoltage of the half-wavelength transmission line in the differential configuration strategy, the duration of the power fluctuation overvoltage, and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage include:

Under the condition of the maximum transmission capacity of the half-wavelength transmission line, the power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy are determined by the electromagnetic transient simulation model of the half-wavelength transmission system. The maximum absorbed energy of the arrester under the action.

The power fluctuation limit requirements include:

1) The power fluctuation overvoltage on the line side of the substation shall not exceed 1.4p.u., and the duration of the power fluctuation overvoltage on the line side of the substation shall not exceed 0.5s;

2) The amplitude of the power fluctuation overvoltage of the half-wavelength transmission line and the duration of the power fluctuation overvoltage of the half-wavelength transmission line both meet the temporary overvoltage withstand performance of the arrester;

3) The maximum absorbed energy of the arrester along the half-wavelength transmission line under the action of power fluctuation and overvoltage meets the energy absorption capability of the arrester.

The optimization of the differentiated configuration strategy includes:

Suppose the installation position of the arrester on the half-wavelength transmission line is L ₁ ,…,L _h ,…,L _H , the maximum absorbed energy of a single group of arresters is E _h , h=1,2,…,H, H represents the half-wavelength transmission line The total number of installation positions of the arrester;

If E _h < _0.5EM and there are at least two sets of arresters at the end of the line unit and inside, update the differentiated configuration strategy according to the principle of reducing one set of arresters each time from the head end of the line unit to the end of the line unit, and according to the half-wavelength transmission system The electromagnetic transient simulation model of the updated differential configuration strategy determines the power fluctuation overvoltage of the half-wavelength transmission line, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage, and judges the updated In the differentiated configuration strategy, whether the power fluctuation overvoltage of the half-wavelength transmission line, the duration of the power fluctuation overvoltage, and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage simultaneously meet the power fluctuation limit requirements. The configuration strategy is used as the final arrester configuration strategy, otherwise the differentiated configuration strategy before the update is used as the final arrester configuration strategy;

If 0.5E _M ≤ E _h ≤ E _M and the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage simultaneously satisfy the power fluctuation limit requirements, the differentiated configuration strategy is used as the final arrester configuration strategy.

The modification to the differentiated configuration strategy includes:

Let the end points of the line unit and the installation position of the internal arrester be L ₁ ,…,L _i ,…,L _N , i=1,2,…,N, N represents the total number of installation positions of the arrester in the line unit, and L _i represents the first i installation positions;

If L _i is close to L ₁ , then at L ₁ and the position close to the head end of the line unit and the distance d from L ₁ , the differentiated configuration strategy is modified according to the principle of adding a group of arresters each time, until the half wavelength in the differentiated configuration strategy The power fluctuation overvoltage of the transmission line, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage meet the power fluctuation limit requirements at the same time, and the revised differentiated configuration strategy is used as the final arrester configuration strategy;

If _{Li is close to L N ,} the differential configuration strategy is revised according to the principle of adding a group of arresters at a position close to the end of the half-wavelength transmission line and the distance from _LN is d, until the half-wavelength transmission line in the differential configuration strategy The power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage meet the power fluctuation limit requirements at the same time, and the revised differentiated configuration strategy is used as the final arrester configuration strategy.

The present invention also provides a control device for power fluctuation overvoltage of half-wavelength transmission line, comprising:

The first determination module is used to determine the uniform configuration strategy of the arrester along the half-wavelength transmission line and the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform configuration strategy;

The second determination module is used to determine the differentiated configuration strategy of the arrester along the half-wavelength transmission line according to the maximum absorbed energy of the arrester under the action of power fluctuation overvoltage in the uniform configuration strategy, and to determine the power fluctuation of the half-wavelength transmission line in the differentiated configuration strategy The duration of overvoltage, power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of power fluctuation overvoltage;

The judgment module is used to judge whether the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy, the duration of the power fluctuation overvoltage, and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage meet the power fluctuation limit requirements at the same time. If satisfied, the differentiated configuration strategy is optimized, otherwise, the differentiated configuration strategy is corrected.

The power fluctuation overvoltage of the half-wavelength transmission line includes the overvoltage that occurs on the half-wavelength transmission line when the power fluctuation generated in the case of a fault on the half-wavelength transmission line exceeds the natural power;

The amplitude of the power fluctuation overvoltage is proportional to the ratio of the power fluctuation to the natural power of the half-wavelength transmission line;

The duration of the power fluctuation overvoltage is consistent with the power fluctuation time of the half-wavelength transmission line;

If the fault is a single-phase instantaneous ground fault, the fault process of the single-phase instantaneous ground fault includes a fault period process, a reclosing process and a swing process.

The first determining module is specifically used for:

The half-wavelength transmission line is evenly divided into multiple line units with a fixed length, and the same number of arresters are installed at the end of each line unit.

The first determining module is specifically used for:

Under the condition of the maximum transmission capacity of the half-wavelength transmission line, the maximum absorbed energy of the arrester under the action of power fluctuation overvoltage in the uniform configuration strategy is determined by the electromagnetic transient simulation model of the half-wavelength transmission system.

The second determining module is specifically used for:

Based on the principle that the maximum absorbed energy of a single group of arresters does not exceed 80% of the energy absorption capacity of the arrester, that each arrester installation position can be installed with at most two groups of arresters, and that the arrester should be installed at the end of the line unit first, at the end of each line unit Terminals and internally mounted surge arresters.

The second determining module is specifically used for:

Determine the end points of the line unit and the installed number of internal arresters, including:

Assume that m groups of arresters are installed at the end terminals and inside of the line unit, and the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform configuration strategy is E _U , when E _U <0.8EM, _m =1; when E _U ≥ When 0.8E _M , m=[E _U /0.8E _M ], [] means rounding off, where E _M is the energy absorption capability of the arrester;

Determine the end point of the line unit and the installation location of the internal arrester, including:

When m=1, install a group of arresters at the end of the line unit;

When m=2, install two sets of arresters at the end of the line unit;

When m ≥ 3, two sets of arresters are installed at the end points of the line unit, and the remaining arresters are arranged inside the line unit as follows:

m为奇数时，

The remaining arresters are arranged at positions with distances d, 2d, ..., kd from the end point of the line unit, where k is a natural number, d represents the span of the half-wavelength transmission line, and when m is an even number,

When m is odd,

The second determining module is specifically used for:

Under the condition of the maximum transmission capacity of the half-wavelength transmission line, the power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy are determined by the electromagnetic transient simulation model of the half-wavelength transmission system. The maximum absorbed energy of the arrester under the action.

The judging module is specifically used to determine the following power fluctuation limit requirements:

1) The power fluctuation overvoltage on the line side of the substation shall not exceed 1.4p.u., and the duration of the power fluctuation overvoltage on the line side of the substation shall not exceed 0.5s;

2) The amplitude of the power fluctuation overvoltage of the half-wavelength transmission line and the duration of the power fluctuation overvoltage of the half-wavelength transmission line both meet the temporary overvoltage withstand performance of the arrester;

3) The maximum absorbed energy of the arrester along the half-wavelength transmission line under the action of power fluctuation and overvoltage meets the energy absorption capability of the arrester.

The judgment module specifically optimizes the differentiated configuration strategy according to the following process:

Suppose the installation position of the arrester on the half-wavelength transmission line is L ₁ ,…,L _h ,…,L _H , the maximum absorbed energy of a single group of arresters is E _h , h=1,2,…,H, H represents the half-wavelength transmission line The total number of installation positions of the arrester;

If E _h < _0.5EM and there are at least two sets of arresters at the end of the line unit and inside, update the differentiated configuration strategy according to the principle of reducing one set of arresters each time from the head end of the line unit to the end of the line unit, and according to the half-wavelength transmission system The electromagnetic transient simulation model of the updated differential configuration strategy determines the power fluctuation overvoltage of the half-wavelength transmission line, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage, and judges the updated In the differentiated configuration strategy, whether the power fluctuation overvoltage of the half-wavelength transmission line, the duration of the power fluctuation overvoltage, and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage simultaneously meet the power fluctuation limit requirements. The configuration strategy is used as the final arrester configuration strategy, otherwise the differentiated configuration strategy before the update is used as the final arrester configuration strategy;

If 0.5E _M ≤ E _h ≤ E _M and the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage simultaneously satisfy the power fluctuation limit requirements, the differentiated configuration strategy is used as the final arrester configuration strategy.

The judging module specifically modifies the differentiated configuration strategy according to the following process:

Let the end points of the line unit and the installation position of the internal arrester be L ₁ ,…,L _i ,…,L _N , i=1,2,…,N, N represents the total number of installation positions of the arrester in the line unit, and L _i represents the first i installation positions;

If L _i is close to L ₁ , then at L ₁ and the position close to the head end of the line unit and the distance d from L ₁ , the differentiated configuration strategy is modified according to the principle of adding a group of arresters each time, until the half wavelength in the differentiated configuration strategy The power fluctuation overvoltage of the transmission line, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage meet the power fluctuation limit requirements at the same time, and the revised differentiated configuration strategy is used as the final arrester configuration strategy;

If _{Li is close to L N ,} the differential configuration strategy is revised according to the principle of adding a group of arresters at a position close to the end of the half-wavelength transmission line and the distance from _LN is d, until the half-wavelength transmission line in the differential configuration strategy The power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage meet the power fluctuation limit requirements at the same time, and the revised differentiated configuration strategy is used as the final arrester configuration strategy.

Compared with the closest prior art, the technical solution provided by the present invention has the following beneficial effects:

In the method for controlling the power fluctuation overvoltage of the half-wavelength transmission line provided by the present invention, the uniform configuration strategy of the arrester along the half-wavelength transmission line and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage in the uniform configuration strategy are first determined, and then according to the uniform configuration The maximum absorbed energy of the arrester under the action of power fluctuation overvoltage in the strategy determines the differentiated configuration strategy of the arrester along the half-wavelength transmission line, and determines the power fluctuation overvoltage and the duration of the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy and the maximum absorbed energy of the arrester under the action of the power fluctuation and overvoltage, and then judge whether the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage At the same time, the power fluctuation limit requirements are met. If they are met at the same time, the differentiated configuration strategy is optimized. Otherwise, the differentiated configuration strategy is revised to obtain the final differentiated configuration strategy to realize the control of the power fluctuation and overvoltage of the half-wavelength transmission line;

The device for controlling power fluctuation overvoltage of a half-wavelength transmission line provided by the present invention includes a first determination module for determining a uniform arrangement strategy of arresters along the half-wavelength transmission line and the maximum absorbed energy of the arrester under the action of power fluctuation overvoltage in the uniform arrangement strategy , It is used to determine the differentiated configuration strategy of arresters along the half-wavelength transmission line according to the maximum absorbed energy of the arrester under the action of power fluctuation overvoltage in the uniform configuration strategy, and to determine the power fluctuation overvoltage and power of the half-wavelength transmission line in the differentiated configuration strategy. The second determining module for the duration of the fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage, and the second determination module for judging the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy, the duration of the power fluctuation overvoltage and the Whether the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage meets the power fluctuation limit requirements at the same time, if it meets the requirements at the same time, the differentiated configuration strategy is optimized, otherwise the judgment module that corrects the differentiated configuration strategy, and finally obtains the final differentiated configuration strategy to realize the control of power fluctuation and overvoltage of half-wavelength transmission line;

The method for controlling the power fluctuation overvoltage of the half-wavelength transmission line provided by the present invention defines the power fluctuation overvoltage of the half-wavelength transmission line for the first time, and determines that the amplitude of the power fluctuation overvoltage including the power fluctuation overvoltage is approximately the same as that of the power fluctuation and the half-wavelength transmission line. The ratio of the natural power of the line and the consistency of the duration of the power fluctuation and overvoltage with the power fluctuation time of the half-wavelength transmission line provide the basis for the research of the half-wavelength transmission line;

The power fluctuation limit requirement in the method for controlling the power fluctuation overvoltage of the half-wavelength transmission line provided by the present invention includes that the power fluctuation overvoltage on the line side of the substation is not more than 1.4p.u. and the duration of the power fluctuation overvoltage on the line side of the substation is not more than 0.5s The amplitude of the power fluctuation overvoltage of the half-wavelength transmission line and the duration of the power fluctuation overvoltage of the half-wavelength transmission line both meet the temporary overvoltage withstand performance of the arrester and the maximum power fluctuation overvoltage of the arrester along the half-wavelength transmission line. There are three aspects that the absorbed energy satisfies the absorber energy absorption capacity of the arrester, which provides a judgment basis for the control of power fluctuation and overvoltage;

The method for controlling the power fluctuation overvoltage of the half-wavelength transmission line provided by the invention can effectively solve the problem of the power fluctuation overvoltage of the half-wavelength power transmission system, and can ensure the safe operation of the half-wavelength power transmission system, and simultaneously suppress the power fluctuation and overvoltage of the half-wavelength transmission line. provide a basis and basis;

The method for controlling the power fluctuation overvoltage of the half-wavelength transmission line provided by the present invention solves the technical problem of the new type of overvoltage (that is, the power fluctuation overvoltage of the half-wavelength transmission line) faced by the half-wavelength transmission technology, and has a great impact on the half-wavelength AC transmission technology test project. Provide strong technical support for implementation.

Description of drawings

1 is a flowchart of a method for controlling power fluctuation overvoltage of a half-wavelength transmission line in Embodiment 1 of the present invention;

2 is a schematic diagram of the sequence and process of a single-phase grounding transient fault occurring in a half-wavelength transmission line in Embodiment 1 of the present invention;

3 is a schematic diagram of the wiring of the half-wavelength power transmission system in Embodiment 2 of the present invention;

Fig. 4 is the power waveform diagram of three stages at the head end of the sound phase of the single-phase instantaneous ground fault process of the UHV half-wavelength transmission line in Embodiment 2 of the present invention;

5 is a schematic diagram of the power fluctuation and overvoltage distribution characteristics of the UHV half-wavelength transmission line during the single-phase instantaneous grounding fault process in Embodiment 2 of the present invention;

6 is a waveform diagram of three-stage power fluctuation overvoltage in the middle of a sound phase line of a UHV half-wavelength transmission line during a single-phase instantaneous ground fault process in Embodiment 2 of the present invention;

7 is a schematic diagram of the maximum absorbed energy distribution characteristics of the arrester along the UHV half-wavelength transmission line under the uniform configuration strategy in Embodiment 2 of the present invention;

8 is a schematic diagram of the number of surge arresters that need to be configured for line units of UHV half-wavelength transmission lines under the differentiated configuration strategy in Embodiment 2 of the present invention;

9 is a schematic diagram of the configuration strategy of the 10th line unit 8 groups of arresters under the differentiated configuration strategy in Embodiment 2 of the present invention;

10 is a schematic diagram of the configuration strategy of the 12th line unit 7 groups of arresters under the differentiated configuration strategy in Embodiment 2 of the present invention;

11 is a power fluctuation overvoltage waveform diagram of an ultra-high voltage half-wavelength transmission line under the differentiated strategy scheme in Embodiment 2 of the present invention;

Fig. 12 is the maximum absorbed energy distribution diagram of the arrester along the UHV half-wavelength transmission line under the differentiated configuration strategy in Embodiment 2 of the present invention;

13 is a power fluctuation overvoltage waveform diagram of an ultra-high voltage half-wavelength transmission line under the optimized differential configuration strategy in Embodiment 2 of the present invention;

FIG. 14 is a distribution diagram of the maximum absorbed energy of the arrester along the UHV half-wavelength transmission line under the optimized differentiated configuration strategy in Embodiment 2 of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings.

Embodiment 1 of the present invention provides a method for controlling power fluctuation overvoltage of a half-wavelength transmission line. The specific flowchart of the method is shown in FIG. 1 , and the specific process is as follows:

S101: Determine the uniform arrangement strategy of the arrester along the half-wavelength transmission line and the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform arrangement strategy;

S102: According to the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage in the uniform configuration strategy obtained in S101, determine the differentiated configuration strategy of the arrester along the half-wavelength transmission line, and determine the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy , the duration of power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of power fluctuation overvoltage;

S103: Determine whether the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy obtained in S102, the duration of the power fluctuation overvoltage, and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage simultaneously meet the power fluctuation limit requirements. If satisfied, the differentiated configuration strategy is optimized, otherwise, the differentiated configuration strategy is corrected.

The power fluctuation overvoltage of the half-wavelength transmission line mentioned in Embodiment 1 of the present invention refers to the overvoltage that occurs on the half-wavelength transmission line when the power fluctuation generated in the case of a fault on the half-wavelength transmission line exceeds the natural power;

The amplitude of the above power fluctuation overvoltage is proportional to the ratio of the power fluctuation to the natural power of the half-wavelength transmission line;

The duration of the above power fluctuation overvoltage is consistent with the power fluctuation time of the half-wavelength transmission line;

If the fault is a single-phase instantaneous grounding fault, the fault process of the single-phase instantaneous grounding fault includes the fault period process, the reclosing process and the swing process. The specific sequence and process of the single-phase instantaneous grounding fault on the half-wavelength transmission line are shown in Figure 2. t ₀ in Fig. 2 is the moment when the single-phase grounding fault occurs in the half-wavelength transmission line, t _B1 is the tripping moment of the faulty phase circuit breaker; t _B2 is the reclosing moment of the faulty phase circuit breaker.

S101 specifically includes the following steps:

1. Determine the uniform configuration strategy of arresters along the half-wavelength transmission line according to the following process:

The half-wavelength transmission line is evenly divided into multiple line units with a fixed length, and the same number of arresters are installed at the end of each line unit;

2. Determine the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform configuration strategy according to the following process:

Under the condition of the maximum transmission capacity of the half-wavelength transmission line, the maximum absorbed energy of the arrester under the action of power fluctuation overvoltage in the uniform configuration strategy is determined by the electromagnetic transient simulation model of the half-wavelength transmission system.

S102 specifically includes the following steps:

1. According to the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform configuration strategy, the differentiated configuration strategy of the arrester along the half-wavelength transmission line is determined. The specific process is as follows:

Based on the principle that the maximum absorbed energy of a single group of arresters does not exceed 80% of the energy absorption capacity of the arrester, that each arrester installation position can be installed with at most two groups of arresters, and that the arrester should be installed at the end of the line unit first, at the end of each line unit The end point and the internal installation of the arrester; the specific process of the end point of the line unit and the internal installation of the arrester is as follows:

1) Determine the terminal end of the line unit and the number of installations of the internal arrester, specifically:

Assume that m groups of arresters are installed at the end terminals and inside of the line unit, and the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform configuration strategy is E _U , when E _U <0.8EM, _m =1; when E _U ≥ When 0.8E _M , m=[E _U /0.8E _M ], [] means rounding off, where E _M is the energy absorption capability of the arrester;

2) Determine the end point of the line unit and the installation position of the internal arrester. There are the following three situations:

①When m=1, install a group of arresters at the end of the line unit;

②When m=2, install two sets of arresters at the end points of the line unit;

③When m ≥ 3, two sets of arresters are installed at the end points of the line unit, and the remaining arresters are arranged inside the line unit as follows:

m为奇数时，

The remaining arresters are arranged at positions with distances d, 2d, ..., kd from the end point of the line unit, where k is a natural number, d represents the span of the half-wavelength transmission line, and when m is an even number,

When m is odd,

2. Determine the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage. The specific process is as follows:

Under the condition of the maximum transmission capacity of the half-wavelength transmission line, the power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy are determined by the electromagnetic transient simulation model of the half-wavelength transmission system. The maximum absorbed energy of the arrester under the action.

The above-mentioned power fluctuation limit requirements specifically include the following three aspects:

1) The power fluctuation overvoltage on the line side of the substation shall not exceed 1.4p.u., and the duration of the power fluctuation overvoltage on the line side of the substation shall not exceed 0.5s;

2) The amplitude of the power fluctuation overvoltage of the half-wavelength transmission line and the duration of the power fluctuation overvoltage of the half-wavelength transmission line both meet the temporary overvoltage withstand performance of the arrester;

3) The maximum absorbed energy of the arrester along the half-wavelength transmission line under the action of power fluctuation and overvoltage meets the energy absorption capability of the arrester.

In the above S103, when the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy, the duration of the power fluctuation overvoltage, and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage simultaneously meet the power fluctuation limit requirements, the following procedures are used. Differentiated configuration strategy for optimization:

First, the installation positions of the arresters on the half-wavelength transmission line are set as L ₁ ,…,L _h ,…,L _H , the maximum energy absorbed by a single group of arresters is E _h , h=1,2,…,H, and H represents the half-wavelength transmission line The total number of installation positions of the upper arrester;

Then it is divided into the following two cases:

①If E _h < _0.5EM and there are at least two sets of arresters at the end of the line unit and inside the line unit, update the differentiated configuration strategy according to the principle of reducing one set of arresters from the head end of the line unit to the end of the line unit, and transmit power according to the half-wavelength The electromagnetic transient simulation model of the system determines the power fluctuation overvoltage of the half-wavelength transmission line, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage in the updated differentiated configuration strategy, and judges the updated Whether the power fluctuation overvoltage of the half-wavelength transmission line, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage in the differential configuration strategy of the The different configuration strategy is used as the final arrester configuration strategy, otherwise the differentiated configuration strategy before the update is used as the final arrester configuration strategy;

②If 0.5E _M ≤ E _h ≤ E _M and the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage can satisfy the power fluctuation at the same time If the limit requirements are met, the differentiated configuration strategy is used as the final arrester configuration strategy.

In the above S103, when the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy, the duration of the power fluctuation overvoltage, and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage cannot meet the power fluctuation limit requirements at the same time, follow the following process. Correction to the differentiated configuration strategy:

Let the terminal end of the line unit and the installation position of the internal arrester be L ₁ ,…,L _i ,…,L _N , i=1,2,…,N, N represents the total number of installation positions of the arrester in the line unit, and L _i represents i-th installation location;

Then it is divided into the following two cases:

①If L _i is close to L ₁ , at L ₁ and at the position close to the head end of the line unit and the distance d from L ₁ , the differentiated configuration strategy is modified according to the principle of adding a group of arresters each time, until half of the differentiated configuration strategy is in place. The power fluctuation overvoltage of the wavelength transmission line, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage meet the power fluctuation limit requirements at the same time, and the revised differentiated configuration strategy is used as the final arrester configuration strategy ;

_②If Li is close to L _N , the differential configuration strategy is modified according to the principle of adding a group of arresters at a position close to the end of the half-wavelength transmission line and the distance d from L _N until the half-wavelength power transmission in the differential configuration strategy The power fluctuation overvoltage of the line, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage meet the power fluctuation limit requirements at the same time, and the revised differentiated configuration strategy is used as the final arrester configuration strategy.

Based on the same inventive concept, Embodiment 1 of the present invention also provides a control device for power fluctuation overvoltage of half-wavelength transmission line. The principle of these devices to solve the problem is similar to the control method for power fluctuation overvoltage of half-wavelength transmission line. The control device for the power fluctuation overvoltage of the half-wavelength transmission line provided in Example 1 includes a first determination module, a second determination module and a judgment module. The specific functions of the above three modules are described below:

The first determining module is used to determine the uniform configuration strategy of the arrester along the half-wavelength transmission line and the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform configuration strategy;

The second determination module is used to determine the differential configuration strategy of the arrester along the half-wavelength transmission line according to the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform configuration strategy, and to determine the half-wavelength transmission line in the differentiated configuration strategy. The power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage;

The judgment module is used to judge whether the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage simultaneously meet the power fluctuation limit requirements. If both are satisfied, the differentiated configuration strategy is optimized, otherwise, the differentiated configuration strategy is corrected.

The power fluctuation overvoltage of the above-mentioned half-wavelength transmission line refers to the overvoltage that occurs on the half-wavelength transmission line when the power fluctuation exceeds the natural power when a fault occurs on the half-wavelength transmission line;

The amplitude of the above-mentioned power fluctuation overvoltage is proportional to the ratio of the power fluctuation to the natural power of the half-wavelength transmission line;

The duration of the above-mentioned power fluctuation overvoltage is consistent with the power fluctuation time of the half-wavelength transmission line;

If the fault is a single-phase instantaneous ground fault, the fault process of the single-phase instantaneous ground fault includes the process during the fault, the reclosing process and the swing process.

The above-mentioned first determination module determines the uniform configuration strategy of the arrester along the half-wavelength transmission line according to the following process:

The half-wavelength transmission line is evenly divided into multiple line units with a fixed length, and the same number of arresters are installed at the end of each line unit.

The above-mentioned first determination module determines the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform configuration strategy according to the following process:

Under the condition of the maximum transmission capacity of the half-wavelength transmission line, the maximum absorbed energy of the arrester under the action of power fluctuation overvoltage in the uniform configuration strategy is determined by the electromagnetic transient simulation model of the half-wavelength transmission system.

The above-mentioned second determination module determines the differentiated configuration strategy of the arrester along the half-wavelength transmission line according to the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform configuration strategy according to the following process:

Based on the principle that the maximum absorbed energy of a single group of arresters does not exceed 80% of the energy absorption capacity of the arrester, that each arrester installation position can be installed with at most two groups of arresters, and that the arrester should be installed at the end of the line unit first, at the end of each line unit The specific process of installing the arrester at the end point and inside, and the end point of the line unit and the inner installation of the arrester is as follows:

1. Determine the end points of the line unit and the installation number of internal arresters, including:

Assume that m groups of arresters are installed at the end terminals and inside of the line unit, and the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform configuration strategy is E _U , when E _U <0.8EM, _m =1; when E _U ≥ When 0.8E _M , m=[E _U /0.8E _M ], [] means rounding off, where E _M is the energy absorption capability of the arrester;

2. Determine the end point of the line unit and the installation position of the internal arrester, which can be divided into the following three situations:

①When m=1, install a group of arresters at the end of the line unit;

②When m=2, install two sets of arresters at the end points of the line unit;

③When m ≥ 3, two sets of arresters are installed at the end points of the line unit, and the remaining arresters are arranged inside the line unit as follows:

m为奇数时，

The remaining arresters are arranged at positions with distances d, 2d, ..., kd from the end point of the line unit, where k is a natural number, d represents the span of the half-wavelength transmission line, and when m is an even number,

When m is odd,

Under the condition of the maximum transmission capacity of the half-wavelength transmission line, the above-mentioned second determination module determines the power fluctuation overvoltage and the duration of the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy through the electromagnetic transient simulation model of the half-wavelength transmission system. The maximum absorbed energy of the arrester under the action of time and power fluctuation overvoltage.

The above judgment module is specifically used to determine the following power fluctuation limit requirements:

1) The power fluctuation overvoltage on the line side of the substation shall not exceed 1.4p.u., and the duration of the power fluctuation overvoltage on the line side of the substation shall not exceed 0.5s;

2) The amplitude of the power fluctuation overvoltage of the half-wavelength transmission line and the duration of the power fluctuation overvoltage of the half-wavelength transmission line both meet the temporary overvoltage withstand performance of the arrester;

3) The maximum absorbed energy of the arrester along the half-wavelength transmission line under the action of power fluctuation and overvoltage meets the energy absorption capability of the arrester.

When the above judgment module meets the power fluctuation limit requirements for the power fluctuation overvoltage of the half-wavelength transmission line, the duration of the power fluctuation overvoltage, and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage while meeting the power fluctuation limit requirements in the differentiated configuration strategy, the following procedures are used. Differentiated configuration strategy for optimization:

First, the installation positions of the arresters on the half-wavelength transmission line are set as L ₁ ,…,L _h ,…,L _H , the maximum energy absorbed by a single group of arresters is E _h , h=1,2,…,H, and H represents the half-wavelength transmission line The total number of installation positions of the upper arrester;

Then there are two cases:

①If E _h < _0.5EM and there are at least two sets of arresters at the end of the line unit and inside, update the differentiated configuration strategy according to the principle of reducing one set of arresters each time from the head end of the line unit to the end of the line unit, and transmit power according to half-wavelength The electromagnetic transient simulation model of the system determines the power fluctuation overvoltage of the half-wavelength transmission line in the updated differentiated configuration strategy, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage, and judges the updated Whether the power fluctuation overvoltage of the half-wavelength transmission line, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage in the differentiated configuration strategy of the half-wavelength transmission line simultaneously meet the power fluctuation limit requirements, and if so, update the difference The differentiated configuration strategy is used as the final arrester configuration strategy, otherwise the differentiated configuration strategy before the update is used as the final arrester configuration strategy;

②If 0.5E _M ≤ E _h ≤ E _M and the power fluctuation overvoltage of the half-wavelength transmission line in the differentiated configuration strategy, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage can satisfy the power fluctuation at the same time If the limit requirements are met, the differentiated configuration strategy is used as the final arrester configuration strategy.

In the differential configuration strategy, when the power fluctuation overvoltage of the half-wavelength transmission line, the duration of the power fluctuation overvoltage, and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage cannot meet the power fluctuation limit requirements at the same time, the above judgment module will not be able to meet the power fluctuation limit requirements at the same time. Configuration policy to fix:

Let the terminal end of the line unit and the installation position of the internal arrester be L ₁ ,…,L _i ,…,L _N , i=1,2,…,N, N represents the total number of installation positions of the arrester in the line unit, and L _i represents i-th installation location;

Then there are two cases:

①If L _i is close to L ₁ , at L ₁ and at the position close to the head end of the line unit and the distance d from L ₁ , the differentiated configuration strategy is modified according to the principle of adding a group of arresters each time, until half of the differentiated configuration strategy is in place. The power fluctuation overvoltage of the wavelength transmission line, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage meet the power fluctuation limit requirements at the same time, and the revised differentiated configuration strategy is used as the final arrester configuration strategy ;

_②If Li is close to L _N , the differential configuration strategy is modified according to the principle of adding a group of arresters at a position close to the end of the half-wavelength transmission line and the distance d from L _N until the half-wavelength power transmission in the differential configuration strategy The power fluctuation overvoltage of the line, the duration of the power fluctuation overvoltage and the maximum absorbed energy of the arrester under the action of the power fluctuation overvoltage meet the power fluctuation limit requirements at the same time, and the revised differentiated configuration strategy is used as the final arrester configuration strategy.

Example 2

Taking the single-circuit UHV half-wavelength power transmission system as an example, the application of the control method for the power fluctuation overvoltage of the half-wavelength AC power transmission system proposed by the present invention will be described below:

The wiring diagram of a point-to-grid UHV half-wavelength transmission system is shown in Figure 3. The sending end adopts 10 600MW units to boost the voltage to 1000kV, and is connected to the receiving end system through a 3000km line erected in a single circuit, and the receiving end is directly connected to 1000kV grid. The receiving end adopts a single-machine infinite system, and its short-circuit capacity is 40kA before the half-wavelength transmission line is connected. Its maximum transmission power is designed according to 5000MW.

The approximate sequence parameters of the 1000kV single-circuit line are shown in Table 1:

Table 1

1050kV下自然功率为4485MW(1p.u.)，波长为5898km，精确半波长为2949km。研究中设定半波长交流线路长度为3000km，共30段，每段100km。Ignoring the line loss, according to Table 1, the wave impedance of the UHV line can be obtained as

The natural power at 1050kV is 4485MW (1p.u.), the wavelength is 5898km, and the exact half wavelength is 2949km. In the study, the length of the half-wavelength AC line is set to 3000km, with a total of 30 sections, each section 100km.

The rated voltage of the arrester along the UHV half-wavelength transmission system is 876kV, and its requirements for withstanding temporary overvoltage are shown in Table 2, and its energy absorption tolerance E _M is 42MJ.

The specific process of the control method for the power fluctuation overvoltage of the half-wavelength power transmission system provided in the second embodiment of the present invention is as follows:

Step 1: Determine the uniform configuration strategy of arresters along the half-wavelength transmission line and the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform configuration strategy:

Step 1-1: When a single-phase transient fault occurs on the UHV half-wavelength transmission line, there is a high-amplitude power fluctuation on the half-wavelength transmission line, as shown in Figure 4. When the power fluctuation exceeds the natural power, overvoltage occurs along the half-wavelength transmission line, and the extreme point of overvoltage along the line is located in the middle of the line, as shown in Figure 5. The overvoltage at the extreme point position is shown in Figure 6, and its amplitude (per unit value) is about the ratio of power fluctuation to natural power, and the duration of overvoltage is consistent with the time of power fluctuation. The overvoltage is the power fluctuation overvoltage defined in the present invention. Power fluctuation overvoltage is characterized by a temporary overvoltage category, with high amplitude, long duration, and wide coverage along the line.

The single-phase instantaneous grounding fault is used as the power fluctuation overvoltage of the half-wavelength transmission line to study the fault condition, and the single-phase instantaneous grounding process is divided into three stages: the fault process, the reclosing period and the system swing process after the reclosing is successful. The time t ₀ of the single-phase grounding fault on the half-wavelength transmission line is 4s, the tripping time of the faulty phase circuit breaker is t _B1 and it is _4.125s ; the reclosing time of the faulty phase circuit breaker is 5.025s.

Step 1-2: Divide the UHV half-wavelength transmission line into 30 line units evenly with a fixed length of 100km, and install 2 sets of lightning arresters at the end of each line unit.

Step 1-3: The maximum absorbed energy of the arrester under the uniform configuration strategy is determined according to the following process: Under the condition that the maximum transmission capacity of the UHV half-wavelength transmission line is 5000MW, the uniform configuration strategy is determined through the electromagnetic transient simulation model of the half-wavelength transmission system. The maximum absorbed energy of the arrester under the action of power fluctuation overvoltage during the single-phase instantaneous ground fault process is shown in Figure 7.

Step 2: Determine the differentiated configuration strategy of arresters along the half-wavelength transmission line according to the maximum absorbed energy of the arrester under the action of power fluctuation overvoltage in the uniform configuration strategy, and determine the power fluctuation overvoltage and power of the half-wavelength transmission line in the differentiated configuration strategy Duration of fluctuating overvoltage and maximum absorbed energy of arrester under the action of power fluctuating overvoltage:

Step 2-1: Determine the differentiated configuration strategy of arresters along the UHV half-wavelength transmission line according to the maximum absorbed energy of the arrester. The principle of installing at most two sets of arresters at the installation location is to install arresters at the endpoints of each line unit and inside the line unit. The line unit determines the installed number of arresters according to the following procedure:

Assume that m groups of arresters are installed at the end terminals and inside of the line unit, and the maximum absorbed energy of the arrester under the action of power fluctuation and overvoltage in the uniform configuration strategy is E _U , when E _U <0.8EM, _m =1; when E _U ≥ When 0.8E _M , m=[E _U /0.8E _M ], [] means rounding off, where E _M is the energy absorption capability of the arrester. As a result, each line unit along the UHV half-wavelength transmission line needs to be equipped with the number of arresters, including the end point and the interior of the line unit, as shown in Figure 8, a total of 93 groups of arresters.

The line unit determines the end point of the line unit and the installation position of the internal arrester according to the following procedure:

When m=1, install a group of arresters at the end of the line unit;

When m=2, install two sets of arresters at the end of the line unit;

When m ≥ 3, two sets of arresters are installed at the end points of the line unit, and the remaining arresters are arranged inside the line unit as follows:

m为奇数时，

The remaining arresters are arranged at positions with a distance of 400m, 800m, ..., k × 400m from the end point of the line unit, where k is a natural number, the span of the UHV half-wavelength transmission line is 400m, and when m is an even number,

When m is odd,

Taking the 10th line unit (the line unit from 900km to 1000km from the head end of the line) and the 12th line unit (the line unit from 1100km to 1200km from the head end of the line) as examples, the configuration positions of multiple groups of arresters are explained:

As shown in Figure 8, the 10th line unit needs to be equipped with 8 groups of arresters, so two groups of arresters are installed at the end points of the line unit, and a total of 6 groups of arresters need to be installed inside the line. The 6 groups of arresters inside the line are arranged at positions of 400m, 800m and 1200m from the end point of the line unit, as shown in Figure 9.

As shown in Figure 9, the 12th line unit needs to be equipped with a total of 7 sets of lightning arresters, then two sets of lightning arresters are installed at the end points of the line unit, and a total of 5 sets of lightning arresters need to be installed inside the line. The 5 groups of arresters inside the line are arranged at positions of 400m, 800m and 1200m from the end point of the line unit, as shown in Figure 10.

Step 2-2: Under the condition that the maximum transmission capacity of the UHV half-wavelength transmission line is 5000MW, determine the power fluctuation overvoltage and power fluctuation overvoltage of the half-wavelength transmission line under the differentiated configuration strategy through the electromagnetic transient simulation model of the half-wavelength transmission system Duration and maximum absorbed energy of the arrester: the maximum amplitude of power fluctuation along the line overvoltage is 1.56pu, and the overvoltage duration of 1.5～1.56pu is 1.15s, as shown in Figure 11; UHV half-wavelength arrester along the line (single group) The maximum absorbed energy distribution is shown in Figure 12.

Step 3: Determine whether the power fluctuation overvoltage of the half-wavelength transmission line, the power fluctuation overvoltage duration and the maximum absorbed energy of the arrester meet the power fluctuation limit requirements under the differentiated configuration strategy at the same time, and if they meet both, optimize the differentiated configuration strategy , otherwise make corrections to the differentiated configuration strategy:

Step 3-1: Determine the following power fluctuation limit requirements for half-wavelength transmission systems:

1) The power fluctuation overvoltage on the line side of the UHV substation shall not exceed 1.4p.u., and the duration of the power fluctuation overvoltage on the line side of the substation shall not exceed 0.5s;

2) The amplitude of the power fluctuation overvoltage of the half-wavelength transmission line and the duration of the power fluctuation overvoltage of the half-wavelength transmission line both meet the temporary overvoltage withstand performance of the arrester, as shown in Table 2:

Table 2

3) The maximum absorbed energy of the arrester along the half-wavelength transmission line under the action of power fluctuation and overvoltage meets the energy absorption capability of the arrester.

Step 3-2: Optimize the differentiated configuration strategy:

Suppose the installation position of the arrester on the UHV half-wavelength transmission line is L ₁ ,…,L _h ,…,L _H , and the maximum absorbed energy of a single group of arresters in L _h is E _h , h=1,2,…,H, H represents half The total number of installation positions of arresters on wavelength transmission lines.

According to Figure 12, the maximum absorbed energy of the arresters of the 14th, 15th and 16th line units is less than 21MJ (0.5EM), and there are at least two sets of arresters at the end and inside; the maximum absorbed energy of the arresters of other line units satisfies 0.5E _M ≤ E _h ≤ E _M , and the power fluctuation overvoltage and the power fluctuation overvoltage duration meet the power fluctuation limit requirements. Therefore, according to the principle of reducing a group of arresters from the head end of the line unit to the end of the line unit, the configuration quantities of the arresters of the 14th, 15th and 16th line units in the differentiated configuration strategy are updated. And according to the electromagnetic transient simulation model of the half-wavelength transmission system, the power fluctuation overvoltage of the half-wavelength transmission line, the power fluctuation overvoltage duration and the maximum absorbed energy of the arrester under the updated differentiated configuration strategy are determined: the power fluctuation overvoltage along the line is the largest The amplitude is 1.56pu, and the overvoltage duration of 1.5～1.56pu is 1.15s, as shown in Figure 13; the maximum absorbed energy distribution of UHV half-wavelength arresters (single group) along the line is shown in Figure 14. The above results can meet the power fluctuation limit requirements, so the updated differentiated configuration strategy is used as the final arrester configuration strategy. A total of 90 sets of arresters are required for UHV half-wavelength transmission lines.

For the convenience of description, each part of the device described above is divided into various modules or units by function and described respectively. Of course, when implementing the present application, the functions of each module or unit may be implemented in one or more software or hardware.

As will be appreciated by those skilled in the art, the embodiments of the present application may be provided as a method, a system, or a computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It will be understood that each flow and/or block in the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in the flow or blocks of the flowcharts and/or the block or blocks of the block diagrams.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Those of ordinary skill in the art can still modify or equivalently replace the specific embodiments of the present invention with reference to the above embodiments. Any modifications or equivalent substitutions that depart from the spirit and scope of the present invention are all within the protection scope of the claims of the present invention for which the application is pending.

Claims (16)

1. A control method for half-wavelength transmission line power fluctuation overvoltage is characterized by comprising the following steps:

determining the maximum absorption energy of the arrester under the action of power fluctuation overvoltage in a uniform configuration strategy and a uniform configuration strategy of the arrester along the half-wavelength power transmission line;

determining a differential configuration strategy of the arrester along the half-wavelength power transmission line according to the maximum absorption energy of the arrester under the action of the power fluctuation overvoltage in the uniform configuration strategy, and determining the power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the maximum absorption energy of the arrester under the action of the power fluctuation overvoltage in the differential configuration strategy;

judging whether the power fluctuation overvoltage of the half-wavelength power transmission line, the duration of the power fluctuation overvoltage and the maximum absorption energy of the lightning arrester under the action of the power fluctuation overvoltage in the differential configuration strategy simultaneously meet the power fluctuation limiting requirement, if so, optimizing the differential configuration strategy, and otherwise, correcting the differential configuration strategy;

the power fluctuation overvoltage of the half-wavelength power transmission line comprises overvoltage which occurs on the half-wavelength power transmission line when power fluctuation generated under the condition that the half-wavelength power transmission line has a fault exceeds natural power;

the amplitude of the power fluctuation overvoltage is proportional to the ratio of the power fluctuation to the natural power of the half-wavelength power transmission line;

the duration of the power fluctuation overvoltage is consistent with the power fluctuation time of the half-wavelength power transmission line;

if the fault is a single-phase instantaneous earth fault, the fault process of the single-phase instantaneous earth fault comprises a fault period process, a reclosing process and a swinging process;

the uniform configuration strategy of the arrester along the half-wavelength power transmission line is determined according to the following processes:

uniformly dividing the half-wavelength power transmission line into a plurality of line units in a fixed length, and installing the same group number of lightning arresters at the end point of each line unit;

the maximum absorption energy of the arrester under the action of power fluctuation overvoltage in the uniform configuration strategy is determined according to the following process:

under the condition of the maximum power transmission capacity of the half-wavelength power transmission line, determining the maximum absorption energy of the lightning arrester under the action of power fluctuation overvoltage in a uniform configuration strategy through an electromagnetic transient simulation model of the half-wavelength power transmission system;

the differential configuration strategy for determining the arrester along the half-wavelength power transmission line according to the maximum absorption energy of the arrester under the action of power fluctuation overvoltage in the uniform configuration strategy comprises the following steps:

the lightning arresters are arranged at the tail end points and the interior of each line unit on the principle that the maximum absorption energy of a single group of lightning arresters does not exceed 80% of the energy absorption capacity of the lightning arresters, at most two groups of lightning arresters are arranged at each lightning arrester installation position, and the lightning arresters are preferentially arranged at the tail ends of the line units.

2. The method of controlling power fluctuation overvoltage of a half-wavelength power transmission line according to claim 1, wherein the terminal end point of the line unit and the internally installed lightning arrester include:

determining the number of terminal ends of the line units and the number of installations of the internal arresters, comprising:

the terminal end points and the interior of the line unit are provided with m groups of lightning arresters, and the maximum absorption energy of the lightning arresters under the action of power fluctuation overvoltage in a uniform configuration strategy is E_UWhen E is_U＜0.8E_MWhen m is 1; when E is_U≥0.8E_MWhen m is ═ E_U/0.8E_M]，[]Denotes rounding off, where E_MThe ability to withstand the energy absorbed by the arrester;

determining the terminal end point of the line unit and the installation position of the internal arrester, including:

when m is 1, a group of lightning arresters are installed at the tail end of the line unit;

when m is 2, two groups of lightning arresters are installed at the end points of the tail end of the line unit;

when m is more than or equal to 3, two groups of lightning arresters are installed at the end points of the line unit, and the rest lightning arresters are arranged in the line unit according to the following modes:

the rest lightning arresters are arranged at positions which are at distances of d, 2d, … and kd from the tail end of the line unit, wherein k is a natural number, d represents the span of the half-wavelength transmission line, and when m is an even number,

when m is an odd number, the number of the carbon atoms,

3. the method for controlling the power fluctuation overvoltage of the half-wavelength power transmission line according to claim 2, wherein the determining the power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the maximum absorption energy of the lightning arrester under the action of the power fluctuation overvoltage of the half-wavelength power transmission line in the differential configuration strategy comprises:

under the condition of the maximum power transmission capacity of the half-wavelength power transmission line, determining the power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the maximum absorption energy of the lightning arrester under the action of the power fluctuation overvoltage in a differential configuration strategy through an electromagnetic transient simulation model of the half-wavelength power transmission system.

4. The method for controlling the power fluctuation overvoltage of the half-wavelength power transmission line according to claim 3, wherein the power fluctuation limitation requirement includes:

1) the power fluctuation overvoltage of the transformer substation line side is not more than 1.4p.u., and the duration time of the power fluctuation overvoltage of the transformer substation line side is not more than 0.5 s;

2) the amplitude of the power fluctuation overvoltage of the half-wavelength power transmission line and the duration of the power fluctuation overvoltage of the half-wavelength power transmission line meet the temporary overvoltage tolerance of the lightning arrester;

3) the maximum absorption energy of the arrester along the half-wavelength power transmission line under the action of power fluctuation overvoltage meets the tolerance capability of the arrester for absorbing energy.

5. The method of claim 4, wherein the optimizing the differential configuration strategy comprises:

the installation position of the lightning arrester on the half-wavelength transmission line is set to be L₁,…,L_h,…,L_HThe maximum absorption energy of the single-group lightning arrester is E_hH is 1,2, …, H, H represents the total number of installation positions of the lightning arrester on the half-wavelength transmission line;

if E_h＜0.5E_MAnd the end point and the interior of the line unit are provided with at least two groups of lightning arresters, the differential configuration strategy is updated according to the principle that one group of lightning arresters is reduced from the head end of the line unit to the tail end of the line unit each time, the power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the maximum absorption energy of the lightning arresters under the action of the power fluctuation overvoltage of the half-wavelength power transmission line in the updated differential configuration strategy are determined according to an electromagnetic transient simulation model of the half-wavelength power transmission system, and the updated maximum absorption energy of the lightning arresters under the action of the half-wavelength power fluctuation overvoltage in the differential configuration strategy is judgedWhether the power fluctuation overvoltage, the duration time of the power fluctuation overvoltage and the maximum absorption energy of the lightning arrester under the action of the power fluctuation overvoltage of the long power transmission line meet the power fluctuation limiting requirement or not simultaneously, if so, taking the updated differential configuration strategy as a final lightning arrester configuration strategy, and otherwise, taking the differential configuration strategy before updating as a final lightning arrester configuration strategy;

if 0.5E_M≤E_h≤E_MAnd the power fluctuation overvoltage of the half-wavelength power transmission line, the duration of the power fluctuation overvoltage and the maximum absorption energy of the arrester under the action of the power fluctuation overvoltage in the differential configuration strategy simultaneously meet the power fluctuation limiting requirement, and then the differential configuration strategy is used as a final arrester configuration strategy.

6. The method for controlling the power fluctuation overvoltage of the half-wavelength power transmission line according to claim 4, wherein the correcting the differential configuration strategy comprises:

setting the terminal end point of the line unit and the installation position of the internal lightning arrester as L₁,…,L_i,…,L_NI is 1,2, …, N represents the total number of lightning arrester installation positions in the line unit, L_iIndicates the ith mounting position;

if L is_iClose to L₁Then at L₁And near the head end of the line unit and with L₁Correcting the differentiated configuration strategy at the position with the distance d according to the principle of adding a group of lightning arresters at each time until the power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the maximum absorption energy of the lightning arresters under the action of the power fluctuation overvoltage in the differentiated configuration strategy simultaneously meet the power fluctuation limiting requirement, and taking the corrected differentiated configuration strategy as a final lightning arrester configuration strategy;

if L is_iClose to L_NThen near the end of the half-wavelength transmission line and L_NAnd correcting the differential configuration strategy at the position with the distance d according to the principle of adding a group of lightning arresters at each time until the power fluctuation overvoltage of the half-wavelength power transmission line in the differential configuration strategyThe duration of the power fluctuation overvoltage and the maximum absorption energy of the arrester under the action of the power fluctuation overvoltage meet the power fluctuation limiting requirement at the same time, and the corrected differential configuration strategy is used as a final arrester configuration strategy.

7. A control device for power fluctuation overvoltage of a half-wavelength power transmission line is characterized by comprising:

the first determining module is used for determining the maximum absorption energy of the arrester under the action of power fluctuation overvoltage in a uniform configuration strategy and a uniform configuration strategy of the arrester along the half-wavelength power transmission line;

the second determination module is used for determining a differential configuration strategy of the arrester along the half-wavelength power transmission line according to the maximum absorption energy of the arrester under the action of the power fluctuation overvoltage in the uniform configuration strategy, and determining the power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the maximum absorption energy of the arrester under the action of the power fluctuation overvoltage in the differential configuration strategy;

the judging module is used for judging whether the power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the maximum absorption energy of the arrester under the action of the power fluctuation overvoltage meet the power fluctuation limiting requirement or not in the differential configuration strategy, if so, the differential configuration strategy is optimized, and otherwise, the differential configuration strategy is corrected;

the uniform configuration strategy of the arrester along the half-wavelength power transmission line is determined according to the following processes:

uniformly dividing the half-wavelength power transmission line into a plurality of line units in a fixed length, and installing the same group number of lightning arresters at the end point of each line unit;

the differential configuration strategy for determining the arrester along the half-wavelength power transmission line according to the maximum absorption energy of the arrester under the action of power fluctuation overvoltage in the uniform configuration strategy comprises the following steps:

the lightning arresters are arranged at the tail end points and the interior of each line unit on the principle that the maximum absorption energy of a single group of lightning arresters does not exceed 80% of the energy absorption capacity of the lightning arresters, at most two groups of lightning arresters are arranged at each lightning arrester installation position, and the lightning arresters are preferentially arranged at the tail ends of the line units.

8. The apparatus of claim 7, wherein the power fluctuation overvoltage of the half-wavelength power transmission line comprises an overvoltage occurring on the half-wavelength power transmission line when a power fluctuation generated in the event of a fault on the half-wavelength power transmission line exceeds a natural power;

the amplitude of the power fluctuation overvoltage is proportional to the ratio of the power fluctuation to the natural power of the half-wavelength power transmission line;

the duration of the power fluctuation overvoltage is consistent with the power fluctuation time of the half-wavelength power transmission line;

if the fault is a single-phase instantaneous earth fault, the fault process of the single-phase instantaneous earth fault comprises a fault period process, a reclosing process and a swinging process.

9. The apparatus for controlling the power fluctuation overvoltage of the half-wavelength power transmission line according to claim 8, wherein the first determining module is specifically configured to:

the half-wavelength transmission line is evenly divided into a plurality of line units in a fixed length, and the same groups of lightning arresters are arranged at the end points of each line unit.

10. The apparatus for controlling the power fluctuation overvoltage of the half-wavelength power transmission line according to claim 9, wherein the first determining module is specifically configured to:

under the condition of the maximum power transmission capacity of the half-wavelength power transmission line, the maximum absorption energy of the lightning arrester under the action of power fluctuation overvoltage in the uniform configuration strategy is determined through an electromagnetic transient simulation model of the half-wavelength power transmission system.

11. The apparatus for controlling the power fluctuation overvoltage of the half-wavelength power transmission line according to claim 10, wherein the second determining module is specifically configured to:

the lightning arresters are arranged at the tail end points and the interior of each line unit on the principle that the maximum absorption energy of a single group of lightning arresters does not exceed 80% of the energy absorption capacity of the lightning arresters, at most two groups of lightning arresters are arranged at each lightning arrester installation position, and the lightning arresters are preferentially arranged at the tail ends of the line units.

12. The apparatus for controlling the power fluctuation overvoltage of the half-wavelength power transmission line according to claim 11, wherein the second determining module is specifically configured to:

determining the number of terminal ends of the line units and the number of installations of the internal arresters, comprising:

the terminal end points and the interior of the line unit are provided with m groups of lightning arresters, and the maximum absorption energy of the lightning arresters under the action of power fluctuation overvoltage in a uniform configuration strategy is E_UWhen E is_U＜0.8E_MWhen m is 1; when E is_U≥0.8E_MWhen m is ═ E_U/0.8E_M]，[]Denotes rounding off, where E_MThe ability to withstand the energy absorbed by the arrester;

determining the terminal end point of the line unit and the installation position of the internal arrester, including:

when m is equal to 1, a group of lightning arresters are installed at the tail end of the line unit;

when m is 2, two groups of lightning arresters are installed at the end points of the tail end of the line unit;

when m is more than or equal to 3, two groups of lightning arresters are installed at the end points of the line unit, and the rest lightning arresters are arranged in the line unit according to the following modes:

the rest lightning arresters are arranged at positions which are at distances of d, 2d, … and kd from the tail end of the line unit, wherein k is a natural number, d represents the span of the half-wavelength transmission line, and when m is an even number,

when m is an odd number, the number of the carbon atoms,

13. the apparatus for controlling the power fluctuation overvoltage of the half-wavelength power transmission line according to claim 12, wherein the second determining module is specifically configured to:

under the condition of the maximum power transmission capacity of the half-wavelength power transmission line, determining the power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the maximum absorption energy of the lightning arrester under the action of the power fluctuation overvoltage of the half-wavelength power transmission line in a differential configuration strategy through an electromagnetic transient simulation model of the half-wavelength power transmission system.

14. The apparatus for controlling power fluctuation overvoltage of a half-wavelength power transmission line according to claim 13, wherein the determining module is specifically configured to determine the following power fluctuation limiting requirements:

1) the power fluctuation overvoltage of the transformer substation line side is not more than 1.4p.u., and the duration time of the power fluctuation overvoltage of the transformer substation line side is not more than 0.5 s;

2) the amplitude of the power fluctuation overvoltage of the half-wavelength power transmission line and the duration of the power fluctuation overvoltage of the half-wavelength power transmission line meet the temporary overvoltage tolerance of the lightning arrester;

3) the maximum absorption energy of the arrester along the half-wavelength power transmission line under the action of power fluctuation overvoltage meets the tolerance capability of the arrester for absorbing energy.

15. The apparatus for controlling power fluctuation overvoltage of a half-wavelength power transmission line according to claim 14, wherein the determining module optimizes the differentiated configuration strategy according to the following procedures:

the installation position of the lightning arrester on the half-wavelength transmission line is set to be L₁,…,L_h,…,L_HThe maximum absorption energy of the single-group lightning arrester is E_hH is 1,2, …, H, H represents the total number of installation positions of the lightning arrester on the half-wavelength transmission line;

if E_h＜0.5E_MAnd the terminal and the interior of the circuit unitAt least two groups of lightning arresters are shared, the differential configuration strategy is updated according to the principle that one group of lightning arresters is reduced from the head end of the line unit to the tail end of the line unit each time, and determining the power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the maximum absorption energy of the arrester under the action of the power fluctuation overvoltage of the half-wavelength power transmission line in the updated differential configuration strategy according to an electromagnetic transient simulation model of the half-wavelength power transmission system, judging whether the power fluctuation overvoltage, the duration of the power fluctuation overvoltage and the maximum absorption energy of the arrester under the action of the power fluctuation overvoltage in the updated differential configuration strategy simultaneously meet the power fluctuation limiting requirement, if so, taking the updated differential configuration strategy as a final arrester configuration strategy, and otherwise, taking the differential configuration strategy before updating as a final arrester configuration strategy;

if 0.5E_M≤E_h≤E_MAnd the power fluctuation overvoltage of the half-wavelength power transmission line, the duration of the power fluctuation overvoltage and the maximum absorption energy of the arrester under the action of the power fluctuation overvoltage in the differentiated configuration strategy simultaneously meet the power fluctuation limitation requirement, and then the differentiated configuration strategy is used as a final arrester configuration strategy.

16. The device for controlling the power fluctuation overvoltage of the half-wavelength power transmission line according to claim 14, wherein the judging module corrects the differentiated configuration strategy according to the following process:

the terminal end point of the line unit and the installation position of the internal lightning arrester are set to be L₁,…,L_i,…,L_NI is 1,2, …, N represents the total number of lightning arrester installation positions in the line unit, L_iIndicates the ith mounting position;

if L is_iClose to L₁Then at L₁And near the head end of the line unit and with L₁And correcting the differential configuration strategy at the position with the distance d according to the principle of adding a group of lightning arresters at each time until the power fluctuation overvoltage of the half-wavelength power transmission line in the differential configuration strategy, the duration time of the power fluctuation overvoltage and the sum of the power fluctuation overvoltageThe maximum absorption energy of the arrester under the action of power fluctuation overvoltage meets the power fluctuation limiting requirement at the same time, and the corrected differential configuration strategy is used as a final arrester configuration strategy;

if L is_iClose to L_NThen near the end of the half-wavelength transmission line and with L_NAnd (d) correcting the differential configuration strategy at the position with the distance d according to the principle of adding a group of lightning arresters at each time until the power fluctuation overvoltage of the half-wavelength power transmission line, the duration of the power fluctuation overvoltage and the maximum absorption energy of the lightning arresters under the action of the power fluctuation overvoltage in the differential configuration strategy simultaneously meet the power fluctuation limiting requirement, and taking the corrected differential configuration strategy as the final lightning arrester configuration strategy.

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