CN108539757B - Reactive power scheduling method for optical storage cluster of power distribution network - Google Patents

Abstract

The embodiment of the invention provides a reactive power scheduling method for a power distribution network light storage cluster. The method comprises the following steps: judging the reactive power operation interval, and according to the modulation value Q and the actual reactive power Q measured at the grid-connected point_pccDetermining a value delta Q to be adjusted of reactive power by combining the condition of the out-of-limit threshold of the local voltage; and scheduling the reactive power of each energy storage device and each small photovoltaic power station according to the size of the delta Q, when the delta Q is larger than 0, scheduling the increased reactive power of each energy storage device and each small photovoltaic power station, and otherwise, scheduling the decreased reactive power of each energy storage device and each small photovoltaic power station by making the delta Q |. The invention enables a power grid dispatching department to obtain the reactive power dispatching capability which is not possessed originally, reduces or even avoids the problem of voltage out-of-limit, and can deal with complicated and changeable field working conditions.

Description

Reactive power scheduling method for optical storage cluster of power distribution network

Technical Field

The invention relates to the technical field of power grid dispatching, in particular to a reactive power dispatching method for a power distribution network light storage cluster.

Background

The operation mode of 'spontaneous self-use and surplus electricity internet access' of the distributed power generation equipment can bring certain economic benefits for users, and the distributed power generation equipment is popularized in rural areas with backward economic conditions and rich renewable energy sources, and solar power generation is one of a plurality of distributed power generation modes. Solar power generation equipment mainly has: photovoltaic power station, light store up power station, family and store up all-in-one and family photovoltaic equipment etc..

Solar energy has the characteristics of randomness, intermittent property, periodicity, fluctuation and the like, and the power output of photovoltaic equipment for photovoltaic power generation by utilizing the solar energy also has the characteristics. In recent years, photovoltaic poverty alleviation projects belonging to 'precision poverty alleviation' are promoted by governments to be implemented and popularized in villages, towns and rural areas rich in illumination resources. Due to the limitation of power grid communication conditions and lower power levels, the power grid dispatching department does not have the control capability on the equipment currently installed at the tail end of the rural power line; the scattered farmhouses are located at the tail end of a power transmission line of a power system, and the power flow distribution rule of the power system shows that the tail end of the power transmission line is easy to generate the problem of voltage out-of-limit, and the quality of electric energy of the medium-low voltage distribution network lines near a transformer of a transformer area is influenced. When photovoltaic equipment is installed on a roof of a farm house or a farmland, reverse tide caused by inputting active power into a power grid aggravates voltage out-of-limit and seriously affects the quality of electric energy, so that the quality of the electric energy of a low-voltage power distribution network seriously exceeds the national standard, and potential hazards are brought to the safe operation of the power grid.

In the national standard GB/T19964-2012 technical Specification for connecting a photovoltaic power station to an electric power system, the configuration capacity and the voltage level of a grid-connected point of a photovoltaic power station with a voltage level of 10kV or above are specified. Generally, the voltage control is performed by sequentially using the reactive capacity of the photovoltaic power station grid-connected inverter and the reactive capacity of the dynamic reactive power compensation device, but the situation that the reactive power output directions of the grid-connected inverter and the dynamic reactive power compensation device are opposite easily occurs, and the economical efficiency is affected. For the lack of relevant standards for the operation of small photovoltaic power stations with the voltage level below 10kV, the reactive power control of the small photovoltaic power stations can be carried out by utilizing idle reactive capacity in the photovoltaic inverters according to the national standards.

The energy storage equipment can realize four-quadrant operation of active power and reactive power, so that a power distribution network containing the cluster distributed power supply has the capability of flexible regulation, reactive power compensation is provided by absorbing or sending out the reactive power, and the voltage quality of the PCC (point-to-point control) is optimized along with a scheduling instruction.

The power generation modes of the household photovoltaic equipment and the household light storage integrated machine are mainly ' self-generation and self-utilization ', and surplus power is on line '; the photovoltaic unit and the energy storage unit of the household light and energy storage integrated machine are respectively connected in parallel on the same direct current bus. Because the controllable reactive power capacity of the household photovoltaic equipment and the household light-storage integrated machine is very small, the controllable reactive power capacity can not be considered when the reactive power dispatching is carried out.

In the prior art, most grid-connected inverters of independent grid-connected high-voltage-level photovoltaic power stations are subjected to reactive power optimization and voltage control, and with the continuous improvement of the permeability of a low-voltage power distribution network, a power grid dispatching department is required to have the dispatching capability of dispatching low-voltage-level small photovoltaic power stations and energy storage equipment of subordinate wide area clusters and dispatching the reactive power of grid-connected points of 10kV/380V transformer districts, but the current market is lack of related device research and development and dispatching theory support.

Therefore, a safe and reliable electric power communication line is established, and a reactive power scheduling scheme of a power distribution network optical storage equipment cluster is needed to be provided, so that a power grid scheduling department has the scheduling capability for 380V voltage-class small photovoltaic power stations and energy storage equipment, and the operation safety and stability of a power grid are improved.

Disclosure of Invention

The embodiment of the invention provides a reactive power scheduling method for a power distribution network optical storage cluster, which aims to solve the problems in the background art.

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

the embodiment of the invention provides a reactive power scheduling method for a power distribution network optical storage cluster, which is characterized by comprising the following steps:

judging a reactive power operation interval, and according to a reactive power scheduling instruction Q and an actual measurement reactive power Q at a grid connection point_pccDetermining a value delta Q to be adjusted of reactive power by combining the condition of the out-of-limit threshold of the local voltage;

according to the magnitude of the value delta Q to be adjusted of the reactive power, the reactive power of each energy storage device and each small photovoltaic power station is scheduled, when the delta Q is larger than 0, the increased reactive power is scheduled, otherwise, the delta Q is made to be | delta Q |, and the decreased reactive power is scheduled;

when dispatching the increased reactive power, comparing the value delta Q to be adjusted of the reactive power with the maximum reactive margin increment sum sigma delta Q of each energy storage device_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σdelta Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin increment sum sigma delta Q of each small photovoltaic power station_siDetermining a reactive power instruction issued to each small photovoltaic power station;

when dispatching the power reduction reactive power, comparing the value delta Q to be adjusted of the reactive power with the maximum reactive margin decrement sum sigma delta Q of each energy storage device_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σδ Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin decrement sum sigma delta Q of each small photovoltaic power station_siAnd determining a reactive power instruction issued to each small photovoltaic power station.

Preferably, the reactive power operation interval is judged, and the reactive power Q is actually measured at the grid-connected point according to the reactive power scheduling instruction Q_PCCDetermining a value Δ Q to be adjusted of reactive power, including:

setting a reactive power scheduling instruction issued by a power grid scheduling department as Q, and setting actual measured reactive power at the PCC of the current grid-connected point as Q_pccMeasured voltage at PCC is U_pccThe upper limit value of the voltage meeting the voltage control requirement is U_limit-upThe lower limit value of the voltage meeting the voltage control requirement is U_limit-down；

The upper voltage limit deviation value is:

ΔU_up＝U_limit-up-U_pcc； (1)

the lower voltage limit deviation value is:

ΔU_down＝U_limit-down-U_pcc； (2)

according to the formulas (1) and (2), calculating the upper limit deviation value of the reactive power as follows:

in the formula, X is system impedance between a grid-connected point and a power grid balance node;

the lower limit deviation value of the reactive power is as follows:

comparison Q_upAnd Q_downIs in a size relationship of [ Q ]_Small，Q_{Big (a)}]And (3) interval, then:

when Q is_up＞Q_downAnd the reactive power operation interval is as follows: [ Q ]_Small，Q_{Big (a)}]＝[Q_down，Q_up]，

When Q is_up＜Q_downAnd the reactive power operation interval is as follows: [ Q ]_Small，Q_{Big (a)}]＝[Q_up，Q_down]。

Preferably, the reactive power operation interval is judged, and the reactive power Q is actually measured at the grid-connected point according to the reactive power scheduling instruction Q_PCCDetermining a value Δ Q to be adjusted of the reactive power, further comprising:

and judging whether to carry out reactive power dispatching or not according to the reactive power dispatching instruction Q and the reactive power operation interval:

when Q is equal to [ Q ]_Small，Q_{Big (a)}]And then, the reactive power scheduling is carried out,

when in use

When the power is not available, reactive power scheduling is not carried out;

when the reactive power scheduling is carried out, determining a value delta Q to be adjusted of the reactive power as follows:

when Q > Q_{Big (a)}When, Δ Q ═ Q_{Big (a)}-Q_pcc，

When Q < Q_SmallWhen, Δ Q ═ Q_Small-Q_pcc；

The dead zone threshold value of the voltage deviation and the dead zone threshold value of the reactive power deviation are both in the range of the sum of the corresponding allowable fluctuation amount and the measurement error, and the reactive power value to be adjusted delta Q is not scheduled when being smaller than the dead zone threshold value.

Preferably, when the dispatching of the increased reactive power is carried out, the value Δ Q to be adjusted of the reactive power is compared with the sum Σ Δ Q of the maximum reactive headroom increment of each energy storage device_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σdelta Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin increment sum sigma delta Q of each small photovoltaic power station_siDetermining a reactive power instruction issued to each small photovoltaic power station, wherein the reactive power instruction comprises the following steps:

setting the real-time value of the active power of each energy storage device as P_eiReal-time value of reactive power Q_eiRated apparent power of S_ei；

The maximum increment of the reactive margin of each energy storage device is as follows:

the maximum reduction of the reactive margin of each energy storage device is as follows:

according to the formulas (5) and (6), the maximum adjustable reactive power value output by the energy storage equipment is obtained as follows:

the real-time value of active power of each small photovoltaic power station is P_siReal-time value of reactive power Q_siRated apparent power of S_si；

Then the maximum margin of reactive power increment of each small photovoltaic power station is as follows:

the maximum reduction of the reactive power allowance of each small photovoltaic power station is as follows:

according to the formulas (8) and (9), the maximum adjustable reactive power value output by the small photovoltaic power station is obtained as follows:

preferably, when the dispatching of the increased reactive power is carried out, the value Δ Q to be adjusted of the reactive power is compared with the sum Σ Δ Q of the maximum reactive headroom increment of each energy storage device_eiThe size of (a) is (b),determining reactive power commands issued to each energy storage device, and when delta Q > Σdelta Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin increment sum sigma delta Q of each small photovoltaic power station_siThe method determines the reactive power instruction issued to each small photovoltaic power station, and further comprises the following steps:

and (3) dispatching the increased reactive power:

when delta Q is less than or equal to sigma delta Q_eiIn time, the reactive power instruction to be issued to each energy storage device is:

compare each Q_ei' Positive or negative relation if each Q_eiIn the same sign, according to Q_eiThe method comprises the steps of issuing a reactive power instruction to each energy storage device and finishing scheduling;

if each Q_ei' different sign, will Q_eiDividing the power into a positive subset and a negative subset, respectively calculating the sum of absolute values of a positive side and a negative side, and setting the reactive power to be issued of each energy storage device on the side with the smaller sum of the absolute values as Q_{ei Xiao}And ═ 0, and the reactive power redistribution is carried out on the side with the larger sum of the absolute values, the redistribution value is the original value sum on the side with the smaller sum of the absolute values, and then the reactive power instruction issued on the side with the larger sum of the absolute values is as follows:

according to Q_{ei Da}And distributing the side with the larger sum of the absolute values, issuing a reactive power instruction and finishing scheduling.

Preferably, when the dispatching of the increased reactive power is carried out, the value Δ Q to be adjusted of the reactive power is compared with the sum Σ Δ Q of the maximum reactive headroom increment of each energy storage device_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σdelta Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin increment sum sigma delta Q of each small photovoltaic power station_siIs determined toThe reactive power instruction that each small-size photovoltaic power plant issued still includes:

and (3) dispatching the increased reactive power:

when Δ Q > ∑ Δ Q_eiIn time, the reactive power instruction issued to each energy storage device is:

Q_ei′＝Q_ei+ΔQ_ei； (13)

the reactive power to be distributed Δ Q' is then:

ΔQ′＝ΔQ-∑ΔQ_ei； (14)

when delta Q' is less than or equal to sigma delta Q_SiIn time, the reactive power instruction to be issued to each small photovoltaic power station is:

compare each Q_si' Positive or negative relation if each Q_siIn the same sign, according to Q_siIssuing a reactive power instruction to each small photovoltaic power station, and finishing scheduling;

if each Q_si' different sign, will Q_siDividing the power into a positive subset and a negative subset, respectively calculating the sum of absolute values of a positive side and a negative side, and setting the reactive power to be issued of each small photovoltaic power station on the side with the smaller sum of the absolute values as Q_{si is small}And ═ 0, and the reactive power redistribution is carried out on the side with the larger sum of the absolute values, the redistribution value is the original value sum on the side with the smaller sum of the absolute values, and then the reactive power instruction issued on the side with the larger sum of the absolute values is as follows:

according to Q_{Si is large}"distribute and issue the reactive power order to the side with large sum of absolute value, finish the deployment;

when Δ Q' > ∑ Δ Q_SiIn time, the reactive power instruction issued by each small photovoltaic power station is:

Q_si′＝Q_si+ΔQ_si， (17)

according toQ_siAnd sending a reactive power instruction to each small photovoltaic power station to finish scheduling.

Preferably, when the dispatching of the power reduction reactive power is carried out, the value Δ Q to be adjusted of the reactive power is compared with the maximum reactive headroom decrement sum Σ δ Q of each energy storage device_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σδ Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin decrement sum sigma delta Q of each small photovoltaic power station_siDetermining a reactive power instruction issued to each small photovoltaic power station, wherein the reactive power instruction comprises the following steps:

and scheduling the reducing reactive power, wherein if the delta Q is | delta Q |:

when delta Q is less than or equal to sigma delta Q_eiIn time, the reactive power instruction to be issued to each energy storage device is:

compare each Q_ei' Positive or negative relation if each Q_eiIn the same sign, according to Q_eiThe method comprises the steps of issuing a reactive power instruction to each energy storage device and finishing scheduling;

if each Q_ei' different sign, will Q_eiDividing the power into a positive subset and a negative subset, respectively calculating the sum of absolute values of a positive side and a negative side, and setting the reactive power to be issued of each energy storage device on the side with the smaller sum of the absolute values as Q_{ei Xiao}And ═ 0, and the reactive power redistribution is carried out on the side with the larger sum of the absolute values, the redistribution value is the original value sum on the side with the smaller sum of the absolute values, and then the reactive power instruction issued on the side with the larger sum of the absolute values is as follows:

according to Q_{ei Da}And distributing the side with the larger sum of the absolute values, issuing a reactive power instruction and finishing scheduling.

Preferably, when scheduling of reducing reactive power is performed, the reactive power is comparedThe value delta Q to be adjusted of the rate and the maximum reactive margin decrement sum sigma delta Q of each energy storage device_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σδ Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin decrement sum sigma delta Q of each small photovoltaic power station_siThe method determines the reactive power instruction issued to each small photovoltaic power station, and further comprises the following steps:

and scheduling the reducing reactive power, wherein if the delta Q is | delta Q |:

when delta Q > ∑ delta Q_eiIn time, the reactive power instruction issued to each energy storage device is:

Q_ei′＝Q_ei-δQ_ei； (20)

the reactive power to be distributed Δ Q' is then:

ΔQ′＝ΔQ-∑δQ_ei； (21)

when delta Q' is less than or equal to sigma delta Q_SiIn time, the reactive power instruction to be issued to each small photovoltaic power station is:

compare each Q_si' Positive or negative relation if each Q_siIn the same sign, according to Q_siIssuing a reactive power instruction to each small photovoltaic power station, and finishing scheduling;

if each Q_si' different sign, will Q_siDividing the power into a positive subset and a negative subset, respectively calculating the sum of absolute values of a positive side and a negative side, and setting the reactive power to be issued of each small photovoltaic power station on the side with the smaller sum of the absolute values as Q_{si is small}And ═ 0, and the reactive power redistribution is carried out on the side with the larger sum of the absolute values, the redistribution value is the original value sum on the side with the smaller sum of the absolute values, and then the reactive power instruction issued on the side with the larger sum of the absolute values is as follows:

according to Q_{Si is large}"to absolute valueDistributing the large side and issuing a reactive power instruction to finish scheduling;

when delta Q' > ∑ delta Q_SiIn time, the reactive power instruction issued by each small photovoltaic power station is:

Q_si′＝Q_si-δQ_si， (24)

according to Q_siAnd sending a reactive power instruction to each small photovoltaic power station to finish scheduling.

The technical scheme provided by the embodiment of the invention shows that the embodiment of the invention provides a reactive power scheduling method for a power distribution network optical storage cluster, which is applied to an intelligent measurement and control device installed on the low-voltage side of a transformer of a power distribution network 10kV/380V station area, the reactive power scheduling value meeting the voltage operation index is calculated by receiving a reactive power scheduling instruction issued by a superior power grid and combining the condition of a local voltage threshold crossing value, the reactive power of the cluster small photovoltaic power station and the storage battery energy storage equipment connected with a feeder line on the low-voltage side of the station area is distributed, and the cluster small photovoltaic power station and the storage battery energy storage equipment under the control station area are comprehensively planned. The invention can realize the reactive power control of a power grid dispatching department on cluster small photovoltaic power stations, energy storage equipment and the like which are accessed by all low-voltage distribution networks under the feeder line, and stabilizes the voltage at the PCC of the transformer grid-connected point of the transformer in the transformer area along with the reactive power instruction of the dispatching department on the premise that the voltage of the grid-connected point is not out of limit; the problem that the voltage of the power distribution network is out of limit is avoided as far as possible, and the operation safety and stability of the power distribution network are improved.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

Fig. 1 is a flowchart of a reactive power scheduling method for a power distribution network optical storage cluster according to an embodiment of the present invention;

fig. 2 is a processing flow chart of a reactive power scheduling method for a power distribution network optical storage cluster according to an embodiment of the present invention;

fig. 3 is a schematic diagram of an equipment grid-connected structure of a reactive power scheduling method for a power distribution network optical storage cluster according to an embodiment of the present invention;

fig. 4 is a schematic diagram illustrating an acquisition parameter and a reactive power distribution mode of each device in the reactive power scheduling method for the optical storage cluster of the power distribution network according to the embodiment of the present invention;

fig. 5 is a schematic diagram of four-quadrant operation of an energy storage bidirectional converter of a reactive power scheduling method for a power distribution network optical storage cluster according to an embodiment of the present invention;

fig. 6 is a schematic diagram of two-quadrant operation of a photovoltaic inverter of a reactive power scheduling method for a power distribution network optical storage cluster according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or coupled. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

For the convenience of understanding the embodiments of the present invention, the following description will be further explained by taking several specific embodiments as examples in conjunction with the drawings, and the embodiments are not to be construed as limiting the embodiments of the present invention.

Example one

The embodiment of the invention provides a reactive power scheduling method for a power distribution network light storage cluster, aiming at a transformer area of a certain power distribution network 10kV/380V, and distributing reactive power of cluster small photovoltaic power stations and storage battery type energy storage equipment connected with a feeder line at the low-voltage side of the transformer area.

The intelligent measurement and control device carrying the scheduling method provided by the embodiment of the invention is accessed to a grid-connected point at the low-voltage side of the transformer; the intelligent measurement and control device receives a dispatching instruction of a superior power grid department and realizes data acquisition and instruction control of each device in the district scope. The scheduling method provided by the embodiment of the invention requires a communication line with high reliability and high real-time performance for a power grid.

A flow chart of a reactive power scheduling method for a distribution network optical storage cluster according to an embodiment of the present invention is shown in fig. 1.

As shown in fig. 2, the specific steps of the embodiment of the present invention are as follows:

s210: judging a reactive power operation interval, and according to a reactive power scheduling instruction Q and an actual measurement reactive power Q at a grid connection point_pccCombined bookAnd determining a value delta Q to be adjusted of the reactive power under the condition that the ground voltage is out of limit threshold.

Setting a reactive power scheduling instruction issued by a power grid scheduling department as Q, and setting actual measured reactive power at the PCC of the current grid-connected point as Q_pccMeasured voltage at PCC is U_pccThe upper limit value of the voltage meeting the voltage control requirement is U_limit-upThe lower limit value of the voltage meeting the voltage control requirement is U_limit-down。

The upper voltage limit deviation value is:

ΔU_up＝U_limit-up-U_pcc； (1)

the lower voltage limit deviation value is:

ΔU_down＝U_limit-down-U_pcc。 (2)

according to the formulas (1) and (2), calculating the upper limit deviation value of the reactive power as follows:

in the formula, X is the system impedance between the grid-connected point and the power grid balance node.

The lower limit deviation value of the reactive power is as follows:

comparison Q_upAnd Q_downIs in a size relationship of [ Q ]_Small，Q_{Big (a)}]And (3) interval, then:

when Q is_up＞Q_downAnd the reactive power operation interval is as follows: [ Q ]_Small，Q_{Big (a)}]＝[Q_down，Q_up]。

When Q is_up＜Q_downAnd the reactive power operation interval is as follows: [ Q ]_Small，Q_{Big (a)}]＝[Q_up，Q_down]。

According to the reactive power scheduling instruction Q and the reactive power operation interval [ Q ]_Small，Q_{Big (a)}]Judging whether to adjust the reactive powerDegree:

when Q is equal to [ Q ]_Small，Q_{Big (a)}]And then, performing reactive power scheduling.

When in use

And when the power is not used, the reactive power scheduling is not carried out.

When the reactive power is scheduled, determining a value delta Q to be adjusted of the reactive power as follows:

when Q > Q_{Big (a)}When, Δ Q ═ Q_{Big (a)}-Q_pcc。

When Q < Q_SmallWhen, Δ Q ═ Q_Small-Q_pcc。

And the voltage deviation dead zone threshold and the reactive deviation dead zone threshold are both in the range of the sum of the corresponding allowable fluctuation amount and the measurement error, and the reactive power is not scheduled when the value delta Q to be adjusted is smaller than the dead zone threshold.

S220: and scheduling the reactive power of each energy storage device and each small photovoltaic power station according to the value delta Q of the reactive power value to be adjusted, when the delta Q is larger than 0, scheduling the increased reactive power, and otherwise, scheduling the decreased reactive power by making the delta Q equal to | delta Q |.

S230: when dispatching the increased reactive power, comparing the value delta Q to be adjusted of the reactive power with the sum sigma delta Q of the maximum reactive margin increment of each energy storage device_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σdelta Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin increment sum sigma delta Q of each small photovoltaic power station_siAnd determining a reactive power instruction issued to each small photovoltaic power station.

(1) The maximum adjustable reactive power value of each energy storage device and the small photovoltaic power station is calculated as follows:

setting the real-time value of the active power of each energy storage device as P_eiReal-time value of reactive power Q_eiRated apparent power of S_ei(ii) a The maximum increment of the reactive margin of each energy storage device is as follows:

the maximum reduction of the reactive margin of each energy storage device is as follows:

according to the formulas (5) and (6), the maximum adjustable reactive power value output by the energy storage equipment is obtained as follows:

the real-time value of active power of each small photovoltaic power station is P_siReal-time value of reactive power Q_siRated apparent power of S_si(ii) a Then the maximum margin of reactive power increment of each small photovoltaic power station is as follows:

the maximum reduction of the reactive power allowance of each small photovoltaic power station is as follows:

according to the formulas (8) and (9), the maximum adjustable reactive power value output by the small photovoltaic power station is obtained as follows:

(2) and (3) dispatching the increased reactive power:

① when Delta Q is less than or equal to Sigma Delta Q_eiIn time, the reactive power instruction to be issued to each energy storage device is:

compare each Q_ei' Positive or negative relation if each Q_eiThe same sign, thenAccording to Q_eiAnd sending a reactive power instruction to each energy storage device to finish scheduling.

If each Q_ei' different sign, will Q_eiDividing the power into a positive subset and a negative subset, respectively calculating the sum of absolute values of a positive side and a negative side, and setting the reactive power to be issued of each energy storage device on the side with the smaller sum of the absolute values as Q_{ei Xiao}And ═ 0, and the reactive power redistribution is carried out on the side with the larger sum of the absolute values, the redistribution value is the original value sum on the side with the smaller sum of the absolute values, and then the reactive power instruction issued on the side with the larger sum of the absolute values is as follows:

according to Q_{ei Da}And distributing the side with the larger sum of the absolute values, issuing a reactive power instruction and finishing scheduling.

② when DeltaQ > ∑ DeltaQ_eiIn time, the reactive power instruction issued to each energy storage device is:

Q_ei′＝Q_ei+ΔQ_ei(13)

the reactive power to be distributed Δ Q' is then:

ΔQ′＝ΔQ-∑ΔQ_ei(14)

A. when delta Q' is less than or equal to sigma delta Q_SiIn time, the reactive power instruction to be issued to each small photovoltaic power station is:

compare each Q_si' Positive or negative relation if each Q_siIn the same sign, according to Q_siAnd sending a reactive power instruction to each small photovoltaic power station to finish scheduling.

If each Q_si' different sign, will Q_siDividing the power into a positive subset and a negative subset, respectively calculating the sum of absolute values of a positive side and a negative side, and setting the reactive power to be issued of each small photovoltaic power station on the side with the smaller sum of the absolute values as Q_{si is small}With "0" and reactive power on the side with the greater sum of absolute valuesRedistribution, wherein the redistribution value is the original value sum of the smaller side of the absolute value sum, and the reactive power instruction issued to the larger side of the absolute value sum is as follows:

according to Q_{Si is large}And distributing the side with the larger sum of the absolute values, issuing a reactive power instruction and finishing scheduling.

B. When Δ Q' > ∑ Δ Q_SiIn time, the reactive power instruction issued by each small photovoltaic power station is:

Q_si′＝Q_si+ΔQ_si， (17)

according to Q_siAnd sending a reactive power instruction to each small photovoltaic power station to finish scheduling.

S240: when dispatching the power reduction reactive power, comparing the value delta Q to be adjusted of the reactive power with the maximum reactive margin decrement sum sigma delta Q of each energy storage device_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σδ Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin decrement sum sigma delta Q of each small photovoltaic power station_siAnd determining a reactive power instruction issued to each small photovoltaic power station.

And scheduling the reducing reactive power, and if delta Q is | delta Q |:

① when Delta Q is less than or equal to Sigma delta Q_eiIn time, the reactive power instruction to be issued to each energy storage device is:

compare each Q_ei' Positive or negative relation if each Q_eiIn the same sign, according to Q_eiAnd sending a reactive power instruction to each energy storage device to finish scheduling.

If each Q_ei' different sign, will Q_eiDividing the data into positive and negative subsets, respectively calculating the sum of absolute values of positive and negative sides, and dividing the smaller side of the sumEach energy storage device to-be-issued reactive power is set as Q_{ei Xiao}And ═ 0, and the reactive power redistribution is carried out on the side with the larger sum of the absolute values, the redistribution value is the original value sum on the side with the smaller sum of the absolute values, and then the reactive power instruction issued on the side with the larger sum of the absolute values is as follows:

according to Q_{ei Da}And distributing the side with the larger sum of the absolute values, issuing a reactive power instruction and finishing scheduling.

② when DeltaQ > ∑ deltaQ_eiIn time, the reactive power instruction issued to each energy storage device is:

Q_ei′＝Q_ei-δQ_ei(20)

the reactive power to be distributed Δ Q' is then:

ΔQ′＝ΔQ-∑δQ_ei(21)

A. when delta Q' is less than or equal to sigma delta Q_SiIn time, the reactive power instruction to be issued to each small photovoltaic power station is:

compare each Q_si' Positive or negative relation if each Q_siIn the same sign, according to Q_siAnd sending a reactive power instruction to each small photovoltaic power station to finish scheduling.

If each Q_si' different sign, will Q_siDividing the power into a positive subset and a negative subset, respectively calculating the sum of absolute values of a positive side and a negative side, and setting the reactive power to be issued of each small photovoltaic power station on the side with the smaller sum of the absolute values as Q_{si is small}And ═ 0, and the reactive power redistribution is carried out on the side with the larger sum of the absolute values, the redistribution value is the original value sum on the side with the smaller sum of the absolute values, and then the reactive power instruction issued on the side with the larger sum of the absolute values is as follows:

according to Q_{Si is large}And distributing the side with the larger sum of the absolute values, issuing a reactive power instruction and finishing scheduling.

B. When delta Q' > ∑ delta Q_SiIn time, the reactive power instruction issued by each small photovoltaic power station is:

Q_si′＝Q_si-δQ_si(24)

according to Q_siAnd sending a reactive power instruction to each small photovoltaic power station to finish scheduling.

Example two

The embodiment provides a reactive power scheduling method for a power distribution network optical storage cluster, which is specifically applied and realized as follows:

as shown in fig. 3, which is a schematic diagram of a grid-connected structure of a device, the power capacity of a small photovoltaic power station is generally in the range of tens to hundreds of kilowatts, and a photovoltaic array is connected to a grid-connected Point (PCC) through a DC/AC converter; the power capacity of the storage battery type energy storage equipment is generally matched with the photovoltaic capacity accessed in a line and is connected with the PCC point through the DC/AC converter; the photovoltaic array and the low-power grade energy storage battery of the household light and energy storage all-in-one machine are connected to the same DC/AC converter through different DC/DC converters and then connected to a PCC point through the DC/AC converter; the household photovoltaic equipment array is connected with the PCC point through the DC/AC converter.

An intelligent measurement and control device carrying the scheduling method is connected to a grid-connected point on the low-voltage side of the transformer. The intelligent measurement and control device receives a reactive power control instruction issued by a power grid dispatching department according to the following steps: and the energy storage equipment and the small photovoltaic power station sequentially distribute power. And updating and storing the real-time output value of the reactive power of each device and the active power output value which changes according to factors such as environment and the like at regular time. The acquisition parameters and the reactive power distribution mode of each device are schematically shown in fig. 4.

And a reactive power scheduling instruction Q issued by a power grid scheduling department, wherein the actual measured reactive power at the PCC of the current grid-connected point is Q_pcc. The measured voltage at PCC is U_pccThe upper limit value of the voltage meeting the voltage control requirement is U_limit-uElectricity satisfying voltage control requirementThe reduction limit value is U_limit-down. The upper voltage limit deviation value is: delta U_up＝U_limit-up-U_pccThe lower voltage limit deviation value is as follows: delta U_down＝U_limit-down-U_pc. The upper limit deviation value of reactive power thus calculated is:

the lower limit deviation value of the reactive power is as follows:

and X is the system impedance between the grid-connected point and the power grid balance node.

Comparison Q_upAnd Q_downA size relationship, and form [ Q ]_Small，Q_{Big (a)}]An interval. When Q is equal to [ Q ]_Small，Q_{Big (a)}]When, Δ Q ═ Q-Q_pcc(ii) a When Q > Q_{Big (a)}When, Δ Q ═ Q_{Big (a)}-Q_pcc(ii) a When Q < Q_SmallWhen, Δ Q ═ Q_Small-Q_pcc。

And the voltage deviation dead zone threshold and the reactive deviation dead zone threshold are both in the range of the sum of the corresponding allowable fluctuation amount and the measurement error, and the reactive power is not scheduled when the value delta Q to be adjusted is smaller than the dead zone threshold.

Fig. 3 is a schematic diagram showing four-quadrant operation of the energy storage bidirectional converter, and fig. 4 is a schematic diagram showing two-quadrant operation of the photovoltaic inverter. The energy storage bidirectional converter has four-quadrant operation capability, and the photovoltaic inverter has two-quadrant operation capability.

Active power real-time value P of energy storage device_eiIndicating that the real-time value of reactive power is Q_eiRated apparent power of S_eiThe maximum increment of the reactive margin of each energy storage device is

The maximum reactive margin is reduced to

The real-time value of active power of the small photovoltaic power station is P_siReal-time value of reactive power Q_siRated apparent power of S_siThe maximum increment of the reactive margin of each small photovoltaic power station is

The maximum reactive margin is reduced to

The adjustable maximum value of the output reactive power of the energy storage equipment is

The adjustable maximum value of the output reactive power of the small photovoltaic power station is

Fig. 1 shows a flow chart of the scheduling method of this embodiment, which specifically includes the following steps:

1. when the delta Q is larger than 0, increasing the reactive power and entering the step 2, otherwise, making the delta Q be | delta Q |, decreasing the reactive power and entering the step 4.

2. When DeltaQ < SigmaDeltaQ_eiEntering the step 2-1, otherwise, each energy storage device issues a reactive instruction Q_ei′＝Q_ei+ΔQ_eiAnd entering the step 3.

2-1: each energy storage device waits to issue a reactive instruction as

Compare each Q_ei' Positive and negative relationship. If each Q_eiIn the same sign, according to Q_eiAnd issuing an instruction and finishing scheduling. Otherwise, the step 2-2 is entered.

2-2: will Q_eiDividing the reactive power into a positive subset and a negative subset, respectively calculating the sum of absolute values of a positive side and a negative side, and adjusting the reactive power to the side with the larger sum of the absolute values. Setting the reactive power to be issued of each energy storage device on the side with small sum of absolute values as Q_{ei Xiao}When the sum of absolute values is greater, the reactive power is redistributed to the side where the sum of absolute values is greater, and the available distribution value is smallerAnd distributing and issuing reactive power according to the sum of original values of the sides:

and finishing the scheduling.

3. To-be-distributed reactive power delta Q ═ delta Q-Q₁When Δ Q' < Q₂And 3-1, otherwise, each small photovoltaic power station sends a reactive instruction Q_si′＝Q_si+ΔQ_siAnd finishing the scheduling.

3-1: each small photovoltaic power station waits to issue a reactive instruction as

Compare each Q_si' Positive and negative relationship. If each Q_siIn the same sign, according to Q_siAnd issuing an instruction and finishing scheduling. Otherwise, the step 3-2 is entered.

3-2: will Q_siDividing the reactive power into a positive subset and a negative subset, respectively calculating the sum of absolute values of a positive side and a negative side, and adjusting the reactive power to the side with the larger sum of the absolute values. Setting the reactive power to be issued of each small photovoltaic power station on one side with small sum of absolute values as Q_{si is small}And (0) redistributing the reactive power on the side with the larger sum of the absolute values, distributing and issuing the reactive power for the original sum with the smaller sum of the absolute values

And finishing the scheduling.

4. When DeltaQ < SigmaDelta Q_eiEntering the step 4-1; otherwise, each energy storage device issues a reactive instruction Q_ei′＝Q_ei-δQ_eiAnd entering the step 5.

4-1: each energy storage device waits to issue a reactive instruction as

Compare each Q_ei' Positive and negative relationship. If each Q_eiIn the same sign, according to Q_eiAnd issuing an instruction and finishing scheduling. Otherwise, the step 4-2 is entered.

4-2: will Q_ei' divide into positive and negativeAnd the two subsets respectively calculate the sum of absolute values of the positive side and the negative side, and the reactive power is adjusted to the side with the larger sum of the absolute values. Setting the reactive power to be issued of each energy storage device on the side with small sum of absolute values as Q_{ei Xiao}And (0) redistributing the reactive power on the side with the larger sum of the absolute values, distributing and issuing the reactive power for the original sum with the smaller sum of the absolute values

And finishing the scheduling.

5. To-be-distributed reactive power delta Q ═ delta Q-Q₁When Δ Q' < Q₂Entering the step 5-1; otherwise, each small photovoltaic power station issues a reactive instruction Q_si′＝Q_si-δQ_siAnd finishing the scheduling.

5-1: each small photovoltaic power station waits to issue a reactive instruction as

Compare each Q_si' Positive and negative relationship. If each Q_siIn the same sign, according to Q_siAnd issuing an instruction and finishing scheduling. Otherwise, the step 5-2 is entered.

5-2: will Q_siDividing the reactive power into a positive subset and a negative subset, respectively calculating the sum of absolute values of a positive side and a negative side, and adjusting the reactive power to the side with the larger sum of the absolute values. Setting the reactive power to be issued of each small photovoltaic power station on one side with small sum of absolute values as Q_{si is small}And (0) redistributing the reactive power on the side with the larger sum of the absolute values, distributing and issuing the reactive power for the original sum with the smaller sum of the absolute values

And finishing the scheduling.

Compared with the prior art, the invention has the following advantages:

(1) the invention enables the intelligent measurement and control device to accurately obtain the real-time performance parameters of each small photovoltaic power station and energy storage equipment in the low-voltage power distribution network through a reliable communication network, and completes the function of following the reactive power dispatching instruction of a power grid dispatching department as far as possible under the condition of meeting the requirement of not exceeding the limit of voltage through the analysis, calculation and dispatching instruction issuing of the running state.

(2) The invention effectively covers low-voltage-grade small photovoltaic power stations and storage battery type energy storage equipment which are accessed by a single feeder line on the low-voltage side of a transformer of a 10kV/380V transformer area, and has flexible control capability in the working environment of free operation and retreat of the equipment.

(3) The invention enables the reactive power of each small photovoltaic power station and energy storage equipment to output power in the same direction, and improves the economy in dispatching.

(4) The invention is applied to the intelligent measuring and controlling device of the actual engineering and can deal with complicated and changeable field working conditions.

In summary, the embodiment of the present invention designs a reactive power scheduling method for a power distribution network optical storage cluster, which is applied to an intelligent measurement and control device installed on a low-voltage side of a transformer in a power distribution network 10kV/380V area, and calculates a reactive power scheduling value meeting a voltage operation index by receiving a reactive power scheduling instruction issued by a higher-level power grid and combining a local voltage threshold-crossing condition, and distributes reactive power of a cluster small photovoltaic power station and storage battery energy storage equipment connected to a feeder line on the low-voltage side of the area, so as to comprehensively control the small photovoltaic power station, the storage battery energy storage equipment and the like of the cluster in the area. The invention realizes the reactive power control of a power grid dispatching department on cluster small photovoltaic power stations, energy storage equipment and the like which are accessed by all low-voltage distribution networks under the feeder line, and stabilizes the voltage at the PCC of the transformer grid-connected point of the transformer in the transformer area along with the reactive power instruction of the dispatching department on the premise that the voltage of the grid-connected point is not out of limit; the problem that the voltage of the power distribution network is out of limit is avoided as far as possible, and the operation safety and stability of the power distribution network are improved.

Those of ordinary skill in the art will understand that: the figures are merely schematic representations of one embodiment, and the blocks or flow diagrams in the figures are not necessarily required to practice the present invention.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for apparatus or system embodiments, since they are substantially similar to method embodiments, they are described in relative terms, as long as they are described in partial descriptions of method embodiments. The above-described embodiments of the apparatus and system are merely illustrative, and the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (8)

1. A reactive power scheduling method of a power distribution network light storage cluster is characterized by comprising the following steps:

judging a reactive power operation interval, and according to a reactive power scheduling instruction Q and an actual measurement reactive power Q at a grid connection point_pccDetermining a value delta Q to be adjusted of reactive power by combining the condition of the out-of-limit threshold of the local voltage;

according to the magnitude of the value delta Q to be adjusted of the reactive power, the reactive power of each energy storage device and each small photovoltaic power station is scheduled, when the delta Q is larger than 0, the increased reactive power is scheduled, otherwise, the delta Q is made to be | delta Q |, and the decreased reactive power is scheduled;

when dispatching the increased reactive power, comparing the value delta Q to be adjusted of the reactive power with the maximum reactive margin increment sum sigma delta Q of each energy storage device_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σdelta Q_eiComparing the reactive power to be distributedThe sum sigma delta Q of the ratio delta Q' and the maximum reactive margin increment sum of all small photovoltaic power stations_siDetermining a reactive power instruction issued to each small photovoltaic power station;

when dispatching the power reduction reactive power, comparing the value delta Q to be adjusted of the reactive power with the maximum reactive margin decrement sum sigma delta Q of each energy storage device_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σδ Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin decrement sum sigma delta Q of each small photovoltaic power station_siAnd determining a reactive power instruction issued to each small photovoltaic power station.

2. The reactive power scheduling method of the optical storage cluster of the power distribution network according to claim 1, wherein the reactive power operation interval is judged, and the reactive power Q is actually measured at the grid-connected point according to the reactive power scheduling instruction Q_PCCDetermining a value Δ Q to be adjusted of reactive power, including:

setting a reactive power scheduling instruction issued by a power grid scheduling department as Q, and setting actual measured reactive power at the PCC of the current grid-connected point as Q_pccMeasured voltage at PCC is U_pccThe upper limit value of the voltage meeting the voltage control requirement is U_limit-upThe lower limit value of the voltage meeting the voltage control requirement is U_limit-down；

The upper voltage limit deviation value is:

ΔU_up＝U_limit-up-U_pcc； (1)

the lower voltage limit deviation value is:

ΔU_down＝U_limit-down-U_pcc； (2)

according to the formulas (1) and (2), calculating the upper limit deviation value of the reactive power as follows:

in the formula, X is system impedance between a grid-connected point and a power grid balance node;

the lower limit deviation value of the reactive power is as follows:

comparison Q_upAnd Q_downIs in a size relationship of [ Q ]_Small，Q_{Big (a)}]And (3) interval, then:

when Q is_up＞Q_downAnd the reactive power operation interval is as follows: [ Q ]_Small，Q_{Big (a)}]＝[Q_down，Q_up]，

When Q is_up＜Q_downAnd the reactive power operation interval is as follows: [ Q ]_Small，Q_{Big (a)}]＝[Q_up，Q_down]。

3. The reactive power scheduling method of the optical storage cluster of the power distribution network according to claim 2, wherein the reactive power operation interval is judged, and the reactive power Q is actually measured at the grid-connected point according to the reactive power scheduling instruction Q_PCCDetermining a value Δ Q to be adjusted of the reactive power, further comprising:

and judging whether to carry out reactive power dispatching or not according to the reactive power dispatching instruction Q and the reactive power operation interval:

when Q is equal to [ Q ]_Small，Q_{Big (a)}]And then, the reactive power scheduling is carried out,

when in use

When the power is not available, reactive power scheduling is not carried out;

when the reactive power scheduling is carried out, determining a value delta Q to be adjusted of the reactive power as follows:

when Q > Q_{Big (a)}When, Δ Q ═ Q_{Big (a)}-Q_pcc，

When Q < Q_SmallWhen, Δ Q ═ Q_Small-Q_pcc；

The dead zone threshold value of the voltage deviation and the dead zone threshold value of the reactive power deviation are both in the range of the sum of the corresponding allowable fluctuation amount and the measurement error, and the reactive power value to be adjusted delta Q is not scheduled when being smaller than the dead zone threshold value.

4. The method for dispatching reactive power of optical storage clusters of power distribution network according to claim 1, wherein when dispatching the increased reactive power, the value Δ Q to be adjusted of the reactive power is compared with the sum Σ Δ Q of the maximum margin of reactive power increment of each energy storage device_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σdelta Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin increment sum sigma delta Q of each small photovoltaic power station_siDetermining a reactive power instruction issued to each small photovoltaic power station, wherein the reactive power instruction comprises the following steps:

setting the real-time value of the active power of each energy storage device as P_eiReal-time value of reactive power Q_eiRated apparent power of S_ei；

The maximum increment of the reactive margin of each energy storage device is as follows:

the maximum reduction of the reactive margin of each energy storage device is as follows:

according to the formulas (5) and (6), the maximum adjustable reactive power value output by the energy storage equipment is obtained as follows:

the real-time value of active power of each small photovoltaic power station is P_siReal-time value of reactive power Q_siRated apparent power of S_si；

Then the maximum margin of reactive power increment of each small photovoltaic power station is as follows:

the maximum reduction of the reactive power allowance of each small photovoltaic power station is as follows:

according to the formulas (8) and (9), the maximum adjustable reactive power value output by the small photovoltaic power station is obtained as follows:

5. the method for dispatching reactive power of optical storage clusters of power distribution network as claimed in claim 4, wherein when dispatching the increased reactive power, the value Δ Q to be adjusted of the reactive power is compared with the sum of the maximum margin of reactive power increment Σ Δ Q of each energy storage device_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σdelta Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin increment sum sigma delta Q of each small photovoltaic power station_siThe method determines the reactive power instruction issued to each small photovoltaic power station, and further comprises the following steps:

and (3) dispatching the increased reactive power:

when delta Q is less than or equal to sigma delta Q_eiIn time, the reactive power instruction to be issued to each energy storage device is:

compare each Q_ei' Positive or negative relation if each Q_eiIn the same sign, according to Q_eiThe method comprises the steps of issuing a reactive power instruction to each energy storage device and finishing scheduling;

if each Q_ei' different sign, will Q_eiDividing into positive and negative subsets, and finding positive side and negative side respectivelyThe sum of the absolute values of the sides is set as Q, and the reactive power to be issued of each energy storage device on the side with the smaller sum of the absolute values is set as Q_{ei Xiao}And ═ 0, and the reactive power redistribution is carried out on the side with the larger sum of the absolute values, the redistribution value is the original value sum on the side with the smaller sum of the absolute values, and then the reactive power instruction issued on the side with the larger sum of the absolute values is as follows:

according to Q_{ei Da}And distributing the side with the larger sum of the absolute values, issuing a reactive power instruction and finishing scheduling.

6. The method for dispatching reactive power of optical storage clusters of power distribution network as claimed in claim 4, wherein when dispatching the increased reactive power, the value Δ Q to be adjusted of the reactive power is compared with the sum of the maximum margin of reactive power increment Σ Δ Q of each energy storage device_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σdelta Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin increment sum sigma delta Q of each small photovoltaic power station_siThe method determines the reactive power instruction issued to each small photovoltaic power station, and further comprises the following steps:

and (3) dispatching the increased reactive power:

when Δ Q > ∑ Δ Q_eiIn time, the reactive power instruction issued to each energy storage device is:

Q_ei′＝Q_ei+ΔQ_ei； (13)

the reactive power to be distributed Δ Q' is then:

ΔQ′＝ΔQ-∑ΔQ_ei； (14)

when delta Q' is less than or equal to sigma delta Q_SiIn time, the reactive power instruction to be issued to each small photovoltaic power station is:

compare each Q_si' Positive or negative relation if each Q_siIn the same sign, according to Q_siIssuing a reactive power instruction to each small photovoltaic power station, and finishing scheduling;

if each Q_si' different sign, will Q_siDividing the power into a positive subset and a negative subset, respectively calculating the sum of absolute values of a positive side and a negative side, and setting the reactive power to be issued of each small photovoltaic power station on the side with the smaller sum of the absolute values as Q_{si is small}And ═ 0, and the reactive power redistribution is carried out on the side with the larger sum of the absolute values, the redistribution value is the original value sum on the side with the smaller sum of the absolute values, and then the reactive power instruction issued on the side with the larger sum of the absolute values is as follows:

according to Q_{Si is large}"distribute and issue the reactive power order to the side with large sum of absolute value, finish the deployment;

when Δ Q' > ∑ Δ Q_SiIn time, the reactive power instruction issued by each small photovoltaic power station is:

Q_si′＝Q_si+ΔQ_si， (17)

according to Q_siAnd sending a reactive power instruction to each small photovoltaic power station to finish scheduling.

7. The method for dispatching reactive power of optical storage clusters of power distribution network as claimed in claim 1, wherein when dispatching for reducing reactive power, the value Δ Q to be adjusted for reactive power is compared with the maximum reactive headroom decrement sum Σ δ Q of each energy storage device_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σδ Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin decrement sum sigma delta Q of each small photovoltaic power station_siDetermining a reactive power instruction issued to each small photovoltaic power station, wherein the reactive power instruction comprises the following steps:

and scheduling the reducing reactive power, wherein if the delta Q is | delta Q |:

when delta Q is less than or equal to sigma delta Q_eiIn time, the reactive power instruction to be issued to each energy storage device is:

compare each Q_ei' Positive or negative relation if each Q_eiIn the same sign, according to Q_eiThe method comprises the steps of issuing a reactive power instruction to each energy storage device and finishing scheduling;

if each Q_ei' different sign, will Q_eiDividing the power into a positive subset and a negative subset, respectively calculating the sum of absolute values of a positive side and a negative side, and setting the reactive power to be issued of each energy storage device on the side with the smaller sum of the absolute values as Q_{ei Xiao}And ═ 0, and the reactive power redistribution is carried out on the side with the larger sum of the absolute values, the redistribution value is the original value sum on the side with the smaller sum of the absolute values, and then the reactive power instruction issued on the side with the larger sum of the absolute values is as follows:

according to Q_{ei Da}And distributing the side with the larger sum of the absolute values, issuing a reactive power instruction and finishing scheduling.

8. The method according to claim 7, wherein the comparison between the value Δ Q to be adjusted for reactive power and the maximum margin decrement sum Σ δ Q of each energy storage device is performed when scheduling for power reduction is performed_eiDetermining the reactive power instruction issued to each energy storage device, and when delta Q > Σδ Q_eiThen, the reactive power delta Q' to be distributed is compared with the maximum reactive margin decrement sum sigma delta Q of each small photovoltaic power station_siThe method determines the reactive power instruction issued to each small photovoltaic power station, and further comprises the following steps:

and scheduling the reducing reactive power, wherein if the delta Q is | delta Q |:

when delta Q > ∑ delta Q_eiIn time, the reactive power instruction issued to each energy storage device is:

Q_ei′＝Q_ei-δQ_ei； (20)

the reactive power to be distributed Δ Q' is then:

ΔQ′＝ΔQ-∑δQ_ei； (21)

when delta Q' is less than or equal to sigma delta Q_SiIn time, the reactive power instruction to be issued to each small photovoltaic power station is:

compare each Q_si' Positive or negative relation if each Q_siIn the same sign, according to Q_siIssuing a reactive power instruction to each small photovoltaic power station, and finishing scheduling;

if each Q_si' different sign, will Q_siDividing the power into a positive subset and a negative subset, respectively calculating the sum of absolute values of a positive side and a negative side, and setting the reactive power to be issued of each small photovoltaic power station on the side with the smaller sum of the absolute values as Q_{si is small}And ═ 0, and the reactive power redistribution is carried out on the side with the larger sum of the absolute values, the redistribution value is the original value sum on the side with the smaller sum of the absolute values, and then the reactive power instruction issued on the side with the larger sum of the absolute values is as follows:

according to Q_{Si is large}"distribute and issue the reactive power order to the side with large sum of absolute value, finish the deployment;

when delta Q' > ∑ delta Q_SiIn time, the reactive power instruction issued by each small photovoltaic power station is:

Q_si′＝Q_si-δQ_si， (24)

according to Q_siAnd sending a reactive power instruction to each small photovoltaic power station to finish scheduling.

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