An optimization control method and system for reducing multi-station operation losses

Abstract

The present invention discloses an optimization control method and system for reducing the operating losses of multiple substations, and belongs to the technical field of substation power distribution. The method of the present invention includes: obtaining power demand data and characteristic data of different distribution substations; constructing a power balance equation for the flexible interconnection operation of multiple substations according to the power demand data and characteristic data; establishing an objective function and operating constraints for the control objects of multiple substations, and establishing a multi-period and multi-objective optimization control model for the flexible interconnection operation of multiple substations according to the objective function, constraints and power balance equation; solving the optimization control model, obtaining optimization control instructions, and controlling the control objects through the optimization control instructions. The present invention realizes the optimized operation of flexible interconnection of multiple substations, improves the economic efficiency of the regional energy storage system of the substation interconnection participating in the substation management, and improves the load balancing capacity of the substation.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution in substations, and more specifically, to an optimization control method and system for reducing operating losses in multiple substations. Background Art

[0002] Flexible interconnection of substations is a new technology that uses power electronic devices and flexible control technology to achieve interconnection and resource sharing among multiple substations. It is used to solve problems such as large differences in load rates among multiple substations, dynamic capacity expansion, and improved power supply reliability. It does not require the expansion of the original AC equipment and lines in the substation, and provides a DC distribution environment. It can easily accommodate DC elements such as energy storage, fast charging piles, and high-power frequency conversion equipment, and promote the development of AC and DC mixed supply in the substation. However, the current operation control of flexible interconnection of substations is mainly based on the adjustment of the load rate of the substation, and there is little research on its global optimization control strategy, especially the lack of consideration of the operating characteristics of flexible interconnection, which makes it difficult to achieve the economic operation of flexible interconnection of multiple substations under different working conditions.

[0003] Therefore, it is necessary to study the economic operation technology of flexible interconnection among multiple substations, give full play to the advantages of flexible interconnection and mutual assistance between substations, explore the interactive space between flexible resources and power grids, design optimized control strategies for flexible interconnection among substations, decide on the active output of power electronic interconnection devices and interconnected regional energy storage systems, achieve optimized operation under different operating conditions, comprehensively reduce the operating losses of substations and flexible interconnection areas, and promote efficient and economic operation on the substation side. Summary of the invention

[0004] In order to solve the above-mentioned problem that it is difficult to realize the economic operation of multiple zones in different working conditions with flexible interconnection, the present invention proposes an optimization control method for reducing the operating loss of multiple zones, including:

[0005] Obtain power demand data and characteristic data for different distribution substation areas;

[0006] Based on the power demand data and characteristic data, the power balance equation for flexible interconnection of multiple stations is constructed;

[0007] For the control objects of multiple substations, the objective function and operation constraints are established. Based on the objective function, constraints and power balance equation, a multi-period and multi-objective optimization control model for flexible interconnection of multiple substations is established.

[0008] The optimization control model is solved to obtain the optimization control instruction, and the control object is controlled by the optimization control instruction.

[0009] Optional, power demand data and characteristic data, specifically: power demand data of AC and DC loads in different distribution substations at different time periods; characteristic data of power electronic interconnection devices and flexible interconnected regional energy storage systems in multiple substations.

[0010] Optionally, the control objects are power electronic interconnection devices and flexible interconnected regional energy storage systems in multiple areas.

[0011] Optionally, construct a power balance equation for flexible interconnection of multiple zones, specifically:

[0012] According to the power demand data of AC loads in different distribution substations at different time periods and the characteristic data of power electronic interconnection devices in multiple substations, the power balance equation E1 is established as follows:

[0013] P TD,ii,jj =P ac,ii,jj +P ic,ii,jj +ΔP ic,ii,jj ii∈[1,N TD ],jj∈[1,N T ]

[0014]

[0015] Among them, N TD is the number of power electronic interconnection devices, N T is the total number of time periods to be optimized, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period, P ac,ii,jj is the power demand of the AC load in the ii-th substation in the jj-th period, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period, ΔP ic,ii,jj is the operating loss of the power electronic interconnection device in the ii-th substation in the jj-th period, ε ii is the conversion efficiency of the power electronic interconnection device in the ii-th area;

[0016] According to the power demand data and characteristic data of DC loads in different distribution stations at different time periods, the power balance equation E2 is established as follows:

[0017]

[0018]

[0019]

[0020] Among them, P dc,ii,jj is the power demand of the DC load in the ii-th substation in the jj-th period, U ii,jj is the voltage of the node where the ii-th power electronic interconnection device is connected to the flexible interconnection area in the jj-th period. When ii is not equal to node mm, G ii,mmis the mutual conductance between the node in the flexible interconnection region ii and the node mm. When ii and mm are equal, G ii,mm is the self-conductance of node mm, kk is the node of the flexible interconnected regional energy storage system connected to the flexible interconnected regional node, ΔP d,jj is the operating loss of the flexible interconnection area in the jjth period, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period.

[0021] Optionally, the objective function F1 is:

[0022]

[0023]

[0024] Among them, S TD,ii is the rated capacity of the transformer in the ii-th substation, β, γ, δ are weight coefficients, p c,jj is the electricity price in the jjth period, N TD is the number of power electronic interconnection devices, N T is the total number of time periods to be optimized, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period, ΔP d,jj is the operating loss of the flexible interconnection area in the jjth period, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period.

[0025] Optionally, the operating constraints include S1 to S4;

[0026] According to the operating characteristics of the transformer in the substation, the operating constraint condition S1 is established as follows:

[0027]

[0028] Among them, λ ii,min , ii,max are the minimum load rate and maximum load rate of the transformer in the ii-th substation, S TD,ii is the rated capacity of the transformer in the ii-th section, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period;

[0029] According to the operating characteristics of the power electronic interconnection device in the substation area, the operating constraint condition S2 is established as follows:

[0030] -Pic,ii,n ≤P ic,ii,jj ≤P ic,ii,n ii∈[1,N TD ],jj∈[1,N T ]

[0031] Among them, P ic,ii,n is the power capacity of the power electronic interconnection device in the ii-th substation, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period;

[0032] According to the operating characteristics of the energy storage system, the operating constraint condition S3 is established as follows:

[0033] P ess,d,jj ·P ess,c,jj =0 jj∈[1,N T ]

[0034] 0≤P ess,d,jj ≤P ess,n jj∈[1,N T ]

[0035] 0≤P ess,c,jj ≤P ess,n jj∈[1,N T ]

[0036]

[0037] Among them, P ess,n is the power capacity of the energy storage system, SOC jj is the state of charge of the energy storage system at the jjth period, S ess,n is the energy capacity of the energy storage system, μ is the efficiency of the energy storage system, ΔT represents the time resolution, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period;

[0038] According to the safe operating range of the node voltage in the flexible interconnection area, the operating constraint condition S4 is established as follows:

[0039] U ii,jj,min ≤U ii,jj ≤U ii,jj,max ii∈[1,N TD ],jj∈[1,N T ]

[0040] Among them, U ii,jj,min , U ii,jj,min are the minimum and maximum voltage allowed for node ii in the jjth period, U ii,jjIt is the voltage of the node where the ii-th substation power electronic interconnection device is connected to the flexible interconnection area in the jj-th time period.

[0041] Optionally, obtain optimization control instructions, specifically:

[0042] The optimization control model is solved to obtain the node voltage of the flexible interconnection area and the charging and discharging power instructions of the energy storage system, and the power instructions of the power electronic interconnection device are obtained according to the node voltage and the balance equation E2.

[0043] The present invention also proposes an optimization control system for reducing the operation loss of multiple zones, including:

[0044] Data collection unit, to obtain power demand data and characteristic data of different distribution station areas;

[0045] The balance equation construction unit constructs the power balance equation for flexible interconnection of multiple stations based on power demand data and characteristic data;

[0046] The model building unit establishes the objective function and operation constraints for the control objects of multiple substations, and establishes a multi-period and multi-objective optimization control model for the flexible interconnection operation of multiple substations based on the objective function, constraints and power balance equation;

[0047] The instruction acquisition unit solves the optimization control model, obtains the optimization control instruction, and controls the control object through the optimization control instruction.

[0048] Optional, power demand data and characteristic data, specifically: power demand data of AC and DC loads in different distribution substations at different time periods; characteristic data of power electronic interconnection devices and flexible interconnected regional energy storage systems in multiple substations.

[0049] Optionally, the control objects are power electronic interconnection devices and flexible interconnected regional energy storage systems in multiple areas.

[0050] Optionally, construct a power balance equation for flexible interconnection of multiple zones, specifically:

[0051] According to the power demand data of AC loads in different distribution substations at different time periods and the characteristic data of power electronic interconnection devices in multiple substations, the power balance equation E1 is established as follows:

[0052] P TD,ii,jj =P ac,ii,jj +P ic,ii,jj +ΔP ic,ii,jj ii∈[1,N TD ],jj∈[1,N T ]

[0053]

[0054] Among them, N TD is the number of power electronic interconnection devices, N T is the total number of time periods to be optimized, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period, P ac,ii,jj is the power demand of the AC load in the ii-th substation in the jj-th period, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period, ΔP ic,ii,jj is the operating loss of the power electronic interconnection device in the ii-th substation in the jj-th period, ε ii is the conversion efficiency of the power electronic interconnection device in the ii-th area;

[0055] According to the power demand data and characteristic data of DC loads in different distribution stations at different time periods, the power balance equation E2 is established as follows:

[0056]

[0057]

[0058]

[0059] Among them, P dc,ii,jj is the power demand of the DC load in the ii-th substation in the jj-th period, U ii,jj is the voltage of the node where the ii-th power electronic interconnection device is connected to the flexible interconnection area in the jj-th period. When ii is not equal to node mm, G ii,mm is the mutual conductance between the node in the flexible interconnection region ii and the node mm. When ii and mm are equal, G ii,mm is the self-conductance of node mm, kk is the node of the flexible interconnected regional energy storage system connected to the flexible interconnected regional node, ΔP d,jj is the operating loss of the flexible interconnection area in the jjth period, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period.

[0060] Optionally, the objective function F1 is:

[0061]

[0062]

[0063] Among them, S TD,ii is the rated capacity of the transformer in the ii-th substation, β, γ, δ are weight coefficients, p c,jj is the electricity price in the jjth period, NTD is the number of power electronic interconnection devices, N T is the total number of time periods to be optimized, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period, ΔP d,jj is the operating loss of the flexible interconnection area in the jjth period, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period.

[0064] Optionally, the operating constraints include S1 to S4;

[0065] According to the operating characteristics of the transformer in the substation, the operating constraint condition S1 is established as follows:

[0066]

[0067] Among them, λ ii,min , ii,max are the minimum load rate and maximum load rate of the transformer in the ii-th substation, S TD,ii is the rated capacity of the transformer in the ii-th section, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period;

[0068] According to the operating characteristics of the power electronic interconnection device in the substation area, the operating constraint condition S2 is established as follows:

[0069] -P ic,ii,n ≤P ic,ii,jj ≤P ic,ii,n ii∈[1,N TD ],jj∈[1,N T ]

[0070] Among them, P ic,ii,n is the power capacity of the power electronic interconnection device in the ii-th substation, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period;

[0071] According to the operating characteristics of the energy storage system, the operating constraint condition S3 is established as follows:

[0072] P ess,d,jj ·P ess,c,jj =0 jj∈[1,N T ]

[0073] 0≤P ess,d,jj ≤P ess,n jj∈[1,NT ]

[0074] 0≤P ess,c,jj ≤P ess,n jj∈[1,N T ]

[0075]

[0076] Among them, P ess,n is the power capacity of the energy storage system, SOC jj is the state of charge of the energy storage system at the jjth period, S ess,n is the energy capacity of the energy storage system, μ is the efficiency of the energy storage system, ΔT represents the time resolution, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period;

[0077] According to the safe operating range of the node voltage in the flexible interconnection area, the operating constraint condition S4 is established as follows:

[0078] U ii,jj,min ≤U ii,jj ≤U ii,jj,max ii∈[1,N TD ],jj∈[1,N T ]

[0079] Among them, U ii,jj,min , U ii,jj,min are the minimum and maximum voltage allowed for node ii in the jjth period, U ii,jj It is the voltage of the node where the ii-th substation power electronic interconnection device is connected to the flexible interconnection area in the jj-th time period.

[0080] Optionally, obtain optimization control instructions, specifically:

[0081] The optimization control model is solved to obtain the node voltage of the flexible interconnection area and the charging and discharging power instructions of the energy storage system, and the power instructions of the power electronic interconnection device are obtained according to the node voltage and the balance equation E2.

[0082] The present invention realizes the flexible interconnection and optimized operation of multiple substations, improves the economic efficiency of the substation interconnection regional energy storage system participating in the substation management, and improves the load balancing capability of the substation. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 is a flow chart of the method of the present invention;

[0084] Figure 2 A schematic diagram of the flexible interconnection power flow distribution in the station area of ​​the method of the present invention;

[0085] Figure 3 1 is a flow chart for implementing the method of the present invention;

[0086] Figure 4 It is a structural diagram of the system of the present invention. DETAILED DESCRIPTION

[0087] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0088] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0089] The present invention proposes an optimization control method for reducing the operating loss of multiple stations. Figure 1 As shown, including:

[0090] Obtain power demand data and characteristic data for different distribution substation areas;

[0091] Based on the power demand data and characteristic data, the power balance equation for flexible interconnection of multiple stations is constructed;

[0092] For the control objects of multiple substations, the objective function and operation constraints are established. Based on the objective function, constraints and power balance equation, a multi-period and multi-objective optimization control model for flexible interconnection of multiple substations is established.

[0093] The optimization control model is solved to obtain the optimization control instruction, and the control object is controlled by the optimization control instruction.

[0094] The present invention is further described below in conjunction with the embodiments of the present invention:

[0095] The embodiment of the present invention optimizes and controls three distribution stations. The power flow distribution in the stations is as follows: Figure 2 As shown, the implementation process is as follows Figure 3 As shown, including the following:

[0096] The power demand data of AC and DC loads in the three distribution substations at different time periods, as well as the characteristic data of power electronic interconnection devices and flexible interconnection regional energy storage systems are read to construct the power balance equation for flexible interconnection operation of multiple substations.

[0097] The power balance equation of the substation area is E1:

[0098] P TD,ii,jj =P ac,ii,jj +P ic,ii,jj +ΔP ic,ii,jj ii∈[1,N TD ],jj∈[1,N T ]

[0099]

[0100] Flexible interconnection area power balance equation E2:

[0101]

[0102]

[0103]

[0104] Among them, N TD is the number of interconnected areas, given by Figure 2 It can be seen that N TD Equal to 3; N T is the total number of time periods to be optimized; P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period; P ac,ii,jj is the power demand of the AC load in the ii-th substation in the jj-th period; P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation at the jj-th time period; ΔP ic,ii,jj is the operating loss of the power electronic interconnection device in the ii-th substation in the jj-th period; ii is the conversion efficiency of the power electronic interconnection device in the ii-th area; P dc,ii,jj is the power demand of the DC load in the ii-th substation in the jj-th period; U ii,jj is the voltage of the node where the ii-th power electronic interconnection device is connected to the flexible interconnection area in the jj-th time period; when ii and mm are not equal, G ii,mm is the mutual conductance between node ii and node mm in the flexible interconnection region. When ii and mm are equal, G ii,mm is the self-conductance of node ii; kk represents the node of the energy storage system connected to the flexible interconnection area, Figure 2 It can be seen that kk is equal to 2; ΔP d,jj is the operating loss of the flexible interconnection area in the jjth period, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period.

[0105] Taking different regional interconnected devices and flexible interconnected regional energy storage systems as control objects, a multi-period and multi-objective optimization control model for flexible interconnected operation of substations is established.

[0106] Taking into account the reduction of operating losses in the distribution transformer, interconnection device, and flexible interconnection area and the improvement of the efficiency of the energy storage system, the objective function F1 is established:

[0107]

[0108]

[0109] Among them, S TD,ii is the rated capacity of the transformer in the ii-th substation; β, γ, δ are weight coefficients; p c,jj is the electricity price in the jjth period, and min f() represents the minimum value of function f().

[0110] Considering the operating characteristics of the substation transformer, substation interconnection device, energy storage system and the safe operating range of the node voltage in the flexible interconnection area, the corresponding operating constraints S1, S2, S3 and S4 are established respectively.

[0111] Operation constraint S1:

[0112]

[0113] Operation constraint S2:

[0114] -P ic,ii,n ≤P ic,ii,jj ≤P ic,ii,n ii∈[1,N TD ],jj∈[1,N T ]

[0115] Operation constraint S3:

[0116] P ess,d,jj ·P ess,c,jj =0 jj∈[1,N T ]

[0117] 0≤P ess,d,jj ≤P ess,n jj∈[1,N T ]

[0118] 0≤P ess,c,jj ≤P ess,n jj∈[1,N T ]

[0119]

[0120] Operation constraint S4:

[0121] U ii,jj,min ≤U ii,jj ≤U ii,jj,max ii∈[1,N TD ],jj∈[1,N T ]

[0122] Among them, λ ii,min , ii,max are the minimum load rate and maximum load rate of the transformer in the ii-th area respectively; P ic,ii,n is the power capacity of the flexible interconnection device in the ii-th station; P ess,n is the power capacity of the energy storage system; SOC jj is the state of charge of the energy storage system at the jjth period; S ess,n is the energy capacity of the energy storage system; μ is the efficiency of the energy storage system; ΔT represents the time resolution; U ii,jj,min , U ii,jj,min They are respectively the minimum voltage and the maximum voltage allowed for node ii in the jjth time period.

[0123] Based on the above power balance equations E1 and E2, objective function F1 and operation constraints S1, S2, S3 and S4, a multi-period multi-objective optimization control model for flexible interconnection operation of substations is constructed.

[0124] Finally, the flexible regional node voltage and energy storage system charging and discharging power instructions are obtained by solving the above optimization model, and then based on the flexible regional node voltage, the power instruction of the power electronic interconnection device is obtained by the balance equation E2. And it is issued to the interconnection device and energy storage system accordingly to realize the economic operation management of multi-station flexible interconnection.

[0125] The present invention also proposes an optimization control system 200 for reducing the operating losses of multiple stations. Figure 2 As shown, including:

[0126] The data collection unit 201 obtains power demand data and characteristic data of different distribution station areas;

[0127] The balance equation construction unit 202 constructs a power balance equation for flexible interconnection operation of multiple stations according to the power demand data and characteristic data;

[0128] The model building unit 203 establishes an objective function and operating constraints for the control objects of the multiple substations, and establishes a multi-period and multi-objective optimization control model for the flexible interconnection operation of the multiple substations according to the objective function, the constraints and the power balance equation;

[0129] The instruction acquisition unit 204 solves the optimization control model, acquires the optimization control instruction, and controls the control object through the optimization control instruction.

[0130] Among them, the power demand data and characteristic data include: the power demand data of AC and DC loads in different distribution substations at different time periods; the characteristic data of power electronic interconnection devices and flexible interconnected regional energy storage systems in multiple substations.

[0131] Among them, the control objects are power electronic interconnection devices and flexible interconnected regional energy storage systems in multiple areas.

[0132] Among them, the power balance equation for flexible interconnection of multiple stations is constructed as follows:

[0133] According to the power demand data of AC loads in different distribution substations at different time periods and the characteristic data of power electronic interconnection devices in multiple substations, the power balance equation E1 is established as follows:

[0134] P TD,ii,jj =P ac,ii,jj +P ic,ii,jj +ΔP ic,ii,jj ii∈[1,N TD ],jj∈[1,N T ]

[0135]

[0136] Among them, N TD is the number of power electronic interconnection devices, N T is the total number of time periods to be optimized, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period, P ac,ii,jj is the power demand of the AC load in the ii-th substation in the jj-th period, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period, ΔP ic,ii,jj is the operating loss of the power electronic interconnection device in the ii-th substation in the jj-th period, ε ii is the conversion efficiency of the power electronic interconnection device in the ii-th area;

[0137] According to the power demand data and characteristic data of DC loads in different distribution stations at different time periods, the power balance equation E2 is established as follows:

[0138]

[0139]

[0140]

[0141] Among them, P dc,ii,jj is the power demand of the DC load in the ii-th substation in the jj-th period, U ii,jjis the voltage of the node where the ii-th power electronic interconnection device is connected to the flexible interconnection area in the jj-th period. When ii is not equal to node mm, G ii,mm is the mutual conductance between the node in the flexible interconnection region ii and the node mm. When ii and mm are equal, G ii,mm is the self-conductance of node mm, kk is the node of the flexible interconnected regional energy storage system connected to the flexible interconnected regional node, ΔP d,jj is the operating loss of the flexible interconnection area in the jjth period, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period.

[0142] Among them, the objective function F1 is specifically:

[0143]

[0144]

[0145] Among them, S TD,ii is the rated capacity of the transformer in the ii-th substation, β, γ, δ are weight coefficients, p c,jj is the electricity price in the jjth period, N TD is the number of power electronic interconnection devices, N T is the total number of time periods to be optimized, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period, ΔP d,jj is the operating loss of the flexible interconnection area in the jjth period, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period.

[0146] Among them, the operating constraints include S1 to S4;

[0147] According to the operating characteristics of the transformer in the substation, the operating constraint condition S1 is established as follows:

[0148]

[0149] Among them, λ ii,min , ii,max are the minimum load rate and maximum load rate of the transformer in the ii-th substation, S TD,ii is the rated capacity of the transformer in the ii-th section, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period;

[0150] According to the operating characteristics of the power electronic interconnection device in the substation area, the operating constraint condition S2 is established as follows:

[0151] -P ic,ii,n ≤P ic,ii,jj ≤P ic,ii,n ii∈[1,N TD ],jj∈[1,N T ]

[0152] Among them, P ic,ii,n is the power capacity of the power electronic interconnection device in the ii-th substation, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period;

[0153] According to the operating characteristics of the energy storage system, the operating constraint condition S3 is established as follows:

[0154] P ess,d,jj ·P ess,c,jj =0 jj∈[1,N T ]

[0155] 0≤P ess,d,jj ≤P ess,n jj∈[1,N T ]

[0156] 0≤P ess,c,jj ≤P ess,n jj∈[1,N T ]

[0157]

[0158] Among them, P ess,n is the power capacity of the energy storage system, SOC jj is the state of charge of the energy storage system at the jjth period, S ess,n is the energy capacity of the energy storage system, μ is the efficiency of the energy storage system, ΔT represents the time resolution, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period;

[0159] According to the safe operating range of the node voltage in the flexible interconnection area, the operating constraint condition S4 is established as follows:

[0160] U ii,jj,min ≤U ii,jj ≤U ii,jj,max ii∈[1,N TD ],jj∈[1,N T ]

[0161] Among them, U ii,jj,min , Uii,jj,min are the minimum and maximum voltage allowed for node ii in the jjth period, U ii,jj It is the voltage of the node where the ii-th substation power electronic interconnection device is connected to the flexible interconnection area in the jj-th time period.

[0162] Among them, obtaining optimization control instructions is specifically as follows:

[0163] The optimization control model is solved to obtain the node voltage of the flexible interconnection area and the charging and discharging power instructions of the energy storage system, and the power instructions of the power electronic interconnection device are obtained according to the node voltage and the balance equation E2.

[0164] The present invention realizes the optimized operation of flexible interconnection of multiple substations. Combined with the AC and DC loads and energy storage operation conditions of multiple substations at different times, the power electronic interconnection devices and energy storage systems of the substations are used as control resources to establish an optimized control strategy for flexible interconnection of multiple substations, thereby improving the economic efficiency of flexible interconnection of multiple substations.

[0165] The present invention improves the economic efficiency of interconnected regional energy storage systems participating in substation management. By taking advantage of the price differences in different time periods and substation load characteristics, energy storage can be used to reduce peak loads and fill valleys on the substation side, improving the economic benefits of the energy storage system and promoting the flexibility of interconnected operations among multiple substations.

[0166] The present invention improves the load balancing capability of the substation. Taking into account the overall resources of multiple substations, the mutual power of power electronic interconnection devices in different substations is optimized and controlled to improve the load rate of the substation, avoid light load or heavy load operation of the substation, and help improve the resource sharing capability of multiple substations.

[0167] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiments of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0168] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0169] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0170] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0171] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0172] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. An optimization control method for reducing multi-station operation losses, the method comprising: Obtain power demand data and characteristic data for different distribution substation areas; Based on the power demand data and characteristic data, the power balance equation for flexible interconnection of multiple stations is constructed; For the control objects of multiple substations, the objective function and operation constraints are established. Based on the objective function, constraints and power balance equation, a multi-period and multi-objective optimization control model for flexible interconnection of multiple substations is established. Solving the optimization control model, obtaining optimization control instructions, and controlling the control object through the optimization control instructions; The power balance equation for constructing the flexible interconnection operation of multiple stations is specifically: According to the power demand data of AC loads in different distribution substations at different time periods and the characteristic data of power electronic interconnection devices in multiple substations, the power balance equation E1 is established as follows: P TD,ii,jj =P ac,ii,jj +P ic,ii,jj +ΔP ic,ii,jj ii∈[1,N TD ],jj∈[1,N T ] Among them, N TD is the number of power electronic interconnection devices, N T is the total number of time periods to be optimized, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period, P ac,ii,jj is the power demand of the AC load in the ii-th substation in the jj-th period, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period, ΔP ic,ii,jj is the operating loss of the power electronic interconnection device in the ii-th substation in the jj-th period, ε ii is the conversion efficiency of the power electronic interconnection device in the ii-th area; According to the power demand data and characteristic data of DC loads in different distribution stations at different time periods, the power balance equation E2 is established as follows: Among them, P dc,ii,jj is the power demand of the DC load in the ii-th substation in the jj-th period, U ii,jj is the voltage of the node where the ii-th power electronic interconnection device is connected to the flexible interconnection area in the jj-th period. When ii is not equal to node mm, G ii,mm is the mutual conductance between the node in the flexible interconnection region ii and the node mm. When ii and mm are equal, G ii,mm is the self-conductance of node mm, kk is the node of the flexible interconnected regional energy storage system connected to the flexible interconnected regional node, ΔP d,jj is the operating loss of the flexible interconnection area in the jjth period, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period; The objective function F1 is specifically: Among them, S TD,ii is the rated capacity of the transformer in the ii-th substation, β, γ, δ are weight coefficients, and p c,jj is the electricity price in the jjth period, N TD is the number of power electronic interconnection devices, N T is the total number of time periods to be optimized, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period, ΔP d,jj is the operating loss of the flexible interconnection area in the jjth period; The operation constraints include S1 to S4; According to the operating characteristics of the transformer in the substation, the operating constraint condition S1 is established as follows: Among them, λ ii,min , ii,max are the minimum load rate and maximum load rate of the transformer in the ii-th substation, S TD,ii is the rated capacity of the transformer in the ii-th section, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period; According to the operating characteristics of the power electronic interconnection device in the substation area, the operating constraint condition S2 is established as follows: -P ic,ii,n ≤P ic,ii,jj ≤P ic,ii,n ii∈[1,N TD ],jj∈[1,N T ] Among them, P ic,ii,n is the power capacity of the power electronic interconnection device in the ii-th substation, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period; According to the operating characteristics of the energy storage system, the operating constraint condition S3 is established as follows: P ess,d,jj ·P ess,c,jj =0 jj∈[1,N T ] 0≤P ess,d,jj ≤P ess,n jj∈[1,N T ] 0≤P ess,c,jj ≤P ess,n jj∈[1,N T ] Among them, P ess,n is the power capacity of the energy storage system, SOC jj is the state of charge of the energy storage system at the jjth period, S ess,n is the energy capacity of the energy storage system, μ is the efficiency of the energy storage system, ΔT represents the time resolution, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period; According to the safe operating range of the node voltage in the flexible interconnection area, the operating constraint condition S4 is established as follows: U ii,jj,min ≤U ii,jj ≤U ii,jj,max ii∈[1,N TD ],jj∈[1,N T ] Among them, U ii,jj,min , U ii,jj,max are the minimum and maximum voltage allowed for node ii in the jjth period, U ii,jj It is the voltage of the node where the ii-th substation power electronic interconnection device is connected to the flexible interconnection area in the jj-th time period.

2. According to the method described in claim 1, the power demand data and characteristic data are specifically: power demand data of AC and DC loads in different distribution substations at different time periods; characteristic data of power electronic interconnection devices and flexible interconnection regional energy storage systems in multiple substations.

3. According to the method of claim 1, the control object is the power electronic interconnection device and the flexible interconnection regional energy storage system in multiple areas.

4. According to the method of claim 1, the obtaining of the optimization control instruction is specifically: The optimization control model is solved to obtain the node voltage of the flexible interconnection area and the charging and discharging power instructions of the energy storage system, and the power instructions of the power electronic interconnection device are obtained according to the node voltage and the balance equation E2.

5. An optimization control system for reducing the operating losses of multiple stations, the system comprising: Data collection unit, to obtain power demand data and characteristic data of different distribution station areas; The balance equation construction unit constructs the power balance equation for flexible interconnection of multiple stations based on power demand data and characteristic data; The model building unit establishes the objective function and operation constraints for the control objects of multiple substations, and establishes a multi-period and multi-objective optimization control model for the flexible interconnection operation of multiple substations based on the objective function, constraints and power balance equation; An instruction acquisition unit solves the optimization control model, acquires the optimization control instruction, and controls the control object through the optimization control instruction; The power balance equation for constructing the flexible interconnection operation of multiple stations is specifically: According to the power demand data of AC loads in different distribution substations at different time periods and the characteristic data of power electronic interconnection devices in multiple substations, the power balance equation E1 is established as follows: P TD,ii,jj =P ac,ii,jj +P ic,ii,jj +ΔP ic,ii,jj ii∈[1,N TD ],jj∈[1,N T ] Among them, N TD is the number of power electronic interconnection devices, N T is the total number of time periods to be optimized, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period, P ac,ii,jj is the power demand of the AC load in the ii-th substation in the jj-th period, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period, ΔP ic,ii,jj is the operating loss of the power electronic interconnection device in the ii-th substation in the jj-th period, ε ii is the conversion efficiency of the power electronic interconnection device in the ii-th area; According to the power demand data and characteristic data of DC loads in different distribution stations at different time periods, the power balance equation E2 is established as follows: Among them, P dc,ii,jj is the power demand of the DC load in the ii-th substation in the jj-th period, U ii,jj is the voltage of the node where the ii-th power electronic interconnection device is connected to the flexible interconnection area in the jj-th period. When ii is not equal to node mm, G ii,mm is the mutual conductance between the node in the flexible interconnection region ii and the node mm. When ii and mm are equal, G ii,mm is the self-conductance of node mm, kk is the node of the flexible interconnected regional energy storage system connected to the flexible interconnected regional node, ΔP d,jj is the operating loss of the flexible interconnection area in the jjth period, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period; The objective function F1 is specifically: Among them, S TD,ii is the rated capacity of the transformer in the ii-th substation, β, γ, δ are weight coefficients, and p c,jj is the electricity price in the jjth period, N TD is the number of power electronic interconnection devices, N T is the total number of time periods to be optimized, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period, ΔP d,jj is the operating loss of the flexible interconnection area in the jjth period, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period; The operation constraints include S1 to S4; According to the operating characteristics of the transformer in the substation, the operating constraint condition S1 is established as follows: Among them, λ ii,min , ii,max are the minimum load rate and maximum load rate of the transformer in the ii-th substation, S TD,ii is the rated capacity of the transformer in the ii-th substation, P TD,ii,jj is the output power of the transformer in the ii-th substation in the jj-th period; According to the operating characteristics of the power electronic interconnection device in the substation area, the operating constraint condition S2 is established as follows: -P ic,ii,n ≤P ic,ii,jj ≤P ic,ii,n ii∈[1,N TD ],jj∈[1,N T ] Among them, P ic,ii,n is the power capacity of the power electronic interconnection device in the ii-th substation, P ic,ii,jj is the power injected into the flexible interconnection area by the power electronic interconnection device in the ii-th substation in the jj-th period; According to the operating characteristics of the energy storage system, the operating constraint condition S3 is established as follows: P ess,d,jj ·P ess,c,jj =0 jj∈[1,N T ] 0≤P ess,d,jj ≤P ess,n jj∈[1,N T ] 0≤P ess,c,jj ≤P ess,n jj∈[1,N T ] Among them, P ess,n is the power capacity of the energy storage system, SOC jj is the state of charge of the energy storage system at the jjth period, S ess,n is the energy capacity of the energy storage system, μ is the efficiency of the energy storage system, ΔT represents the time resolution, P ess,d,jj is the discharge power of the energy storage system in the jjth period, P ess,c,jj is the charging power of the energy storage system in the jjth period; According to the safe operating range of the node voltage in the flexible interconnection area, the operating constraint condition S4 is established as follows: U ii,jj,min ≤U ii,jj ≤U ii,jj,max ii∈[1,N TD ],jj∈[1,N T ] Among them, U ii,jj,min , U ii,jj,max are the minimum and maximum voltage allowed for node ii in the jjth period, U ii,jj It is the voltage of the node where the ii-th substation power electronic interconnection device is connected to the flexible interconnection area in the jj-th time period.

6. According to the system of claim 5, the power demand data and characteristic data are specifically: power demand data of AC and DC loads in different distribution substations at different time periods; characteristic data of power electronic interconnection devices and flexible interconnection regional energy storage systems in multiple substations.

7. According to the system of claim 5, the control object is the power electronic interconnection device and the flexible interconnection regional energy storage system in multiple areas.

8. According to the system of claim 5, the obtaining of the optimization control instruction is specifically: The optimization control model is solved to obtain the node voltage of the flexible interconnection area and the charging and discharging power instructions of the energy storage system, and the power instructions of the power electronic interconnection device are obtained according to the node voltage and the balance equation E2.

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