Power distribution network double-layer voltage control method and device, electronic equipment and storage medium

Abstract

The invention relates to the technical field of electric power measurement, in particular to a power distribution network double-layer voltage control method, which comprises the following steps: firstly, acquiring a plurality of voltage regulation devices, and dividing the plurality of voltage regulation devices into day-ahead regulation devices and intra-day regulation devices according to response speeds; time granularity is distributed for the day-ahead adjusting equipment and the intra-day adjusting equipment; then, according to the day-ahead optimization target, the time granularity of the day-ahead adjustment equipment and the operation characteristics of the day-ahead adjustment equipment, constructing a day-ahead power distribution network target function and a day-ahead adjustment equipment constraint condition; then, according to the intra-day optimization target, the time granularity of the intra-day adjustment equipment and the operation characteristics of the intra-day adjustment equipment, constructing an intra-day power distribution network target function and intra-day adjustment equipment constraint conditions; and finally, solving the double-layer voltage model by adopting an optimization algorithm to obtain control parameters of the plurality of voltage regulation devices. According to the embodiment of the invention, the optimization of equipment resources and the optimization of energy are realized on the basis of ensuring the quality of electric energy.

Description

Technical Field

[0001] The present invention relates to the technical field of power metering, and in particular to a double-layer voltage control method, device, electronic equipment and storage medium for a distribution network. Background Art

[0002] Under the guidance of the strategic goal of "carbon peak and carbon neutrality", countries around the world are accelerating the construction of a new power system with new energy as the main body. With the rapid development and large-scale promotion and application of renewable energy power generation technology, the installed capacity of distributed generation (DG) such as photovoltaic (PV) and wind power in the distribution network is continuing to increase.

[0003] However, power fluctuations of DG and loads can cause frequent fluctuations in the voltage at distribution network nodes, increase network losses, and even cause the voltage at distribution network nodes to exceed the safe operating range. This will not only seriously affect the power quality and power supply reliability of the distribution network, but also be unfavorable for the absorption of renewable energy.

[0004] Traditional distribution network voltage control is mainly based on voltage reactive power control, which mainly adjusts the voltage of the distribution network by adjusting the tap position of the on-load tap changer (OLTC). However, OLTC has a slow response speed and high operation and maintenance costs. It is not suitable for frequent operation and is difficult to handle voltage fluctuations caused by large-scale DG power fluctuations.

[0005] In addition, due to the large resistance and reactance ratio (R / X) of low-voltage distribution lines, the simple reactive voltage control method is difficult to solve the distribution network voltage fluctuation problem caused by the active power fluctuation of DG and load. Only by comprehensively considering the active and reactive power distribution in the distribution network can efficient voltage control be achieved.

[0006] With the development of power electronics technology, photovoltaic inverter reactive voltage regulation, SVG reactive compensation device, energy storage active voltage regulation and other means have been applied to distribution networks. These voltage regulation devices have a fast response speed and are relatively simple to maintain. They can effectively deal with the voltage fluctuation problem of distribution networks. However, under the premise of the same capacity, these devices require more material and human resources than traditional devices. How to use new equipment and traditional equipment in a balanced way is a problem that needs to be solved urgently.

[0007] Based on this, it is necessary to develop and design a double-layer voltage control method for distribution network. Summary of the invention

[0008] The embodiments of the present invention provide a double-layer voltage control method, device, electronic device and storage medium for a distribution network, which are used to solve the problem in the prior art of how to use fast-response and slow-response voltage regulation devices in a balanced manner to complete voltage regulation of the distribution network.

[0009] In a first aspect, an embodiment of the present invention provides a double-layer voltage control method for a distribution network, comprising:

[0010] Acquire multiple voltage regulating devices, divide the multiple voltage regulating devices into day-ahead regulating devices and intra-day regulating devices according to response speed, and allocate time granularity to the day-ahead regulating devices and the intra-day regulating devices, wherein the voltage regulating device adjusts the voltage of the distribution network by adjusting the output active power and / or reactive power;

[0011] According to the day-ahead optimization target, the time granularity of the day-ahead regulation device and the operation characteristics of the day-ahead regulation device, a day-ahead distribution network objective function and a day-ahead regulation device constraint condition are constructed;

[0012] According to the intraday optimization target, the time granularity of the intraday regulation equipment and the operation characteristics of the intraday regulation equipment, construct the intraday distribution network objective function and the intraday regulation equipment constraint conditions;

[0013] An optimization algorithm is used to solve the double-layer voltage model to obtain control parameters of the multiple voltage regulation devices, wherein the double-layer voltage model is constructed according to the day-ahead distribution network objective function, the day-ahead regulation device constraints, the intraday distribution network objective function and the intraday regulation device constraints.

[0014] In a possible implementation, the day-ahead distribution network objective function is:

[0015]

[0016] In the formula, π t is the active power loss index of the distribution network, P loss,t is the active power loss, C OLTC,t is the action loss index of OLTC, and T is the granularity of the voltage regulation equipment.

[0017] In a possible implementation, the day-ahead regulation equipment constraint condition includes: OLTC constraint, wherein the OLTC constraint is:

[0018]

[0019] Where, e is the difference between the secondary voltage V1 of the inverter and the reference value V ref The difference between t and t is a discrete moment in the operation of OLTC, τ is the counter, ΔT τis a constant determined by the OLTC characteristics and voltage drop. When the OLTC starts running from time t, if the time is greater than or equal to ΔT τ When the counter is incremented, ε is the voltage dead zone, α is the transformer tap position, d is the number of gears that the OLTC tap is changed, T d It is the action delay time when OLTC is running.

[0020] In a possible implementation, the day-ahead regulation equipment constraint condition further includes: an AC power flow constraint and an operation safety constraint, wherein the AC power flow constraint is:

[0021]

[0022] Where P Gi and Q Gi are the active power and reactive power injected into node i, respectively, P Li and Q Li are the active power and reactive power of the load at node i, δ ij is the phase difference between the voltage vectors at node i and node j, G ij and B ij are the conductance and susceptance of the line between node i and node j respectively, and N is the total number of nodes in the power grid;

[0023] The operational safety constraints are:

[0024] V i,min ≤V i ≤V i,max

[0025] Where V i,mi 、V i and V i,max are the voltage upper limit, real-time value and lower limit of grid node i respectively.

[0026] In a possible implementation, constructing an intraday distribution network objective function according to an intraday optimization target, a time granularity of the intraday regulation device, and an operation characteristic of the intraday regulation device includes:

[0027] A distribution network loss objective function is constructed according to the intraday optimization target, the time granularity of the intraday regulation device, and the operating characteristics of the intraday regulation device, wherein the distribution network loss objective function is:

[0028]

[0029] Where N b is the number of branches, P l,t and Q l,t are the active power and reactive power of branch l at time t, Rl is the resistance of the branch, V l,t is the voltage at the first end of branch l at time t;

[0030] The distribution network voltage fluctuation objective function is constructed according to the intraday optimization target, the time granularity of the intraday regulation device, and the operation characteristics of the intraday regulation device, wherein the voltage fluctuation objective function is:

[0031]

[0032] Where V i,t+Δt is the voltage value of node i at time t+Δt;

[0033] A comprehensive objective function is constructed according to the distribution network loss objective function and the voltage fluctuation objective function, wherein the comprehensive objective function is:

[0034] F2=α1f3+α2f4

[0035] Wherein, α1 is the first weight coefficient, and α2 is the second weight coefficient.

[0036] In a possible implementation, the intraday regulation equipment constraint condition includes: photovoltaic inverter constraint, energy storage constraint and SVG constraint, wherein the photovoltaic inverter constraint is:

[0037]

[0038] In the formula, S PV,i is the apparent power of photovoltaic i, P PC,u is the active power of photovoltaic i;

[0039] The energy storage constraint is:

[0040]

[0041] In the formula, S(t) is the remaining available capacity of energy storage at time t, S(t-Δt) is the remaining available capacity of energy storage at time t-Δt, ΔS(t) is the change of the remaining available capacity of energy storage at time t, and P ESS (t) is the active power of energy storage at time t, C ESS is the capacity of the energy storage device, Δt is the time interval, S i is the remaining available capacity of energy storage i, S i as well as are the lower and upper limits of the remaining available capacity of energy storage i, respectively, i,ESS is the active power output by energy storage i, as well as are the minimum and maximum values ​​of the active power output by energy storage i respectively;

[0042] The SVG constraints are:

[0043]

[0044] In the formula, is the reactive power output by the i-th SVG, as well as are the minimum and maximum values ​​of reactive power output by the i-th SVG respectively.

[0045] In a possible implementation, solving the double-layer voltage model using an optimization algorithm to obtain control parameters of the plurality of voltage regulating devices includes:

[0046] The day-ahead distribution network objective function, the day-ahead regulation equipment constraint condition, the intraday distribution network objective function and the intraday regulation equipment constraint condition are combined to obtain the double-layer voltage model;

[0047] inputting parameters of the plurality of voltage regulating devices into the two-layer voltage model;

[0048] Generate the initial population according to the set genetic algorithm parameters;

[0049] The comprehensive operation resource consumption, voltage deviation, network loss and voltage fluctuation are calculated based on the OLTC gear position, SVG, energy storage and PV inverter output power formed in each individual, and the individual fitness is calculated on this basis;

[0050] If there is no individual that meets the individual fitness, multiple elite individuals determined according to the individual fitness are retained, and the population composed of the multiple elite individuals is selected, segmented crossover and segmented mutation operations are performed, and individuals that meet the constraints are selected to enter the next generation population, and jump to the step of calculating the comprehensive operating resource consumption, voltage deviation, network loss and voltage fluctuation size according to the OLTC gear position, SVG, energy storage and photovoltaic inverter output power formed in each individual, and performing individual fitness calculation on this basis;

[0051] If there are individuals that satisfy the individual fitness, the control parameters of the plurality of voltage regulating devices are determined according to the individuals that satisfy the individual fitness.

[0052] In a second aspect, an embodiment of the present invention provides a distribution network double-layer voltage control device, which is used to implement the distribution network double-layer voltage control method described in the first aspect or any possible implementation of the first aspect, and the distribution network double-layer voltage control device includes:

[0053] a regulating device classification module, used for acquiring a plurality of voltage regulating devices, classifying the plurality of voltage regulating devices into day-ahead regulating devices and intra-day regulating devices according to response speed, and allocating time granularity to the day-ahead regulating devices and the intra-day regulating devices, wherein the voltage regulating device adjusts the voltage of the distribution network by adjusting the output active power and / or reactive power;

[0054] A day-ahead regulation equipment objective function construction module is used to construct a day-ahead distribution network objective function and a day-ahead regulation equipment constraint condition according to a day-ahead optimization target, a time granularity of the day-ahead regulation equipment, and an operation characteristic of the day-ahead regulation equipment;

[0055] An intraday regulation equipment objective function construction module is used to construct an intraday distribution network objective function and intraday regulation equipment constraint conditions according to an intraday optimization target, a time granularity of the intraday regulation equipment, and an operation characteristic of the intraday regulation equipment;

[0056] as well as,

[0057] A double-layer voltage control module is used to solve the double-layer voltage model using an optimization algorithm to obtain control parameters of the multiple voltage regulation devices, wherein the double-layer voltage model is constructed based on the day-ahead distribution network objective function, the day-ahead regulation device constraints, the intraday distribution network objective function and the intraday regulation device constraints.

[0058] In a third aspect, an embodiment of the present invention provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, it implements the steps of the method described in the first aspect or any possible implementation method of the first aspect.

[0059] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in the first aspect or any possible implementation of the first aspect are implemented.

[0060] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0061] The embodiment of the present invention discloses a double-layer voltage control method for a distribution network, which first obtains multiple voltage regulation devices, divides the multiple voltage regulation devices into day-ahead regulation devices and intra-day regulation devices according to response speed, and allocates time granularity to the day-ahead regulation devices and the intra-day regulation devices, wherein the voltage regulation device adjusts the voltage of the distribution network by adjusting the output active power and / or reactive power; then, according to the day-ahead optimization target, the time granularity of the day-ahead regulation device and the operating characteristics of the day-ahead regulation device, constructs the day-ahead distribution network objective function and the day-ahead regulation device constraint conditions; then, according to the intra-day optimization target, the time granularity of the day-ahead regulation device and the operating characteristics of the day-ahead regulation device, constructs the intra-day distribution network objective function and the intra-day regulation device constraint conditions; finally, uses an optimization algorithm to solve a double-layer voltage model to obtain control parameters of the multiple voltage regulation devices, wherein the double-layer voltage model is constructed according to the day-ahead distribution network objective function, the day-ahead regulation device constraint conditions, the intra-day distribution network objective function and the intra-day regulation device constraint conditions. The implementation mode of the present invention divides the voltage regulation equipment into day-ahead regulation equipment and intraday regulation equipment according to the response speed, and allocates different time granularities to the two types of equipment. Based on the classification, the target equation and constraint conditions are established for the two types of equipment, and the target equation is solved by using the optimization algorithm to achieve the purpose of reasonably configuring the slow-response voltage regulation equipment and the fast-response voltage regulation equipment. On the basis of ensuring the power quality, the optimization of equipment resources and the optimization of energy are realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0063] Figure 1 is a flow chart of a double-layer voltage control method for a distribution network provided by an embodiment of the present invention;

[0064] Figure 2 It is a block diagram of a double-layer voltage control strategy based on active and reactive power provided by an embodiment of the present invention;

[0065] Figure 3 It is a distribution network multi-time scale active and reactive voltage control strategy diagram provided by an embodiment of the present invention;

[0066] Figure 4 It is a functional block diagram of a double-layer voltage control device for a distribution network provided by an embodiment of the present invention;

[0067] Figure 5It is a functional block diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0068] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, and methods are omitted so as not to obscure the description of the present invention with unnecessary details.

[0069] In order to make the purpose, technical solutions and advantages of the present invention more clear, a specific implementation method will be described below in conjunction with the accompanying drawings.

[0070] The following is a detailed description of an embodiment of the present invention. This example is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0071] Figure 1 A flow chart of a double-layer voltage control method for a distribution network provided in an embodiment of the present invention.

[0072] like Figure 1 As shown, it shows a flow chart of the implementation of the double-layer voltage control method for the distribution network provided by the embodiment of the present invention, which is described in detail as follows:

[0073] In step 101, a plurality of voltage regulating devices are obtained, and the plurality of voltage regulating devices are divided into day-ahead regulating devices and intraday regulating devices according to response speed, and time granularity is allocated to the day-ahead regulating devices and the intraday regulating devices, wherein the voltage regulating devices adjust the voltage of the distribution network by adjusting the output active power and / or reactive power.

[0074] In step 102, according to the day-ahead optimization target, the time granularity of the day-ahead regulation device and the operation characteristics of the day-ahead regulation device, a day-ahead distribution network objective function and day-ahead regulation device constraint conditions are constructed.

[0075] In some implementations, the day-ahead distribution network objective function is:

[0076]

[0077] In the formula, π t is the active power loss index of the distribution network, P loss,t is the active power loss, C oLTC,t is the action loss index of OLTC, and T is the granularity of the voltage regulation equipment.

[0078] In some implementations, the day-ahead regulation equipment constraint condition includes: OLTC constraint, wherein the OLTC constraint is:

[0079]

[0080] Where, e is the difference between the secondary voltage V1 of the inverter and the reference value V ref The difference between t and t is a discrete moment in the operation of OLTC, τ is the counter, ΔT τ is a constant determined by the OLTC characteristics and voltage drop. When the OLTC starts running from time τ, if the time is greater than or equal to ΔT τ When the counter is incremented, ε is the voltage dead zone, α is the transformer tap position, d is the number of gears that the OLTC tap is changed, T d It is the action delay time when OLTC is running.

[0081] In some implementations, the day-ahead regulation equipment constraint condition further includes: an AC power flow constraint and an operation safety constraint, wherein the AC power flow constraint is:

[0082]

[0083] Where P Gi and Q Gi are the active power and reactive power injected into node i, respectively, P Li and Q Li are the active power and reactive power of the load at node i, δ ij is the phase difference between the voltage vectors at node i and node j, G ij and B ij are the conductance and susceptance of the line between node i and node j respectively, and N is the total number of nodes in the power grid;

[0084] The operational safety constraints are:

[0085] V i，min ≤V i ≤V i，max

[0086] Where V i,min 、V i and V i,max are the voltage upper limit, real-time value and lower limit of grid node i respectively.

[0087] Exemplarily, the voltage regulation equipment involved in the present invention patent includes: slow-response traditional equipment OLTC, fast-response equipment photovoltaic inverter, energy storage and SVG. In order to achieve economic optimization, reduce network losses and suppress voltage fluctuations, the optimization goals of different stages of this patent are inconsistent. Considering the life and reliability of OLTC, the number of OLTC actions needs to be reduced, so the control time interval of the first stage is 1 hour; in order to suppress real-time voltage fluctuations, but considering the communication conditions of the distribution network, the control time interval should be less than 1 second.

[0088] The block diagram of the multi-time scale active and reactive voltage control strategy proposed by the present invention is as follows: Figure 1 In order to make the implementation and advantages of the technical method of the present invention clear, the implementation process is described in detail. The implementation process is as follows Figure 2 As shown, the implementation steps are as follows:

[0089] First, a multi-objective optimization model of the day-ahead distribution network is established:

[0090] The goal of day-ahead optimization is to minimize the comprehensive operation cost of the distribution network. The comprehensive operation cost of the distribution network consists of the power loss cost of the distribution network and the action cost of the OLTC. The specific objective function is as follows:

[0091]

[0092] In the formula, π t is the active power loss index of the distribution network, P loss,t is the active power loss, C OLTC,t is the action loss index of OLTC, and T is the granularity of the voltage regulation equipment.

[0093] Then, the constraints of the day-ahead optimization model are given:

[0094] 1) AC power flow equation constraints

[0095]

[0096] Where P Gi and Q Gi are the active power and reactive power injected into node i, respectively, P Li and Q Li are the active power and reactive power of the load at node i, δ ij is the phase difference between the voltage vectors at node i and node j, G ij and B ij are the conductance and susceptance of the line between node i and node j respectively, and N is the total number of nodes in the power grid.

[0097] 2) Operational safety constraints

[0098] V i，min≤V i ≤V i，max

[0099] Where V i,min 、V i and V i,max are the voltage upper limit, real-time value and lower limit of grid node i respectively.

[0100] 3) OLTC Constraints

[0101] This paper adopts the discrete ratio regulation of on-load voltage regulator to control the secondary voltage value of the transformer, and keeps the secondary voltage value of the transformer within the allowable range during operation.

[0102]

[0103] Where, e is the difference between the secondary voltage V1 of the inverter and the reference value V ref The difference between t and t is a discrete moment in the operation of OLTC, τ is the counter, ΔT τ is a constant determined by the OLTC characteristics and voltage drop. When the OLTC starts running from time t, if the time is greater than or equal to ΔT τ When the counter is set to 0, the counter will be incremented by one. ε is the voltage dead zone to avoid unnecessary actions when the OLTC is operating within the voltage allowable range. α is the transformer tap position. d is the number of gears that the OLTC tap changes. T d It is the action delay time when OLTC is running.

[0104] In step 103, according to the intraday optimization target, the time granularity of the intraday regulation equipment and the operation characteristics of the intraday regulation equipment, the intraday distribution network objective function and the intraday regulation equipment constraint conditions are constructed.

[0105] In some embodiments, constructing the intraday distribution network objective function according to the intraday optimization target, the time granularity of the intraday regulation device, and the operation characteristics of the intraday regulation device includes:

[0106] A distribution network loss objective function is constructed according to the intraday optimization target, the time granularity of the intraday regulation device, and the operating characteristics of the intraday regulation device, wherein the distribution network loss objective function is:

[0107]

[0108] Where N b is the number of branches, P l,t and Q l,t are the active power and reactive power of branch l at time t, R l is the resistance of the branch, V l,tis the voltage at the first end of branch l at time t;

[0109] The distribution network voltage fluctuation objective function is constructed according to the intraday optimization target, the time granularity of the intraday regulation device, and the operation characteristics of the intraday regulation device, wherein the voltage fluctuation objective function is:

[0110]

[0111] Where V i,t+Δt is the voltage value of node i at time t+Δt;

[0112] A comprehensive objective function is constructed according to the distribution network loss objective function and the voltage fluctuation objective function, wherein the comprehensive objective function is:

[0113] F2=α1f3+α2f4

[0114] Wherein, α1 is the first weight coefficient, and α2 is the second weight coefficient.

[0115] In some embodiments, the intraday regulation equipment constraint condition includes: photovoltaic inverter constraint, energy storage constraint and SVG constraint, wherein the photovoltaic inverter constraint is:

[0116]

[0117] In the formula, S PV,i is the apparent power of photovoltaic i, P PV,i is the active power of photovoltaic i;

[0118] The energy storage constraint is:

[0119]

[0120] In the formula, S(t) is the remaining available capacity of energy storage at time t, S(t-Δt) is the remaining available capacity of energy storage at time t-Δt, ΔS(t) is the change in the remaining available capacity of energy storage at time t, and P ESS (t) is the active power of energy storage at time t, C ESS is the capacity of the energy storage device, Δt is the time interval, S i is the remaining available capacity of energy storage i, S i as well as are the lower and upper limits of the remaining available capacity of energy storage i, respectively, i,ESS is the active power output by energy storage i, as well as are the minimum and maximum values ​​of the active power output by energy storage i respectively;

[0121] The SVG constraints are:

[0122]

[0123] In the formula, is the reactive power output by the i-th SVG, as well as are the minimum and maximum values ​​of reactive power output by the i-th SVG respectively.

[0124] Exemplarily, in terms of the objective function and constraints of the intraday regulation equipment, the embodiment of the present invention first establishes a multi-objective optimization model of the intraday distribution network:

[0125] The goal of the intraday regulation device is to minimize the network loss of the distribution network. Considering that the distribution network is usually a radial network structure, the objective function of its network loss is as follows:

[0126]

[0127] Where N b is the number of branches, P l,t and Q l,t are the active power and reactive power of branch l at time t, R l is the resistance of the branch, V l,t is the voltage at the beginning of branch l at time t.

[0128] Goal 2 of the intraday regulation equipment is to minimize voltage fluctuations. To suppress voltage fluctuations, it is necessary to ensure that the voltage fluctuation at each point in adjacent time periods is minimal. The objective function is as follows:

[0129]

[0130] Where V i,t+Δt is the voltage value of node i at time t+Δt.

[0131] The intraday model takes into account both network loss and voltage fluctuation, and its comprehensive objective function F2 can be expressed as:

[0132] F2=α1f3+α2f4

[0133] In the formula, α1 is the first weight coefficient, α2 is the second weight coefficient, and the two weight coefficients can be selected according to the needs of distribution network optimization.

[0134] Then the constraints of the intraday optimization model are given

[0135] 1) PV inverter constraints

[0136] Photovoltaic inverter reactive output Q PV It is related to its apparent power and rated active power, so its constraints are as follows:

[0137]

[0138] In the formula, S PV,i is the apparent power of photovoltaic i, P PV,i is the active power of photovoltaic i;

[0139] 2) Energy storage constraints

[0140] Energy storage active power regulation needs to consider not only the device capacity but also the energy storage state of charge (SOC), so its constraints are as follows:

[0141]

[0142] In the formula, S(t) is the remaining available capacity of energy storage at time t, S(t-Δt) is the remaining available capacity of energy storage at time t-Δt, ΔS(t) is the change of the remaining available capacity of energy storage at time t, and P ESS (t) is the active power of energy storage at time t, C ESS is the capacity of the energy storage device, Δt is the time interval, S i is the remaining available capacity of energy storage i, S i as well as are the lower and upper limits of the remaining available capacity of energy storage i, respectively, i,ESS is the active power output by energy storage i, as well as are the minimum and maximum values ​​of the active power output by energy storage i respectively.

[0143] 3) SVG Constraints

[0144] The SVG constraints are:

[0145]

[0146] In the formula, is the reactive power output by the i-th SVG, as well as are the minimum and maximum values ​​of reactive power output by the i-th SVG respectively.

[0147] In step 104, an optimization algorithm is used to solve the double-layer voltage model to obtain control parameters of the multiple voltage regulation devices, wherein the double-layer voltage model is constructed according to the day-ahead distribution network objective function, the day-ahead regulation device constraints, the intraday distribution network objective function and the intraday regulation device constraints.

[0148] In some implementations, step 104 includes:

[0149] The day-ahead distribution network objective function, the day-ahead regulation equipment constraint condition, the intraday distribution network objective function and the intraday regulation equipment constraint condition are combined to obtain the double-layer voltage model;

[0150] inputting parameters of the plurality of voltage regulating devices into the two-layer voltage model;

[0151] Generate the initial population according to the set genetic algorithm parameters;

[0152] The comprehensive operation resource consumption, voltage deviation, network loss and voltage fluctuation are calculated based on the OLTC gear position, SVG, energy storage and PV inverter output power formed in each individual, and the individual fitness is calculated on this basis;

[0153] If there is no individual that meets the individual fitness, multiple elite individuals determined according to the individual fitness are retained, and the population composed of the multiple elite individuals is selected, segmented crossover and segmented mutation operations are performed, and individuals that meet the constraints are selected to enter the next generation population, and jump to the step of calculating the comprehensive operating resource consumption, voltage deviation, network loss and voltage fluctuation size according to the OLTC gear position, SVG, energy storage and photovoltaic inverter output power formed in each individual, and performing individual fitness calculation on this basis;

[0154] If there are individuals that satisfy the individual fitness, the control parameters of the plurality of voltage regulating devices are determined according to the individuals that satisfy the individual fitness.

[0155] Exemplarily, an embodiment of the present invention combines the day-ahead distribution network objective function, the day-ahead regulation equipment constraints, the intraday distribution network objective function and the intraday regulation equipment constraints obtained in the aforementioned steps to obtain a two-layer voltage model. By solving the model, the control parameters of the voltage regulation equipment can be obtained.

[0156] To achieve the above objectives, the embodiment of the present invention uses a genetic algorithm to solve the double-layer voltage optimization model:

[0157] 1) Input system data, including grid parameters, distributed photovoltaic parameters, OLTC parameters, load parameters, energy storage parameters and SVG parameters, and encode the OLTC gear number, SVG reactive capacity, energy storage active capacity and photovoltaic inverter reactive output capacity.

[0158] 2) According to the set genetic algorithm parameters, an initial population is generated, and the comprehensive operating cost, voltage deviation, network loss and voltage fluctuation are calculated according to the OLTC gear position formed in each individual, the output power of SVG, energy storage and photovoltaic inverter, and the fitness is calculated on this basis.

[0159] 3) Using the elite retention strategy, the corresponding population is selected, segmented crossover and segmented mutation operations are performed to select individuals that meet the constraints to enter the next generation population.

[0160] 4) Calculate the fitness function value and save the optimal individual.

[0161] 5) According to the set termination condition, determine whether to end the loop. If so, output the result, otherwise go to 3)

[0162] After the iteration is terminated, the best individual is selected from the population as the target individual, and the parameters of the best target individual are used as the control parameters of the voltage regulation device to complete the control of the voltage regulation device.

[0163] The present invention provides an implementation method for a double-layer voltage control method for a distribution network. The method first obtains a plurality of voltage regulating devices, divides the plurality of voltage regulating devices into day-ahead regulating devices and intraday regulating devices according to response speed, and allocates time granularity to the day-ahead regulating devices and the intraday regulating devices, wherein the voltage regulating device adjusts the voltage of the distribution network by adjusting the output active power and / or reactive power; then, according to the day-ahead optimization target, the time granularity of the day-ahead regulating device and the operating characteristics of the day-ahead regulating device, constructs a day-ahead distribution network objective function and a day-ahead regulating device constraint condition; then, according to the intraday optimization target, the time granularity of the day-ahead regulating device and the operating characteristics of the day-ahead regulating device, constructs an intraday distribution network objective function and an intraday regulating device constraint condition; finally, an optimization algorithm is used to solve a double-layer voltage model to obtain control parameters of the plurality of voltage regulating devices, wherein the double-layer voltage model is constructed according to the day-ahead distribution network objective function, the day-ahead regulating device constraint condition, the intraday distribution network objective function and the intraday regulating device constraint condition. The implementation mode of the present invention divides the voltage regulation equipment into day-ahead regulation equipment and intraday regulation equipment according to the response speed, and allocates different time granularities to the two types of equipment. Based on the classification, the target equation and constraint conditions are established for the two types of equipment, and the target equation is solved by using the optimization algorithm to achieve the purpose of reasonably configuring the slow-response voltage regulation equipment and the fast-response voltage regulation equipment. On the basis of ensuring the power quality, the optimization of equipment resources and the optimization of energy are realized.

[0164] It should be understood that the size of the serial numbers of the steps in the above implementation does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation method of the present invention.

[0165] The following is an implementation of the device of the present invention. For details not described in detail, reference may be made to the corresponding method implementation described above.

[0166] Figure 4 is a functional block diagram of a double-layer voltage control device for a distribution network provided by an embodiment of the present invention, referring to Figure 4 The double-layer voltage control device for the distribution network includes: a regulating device classification module 401, a day-ahead regulating device target function construction module 402, an intraday regulating device target function construction module 403 and a double-layer voltage control module 404, wherein:

[0167] A regulating device classification module 401 is used to obtain multiple voltage regulating devices, classify the multiple voltage regulating devices into day-ahead regulating devices and intra-day regulating devices according to response speed, and allocate time granularity to the day-ahead regulating devices and the intra-day regulating devices, wherein the voltage regulating device adjusts the voltage of the distribution network by adjusting the output active power and / or reactive power;

[0168] A day-ahead regulation equipment objective function construction module 402 is used to construct a day-ahead distribution network objective function and a day-ahead regulation equipment constraint condition according to a day-ahead optimization target, a time granularity of the day-ahead regulation equipment, and an operation characteristic of the day-ahead regulation equipment;

[0169] An intraday regulation equipment objective function construction module 403 is used to construct an intraday distribution network objective function and intraday regulation equipment constraint conditions according to an intraday optimization target, a time granularity of the intraday regulation equipment, and an operation characteristic of the intraday regulation equipment;

[0170] The double-layer voltage control module 404 is used to solve the double-layer voltage model using an optimization algorithm to obtain control parameters of the multiple voltage regulation devices, wherein the double-layer voltage model is constructed based on the day-ahead distribution network objective function, the day-ahead regulation device constraints, the intraday distribution network objective function and the intraday regulation device constraints.

[0171] Figure 5 is a functional block diagram of an electronic device provided by an embodiment of the present invention. Figure 5 As shown, the electronic device 5 of this embodiment includes: a processor 500 and a memory 501, wherein the memory 501 stores a computer program 502 that can be run on the processor 500. When the processor 500 executes the computer program 502, the steps in the above-mentioned distribution network double-layer voltage control method and the embodiment are implemented, for example Figure 1 Steps 101 to 104 are shown.

[0172] Exemplarily, the computer program 502 may be divided into one or more modules / units, and the one or more modules / units are stored in the memory 501 and executed by the processor 500 to implement the present invention.

[0173] The electronic device 5 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The electronic device 5 may include, but is not limited to, a processor 500 and a memory 501. Those skilled in the art will appreciate that Figure 5 It is only an example of the electronic device 5 and does not constitute a limitation of the electronic device 5. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device 5 may also include input and output devices, network access devices, buses, etc.

[0174] The processor 500 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0175] The memory 501 may be an internal storage unit of the electronic device 5, such as a hard disk or memory of the electronic device 5. The memory 501 may also be an external storage device of the electronic device 5, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 5. Further, the memory 501 may also include both an internal storage unit of the electronic device 5 and an external storage device. The memory 501 is used to store the computer program 502 and other programs and data required by the electronic device 5. The memory 501 may also be used to temporarily store data that has been output or is to be output.

[0176] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the implementation method can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method implementation method, which will not be repeated here.

[0177] In the above-mentioned embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0178] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0179] In the embodiments provided by the present invention, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0180] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0181] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0182] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned implementation method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, it can implement the steps of the above-mentioned various methods and device implementation methods. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium.

[0183] The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A double-layer voltage control method for a distribution network, characterized in that: include: Acquire multiple voltage regulating devices, divide the multiple voltage regulating devices into day-ahead regulating devices and intra-day regulating devices according to response speed, and allocate time granularity to the day-ahead regulating devices and the intra-day regulating devices, wherein the voltage regulating device adjusts the voltage of the distribution network by adjusting the output active power and / or reactive power; According to the day-ahead optimization target, the time granularity of the day-ahead regulation device and the operation characteristics of the day-ahead regulation device, a day-ahead distribution network objective function and a day-ahead regulation device constraint condition are constructed; According to the intraday optimization target, the time granularity of the intraday regulation equipment and the operation characteristics of the intraday regulation equipment, construct the intraday distribution network objective function and the intraday regulation equipment constraint conditions; An optimization algorithm is used to solve the double-layer voltage model to obtain control parameters of the multiple voltage regulation devices, wherein the double-layer voltage model is constructed according to the day-ahead distribution network objective function, the day-ahead regulation device constraints, the intraday distribution network objective function and the intraday regulation device constraints.

2. The double-layer voltage control method for distribution network according to claim 1, characterized in that: The day-ahead distribution network objective function is: In the formula, π t is the active power loss index of the distribution network, P loss,t is the active power loss, C OLTC,t is the action loss index of OLTC, and T is the granularity of the voltage regulation equipment.

3. The double-layer voltage control method for distribution network according to claim 1, characterized in that: The day-ahead regulation equipment constraint condition includes: OLTC constraint, wherein the OLTC constraint is: Where, e is the difference between the secondary voltage value V1 of the inverter and the reference value V ref The difference between t and t is a discrete moment in the operation of OLTC, τ is the counter, ΔT τ is a constant determined by the OLTC characteristics and voltage drop. When the OLTC starts running from time τ, if the time is greater than or equal to ΔT τ When the counter is incremented, ε is the voltage dead zone, α is the transformer tap position, d is the number of gears that the OLTC tap is changed, T d It is the action delay time when OLTC is running.

4. The double-layer voltage control method for distribution network according to claim 3, characterized in that: The day-ahead regulation equipment constraint condition also includes: AC power flow constraint and operation safety constraint, wherein the AC power flow constraint is: Where P Gi and Q Gi are the active power and reactive power injected into node i, respectively, P Li and Q Li are the active power and reactive power of the load at node i, δ ij is the phase difference between the voltage vectors at node i and node j, G oj and B ij are the conductance and susceptance of the line between node i and node j respectively, and N is the total number of nodes in the power grid; The operational safety constraints are: In i,min ≤V i ≤V i,max Where V i,min 、V i and V i,max are the voltage upper limit, real-time value and lower limit of grid node i respectively.

5. The double-layer voltage control method for distribution network according to claim 1, characterized in that: The intraday distribution network objective function is constructed according to the intraday optimization target, the time granularity of the intraday regulation device and the operation characteristics of the intraday regulation device, including: A distribution network loss objective function is constructed according to the intraday optimization target, the time granularity of the intraday regulation device, and the operating characteristics of the intraday regulation device, wherein the distribution network loss objective function is: Where N b is the number of branches, P l,t and Q l,t are the active power and reactive power of branch l at time t, R l is the resistance of the branch, V l,t is the voltage at the first end of branch l at time t; The distribution network voltage fluctuation objective function is constructed according to the intraday optimization target, the time granularity of the intraday regulation device, and the operation characteristics of the intraday regulation device, wherein the voltage fluctuation objective function is: Where V i,t+Δt is the voltage value of node i at time t+Δt; A comprehensive objective function is constructed according to the distribution network loss objective function and the voltage fluctuation objective function, wherein the comprehensive objective function is: F2=α1f3+α2f4 Wherein, α1 is the first weight coefficient, and α2 is the second weight coefficient.

6. The double-layer voltage control method for distribution network according to claim 1, characterized in that: The intraday regulation equipment constraint conditions include: photovoltaic inverter constraint, energy storage constraint and SVG constraint, wherein the photovoltaic inverter constraint is: In the formula, S PV,i is the apparent power of photovoltaic i, P PV,i is the active power of photovoltaic i; The energy storage constraint is: In the formula, S(t) is the remaining available capacity of energy storage at time t, S(t-Δt) is the remaining available capacity of energy storage at time t-Δt, ΔS(t) is the change of the remaining available capacity of energy storage at time t, and P ESS (t) is the active power of energy storage at time t, C ESS is the capacity of the energy storage device, Δt is the time interval, S i is the remaining available capacity of energy storage i, S i as well as are the lower and upper limits of the remaining available capacity of energy storage i, respectively, i,ESS is the active power output by energy storage i, as well as are the minimum and maximum values ​​of the active power output by energy storage i respectively; The SVG constraints are: In the formula, is the reactive power output by the i-th SVG, as well as are the minimum and maximum values ​​of reactive power output by the i-th SVG respectively.

7. The double-layer voltage control method for a distribution network according to any one of claims 1 to 6, characterized in that: The adopting of an optimization algorithm to solve the double-layer voltage model to obtain control parameters of the plurality of voltage regulating devices includes: The day-ahead distribution network objective function, the day-ahead regulation equipment constraint condition, the intraday distribution network objective function and the intraday regulation equipment constraint condition are combined to obtain the double-layer voltage model; inputting parameters of the plurality of voltage regulating devices into the two-layer voltage model; Generate the initial population according to the set genetic algorithm parameters; The comprehensive operation resource consumption, voltage deviation, network loss and voltage fluctuation are calculated based on the OLTC gear position, SVG, energy storage and PV inverter output power formed in each individual, and the individual fitness is calculated on this basis; If there is no individual that meets the individual fitness, multiple elite individuals determined according to the individual fitness are retained, and the population composed of the multiple elite individuals is selected, segmented crossover and segmented mutation operations are performed, and individuals that meet the constraints are selected to enter the next generation population, and jump to the step of calculating the comprehensive operating resource consumption, voltage deviation, network loss and voltage fluctuation size according to the OLTC gear position, SVG, energy storage and photovoltaic inverter output power formed in each individual, and performing individual fitness calculation on this basis; If there are individuals that satisfy the individual fitness, the control parameters of the plurality of voltage regulating devices are determined according to the individuals that satisfy the individual fitness.

8. A double-layer voltage control device for a distribution network, characterized in that: Used to implement the distribution network double-layer voltage control method according to any one of claims 1 to 7, the distribution network double-layer voltage control device comprises: a regulating device classification module, used for acquiring a plurality of voltage regulating devices, classifying the plurality of voltage regulating devices into day-ahead regulating devices and intra-day regulating devices according to response speed, and allocating time granularity to the day-ahead regulating devices and the intra-day regulating devices, wherein the voltage regulating device adjusts the voltage of the distribution network by adjusting the output active power and / or reactive power; A day-ahead regulation equipment objective function construction module is used to construct a day-ahead distribution network objective function and a day-ahead regulation equipment constraint condition according to a day-ahead optimization target, a time granularity of the day-ahead regulation equipment, and an operation characteristic of the day-ahead regulation equipment; An intraday regulation equipment objective function construction module is used to construct an intraday distribution network objective function and intraday regulation equipment constraint conditions according to an intraday optimization target, a time granularity of the intraday regulation equipment, and an operation characteristic of the intraday regulation equipment; as well as, A double-layer voltage control module is used to solve the double-layer voltage model using an optimization algorithm to obtain control parameters of the multiple voltage regulation devices, wherein the double-layer voltage model is constructed based on the day-ahead distribution network objective function, the day-ahead regulation device constraints, the intraday distribution network objective function and the intraday regulation device constraints.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method as claimed in any one of claims 1 to 7 are implemented.

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