CN110556862A - Two-stage optimal regulation and control method and device for power distribution network based on photovoltaic cluster - Google Patents

Abstract

The invention relates to a two-stage optimal regulation and control method and a two-stage optimal regulation and control device for a power distribution network based on a photovoltaic cluster, wherein the two-stage optimal regulation and control method comprises the following steps of: determining a first regulation and control scheme of the power distribution network according to the occurrence probability of each operation scene of the power distribution network; carrying out global optimization regulation and control on the power distribution network according to the first regulation and control scheme; when the node voltage in the photovoltaic cluster of the power distribution network is out of limit, a second regulation and control scheme is determined based on the power regulation capacity of distributed photovoltaic and energy storage in the cluster, and the distributed photovoltaic and the energy storage in the photovoltaic cluster of the power distribution network are regulated and controlled by the second regulation and control scheme. According to the technical scheme provided by the invention, the overall situation of the power distribution network and the photovoltaic cluster of the power distribution network are regulated and controlled in two stages, so that the multi-dimensional cooperative optimization regulation and control of various controllable resources in the power distribution network on a time scale and a space scale are realized, the rapidity and the effectiveness of regulation and control are improved, the consumption capacity of the power grid on distributed photovoltaic is improved, and the safe and stable operation of the power distribution network is ensured.

Description

Two-stage optimal regulation and control method and device for power distribution network based on photovoltaic cluster

Technical Field

the invention relates to the field of operation optimization of power systems, in particular to a two-stage optimization regulation and control method and device for a power distribution network based on a photovoltaic cluster.

background

In recent years, due to the rapid development of a photovoltaic power generation technology, distributed photovoltaic is in a situation of large-scale and cluster access to a power distribution network, which has a great influence on the safety, stability and low-loss operation of the power distribution network. The high-permeability distributed photovoltaic grid connection changes the tide distribution of a power grid, causes voltage fluctuation and even overvoltage to cause photovoltaic grid disconnection, and seriously restricts the consumption capability of the power grid to the distributed photovoltaic. The energy storage system can absorb electric energy when photovoltaic active power is excessive, and release electric quantity when the photovoltaic active power is insufficient, so that fluctuation of distributed photovoltaic output can be effectively compensated, and the photovoltaic power generation system is widely applied to a power distribution network in recent years.

At present, an optimization regulation and control method for a high-permeability distributed photovoltaic access power distribution network is researched. For example, a voltage control method of an active power distribution network considering coordination of various devices is provided in the prior research based on model predictive control, and an active power optimization regulation and control method of the active power distribution network considering coordination of multiple time scales is provided in the other research, but the research methods all belong to the global optimization category, and all terminal devices are required to continuously upload relevant information to a regulation and control center for processing, so that great pressure is brought to communication, and a large amount of time is consumed in optimization calculation, so that the optimization regulation and control requirements of a system cannot be met.

disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a two-stage optimal regulation and control method and a two-stage optimal regulation and control device for a power distribution network based on a photovoltaic cluster.

the purpose of the invention is realized by adopting the following technical scheme:

the invention provides a two-stage optimization regulation and control method for a power distribution network based on a photovoltaic cluster, which is improved in that the method comprises the following steps:

Determining a first regulation and control scheme of the power distribution network according to the occurrence probability of each operation scene of the power distribution network;

Regulating and controlling the power distribution network according to the first regulation and control scheme;

when the node voltage in the photovoltaic cluster of the power distribution network is out of limit, a second regulation and control scheme is determined according to the power regulation capacity of distributed photovoltaic and energy storage in the cluster, and the distributed photovoltaic and the energy storage in the photovoltaic cluster of the power distribution network are regulated and controlled according to the second regulation and control scheme.

preferably, the first regulatory protocol comprises: the method comprises the following steps that reactive power of distributed photovoltaic, charging and discharging power of stored energy and active power of adjustable load are connected to nodes in a power distribution network at each moment;

The second regulatory scheme comprises: and the reactive power adjustment quantity and the energy storage charging and discharging power adjustment quantity of the distributed photovoltaic in the photovoltaic cluster of the power distribution network.

preferably, the photovoltaic cluster is a branch line of a feeder line of the power distribution network, wherein the branch line of the feeder line is connected with a distributed photovoltaic and energy storage device or an adjustable load.

Further, the determining a first regulation and control scheme of the power distribution network according to the occurrence probability of each operation scene of the power distribution network includes:

And substituting the occurrence probability of each operation scene of the power distribution network into a pre-established first regulation and control model, and solving to obtain a first regulation and control scheme of the power distribution network.

Further, an objective function in the pre-established first regulation model is determined according to the following formula:

In the above formula, F is the active power lost by the distribution network; p is a radical of_S,tThe probability of the s-th scene of the power distribution network at the time t is obtained; s is the total number of typical scenes reserved after scene analysis of the power distribution network; t is the time number in the regulation period; c (0) is a final node set of a line taking a starting node of the power distribution network as a first node; p_0fthe active power flowing to the node f for the initial node of the power distribution network; j belongs to (1-N), and N is the number of nodes in the power distribution network; p_PV,j,tThe active power of the distributed photovoltaic accessed to the node j at the moment t; p_ch,j,tCharging power of the stored energy accessed to the node j at the moment t; p_dis,j,tthe discharge power of the stored energy accessed to the node j at the moment t; p_CL,j,tThe active power of the adjustable load accessed by the node j at the moment t; p_load,j,tThe active power of the unregulated load accessed by the node j at the moment t.

Further, the power flow constraint condition in the pre-established first regulation and control model is determined according to the following formula:

in the above formula, P_ij,tThe active power of a line ij at the moment t of the power distribution network; i is_ij,tThe current of a line ij at the moment t of the power distribution network; r is_ijthe resistance of a line ij in the power distribution network; x is the number of_ijThe reactance of a line ij in the power distribution network; p_j,tInjecting active power of a node j into the power distribution network at the moment t; p_jk,tThe active power of a line jk at the moment t of the power distribution network; q_ij,tthe reactive power of a line ij at the moment t of the power distribution network is obtained; q_j,tInjecting reactive power of a node j into the power distribution network at the moment t; q_jk,tThe reactive power of a line jk at the moment t of the power distribution network is obtained; j belongs to (1-N), and N is the number of nodes in the power distribution network; i belongs to phi (j), and phi (j) is a set of first nodes of a line with a node j as a last node in the power distribution network; k belongs to theta (j), and theta (j) is a set of end nodes of a line taking a node j as a first node in the power distribution network; p_PV,j,tthe active power of the distributed photovoltaic at the node j at the moment t of the power distribution network is obtained; p_load,j,tthe active power of the adjustable load at the node j at the moment t of the power distribution network is obtained; p_ch,j,tthe charging power of the energy storage device at the node j at the moment t of the power distribution network is obtained; p_dis,j,tThe discharge power of the energy storage device at the node j at the moment t of the power distribution network is obtained; q_PV,j,tDistributing the reactive power of the photovoltaic at a node j at the moment t of the power distribution network; q_load,j,tthe reactive power of the adjustable load device at the node j at the moment t of the power distribution network is obtained; u shape_j,tthe voltage amplitude at the node j at the moment t of the power distribution network is obtained; u shape_i,tthe voltage amplitude value at a node i at the moment t of the power distribution network is obtained;

Determining a node voltage constraint condition in a pre-established first regulation model according to the following formula:

In the above formula, the first and second carbon atoms are,for the voltage amplitude of node j in the distribution networkA lower limit;The upper limit of the voltage amplitude of the node j in the power distribution network is set; u shape_j,tthe voltage amplitude at the node j at the moment t of the power distribution network is obtained;

Determining the operation constraint conditions of the distributed photovoltaic power station in the pre-established first regulation and control model according to the following formula:

In the above formula, the first and second carbon atoms are,The distributed photovoltaic reactive power minimum value of a node j at the moment t of the power distribution network is obtained;the maximum value of the distributed photovoltaic reactive power of a node j at the moment t of the power distribution network is obtained;

wherein,S_PV,jThe capacity of a distributed photovoltaic inverter of a node j in the power distribution network;The active output prediction value of the distributed photovoltaic power station of the node j at the moment t of the power distribution network is obtained;

Determining an energy storage operation constraint condition in a pre-established first regulation and control model according to the following formula:

in the above formula, E_SOC,j,tthe electric quantity of the energy storage device of the node j at the moment t of the power distribution network is; e_SOC,j,t+ΔtThe electric quantity of the energy storage device is the t + delta t moment node j of the power distribution network;limiting the energy storage capacity of an energy storage device of a node j in the power distribution network;Limiting the energy storage capacity of an energy storage device of a node j in the power distribution network;The maximum charging power of the energy storage device of the node j in the power distribution network;The maximum discharge power of the energy storage device of the node j in the power distribution network;

determining an adjustable load device power constraint condition in a pre-established first regulation and control model according to the following formula:

in the above formula, P_CL,j,tthe actual power consumption of the adjustable load device is the node j at the moment t of the power distribution network; w_j,minThe minimum electric quantity requirement of the adjustable load device of the node j in the power distribution network is set; w_j,maxThe maximum value of the electric quantity requirement of the adjustable load device of the node j in the power distribution network; Δ t is the time interval of the first modulation scheme; t is the time number in the regulation period;

Wherein,ε_minThe minimum value of the proportion of the actual power consumption of the adjustable load device in the power distribution network to the expected power consumption is obtained; epsilon_maxthe maximum value of the proportion of the actual power consumption of the adjustable load device of the power distribution network to the expected power consumption is obtained;the expected power consumption at the moment t is set for the adjustable load of the distribution network.

further, the determining a second regulation and control scheme according to the power regulation capability of the distributed photovoltaic and the stored energy in the photovoltaic cluster of the power distribution network, and regulating and controlling the distributed photovoltaic and the stored energy in the distributed photovoltaic cluster by using the second regulation and control scheme includes:

And substituting the maximum and minimum reactive power values and the maximum and minimum stored charge and discharge power values of the distributed photovoltaic in the power distribution network cluster into a pre-established second regulation and control model, solving the second regulation and control model, and obtaining a second regulation and control scheme of the power distribution network.

Further, an objective function in the pre-established second regulation model is determined according to the following formula:

in the above formula, F_vadjusting the minimum power of distributed photovoltaic and energy storage in the distributed photovoltaic cluster;The method comprises the steps of collecting all distributed photovoltaic in a cluster; delta Q_PV,xAdjusting the reactive power of the xth distributed photovoltaic in the cluster;the maximum value of the reactive power of the x-th distributed photovoltaic in the cluster;the method comprises the steps of collecting all stored energy in a cluster; delta P_ch,yAdjusting the charging power of the y-th stored energy in the cluster;The maximum value of the charging power of the y-th stored energy in the cluster; d_ch,yA charging coefficient for the y-th stored energy in the cluster; d_ch,y∈(0,1)；ΔP_dis,yAdjusting the discharge power of the y-th stored energy in the cluster;For the y-th energy storage in the clusterMaximum value of discharge power of; d_dis,ythe discharge coefficient of the y-th stored energy in the cluster; d_dis,y∈(0,1)。

Further, the power constant constraint condition in the pre-established second regulation model is determined according to the following formula:

in the above formula, the first and second carbon atoms are,is an initial active power value flowing into a starting node of the cluster; p_Cthe active power value which flows into the initial node of the cluster after being adjusted by the second regulation scheme is obtained;an initial reactive power value for a starting node of the cluster; q_Cthe active power value which flows into the initial node of the cluster after being adjusted by the second regulation scheme is obtained;

determining a power flow constraint condition in a pre-established second regulation and control model according to the following formula:

in the above formula, P_αβ,tthe active power of the line alpha beta in the photovoltaic cluster of the power distribution network at the moment t; i is_αβ,tThe current of the line alpha beta in the photovoltaic cluster of the power grid at the moment t; r is_αβResistance of a line α β in a photovoltaic cluster for a distribution network; p_β,tInjecting active power of a node beta in a photovoltaic cluster of the power distribution network at the time t; p_βγ,tActive power of a line beta gamma in a photovoltaic cluster of the power distribution network at the moment t; q_αβ,tThe reactive power of the line alpha beta in the photovoltaic cluster of the power distribution network at the moment t; x is the number of_αβIs the reactance of the line alpha beta in the photovoltaic cluster of the distribution network; q_β,tInjecting reactive power of a node beta in a cluster of the power distribution network at the time t; q_βγ,tFor distributing power at time treactive power of lines β γ in the cluster of nets; beta belongs to (1-M), wherein M is the number of nodes in a photovoltaic cluster of the power distribution network; alpha belongs to psi (beta), and psi (beta) is a set of line head nodes taking a node beta as a tail node in a photovoltaic cluster of a power distribution network;The method comprises the steps that a line end node set taking a node beta as a first node in a photovoltaic cluster of a power distribution network is formed; p_PV,β,tActive power of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t; p_CL,β,tThe active power of the adjustable load at the position of a node beta in the photovoltaic cluster of the power distribution network at the moment t; p_load,β,tThe active power of the unregulated load at the node beta in the photovoltaic cluster of the power distribution network at the moment t; p_ch,β,tthe energy storage charging power of an access node beta in the photovoltaic cluster of the power distribution network at the moment t is obtained; p_dis,β,tThe discharge power is the stored energy discharge power of an access node beta in the photovoltaic cluster of the power distribution network at the moment t; q_PV,β,tthe reactive power of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t; q_CL,β,tThe reactive power of the adjustable load at the position of a node beta in the photovoltaic cluster of the power distribution network at the moment t; q_load,β,tthe reactive power of the non-adjustable load at the position of a node beta in a photovoltaic cluster of the power distribution network at the moment t; u shape_β,tThe voltage amplitude of a node beta in a photovoltaic cluster of the power distribution network at the time t is obtained; u shape_α,tThe voltage amplitude of a node alpha in a cluster of the power distribution network at the time t is obtained;

and determining a node voltage constraint condition in a pre-established second regulation and control model according to the following formula:

In the above formula, the first and second carbon atoms are,The lower limit of the voltage amplitude of the node beta in the photovoltaic cluster of the power distribution network;for distribution networksThe upper limit of the voltage amplitude of the node beta in the photovoltaic cluster;

Determining a distributed photovoltaic operation constraint condition in a pre-established second regulation and control model according to the following formula:

in the above formula,. DELTA.Q_PV,β,tadjusting a reactive power value of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t;The minimum value of the reactive power of the distributed photovoltaic of the access node beta in the cluster of the power distribution network at the moment t;the maximum value of the reactive power of the distributed photovoltaic of the access node beta in the photovoltaic cluster of the power distribution network at the moment t;

wherein,S_PV,βThe capacity of the photovoltaic inverter at a node beta in a cluster of the power distribution network; p_PV,β,tthe active output prediction value of distributed photovoltaic of a node beta in a photovoltaic cluster of the power distribution network at the time t is obtained;

And determining an energy storage operation constraint condition in a pre-established second regulation and control model according to the following formula:

In the above formula, E_SOC,β,tThe electric quantity of the stored energy of the access node beta in the photovoltaic cluster of the power distribution network at the moment t;The method comprises the steps of obtaining an energy storage capacity lower limit value of an access node beta in a photovoltaic cluster of a power distribution network;the method comprises the steps of obtaining an upper limit value of energy storage capacity of an access node beta in a photovoltaic cluster of a power distribution network; delta P_ch,β,tAdjusting the charging power of the energy storage of an access node beta in the photovoltaic cluster of the power distribution network at the moment t;The maximum charging power of the energy storage at the position of an access node beta in a photovoltaic cluster of the power distribution network is obtained;the maximum discharge power of the stored energy at an access node beta in a photovoltaic cluster of the power distribution network is obtained; delta P_dis,β,tAnd adjusting the discharge power of the stored energy of the access node beta in the cluster of the power distribution network at the moment t.

the invention provides a two-stage optimization regulation and control device for a power distribution network based on a photovoltaic cluster, which is improved in that the device comprises:

The determining module is used for determining a first regulation and control scheme of the power distribution network according to the occurrence probability of each operation scene of the power distribution network;

the regulation and control module is used for regulating and controlling the power distribution network according to the first regulation and control scheme;

When the node voltage in the photovoltaic cluster of the power distribution network is out of limit, a second regulation and control scheme is determined according to the power regulation capacity of distributed photovoltaic and energy storage in the cluster, and the distributed photovoltaic and the energy storage in the photovoltaic cluster of the power distribution network are regulated and controlled according to the second regulation and control scheme.

preferably, the first regulatory protocol comprises: the method comprises the following steps that reactive power of distributed photovoltaic, charging and discharging power of stored energy and active power of adjustable load are connected to nodes in a power distribution network at each moment;

the second regulatory scheme comprises: and the reactive power adjustment quantity and the energy storage charging and discharging power adjustment quantity of the distributed photovoltaic in the photovoltaic cluster of the power distribution network.

preferably, the photovoltaic cluster is a branch line of a feeder line of the power distribution network, wherein the branch line of the feeder line is connected with a distributed photovoltaic and energy storage device or an adjustable load.

further, the determining module is configured to:

And substituting the occurrence probability of each operation scene of the power distribution network into a pre-established first regulation and control model, and solving to obtain a first regulation and control scheme of the power distribution network.

Further, an objective function in the pre-established first regulation model is determined according to the following formula:

In the above formula, F is the active power lost by the distribution network; p is a radical of_S,tThe probability of the s-th scene of the power distribution network at the time t is obtained; s is the total number of typical scenes reserved after scene analysis of the power distribution network; t is the time number in the regulation period; c (0) is a final node set of a line taking a starting node of the power distribution network as a first node; p_0fThe active power flowing to the node f for the initial node of the power distribution network; j belongs to (1-N), and N is the number of nodes in the power distribution network; p_PV,j,tThe active power of the distributed photovoltaic accessed to the node j at the moment t; p_ch,j,tCharging power of the stored energy accessed to the node j at the moment t; p_dis,j,tThe discharge power of the stored energy accessed to the node j at the moment t; p_CL,j,tThe active power of the adjustable load accessed by the node j at the moment t; p_load,j,tthe active power of the unregulated load accessed by the node j at the moment t.

further, the power flow constraint condition in the pre-established first regulation and control model is determined according to the following formula:

In the above formula, P_ij,tthe active power of a line ij at the moment t of the power distribution network; i is_ij,tThe current of a line ij at the moment t of the power distribution network; r is_ijThe resistance of a line ij in the power distribution network; x is the number of_ijthe reactance of a line ij in the power distribution network; p_j,tinjecting active power of a node j into the power distribution network at the moment t; p_jk,tthe active power of a line jk at the moment t of the power distribution network; q_ij,tThe reactive power of a line ij at the moment t of the power distribution network is obtained; q_j,tinjecting reactive power of a node j into the power distribution network at the moment t; q_jk,tThe reactive power of a line jk at the moment t of the power distribution network is obtained; j belongs to (1-N), and N is the number of nodes in the power distribution network; i belongs to phi (j), and phi (j) is a set of first nodes of a line with a node j as a last node in the power distribution network; k belongs to theta (j), and theta (j) is a set of end nodes of a line taking a node j as a first node in the power distribution network; p_PV,j,tthe active power of the distributed photovoltaic at the node j at the moment t of the power distribution network is obtained; p_load,j,tThe active power of the adjustable load at the node j at the moment t of the power distribution network is obtained; p_ch,j,tThe charging power of the energy storage device at the node j at the moment t of the power distribution network is obtained; p_dis,j,tThe discharge power of the energy storage device at the node j at the moment t of the power distribution network is obtained; q_PV,j,tDistributing the reactive power of the photovoltaic at a node j at the moment t of the power distribution network; q_load,j,tThe reactive power of the adjustable load device at the node j at the moment t of the power distribution network is obtained; u shape_j,tThe voltage amplitude at the node j at the moment t of the power distribution network is obtained; u shape_i,tthe voltage amplitude value at a node i at the moment t of the power distribution network is obtained;

Determining a node voltage constraint condition in a pre-established first regulation model according to the following formula:

in the above formula, the first and second carbon atoms are,The lower limit of the voltage amplitude of the node j in the power distribution network is set;the upper limit of the voltage amplitude of the node j in the power distribution network is set; u shape_j,tThe voltage amplitude at the node j at the moment t of the power distribution network is obtained;

Determining the operation constraint conditions of the distributed photovoltaic power station in the pre-established first regulation and control model according to the following formula:

in the above formula, the first and second carbon atoms are,the distributed photovoltaic reactive power minimum value of a node j at the moment t of the power distribution network is obtained;the maximum value of the distributed photovoltaic reactive power of a node j at the moment t of the power distribution network is obtained;

wherein,S_PV,jthe capacity of a distributed photovoltaic inverter of a node j in the power distribution network;The distributed photovoltaic active output prediction value of the node j at the moment t of the power distribution network is obtained;

determining an energy storage operation constraint condition in a pre-established first regulation and control model according to the following formula:

in the above formula, E_SOC,j,tThe electric quantity of the energy storage device of the node j at the moment t of the power distribution network is; e_SOC,j,t+Δtthe electric quantity of the energy storage device is the t + delta t moment node j of the power distribution network;limiting the energy storage capacity of an energy storage device of a node j in the power distribution network;limiting the energy storage capacity of an energy storage device of a node j in the power distribution network;The maximum charging power of the energy storage device of the node j in the power distribution network;the maximum discharge power of the energy storage device of the node j in the power distribution network;

determining an adjustable load device power constraint condition in a pre-established first regulation and control model according to the following formula:

In the above formula, P_CL,j,tThe actual power consumption of the adjustable load device is the node j at the moment t of the power distribution network; w_j,minThe minimum electric quantity requirement of the adjustable load device of the node j in the power distribution network is set; w_j,maxThe maximum value of the electric quantity requirement of the adjustable load device of the node j in the power distribution network; Δ t is the time interval of the first modulation scheme; t is the time number in the regulation period;

wherein,ε_minThe minimum value of the proportion of the actual power consumption of the adjustable load device in the power distribution network to the expected power consumption is obtained; epsilon_maxThe maximum value of the proportion of the actual power consumption of the adjustable load device of the power distribution network to the expected power consumption is obtained;The expected power consumption at the moment t is set for the adjustable load of the distribution network.

further, the determining a second regulation and control scheme according to the power regulation capability of the distributed photovoltaic and the stored energy in the photovoltaic cluster of the power distribution network, and regulating and controlling the distributed photovoltaic and the stored energy in the distributed photovoltaic cluster by using the second regulation and control scheme includes:

And substituting the maximum and minimum reactive power values and the maximum and minimum stored charge and discharge power values of the distributed photovoltaic in the power distribution network cluster into a pre-established second regulation and control model, solving the second regulation and control model, and obtaining a second regulation and control scheme of the power distribution network.

Further, an objective function in the pre-established second regulation model is determined according to the following formula:

in the above formula, F_vAdjusting the minimum power of distributed photovoltaic and energy storage in the distributed photovoltaic cluster;The method comprises the steps of collecting all distributed photovoltaic in a cluster; delta Q_PV,xadjusting the reactive power of the xth distributed photovoltaic in the cluster;The maximum value of the reactive power of the x-th distributed photovoltaic in the cluster;the method comprises the steps of collecting all stored energy in a cluster; delta P_ch,yAdjusting the charging power of the y-th stored energy in the cluster;The maximum value of the charging power of the y-th stored energy in the cluster; d_ch,ya charging coefficient for the y-th stored energy in the cluster; d_ch,y∈(0,1)；ΔP_dis,yAdjusting the discharge power of the y-th stored energy in the cluster;The maximum value of the discharge power of the y-th stored energy in the cluster; d_dis,yThe discharge coefficient of the y-th stored energy in the cluster; d_dis,y∈(0,1)。

further, the power constant constraint condition in the pre-established second regulation model is determined according to the following formula:

in the above formula, the first and second carbon atoms are,Is an initial active power value flowing into a starting node of the cluster; p_CThe active power value which flows into the initial node of the cluster after being adjusted by the second regulation scheme is obtained;An initial reactive power value for a starting node of the cluster; q_Cthe active power value which flows into the initial node of the cluster after being adjusted by the second regulation scheme is obtained;

Determining a power flow constraint condition in a pre-established second regulation and control model according to the following formula:

in the above formula, P_αβ,tThe active power of the line alpha beta in the photovoltaic cluster of the power distribution network at the moment t; i is_αβ,tThe current of the line alpha beta in the photovoltaic cluster of the power grid at the moment t; r is_αβResistance of a line α β in a photovoltaic cluster for a distribution network; p_β,tinjecting active power of a node beta in a photovoltaic cluster of the power distribution network at the time t; p_βγ,tActive power of a line beta gamma in a photovoltaic cluster of the power distribution network at the moment t; q_αβ,tthe reactive power of the line alpha beta in the photovoltaic cluster of the power distribution network at the moment t; x is the number of_αβIs the reactance of the line alpha beta in the photovoltaic cluster of the distribution network; q_β,tInjecting reactive power of a node beta in a cluster of the power distribution network at the time t; q_βγ,tthe reactive power of the line beta gamma in the cluster of the power distribution network at the moment t; beta belongs to (1-M), wherein M is the number of nodes in a photovoltaic cluster of the power distribution network; alpha belongs to psi (beta), and psi (beta) is a set of line head nodes taking a node beta as a tail node in a photovoltaic cluster of a power distribution network;the method comprises the steps that a line end node set taking a node beta as a first node in a photovoltaic cluster of a power distribution network is formed; p_PV,β,tActive power of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t; p_CL,β,tthe active power of the adjustable load at the position of a node beta in the photovoltaic cluster of the power distribution network at the moment t; p_load,β,tthe active power of the unregulated load at the node beta in the photovoltaic cluster of the power distribution network at the moment t; p_ch,β,tthe energy storage charging power of an access node beta in the photovoltaic cluster of the power distribution network at the moment t is obtained; p_dis,β,tThe discharge power is the stored energy discharge power of an access node beta in the photovoltaic cluster of the power distribution network at the moment t; q_PV,β,tthe reactive power of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t; q_CL,β,tthe reactive power of the adjustable load at the position of a node beta in the photovoltaic cluster of the power distribution network at the moment t; q_load,β,tthe reactive power of the non-adjustable load at the position of a node beta in a photovoltaic cluster of the power distribution network at the moment t; u shape_β,tthe voltage amplitude of a node beta in a photovoltaic cluster of the power distribution network at the time t is obtained; u shape_α,tthe voltage amplitude of a node alpha in a cluster of the power distribution network at the time t is obtained;

And determining a node voltage constraint condition in a pre-established second regulation and control model according to the following formula:

in the above formula, the first and second carbon atoms are,The lower limit of the voltage amplitude of the node beta in the photovoltaic cluster of the power distribution network;the upper limit of the voltage amplitude of the node beta in the photovoltaic cluster of the power distribution network is set;

Determining a distributed photovoltaic operation constraint condition in a pre-established second regulation and control model according to the following formula:

In the above formula,. DELTA.Q_PV,β,tadjusting a reactive power value of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t;the minimum value of the reactive power of the distributed photovoltaic of the access node beta in the cluster of the power distribution network at the moment t;the maximum value of the reactive power of the distributed photovoltaic of the access node beta in the photovoltaic cluster of the power distribution network at the moment t;

wherein,S_PV,βThe capacity of the photovoltaic inverter at a node beta in a cluster of the power distribution network; p_PV,β,tthe active output prediction value of distributed photovoltaic of a node beta in a photovoltaic cluster of the power distribution network at the time t is obtained;

And determining an energy storage operation constraint condition in a pre-established second regulation and control model according to the following formula:

In the above formula, E_SOC,β,tthe electric quantity of the stored energy of the access node beta in the photovoltaic cluster of the power distribution network at the moment t;The method comprises the steps of obtaining an energy storage capacity lower limit value of an access node beta in a photovoltaic cluster of a power distribution network;The method comprises the steps of obtaining an upper limit value of energy storage capacity of an access node beta in a photovoltaic cluster of a power distribution network; delta P_ch,β,tadjusting the charging power of the energy storage of an access node beta in the photovoltaic cluster of the power distribution network at the moment t;the maximum charging power of the energy storage at the position of an access node beta in a photovoltaic cluster of the power distribution network is obtained;The maximum discharge power of the stored energy at an access node beta in a photovoltaic cluster of the power distribution network is obtained; delta P_dis,β,tAnd adjusting the discharge power of the stored energy of the access node beta in the cluster of the power distribution network at the moment t.

Compared with the closest prior art, the invention has the following beneficial effects:

The invention provides a two-stage optimization regulation and control method and device for a power distribution network based on a photovoltaic cluster, wherein a first regulation and control scheme of the power distribution network is determined according to the occurrence probability of each operation scene of the power distribution network; regulating and controlling the power distribution network according to the first regulation and control scheme; when the voltage of the nodes in the cluster of the power distribution network is out of limit, a second regulation and control scheme is determined according to the maximum reactive power value of the photovoltaic nodes in the cluster of the power distribution network and the maximum charge-discharge power value of the energy storage node, and each node in the cluster of the power distribution network is regulated and controlled according to the second regulation and control scheme. According to the technical scheme, the overall situation of the power distribution network and the cluster of the power distribution network are utilized to realize multi-dimensional cooperative optimization regulation and control of multiple kinds of controllable resources in the power distribution network and the cluster of the power distribution network on a time scale and a space scale, so that the rapidity and the effectiveness of regulation and control are improved, the consumption capacity of the power grid on distributed photovoltaic is improved, and the safe operation of the power distribution network is ensured.

Drawings

FIG. 1 is a flow chart of a two-stage optimal regulation and control method for a power distribution network based on a photovoltaic cluster, provided by the invention;

FIG. 2 is a schematic diagram of cluster partitioning provided by the present invention;

fig. 3 is a structural diagram of a two-stage optimization regulation and control device for a power distribution network based on a photovoltaic cluster provided by the invention.

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

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

the invention provides a two-stage optimization regulation and control method for a power distribution network based on a photovoltaic cluster, which comprises the following steps of:

Determining a first regulation and control scheme of the power distribution network according to the occurrence probability of each operation scene of the power distribution network;

regulating and controlling the power distribution network according to the first regulation and control scheme;

when the node voltage in the photovoltaic cluster of the power distribution network is out of limit, a second regulation and control scheme is determined according to the power regulation capacity of distributed photovoltaic and energy storage in the cluster, and the distributed photovoltaic and the energy storage in the photovoltaic cluster of the power distribution network are regulated and controlled according to the second regulation and control scheme.

specifically, the first regulation and control scheme comprises: the method comprises the following steps that reactive power of distributed photovoltaic, charging and discharging power of stored energy and active power of adjustable load are connected to nodes in a power distribution network at each moment;

The second regulatory scheme comprises: and the reactive power adjustment quantity and the energy storage charging and discharging power adjustment quantity of the distributed photovoltaic in the photovoltaic cluster of the power distribution network.

The photovoltaic cluster is a branch line of a feeder line of the power distribution network, wherein the branch line of the feeder line is connected with a distributed photovoltaic and energy storage device or an adjustable load.

in the optimal embodiment of the invention, because the photovoltaic output and load requirements have strong uncertainty and the prediction error is large, the uncertainty of the distributed photovoltaic and load is described by adopting a scene analysis method, and the uncertainty problem is converted into the certainty problem to be solved, so that the first regulation and control scheme coordinates all active and reactive adjustable units in the power distribution network based on scene analysis, and optimizes the output behavior of each adjustable unit in a period T in the future by taking delta T as a time interval.

The first regulation and control scheme for determining the power distribution network according to the occurrence probability of each operation scene of the power distribution network comprises the following steps:

And substituting the occurrence probability of each operation scene of the power distribution network into a pre-established first regulation and control model, and solving to obtain a first regulation and control scheme of the power distribution network.

Wherein, an objective function in a pre-established first regulation and control model is determined according to the following formula:

in the above formula, F is the active power lost by the distribution network; p is a radical of_S,tThe probability of the s-th scene of the power distribution network at the time t is obtained; s is the total number of typical scenes reserved after scene analysis of the power distribution network; t is the time number in the regulation period; c (0) is a final node set of a line taking a starting node of the power distribution network as a first node; p_0fThe active power flowing to the node f for the initial node of the power distribution network; j belongs to (1-N), and N is the number of nodes in the power distribution network; p_PV,j,tThe active power of the distributed photovoltaic accessed to the node j at the moment t; p_ch,j,tCharging power of the stored energy accessed to the node j at the moment t; p_dis,j,tThe discharge power of the stored energy accessed to the node j at the moment t; p_CL,j,tThe active power of the adjustable load accessed by the node j at the moment t; p_load,j,tthe active power of the unregulated load accessed by the node j at the moment t.

determining a power flow constraint condition in a pre-established first regulation and control model according to the following formula:

in the above formula, P_ij,tthe active power of a line ij at the moment t of the power distribution network; i is_ij,tThe current of a line ij at the moment t of the power distribution network; r is_ijthe resistance of a line ij in the power distribution network; x is the number of_ijThe reactance of a line ij in the power distribution network; p_j,tInjecting active power of a node j into the power distribution network at the moment t; p_jk,tThe active power of a line jk at the moment t of the power distribution network; q_ij,tthe reactive power of a line ij at the moment t of the power distribution network is obtained; q_j,tfor distribution networksInjecting reactive power of a node j at the time t; q_jk,tthe reactive power of a line jk at the moment t of the power distribution network is obtained; j belongs to (1-N), and N is the number of nodes in the power distribution network; i belongs to phi (j), and phi (j) is a set of first nodes of a line with a node j as a last node in the power distribution network; k belongs to theta (j), and theta (j) is a set of end nodes of a line taking a node j as a first node in the power distribution network; p_PV,j,tThe active power of the distributed photovoltaic at the node j at the moment t of the power distribution network is obtained; p_load,j,tThe active power of the adjustable load at the node j at the moment t of the power distribution network is obtained; p_ch,j,tthe charging power of the energy storage device at the node j at the moment t of the power distribution network is obtained; p_dis,j,tthe discharge power of the energy storage device at the node j at the moment t of the power distribution network is obtained; q_PV,j,tdistributing the reactive power of the photovoltaic at a node j at the moment t of the power distribution network; q_load,j,tThe reactive power of the adjustable load device at the node j at the moment t of the power distribution network is obtained; u shape_j,tThe voltage amplitude at the node j at the moment t of the power distribution network is obtained; u shape_i,tthe voltage amplitude value at a node i at the moment t of the power distribution network is obtained;

Determining a node voltage constraint condition in a pre-established first regulation model according to the following formula:

In the above formula, the first and second carbon atoms are,The lower limit of the voltage amplitude of the node j in the power distribution network is set;The upper limit of the voltage amplitude of the node j in the power distribution network is set; u shape_j,tThe voltage amplitude at the node j at the moment t of the power distribution network is obtained;

determining the operation constraint conditions of the distributed photovoltaic power station in the pre-established first regulation and control model according to the following formula:

in the above formula, the first and second carbon atoms are,The distributed photovoltaic reactive power minimum value of a node j at the moment t of the power distribution network is obtained;The maximum value of the distributed photovoltaic reactive power of a node j at the moment t of the power distribution network is obtained; wherein,S_PV,jthe capacity of a distributed photovoltaic inverter of a node j in the power distribution network;The distributed photovoltaic active output prediction value of the node j at the moment t of the power distribution network is obtained;

determining an energy storage operation constraint condition in a pre-established first regulation and control model according to the following formula:

in the above formula, E_SOC,j,tThe electric quantity of the energy storage device of the node j at the moment t of the power distribution network is; e_SOC,j,t+ΔtThe electric quantity of the energy storage device is the t + delta t moment node j of the power distribution network;Limiting the energy storage capacity of an energy storage device of a node j in the power distribution network;limiting the energy storage capacity of an energy storage device of a node j in the power distribution network;The maximum charging power of the energy storage device of the node j in the power distribution network;The maximum discharge power of the energy storage device of the node j in the power distribution network;

determining an adjustable load device power constraint condition in a pre-established first regulation and control model according to the following formula:

in the above formula, P_CL,j,tthe actual power consumption of the adjustable load device is the node j at the moment t of the power distribution network; w_j,minThe minimum electric quantity requirement of the adjustable load device of the node j in the power distribution network is set; w_j,maxThe maximum value of the electric quantity requirement of the adjustable load device of the node j in the power distribution network; Δ t is the time interval of the first modulation scheme; t is the time number in the regulation period; wherein,ε_minThe minimum value of the proportion of the actual power consumption of the adjustable load device in the power distribution network to the expected power consumption is obtained; epsilon_maxthe maximum value of the proportion of the actual power consumption of the adjustable load device of the power distribution network to the expected power consumption is obtained;the expected power consumption at the moment t is set for the adjustable load of the distribution network.

In the optimal embodiment of the invention, as the number of distributed photovoltaics in the power distribution network is large, the overall regulation and control calculation in the first regulation and control scheme is complex and takes long time, the purpose of cluster division is to divide the power distribution network into local power distribution networks with autonomous capability according to the distribution of the distributed photovoltaics and other controllable units, so as to realize the rapid regulation and control of the power flow and the voltage level of a cluster area; the partitioned objects in a cluster need to have electrical connection and electrical distances of the objects are close for complementary power exchange, so that cluster partitioning can be performed according to the following principle: as shown in fig. 2, if there are a large number of distributed photovoltaic accesses on a branch line of a feeder line, and an energy storage device or an adjustable load is connected at the same time, the branch line is regarded as 1 distributed photovoltaic cluster with regional autonomy.

In an optimal embodiment of the present invention, the determining a second regulation and control scheme according to the power regulation capability of distributed photovoltaic and energy storage in a photovoltaic cluster of a power distribution network, and regulating and controlling the distributed photovoltaic and energy storage in the distributed photovoltaic cluster by using the second regulation and control scheme includes:

and substituting the maximum and minimum reactive power values and the maximum and minimum stored charge and discharge power values of the distributed photovoltaic in the power distribution network cluster into a pre-established second regulation and control model, solving the second regulation and control model, and obtaining a second regulation and control scheme of the power distribution network.

wherein the objective function in the pre-established second regulation model is determined according to the following formula:

In the above formula, F_vadjusting the minimum power of distributed photovoltaic and energy storage in the distributed photovoltaic cluster;the method comprises the steps of collecting all distributed photovoltaic in a cluster; delta Q_PV,xAdjusting the reactive power of the xth distributed photovoltaic in the cluster;The maximum value of the reactive power of the x-th distributed photovoltaic in the cluster;the method comprises the steps of collecting all stored energy in a cluster; delta P_ch,yAdjusting the charging power of the y-th stored energy in the cluster;the maximum value of the charging power of the y-th stored energy in the cluster; d_ch,yA charging coefficient for the y-th stored energy in the cluster; d_ch,y∈(0,1)；ΔP_dis,yAdjusting the discharge power of the y-th stored energy in the cluster;The maximum value of the discharge power of the y-th stored energy in the cluster; d_dis,ythe discharge coefficient of the y-th stored energy in the cluster; d_dis,y∈(0,1)。

determining a power constant constraint condition in a pre-established second regulation model according to the following formula:

In the above formula, the first and second carbon atoms are,is an initial active power value flowing into a starting node of the cluster; p_Cthe active power value which flows into the initial node of the cluster after being adjusted by the second regulation scheme is obtained;An initial reactive power value for a starting node of the cluster; q_Cthe active power value which flows into the initial node of the cluster after being adjusted by the second regulation scheme is obtained;

determining a power flow constraint condition in a pre-established second regulation and control model according to the following formula:

In the above formula, P_αβ,tThe active power of the line alpha beta in the photovoltaic cluster of the power distribution network at the moment t; i is_αβ,tThe current of the line alpha beta in the photovoltaic cluster of the power grid at the moment t; r is_αβresistance of a line α β in a photovoltaic cluster for a distribution network; p_β,tinjecting active power of a node beta in a photovoltaic cluster of the power distribution network at the time t; p_βγ,tActive power of a line beta gamma in a photovoltaic cluster of the power distribution network at the moment t; q_αβ,tthe reactive power of the line alpha beta in the photovoltaic cluster of the power distribution network at the moment t; x is the number of_αβIs the reactance of the line alpha beta in the photovoltaic cluster of the distribution network; q_β,tIs at t timeinjecting reactive power of a node beta in a cluster of the power distribution network; q_βγ,tthe reactive power of the line beta gamma in the cluster of the power distribution network at the moment t; beta belongs to (1-M), wherein M is the number of nodes in a photovoltaic cluster of the power distribution network; alpha belongs to psi (beta), and psi (beta) is a set of line head nodes taking a node beta as a tail node in a photovoltaic cluster of a power distribution network;the method comprises the steps that a line end node set taking a node beta as a first node in a photovoltaic cluster of a power distribution network is formed; p_PV,β,tActive power of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t; p_CL,β,tthe active power of the adjustable load at the position of a node beta in the photovoltaic cluster of the power distribution network at the moment t; p_load,β,tThe active power of the unregulated load at the node beta in the photovoltaic cluster of the power distribution network at the moment t; p_ch,β,tThe energy storage charging power of an access node beta in the photovoltaic cluster of the power distribution network at the moment t is obtained; p_dis,β,tthe discharge power is the stored energy discharge power of an access node beta in the photovoltaic cluster of the power distribution network at the moment t; q_PV,β,tThe reactive power of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t; q_CL,β,tThe reactive power of the adjustable load at the position of a node beta in the photovoltaic cluster of the power distribution network at the moment t; q_load,β,tthe reactive power of the non-adjustable load at the position of a node beta in a photovoltaic cluster of the power distribution network at the moment t; u shape_β,tthe voltage amplitude of a node beta in a photovoltaic cluster of the power distribution network at the time t is obtained; u shape_α,tthe voltage amplitude of a node alpha in a cluster of the power distribution network at the time t is obtained;

And determining a node voltage constraint condition in a pre-established second regulation and control model according to the following formula:

In the above formula, the first and second carbon atoms are,the lower limit of the voltage amplitude of the node beta in the photovoltaic cluster of the power distribution network;The upper limit of the voltage amplitude of the node beta in the photovoltaic cluster of the power distribution network is set;

Determining a distributed photovoltaic operation constraint condition in a pre-established second regulation and control model according to the following formula:

In the above formula,. DELTA.Q_PV,β,tadjusting a reactive power value of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t;The minimum value of the reactive power of the distributed photovoltaic of the access node beta in the cluster of the power distribution network at the moment t;the maximum value of the reactive power of the distributed photovoltaic of the access node beta in the photovoltaic cluster of the power distribution network at the moment t; wherein,S_PV,βthe capacity of the photovoltaic inverter at a node beta in a cluster of the power distribution network; p_PV,β,tthe active output prediction value of distributed photovoltaic of a node beta in a photovoltaic cluster of the power distribution network at the time t is obtained;

And determining an energy storage operation constraint condition in a pre-established second regulation and control model according to the following formula:

in the above formula, E_SOC,β,tThe electric quantity of the stored energy of the access node beta in the photovoltaic cluster of the power distribution network at the moment t;The method comprises the steps of obtaining an energy storage capacity lower limit value of an access node beta in a photovoltaic cluster of a power distribution network;The method comprises the steps of obtaining an upper limit value of energy storage capacity of an access node beta in a photovoltaic cluster of a power distribution network; delta P_ch,β,tAdjusting the charging power of the energy storage of an access node beta in the photovoltaic cluster of the power distribution network at the moment t;the maximum charging power of the energy storage at the position of an access node beta in a photovoltaic cluster of the power distribution network is obtained;The maximum discharge power of the stored energy at an access node beta in a photovoltaic cluster of the power distribution network is obtained; delta P_dis,β,tAnd adjusting the discharge power of the stored energy of the access node beta in the cluster of the power distribution network at the moment t.

in the optimal embodiment of the invention, the first regulation and control stage and the second regulation and control stage are both complex non-convex nonlinear problems which are difficult to solve, and the problem is converted into a second-order cone programming problem to be solved, so that the difficulty in solving the problem can be effectively improved, and the solving efficiency is greatly improved;

firstly, new variables are introduced, and the original regulation model is involvedandandAre replaced by the following forms:And

After replacement, only in the power flow constraint in the regulatory modelThe method is a non-convex non-linear constraint, and therefore, the second-order cone relaxation method is relaxed according to the basic principle of the second-order cone relaxation method, and the specific method is as follows:

It is rewritten as a standard second order cone, i.e.:

therefore, the original regulation and control model is converted into a second-order cone planning model capable of being solved efficiently, and a solver such as Mosek or Cplex can be adopted to realize efficient solving of the model.

the invention provides a two-stage optimization regulation and control device for a power distribution network based on a photovoltaic cluster, as shown in fig. 3, the device comprises:

The determining module is used for determining a first regulation and control scheme of the power distribution network according to the occurrence probability of each operation scene of the power distribution network;

the regulation and control module is used for regulating and controlling the power distribution network according to the first regulation and control scheme;

when the node voltage in the photovoltaic cluster of the power distribution network is out of limit, a second regulation and control scheme is determined according to the power regulation capacity of distributed photovoltaic and energy storage in the cluster, and the distributed photovoltaic and the energy storage in the photovoltaic cluster of the power distribution network are regulated and controlled according to the second regulation and control scheme.

specifically, the first regulation and control scheme comprises: the method comprises the following steps that reactive power of distributed photovoltaic, charging and discharging power of stored energy and active power of adjustable load are connected to nodes in a power distribution network at each moment;

the second regulatory scheme comprises: and the reactive power adjustment quantity and the energy storage charging and discharging power adjustment quantity of the distributed photovoltaic in the photovoltaic cluster of the power distribution network.

the photovoltaic cluster is a branch line of a feeder line of the power distribution network, wherein the branch line of the feeder line is connected with a distributed photovoltaic and energy storage device or an adjustable load.

in a preferred embodiment of the present invention, the determining module is configured to:

And substituting the occurrence probability of each operation scene of the power distribution network into a pre-established first regulation and control model, and solving to obtain a first regulation and control scheme of the power distribution network.

Wherein, an objective function in a pre-established first regulation and control model is determined according to the following formula:

in the above formula, F is the active power lost by the distribution network; p is a radical of_S,tthe probability of the s-th scene of the power distribution network at the time t is obtained; s is the total number of typical scenes reserved after scene analysis of the power distribution network; t is the time number in the regulation period; c (0) is a final node set of a line taking a starting node of the power distribution network as a first node; p_0fThe active power flowing to the node f for the initial node of the power distribution network; j belongs to (1-N), and N is the number of nodes in the power distribution network; p_PV,j,tthe active power of the distributed photovoltaic accessed to the node j at the moment t; p_ch,j,tcharging power of the stored energy accessed to the node j at the moment t; p_dis,j,tThe discharge power of the stored energy accessed to the node j at the moment t; p_CL,j,tThe active power of the adjustable load accessed by the node j at the moment t; p_load,j,tThe active power of the unregulated load accessed by the node j at the moment t.

Determining a power flow constraint condition in a pre-established first regulation and control model according to the following formula:

In the above formula, P_ij,tthe active power of a line ij at the moment t of the power distribution network; i is_ij,tThe current of a line ij at the moment t of the power distribution network; r is_ijThe resistance of a line ij in the power distribution network; x is the number of_ijFor in the distribution networkreactance of line ij; p_j,tInjecting active power of a node j into the power distribution network at the moment t; p_jk,tThe active power of a line jk at the moment t of the power distribution network; q_ij,tThe reactive power of a line ij at the moment t of the power distribution network is obtained; q_j,tinjecting reactive power of a node j into the power distribution network at the moment t; q_jk,tthe reactive power of a line jk at the moment t of the power distribution network is obtained; j belongs to (1-N), and N is the number of nodes in the power distribution network; i belongs to phi (j), and phi (j) is a set of first nodes of a line with a node j as a last node in the power distribution network; k belongs to theta (j), and theta (j) is a set of end nodes of a line taking a node j as a first node in the power distribution network; p_PV,j,tthe active power of the distributed photovoltaic at the node j at the moment t of the power distribution network is obtained; p_load,j,tthe active power of the adjustable load at the node j at the moment t of the power distribution network is obtained; p_ch,j,tThe charging power of the energy storage device at the node j at the moment t of the power distribution network is obtained; p_dis,j,tthe discharge power of the energy storage device at the node j at the moment t of the power distribution network is obtained; q_PV,j,tdistributing the reactive power of the photovoltaic at a node j at the moment t of the power distribution network; q_load,j,tthe reactive power of the adjustable load device at the node j at the moment t of the power distribution network is obtained; u shape_j,tThe voltage amplitude at the node j at the moment t of the power distribution network is obtained; u shape_i,tThe voltage amplitude value at a node i at the moment t of the power distribution network is obtained;

determining a node voltage constraint condition in a pre-established first regulation model according to the following formula:

in the above formula, the first and second carbon atoms are,The lower limit of the voltage amplitude of the node j in the power distribution network is set;The upper limit of the voltage amplitude of the node j in the power distribution network is set; u shape_j,tthe voltage amplitude at the node j at the moment t of the power distribution network is obtained;

Determining the operation constraint conditions of the distributed photovoltaic in the pre-established first regulation and control model according to the following formula:

In the above formula, the first and second carbon atoms are,the distributed photovoltaic reactive power minimum value of a node j at the moment t of the power distribution network is obtained;the maximum value of the distributed photovoltaic reactive power of a node j at the moment t of the power distribution network is obtained;

Wherein,S_PV,jThe capacity of a distributed photovoltaic inverter of a node j in the power distribution network;The distributed photovoltaic active output prediction value of the node j at the moment t of the power distribution network is obtained;

determining an energy storage operation constraint condition in a pre-established first regulation and control model according to the following formula:

In the above formula, E_SOC,j,tthe electric quantity of the energy storage device of the node j at the moment t of the power distribution network is; e_SOC,j,t+ΔtThe electric quantity of the energy storage device is the t + delta t moment node j of the power distribution network;Limiting the energy storage capacity of an energy storage device of a node j in the power distribution network;Limiting the energy storage capacity of an energy storage device of a node j in the power distribution network;the maximum charging power of the energy storage device of the node j in the power distribution network;The maximum discharge power of the energy storage device of the node j in the power distribution network;

Determining an adjustable load device power constraint condition in a pre-established first regulation and control model according to the following formula:

In the above formula, P_CL,j,tthe actual power consumption of the adjustable load device is the node j at the moment t of the power distribution network; w_j,minThe minimum electric quantity requirement of the adjustable load device of the node j in the power distribution network is set; w_j,maxthe maximum value of the electric quantity requirement of the adjustable load device of the node j in the power distribution network; Δ t is the time interval of the first modulation scheme; t is the time number in the regulation period;

Wherein,ε_minthe minimum value of the proportion of the actual power consumption of the adjustable load device in the power distribution network to the expected power consumption is obtained; epsilon_maxthe maximum value of the proportion of the actual power consumption of the adjustable load device of the power distribution network to the expected power consumption is obtained;the expected power consumption at the moment t is set for the adjustable load of the distribution network.

in an optimal embodiment of the present invention, the determining a second regulation and control scheme according to the power regulation capability of distributed photovoltaic and energy storage in a photovoltaic cluster of a power distribution network, and regulating and controlling the distributed photovoltaic and energy storage in the distributed photovoltaic cluster by using the second regulation and control scheme includes:

and substituting the maximum and minimum reactive power values and the maximum and minimum stored charge and discharge power values of the distributed photovoltaic in the power distribution network cluster into a pre-established second regulation and control model, solving the second regulation and control model, and obtaining a second regulation and control scheme of the power distribution network.

wherein the objective function in the pre-established second regulation model is determined according to the following formula:

in the above formula, F_vadjusting the minimum power of distributed photovoltaic and energy storage in the distributed photovoltaic cluster;The method comprises the steps of collecting all distributed photovoltaic in a cluster; delta Q_PV,xAdjusting the reactive power of the xth distributed photovoltaic in the cluster;The maximum value of the reactive power of the x-th distributed photovoltaic in the cluster;The method comprises the steps of collecting all stored energy in a cluster; delta P_ch,yAdjusting the charging power of the y-th stored energy in the cluster;the maximum value of the charging power of the y-th stored energy in the cluster; d_ch,ya charging coefficient for the y-th stored energy in the cluster; d_ch,y∈(0,1)；ΔP_dis,yadjusting the discharge power of the y-th stored energy in the cluster;The maximum value of the discharge power of the y-th stored energy in the cluster; d_dis,yThe discharge coefficient of the y-th stored energy in the cluster; d_dis,y∈(0,1)。

determining a power constant constraint condition in a pre-established second regulation model according to the following formula:

In the above formula, the first and second carbon atoms are,is an initial active power value flowing into a starting node of the cluster; p_Cthe active power value which flows into the initial node of the cluster after being adjusted by the second regulation scheme is obtained;An initial reactive power value for a starting node of the cluster; q_CThe active power value which flows into the initial node of the cluster after being adjusted by the second regulation scheme is obtained;

Determining a power flow constraint condition in a pre-established second regulation and control model according to the following formula:

In the above formula, P_αβ,tthe active power of the line alpha beta in the photovoltaic cluster of the power distribution network at the moment t; i is_αβ,tThe current of the line alpha beta in the photovoltaic cluster of the power grid at the moment t; r is_αβResistance of a line α β in a photovoltaic cluster for a distribution network; p_β,tinjecting active power of a node beta in a photovoltaic cluster of the power distribution network at the time t; p_βγ,tActive power of a line beta gamma in a photovoltaic cluster of the power distribution network at the moment t; q_αβ,tThe reactive power of the line alpha beta in the photovoltaic cluster of the power distribution network at the moment t; x is the number of_αβis the reactance of the line alpha beta in the photovoltaic cluster of the distribution network; q_β,tinjecting reactive power of a node beta in a cluster of the power distribution network at the time t; q_βγ,tThe reactive power of the line beta gamma in the cluster of the power distribution network at the moment t; beta belongs to (1-M), wherein M is the number of nodes in a photovoltaic cluster of the power distribution network; alpha belongs to psi (beta), and psi (beta) is a set of line head nodes taking a node beta as a tail node in a photovoltaic cluster of a power distribution network;Line taking node beta as first node in photovoltaic cluster of power distribution networkA set of end nodes; p_PV,β,tactive power of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t; p_CL,β,tthe active power of the adjustable load at the position of a node beta in the photovoltaic cluster of the power distribution network at the moment t; p_load,β,tThe active power of the unregulated load at the node beta in the photovoltaic cluster of the power distribution network at the moment t; p_ch,β,tThe energy storage charging power of an access node beta in the photovoltaic cluster of the power distribution network at the moment t is obtained; p_dis,β,tthe discharge power is the stored energy discharge power of an access node beta in the photovoltaic cluster of the power distribution network at the moment t; q_PV,β,tThe reactive power of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t; q_CL,β,tThe reactive power of the adjustable load at the position of a node beta in the photovoltaic cluster of the power distribution network at the moment t; q_load,β,tThe reactive power of the non-adjustable load at the position of a node beta in a photovoltaic cluster of the power distribution network at the moment t; u shape_β,tThe voltage amplitude of a node beta in a photovoltaic cluster of the power distribution network at the time t is obtained; u shape_α,tThe voltage amplitude of a node alpha in a cluster of the power distribution network at the time t is obtained;

and determining a node voltage constraint condition in a pre-established second regulation and control model according to the following formula:

In the above formula, the first and second carbon atoms are,the lower limit of the voltage amplitude of the node beta in the photovoltaic cluster of the power distribution network;the upper limit of the voltage amplitude of the node beta in the photovoltaic cluster of the power distribution network is set;

Determining a distributed photovoltaic operation constraint condition in a pre-established second regulation and control model according to the following formula:

In the above formula,. DELTA.Q_PV,β,tAdjusting a reactive power value of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t;The minimum value of the reactive power of the distributed photovoltaic of the access node beta in the cluster of the power distribution network at the moment t;the maximum value of the reactive power of the distributed photovoltaic of the access node beta in the photovoltaic cluster of the power distribution network at the moment t;

wherein,S_PV,βThe capacity of the photovoltaic inverter at a node beta in a cluster of the power distribution network; p_PV,β,tThe active output prediction value of distributed photovoltaic of a node beta in a photovoltaic cluster of the power distribution network at the time t is obtained;

And determining an energy storage operation constraint condition in a pre-established second regulation and control model according to the following formula:

In the above formula, E_SOC,β,tThe electric quantity of the stored energy of the access node beta in the photovoltaic cluster of the power distribution network at the moment t;The method comprises the steps of obtaining an energy storage capacity lower limit value of an access node beta in a photovoltaic cluster of a power distribution network;The method comprises the steps of obtaining an upper limit value of energy storage capacity of an access node beta in a photovoltaic cluster of a power distribution network; delta P_ch,β,tadjusting the charging power of the energy storage of an access node beta in the photovoltaic cluster of the power distribution network at the moment t;For storing energy at access node beta in photovoltaic cluster of power distribution networkA maximum charging power;the maximum discharge power of the stored energy at an access node beta in a photovoltaic cluster of the power distribution network is obtained; delta P_dis,β,tAnd adjusting the discharge power of the stored energy of the access node beta in the cluster of the power distribution network at the moment t.

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

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

these computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.

Claims (10)

1. A two-stage optimization regulation and control method for a power distribution network based on a photovoltaic cluster is characterized by comprising the following steps:

Determining a first regulation and control scheme of the power distribution network according to the occurrence probability of each operation scene of the power distribution network;

regulating and controlling the power distribution network according to the first regulation and control scheme;

When the node voltage in the photovoltaic cluster of the power distribution network is out of limit, a second regulation and control scheme is determined according to the power regulation capacity of distributed photovoltaic and energy storage in the cluster, and the distributed photovoltaic and the energy storage in the photovoltaic cluster of the power distribution network are regulated and controlled according to the second regulation and control scheme.

2. The method of claim 1, wherein the first regulatory scheme comprises: the method comprises the following steps that reactive power of distributed photovoltaic, charging and discharging power of stored energy and active power of adjustable load are connected to nodes in a power distribution network at each moment;

The second regulatory scheme comprises: and the reactive power adjustment quantity and the energy storage charging and discharging power adjustment quantity of the distributed photovoltaic in the photovoltaic cluster of the power distribution network.

3. The method according to claim 1, wherein the photovoltaic cluster is a branch line of a feeder of a distribution grid, wherein the branch line of the feeder is terminated with a distributed photovoltaic and energy storage device or an adjustable load.

4. The method of claim 2, wherein determining the first regulation and control scheme for the power distribution network based on the probability of occurrence of each operational scenario of the power distribution network comprises:

And substituting the occurrence probability of each operation scene of the power distribution network into a pre-established first regulation and control model, and solving to obtain a first regulation and control scheme of the power distribution network.

5. The method of claim 4, wherein the objective function in the pre-established first regulatory model is determined according to the following equation:

in the above formula, F is the active power lost by the distribution network; p is a radical of_S,tthe probability of the s-th scene of the power distribution network at the time t is obtained; s is the total number of typical scenes reserved after scene analysis of the power distribution network; t is the time number in the regulation period; c (0) is a final node set of a line taking a starting node of the power distribution network as a first node; p_0fThe active power flowing to the node f for the initial node of the power distribution network; j belongs to (1-N), and N is the number of nodes in the power distribution network; p_PV,j,tThe active power of the distributed photovoltaic accessed to the node j at the moment t; p_ch,j,tcharging power of the stored energy accessed to the node j at the moment t; p_dis,j,tthe discharge power of the stored energy accessed to the node j at the moment t; p_CL,j,tThe active power of the adjustable load accessed by the node j at the moment t; p_load,j,tThe active power of the unregulated load accessed by the node j at the moment t.

6. The method of claim 4, wherein the power flow constraints in the pre-established first regulatory model are determined as follows:

In the above formula, P_ij,tThe active power of a line ij at the moment t of the power distribution network; i is_ij,tThe current of a line ij at the moment t of the power distribution network; r is_ijThe resistance of a line ij in the power distribution network; x is the number of_ijThe reactance of a line ij in the power distribution network; p_j,tInjecting active power of a node j into the power distribution network at the moment t; p_jk,tThe active power of a line jk at the moment t of the power distribution network; q_ij,tThe reactive power of a line ij at the moment t of the power distribution network is obtained; q_j,tInjecting reactive power of a node j into the power distribution network at the moment t; q_jk,tThe reactive power of a line jk at the moment t of the power distribution network is obtained; j belongs to (1-N), and N is the number of nodes in the power distribution network; i belongs to phi (j), and phi (j) is a set of first nodes of a line with a node j as a last node in the power distribution network; k belongs to theta (j), and theta (j) is a set of end nodes of a line taking a node j as a first node in the power distribution network; p_PV,j,tthe active power of the distributed photovoltaic at the node j at the moment t of the power distribution network is obtained; p_load,j,tthe active power of the adjustable load at the node j at the moment t of the power distribution network is obtained; p_ch,j,tthe charging power of the energy storage device at the node j at the moment t of the power distribution network is obtained; p_dis,j,tthe discharge power of the energy storage device at the node j at the moment t of the power distribution network is obtained; q_PV,j,tdistributing the reactive power of the photovoltaic at a node j at the moment t of the power distribution network; q_load,j,tThe reactive power of the adjustable load device at the node j at the moment t of the power distribution network is obtained; u shape_j,tthe voltage amplitude at the node j at the moment t of the power distribution network is obtained; u shape_i,tThe voltage amplitude value at a node i at the moment t of the power distribution network is obtained;

Determining a node voltage constraint condition in a pre-established first regulation model according to the following formula:

In the above formula, the first and second carbon atoms are,the lower limit of the voltage amplitude of the node j in the power distribution network is set;the upper limit of the voltage amplitude of the node j in the power distribution network is set; u shape_j,tThe voltage amplitude at the node j at the moment t of the power distribution network is obtained;

determining the operation constraint conditions of the distributed photovoltaic in the pre-established first regulation and control model according to the following formula:

In the above formula, the first and second carbon atoms are,The distributed photovoltaic reactive power minimum value of a node j at the moment t of the power distribution network is obtained;The maximum value of the distributed photovoltaic reactive power of a node j at the moment t of the power distribution network is obtained;

wherein,S_PV,jthe capacity of a distributed photovoltaic inverter of a node j in the power distribution network;The distributed photovoltaic active output prediction value of the node j at the moment t of the power distribution network is obtained;

Determining an energy storage operation constraint condition in a pre-established first regulation and control model according to the following formula:

In the above formula, E_SOC,j,tThe electric quantity of the energy storage device of the node j at the moment t of the power distribution network is; e_SOC,j,t+ΔtFor node j at time t + Δ t of the distribution networkthe amount of power of the energy storage device;Limiting the energy storage capacity of an energy storage device of a node j in the power distribution network;limiting the energy storage capacity of an energy storage device of a node j in the power distribution network;The maximum charging power of the energy storage device of the node j in the power distribution network;The maximum discharge power of the energy storage device of the node j in the power distribution network;

Determining an adjustable load device power constraint condition in a pre-established first regulation and control model according to the following formula:

in the above formula, P_CL,j,tthe actual power consumption of the adjustable load device is the node j at the moment t of the power distribution network; w_j,minthe minimum electric quantity requirement of the adjustable load device of the node j in the power distribution network is set; w_j,maxThe maximum value of the electric quantity requirement of the adjustable load device of the node j in the power distribution network; Δ t is the time interval of the first modulation scheme; t is the time number in the regulation period;

Wherein,ε_minThe minimum value of the proportion of the actual power consumption of the adjustable load device in the power distribution network to the expected power consumption is obtained; epsilon_maxthe maximum value of the proportion of the actual power consumption of the adjustable load device of the power distribution network to the expected power consumption is obtained;The expected power consumption at the moment t is set for the adjustable load of the distribution network.

7. the method of claim 2, wherein the determining a second regulation scheme according to the power regulation capability of the distributed photovoltaic and the stored energy in the photovoltaic cluster of the power distribution network, and regulating the distributed photovoltaic and the stored energy in the distributed photovoltaic cluster with the second regulation scheme comprises:

And substituting the maximum and minimum reactive power values and the maximum and minimum stored charge and discharge power values of the distributed photovoltaic in the power distribution network cluster into a pre-established second regulation and control model, solving the second regulation and control model, and obtaining a second regulation and control scheme of the power distribution network.

8. the method of claim 7, wherein the objective function in the pre-established second regulatory model is determined according to the following equation:

In the above formula, F_vAdjusting the minimum power of distributed photovoltaic and energy storage in the distributed photovoltaic cluster;the method comprises the steps of collecting all distributed photovoltaic in a cluster; delta Q_PV,xAdjusting the reactive power of the xth distributed photovoltaic in the cluster;the maximum value of the reactive power of the x-th distributed photovoltaic in the cluster;The method comprises the steps of collecting all stored energy in a cluster; delta P_ch,yAdjusting the charging power of the y-th stored energy in the cluster;The maximum value of the charging power of the y-th stored energy in the cluster; d_ch,ya charging coefficient for the y-th stored energy in the cluster; d_ch,y∈(0,1)；ΔP_dis,yAdjusting the discharge power of the y-th stored energy in the cluster;the maximum value of the discharge power of the y-th stored energy in the cluster; d_dis,ythe discharge coefficient of the y-th stored energy in the cluster; d_dis,y∈(0,1)。

9. The method of claim 7, wherein the power constancy constraint in the pre-established second regulation model is determined as follows:

In the above formula, the first and second carbon atoms are,Is an initial active power value flowing into a starting node of the cluster; p_CThe active power value which flows into the initial node of the cluster after being adjusted by the second regulation scheme is obtained;an initial reactive power value for a starting node of the cluster; q_CThe active power value which flows into the initial node of the cluster after being adjusted by the second regulation scheme is obtained;

Determining a power flow constraint condition in a pre-established second regulation and control model according to the following formula:

in the above formula, P_αβ,tfor light of the distribution network at time tActive power of line α β in the photovoltaic cluster; i is_αβ,tThe current of the line alpha beta in the photovoltaic cluster of the power grid at the moment t; r is_αβresistance of a line α β in a photovoltaic cluster for a distribution network; p_β,tinjecting active power of a node beta in a photovoltaic cluster of the power distribution network at the time t; p_βγ,tActive power of a line beta gamma in a photovoltaic cluster of the power distribution network at the moment t; q_αβ,tThe reactive power of the line alpha beta in the photovoltaic cluster of the power distribution network at the moment t; x is the number of_αβIs the reactance of the line alpha beta in the photovoltaic cluster of the distribution network; q_β,tinjecting reactive power of a node beta in a cluster of the power distribution network at the time t; q_βγ,tThe reactive power of the line beta gamma in the cluster of the power distribution network at the moment t; beta belongs to (1-M), wherein M is the number of nodes in a photovoltaic cluster of the power distribution network; alpha belongs to psi (beta), and psi (beta) is a set of line head nodes taking a node beta as a tail node in a photovoltaic cluster of a power distribution network; The method comprises the steps that a line end node set taking a node beta as a first node in a photovoltaic cluster of a power distribution network is formed; p_PV,β,tactive power of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t; p_CL,β,tthe active power of the adjustable load at the position of a node beta in the photovoltaic cluster of the power distribution network at the moment t; p_load,β,tthe active power of the unregulated load at the node beta in the photovoltaic cluster of the power distribution network at the moment t; p_ch,β,tthe energy storage charging power of an access node beta in the photovoltaic cluster of the power distribution network at the moment t is obtained; p_dis,β,tthe discharge power is the stored energy discharge power of an access node beta in the photovoltaic cluster of the power distribution network at the moment t; q_PV,β,tThe reactive power of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t; q_CL,β,tThe reactive power of the adjustable load at the position of a node beta in the photovoltaic cluster of the power distribution network at the moment t; q_load,β,tThe reactive power of the non-adjustable load at the position of a node beta in a photovoltaic cluster of the power distribution network at the moment t; u shape_β,tnode beta in photovoltaic cluster for power distribution networkVoltage amplitude at time t; u shape_α,tthe voltage amplitude of a node alpha in a cluster of the power distribution network at the time t is obtained;

And determining a node voltage constraint condition in a pre-established second regulation and control model according to the following formula:

in the above formula, the first and second carbon atoms are,The lower limit of the voltage amplitude of the node beta in the photovoltaic cluster of the power distribution network;the upper limit of the voltage amplitude of the node beta in the photovoltaic cluster of the power distribution network is set;

Determining a distributed photovoltaic operation constraint condition in a pre-established second regulation and control model according to the following formula:

in the above formula,. DELTA.Q_PV,β,tAdjusting a reactive power value of distributed photovoltaic of an access node beta in a photovoltaic cluster of the power distribution network at the moment t;The minimum value of the reactive power of the distributed photovoltaic of the access node beta in the cluster of the power distribution network at the moment t;the maximum value of the reactive power of the distributed photovoltaic of the access node beta in the photovoltaic cluster of the power distribution network at the moment t;

wherein,S_PV,βphotovoltaic inverter at node beta in cluster for power distribution networkthe capacity of (a); p_PV,β,tThe active output prediction value of distributed photovoltaic of a node beta in a photovoltaic cluster of the power distribution network at the time t is obtained;

and determining an energy storage operation constraint condition in a pre-established second regulation and control model according to the following formula:

in the above formula, E_SOC,β,tthe electric quantity of the stored energy of the access node beta in the photovoltaic cluster of the power distribution network at the moment t;The method comprises the steps of obtaining an energy storage capacity lower limit value of an access node beta in a photovoltaic cluster of a power distribution network;The method comprises the steps of obtaining an upper limit value of energy storage capacity of an access node beta in a photovoltaic cluster of a power distribution network; delta P_ch,β,tAdjusting the charging power of the energy storage of an access node beta in the photovoltaic cluster of the power distribution network at the moment t;The maximum charging power of the energy storage at the position of an access node beta in a photovoltaic cluster of the power distribution network is obtained;the maximum discharge power of the stored energy at an access node beta in a photovoltaic cluster of the power distribution network is obtained; delta P_dis,β,tand adjusting the discharge power of the stored energy of the access node beta in the cluster of the power distribution network at the moment t.

10. A two-stage optimization regulation and control device for a power distribution network based on a photovoltaic cluster is characterized by comprising:

the determining module is used for determining a first regulation and control scheme of the power distribution network according to the occurrence probability of each operation scene of the power distribution network;

The regulation and control module is used for regulating and controlling the power distribution network according to the first regulation and control scheme;

when the node voltage in the photovoltaic cluster of the power distribution network is out of limit, a second regulation and control scheme is determined according to the power regulation capacity of distributed photovoltaic and energy storage in the cluster, and the distributed photovoltaic and the energy storage in the photovoltaic cluster of the power distribution network are regulated and controlled according to the second regulation and control scheme.