Pure new energy power system regulation and control method and device considering energy storage control

Abstract

The invention discloses a pure new energy power system regulation and control method and device considering energy storage control. The method comprises the following steps: acquiring basic data of a pure new energy power system; according to the basic data, taking the total operation cost of the power system and the total voltage deviation of each node of the power grid as a target; constructing an objective function of the pure new energy power system regulation and control model and a wind generating set output constraint, a photovoltaic generating set output constraint, an energy storage operation constraint, a direct current channel operation constraint, a power flow constraint and a safe operation constraint of the objective function; and under the constraint of the constraints, solving the target function, generating the wind generating set output, the photovoltaic generating set output, the energy storage active absorption power and the direct current transmission power of the pure new energy power system when the total operation cost of the power system and the total voltage deviation of each node of the power grid are comprehensively minimum, and regulating and controlling the pure new energy power system. According to the invention, the voltage stability of the pure new energy power system can be improved.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a method and device for regulating a pure new energy electric power system taking energy storage control into account. Background Art

[0002] Vigorously developing new energy power generation such as wind and light, and gradually replacing traditional fossil energy units, is an important way to accelerate the construction of new power systems and promote the green and low-carbon transformation of energy. Under this development background, small regional power systems can make full use of regional resources, build a development pattern of coordinated operation of source, grid, load and storage, and achieve 100% new energy power supply in the region. However, the operation and control of 100% new energy power systems are significantly different from those of existing power grids. The uncertainty of new energy output makes it difficult to ensure the balance of active power in the system under safe operating conditions, and there may be a shortage of new energy power supply or abandonment of wind and light. For 100% new energy power systems far away from load centers and without synchronous power supply support, their power grid strength is low, and the voltage stability margin and dynamic voltage support capacity are greatly reduced compared with power systems dominated by traditional synchronous power supplies, and voltage stability issues are prominent. Summary of the invention

[0003] The embodiments of the present invention provide a method and device for regulating a pure renewable energy power system taking into account energy storage control, which can effectively reduce the average voltage deviation of the system and increase the node voltage safety margin of the system while reducing the total operating cost of the pure renewable energy power system, thereby improving voltage stability.

[0004] An embodiment of the present invention provides a pure renewable energy power system control method taking into account energy storage control, comprising:

[0005] Obtaining basic data of a pure renewable energy power system; wherein the basic data includes: grid node data, grid branch data, wind turbine power data, photovoltaic power data, energy storage device power data, energy storage device load data, and DC channel performance data;

[0006] According to the basic data, the objective function of the pure new energy power system control model is constructed with the goal of minimizing the total operating cost of the power system and the total voltage deviation of each node of the power grid; and the wind turbine output constraint, photovoltaic generator output constraint, energy storage operation constraint, DC channel operation constraint, power flow constraint and safe operation constraint of the objective function are constructed based on the basic data;

[0007] Under the constraints of wind turbine output constraints, photovoltaic generator output constraints, energy storage operation constraints, DC channel operation constraints, power flow constraints and safe operation constraints, the objective function is solved to generate the wind turbine output, photovoltaic generator output, energy storage active absorption power and DC transmission power of the pure new energy power system when the total operation cost of the power system and the total voltage deviation of each node of the power grid are minimized;

[0008] The wind turbines, photovoltaic generators, energy storage devices and DC channels of the pure renewable energy power system are regulated according to the output of the wind turbines, photovoltaic generators, active energy absorption power and DC transmission power of the pure renewable energy power system.

[0009] Furthermore, the grid node data includes: the total number of grid nodes, the voltage reference value of each node, the upper voltage limit of each node, and the lower voltage limit of each node;

[0010] The power grid branch data includes: resistance values ​​of each branch, reactance values ​​of each branch, upper limit value matrix of each branch current, lower limit value matrix of each branch current and upper limit value of each branch transmission power;

[0011] The wind turbine generator power data includes: the upper limit of actual active power injected by the wind turbine into each node, the lower limit of actual active power injected by the wind turbine into each node, the upper limit of actual reactive power injected by the wind turbine into each node, the lower limit of actual reactive power injected by the wind turbine into each node and the power factor angle of the wind turbine converter;

[0012] The power data of the photovoltaic power generation group includes: the upper limit of the actual active power injected by photovoltaic into each node, the lower limit of the actual active power injected by photovoltaic into each node, the upper limit of the actual reactive power injected by photovoltaic into each node, the lower limit of the actual reactive power injected by photovoltaic into each node and the power factor angle of the photovoltaic converter;

[0013] The energy storage device power data includes: the maximum active power absorbed and released by each node energy storage, the maximum reactive power released by each node energy storage, the minimum reactive power released by each node energy storage, the maximum reactive power absorbed by each node energy storage, the minimum reactive power absorbed by each node energy storage, the maximum value of the energy storage converter power factor, and the minimum value of the energy storage converter power factor;

[0014] The energy storage device load data includes: the rated capacity of each node energy storage, the initial charge of each node energy storage, the efficiency of each node energy storage absorbing power and the efficiency of each node energy storage releasing power;

[0015] The DC channel performance data includes: an upper limit of DC channel capacity, a lower limit of DC channel capacity, a maximum ramp-up rate of DC transmission power, a maximum ramp-down rate of DC transmission power, and a minimum DC constant operation time.

[0016] Furthermore, the objective function is specifically:

[0017] min F = γ1F1 + γ2F2;

[0018]

[0019] Among them, F is the objective function of the pure renewable energy power system control model; F1 is the total operating cost of the power system; F2 is the total voltage deviation of each node in the power grid; γ1 is the weight coefficient of the power system economic index; γ2 is the weight coefficient of the power system security index; g 1,t is the network loss of the system at time t; g 2,t is the amount of wind and solar power abandoned at time t; g 3,t is the interaction power between energy storage and grid at time t; g 4,t is the DC regulation value of the system at time t; T is the dispatching period; N is the total number of grid nodes; V i,t is the effective value of the voltage at node i at time t; V i,N is the voltage reference value of node i; c1 is the network loss cost coefficient; c2 is the wind and solar abandonment penalty coefficient; c3 is the energy storage operation cost coefficient; c4 is the DC regulation cost coefficient; I ij,t is the effective value of the current in branch ij at time t; R ij is the resistance value of branch ij; is the wind turbine power connected to node i at time t; is the actual active power injected into node i by the wind turbine at time t; is the photovoltaic power connected to node i at time t; is the actual active power injected into node i by photovoltaic at time t; is the active absorbed power of energy storage at node i at time t; is the active released power of energy storage at node i at time t; is the DC transmission power at time t; Δt represents the time interval; is the DC transmission power at time t-1.

[0020] Furthermore, the wind turbine generator set output constraint includes:

[0021]

[0022] in, is the actual active power injected into node i by the wind turbine at time t; is the lower limit of the actual active power injected by the wind turbine into node i; is the upper limit of the actual active power injected by the wind turbine into node i; is the actual reactive power injected by the wind turbine into node i at time t; is the lower limit of the actual reactive power injected by the wind turbine into node i; is the upper limit of the actual reactive power injected by the wind turbine into node i; is the power factor angle of the wind turbine converter at node i.

[0023] Furthermore, the photovoltaic power generation group output constraint includes:

[0024]

[0025]

[0026] in, is the actual active power injected into node i by photovoltaic at time t; is the lower limit of the actual active power injected into the photovoltaic node i; is the upper limit of the actual active power injected into the photovoltaic node i; is the actual reactive power injected by PV into node i at time t; is the lower limit of the actual reactive power injected into the photovoltaic node i; is the upper limit of the actual reactive power injected into the photovoltaic node i; is the power factor angle of the photovoltaic converter at node i.

[0027] Furthermore, the energy storage operation constraints include:

[0028]

[0029] E i,t (0) = E i,0 ;

[0030]

[0031] in, is the active absorbed power of energy storage at node i at time t; is the active released power of energy storage at node i at time t; is the maximum active power absorbed and released by the energy storage at node i; is the minimum reactive power absorbed by the energy storage at node i; is the maximum reactive power absorbed by the energy storage at node i; is the reactive absorption power of energy storage at node i at time t; is the reactive power released by the energy storage of node i at time t; is the maximum value of the power factor of the energy storage converter at node i; is the minimum value of the power factor of the energy storage converter at node i; is the state of absorption and release of power of energy storage at node i at time t, 1 represents release power and 0 represents absorption power; is the rated capacity of energy storage at node i; E i,0 is the initial charge of energy storage at node i; E i,t is the energy storage charge of node i in scheduling at time t; is the minimum charge of energy storage for node i; is the maximum charge of energy storage for node i; The efficiency of energy storage absorbing power for node i; is the efficiency of energy storage and power release at node i; T is the scheduling period.

[0032] Furthermore, the DC channel operation constraints include:

[0033]

[0034] in, is the DC transmission power at time t; is the lower limit of DC channel capacity; is the upper limit of DC channel capacity; DR DC UR is the maximum ramp-up rate of DC transmission power; DC is the maximum downslope rate of DC transmission power; Indicates whether the DC is performing power regulation at time t, using a Boolean value; τ is the minimum constant operating time of the DC.

[0035] Furthermore, the power flow constraint includes:

[0036]

[0037] in, is the active power injected into node i at time t; is the reactive power injected into node i at time t; is the active load of node i at time t; is the reactive load of node i at time t; A btn , A bfn Represents the power flow relationship between nodes i and j in the system. When power flows from node i to node j, A btn is 1; when power flows from node j to node i, A bfn I ij,t is the effective value of the current in branch ij at time t; P ij,t is the active power transmitted by branch ij at time t; Q ij,t is the reactive power transmitted by branch ij at time t; R ij is the resistance value of branch ij; X ij is the reactance value of branch ij; V i,t is the effective value of the voltage at node i at time t; V j,tis the effective value of the voltage at node j at time t.

[0038] Furthermore, the safety operation constraints include:

[0039]

[0040] in, is the lower limit of the voltage at node i; is the upper voltage limit of node i; is the lower limit value matrix of branch ij current; is the upper limit value matrix of branch ij current; S ij,max is the upper limit of the transmission power of branch ij; P ij,t is the active power transmitted by branch ij at time t; Q ij,t is the reactive power transmitted by branch ij at time t.

[0041] Based on the above method embodiment, the present invention provides a corresponding device embodiment;

[0042] An embodiment of the present invention provides a pure new energy power system control device taking into account energy storage control, including: a data acquisition module, a model and constraint condition construction module, a model solving module and a control module;

[0043] The data acquisition module is used to acquire basic data of the pure new energy power system; wherein the basic data includes: grid node data, grid branch data, wind turbine power data, photovoltaic power data, energy storage device power data, energy storage device load data, and DC channel performance data;

[0044] The model and constraint condition construction module is used to construct the objective function of the pure new energy power system control model based on the basic data, with the total operation cost of the power system and the total voltage deviation of each node of the power grid as the comprehensive minimum as the goal; and construct the wind turbine output constraint, photovoltaic generator output constraint, energy storage operation constraint, DC channel operation constraint, power flow constraint and safe operation constraint of the objective function based on the basic data;

[0045] The model solving module is used to solve the objective function under the constraints of wind turbine output constraints, photovoltaic generator output constraints, energy storage operation constraints, DC channel operation constraints, power flow constraints and safe operation constraints, and generate the wind turbine output, photovoltaic generator output, energy storage active absorption power and DC transmission power of the pure new energy power system when the total operation cost of the power system and the total voltage deviation of each node of the power grid are minimized;

[0046] The control module is used to control the wind turbine generator set, photovoltaic generator set, energy storage device and DC channel of the pure new energy power system according to the output of the wind turbine generator set, photovoltaic generator set, energy storage active absorption power and DC transmission power of the pure new energy power system.

[0047] The following beneficial effects are achieved by implementing the present invention:

[0048] The present invention provides a pure renewable energy power system control method and device taking energy storage control into account. The method constructs an objective function of a pure renewable energy power system control model based on basic data of the pure renewable energy power system and wind generator set output constraints, photovoltaic generator set output constraints, energy storage operation constraints, DC channel operation constraints, power flow constraints and safe operation constraints corresponding to the objective function. Then, the objective function is solved under the above-mentioned constraint conditions to generate the wind generator set output, photovoltaic generator set output, energy storage active absorption power and DC transmission power of the pure renewable energy power system when the total operation cost of the power system and the total voltage deviation of each node of the power grid are comprehensively minimized. Then, the wind generator set, photovoltaic generator set, energy storage device and DC channel of the pure renewable energy power system are controlled according to the wind generator set output, photovoltaic generator set output, energy storage active absorption power and DC transmission power of the pure renewable energy power system. By constructing an objective function of a pure renewable energy power system control model based on the total operation cost of the power system and the total voltage deviation of each node of the power grid, the average voltage deviation of the system is effectively reduced, and the node voltage safety margin of the system is increased, thereby improving voltage stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a flow chart of a method for regulating a pure renewable energy power system taking into account energy storage control provided by an embodiment of the present invention.

[0050] Figure 2 It is a pure renewable energy power system control system model provided by an embodiment of the present invention.

[0051] Figure 3 This is a system average voltage deviation curve diagram provided by an embodiment of the present invention.

[0052] Figure 4 It is a system node voltage safety margin diagram provided by an embodiment of the present invention.

[0053] Figure 5 This is a structural diagram of a pure new energy power system control device taking into account energy storage control provided by an embodiment of the present invention DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] like Figure 1 As shown, a pure renewable energy power system control method taking into account energy storage control is provided in one embodiment of the present invention, comprising:

[0056] Step S1: Obtain basic data of a pure renewable energy power system; wherein the basic data includes: grid node data, grid branch data, wind turbine power data, photovoltaic power data, energy storage device power data, energy storage device load data, and DC channel performance data;

[0057] Step S2: Based on the basic data, the objective function of the pure new energy power system control model is constructed with the goal of minimizing the total operation cost of the power system and the total voltage deviation of each node of the power grid; and the wind turbine output constraint, photovoltaic generator output constraint, energy storage operation constraint, DC channel operation constraint, power flow constraint and safe operation constraint of the objective function are constructed based on the basic data;

[0058] Step S3: Under the constraints of wind turbine output constraints, photovoltaic generator output constraints, energy storage operation constraints, DC channel operation constraints, power flow constraints and safe operation constraints, the objective function is solved to generate the wind turbine output, photovoltaic generator output, energy storage active absorption power and DC transmission power of the pure new energy power system when the total operation cost of the power system and the total voltage deviation of each node of the power grid are minimized;

[0059] Step S4: regulating the wind turbine generator set, photovoltaic generator set, energy storage device and DC channel of the pure renewable energy power system according to the wind turbine generator set output, photovoltaic generator set output, energy storage active absorption power and DC transmission power of the pure renewable energy power system.

[0060] It should be noted that before executing the above steps, you need to build Figure 2 The pure renewable energy power system model shown in Figure 2 not only includes renewable energy output equipment, but also takes into account energy storage control and DC transmission characteristics. Figure 2As shown in the figure, in this pure renewable energy power system model, there are wind power stations, photovoltaic power stations and energy storage devices associated with the AC network. The pure renewable energy power system model uses the DC channel as a medium to achieve power transmission with the external AC grid; the AC network includes local loads. In this model, the power source is mainly the output of wind power stations and photovoltaic power stations.

[0061] Based on the constructed pure renewable energy power system model, the pure renewable energy power system is regulated and controlled.

[0062] For step S1, basic data of the pure renewable energy power system is obtained. In a preferred embodiment, the grid node data includes: the total number of grid nodes, the voltage reference value of each node, the voltage upper limit of each node, and the voltage lower limit of each node; the grid branch data includes: the resistance value of each branch, the reactance value of each branch, the current upper limit value matrix of each branch, the current lower limit value matrix of each branch, and the transmission power upper limit value of each branch; the power data of the wind turbine generator set includes: the actual active power upper limit injected by the wind turbine into each node, the actual active power lower limit injected by the wind turbine into each node, the actual reactive power upper limit injected by the wind turbine into each node, the actual reactive power lower limit injected by the wind turbine into each node, and the power factor angle of the wind turbine converter; the power data of the photovoltaic generator set includes: the actual active power upper limit injected by the photovoltaic into each node, the actual active power lower limit injected by the photovoltaic into each node, the actual reactive power upper ... The actual reactive power lower limit of each node and the power factor angle of the photovoltaic converter are input; the power data of the energy storage device, including: the maximum active power absorbed and released by the energy storage at each node, the maximum reactive power released by the energy storage at each node, the minimum reactive power released by the energy storage at each node, the maximum reactive power absorbed by the energy storage at each node, the minimum reactive power absorbed by the energy storage at each node, the maximum power factor of the energy storage converter and the minimum power factor of the energy storage converter; the load data of the energy storage device, including: the rated capacity of the energy storage at each node, the initial charge of the energy storage at each node, the efficiency of the energy storage absorbing power at each node and the efficiency of the energy storage releasing power at each node; the DC channel performance data, including: the upper limit of the DC channel capacity, the lower limit of the DC channel capacity, the maximum ramp-up rate of the DC transmission power, the maximum ramp-down rate of the DC transmission power and the minimum DC constant operation time.

[0063] For step S2, based on the basic data obtained in step S1, the economy and safety of the power grid operation are comprehensively considered. When constructing the objective function of the pure new energy power system control model, the total operating cost of the power system and the total voltage deviation of each node in the power grid are taken as the goal to be minimized; among which, the total operating cost of the power system takes into account the network loss cost, the cost of wind and solar power abandonment, the energy storage operation cost and the DC regulation cost.

[0064] In a preferred embodiment, the objective function is specifically:

[0065] min F = γ1F1 + γ2F2;

[0066]

[0067] Among them, F is the objective function of the pure renewable energy power system control model; F1 is the total operating cost of the power system; F2 is the total voltage deviation of each node in the power grid; γ1 is the weight coefficient of the power system economic index; γ2 is the weight coefficient of the power system security index; g 1,t is the network loss of the system at time t; g 2,t is the amount of wind and solar power abandoned at time t; g 3,t is the interaction power between energy storage and grid at time t; g 4,t is the DC regulation value of the system at time t; T is the scheduling period, which is 24h in the present invention; N is the total number of grid nodes; V i,t is the effective value of the voltage at node i at time t; V i,N is the voltage reference value of node i; c1 is the network loss cost coefficient; c2 is the wind and solar abandonment penalty coefficient; c3 is the energy storage operation cost coefficient; c4 is the DC regulation cost coefficient; I ij,t is the effective value of the current in branch ij at time t; R ij is the resistance value of branch ij; is the wind turbine power connected to node i at time t; is the actual active power injected into node i by the wind turbine at time t; is the photovoltaic power connected to node i at time t; is the actual active power injected into node i by photovoltaic at time t; is the active absorbed power of energy storage at node i at time t; is the active released power of energy storage at node i at time t; is the DC transmission power at time t; Δt represents the time interval; is the DC transmission power at time t-1.

[0068] It should be noted that in the present invention, The form of represents the DC transmission power at time t, that is, the physical quantity; The form of represents the DC transmission power value at time t, that is, the specific reference of the physical quantity. The other parameters can refer to these two expressions and will not be repeated here.

[0069] It should be noted that since the two components F1 and F2 of the objective function F have different dimensions, a linear weighted approach is adopted when minimizing the objective function, and the size of the weight coefficients γ1 and γ2 are used to characterize the relative importance of the economic index F1 and the safety index F2 in the pure energy and power system.

[0070] Furthermore, based on the pure renewable energy power system model, the operating characteristics of wind turbines, photovoltaic generators, energy storage devices and DC channels are fully considered to construct the wind turbine output constraints, photovoltaic generator output constraints, energy storage operation constraints, DC channel operation constraints, power flow constraints and safe operation constraints of the above objective function.

[0071] The output of a wind turbine generator set mainly considers the active power and reactive power output constraints of the wind turbine generator set. In a preferred embodiment, the output constraints of a wind turbine generator set include:

[0072]

[0073]

[0074] in, is the actual active power injected into node i by the wind turbine at time t; is the lower limit of the actual active power injected by the wind turbine into node i; is the upper limit of the actual active power injected by the wind turbine into node i; is the actual reactive power injected by the wind turbine into node i at time t; is the lower limit of the actual reactive power injected by the wind turbine into node i; is the upper limit of the actual reactive power injected by the wind turbine into node i; is the power factor angle of the wind turbine converter at node i, Take 0.9.

[0075] The output of the photovoltaic generator set mainly considers the active power and reactive power output constraints of the photovoltaic generator set. In a preferred embodiment, the output constraints of the photovoltaic generator set include:

[0076]

[0077] in, is the actual active power injected into node i by photovoltaic at time t; is the lower limit of the actual active power injected into the photovoltaic node i; is the upper limit of the actual active power injected into the photovoltaic node i; is the actual reactive power injected by PV into node i at time t; is the lower limit of the actual reactive power injected into the photovoltaic node i; is the upper limit of the actual reactive power injected into the photovoltaic node i; is the power factor angle of the photovoltaic converter at node i, The value is 0.95.

[0078] For energy storage devices, they must meet certain operating constraints during operation, mainly including energy storage absorption and release power constraints, energy storage capacity constraints, and ensuring that the capacity is the same at the beginning and end of the scheduling cycle. Based on the above considerations, constraints that are conducive to energy storage cycle scheduling are constructed. In a preferred embodiment, energy storage operation constraints include:

[0079]

[0080]

[0081] E i,t (0) = E i,0 ;

[0082]

[0083] in, is the active absorbed power of energy storage at node i at time t; is the active released power of energy storage at node i at time t; is the maximum active power absorbed and released by the energy storage at node i; is the minimum reactive power absorbed by the energy storage at node i; is the maximum reactive power absorbed by the energy storage at node i; is the reactive absorption power of energy storage at node i at time t; is the reactive power released by the energy storage of node i at time t; is the maximum value of the power factor of the energy storage converter at node i; is the minimum value of the power factor of the energy storage converter at node i; is the state of absorption and release of power of energy storage at node i at time t, 1 represents release power and 0 represents absorption power; is the rated capacity of energy storage at node i; E i,0 is the initial charge of energy storage at node i; E i,t is the energy storage charge of node i in scheduling at time t; is the minimum charge of energy storage for node i; is the maximum charge of energy storage for node i; The efficiency of energy storage absorbing power for node i; is the efficiency of energy storage and power release at node i; T is the scheduling period.

[0084] As for the DC channel, it is the medium for the pure renewable energy power system to exchange power with the outside world. It mainly exchanges power through flexible DC. When the DC channel transmits power, its power transmission curve is limited by the capacity and operation mode of the DC channel. Based on this limitation, the DC channel operation constraint is constructed. In a preferred embodiment, the DC channel operation constraint includes:

[0085]

[0086] in, is the DC transmission power at time t; is the lower limit of DC channel capacity; is the upper limit of DC channel capacity; DR DC UR is the maximum ramp-up rate of DC transmission power; DC is the maximum downslope rate of DC transmission power; Indicates whether the DC is performing power regulation at time t, using a Boolean value; τ is the minimum constant operating time of the DC. It should be noted that is a 0-1 variable, indicating whether the DC power is regulated at time t. If the DC power is regulated at time t, then is 1, if the DC power is not regulated at time t, then is 0; It means that any time t+τ is greater than or equal to T, it must satisfy

[0087] In addition to the above constraints, additional consideration must be given to the power flow constraints that need to be met during the overall power flow operation of the pure renewable energy power system and the safety operation constraints that ensure the safe operation of the pure renewable energy power system.

[0088] The power flow model of the power system in the form of Distflow is used to construct the power flow constraint. In a preferred embodiment, the power flow constraint includes:

[0089]

[0090] in, is the active power injected into node i at time t; is the reactive power injected into node i at time t; is the active load of node i at time t; is the reactive load of node i at time t; A btn , A bfn Represents the power flow relationship between nodes i and j in the system. When power flows from node i to node j, A btn is 1; when power flows from node j to node i, A bfn I ij,t is the effective value of the current in branch ij at time t; P ij,t is the active power transmitted by branch ij at time t; Q ij,t is the reactive power transmitted by branch ij at time t; R ij is the resistance value of branch ij; X ij is the reactance value of branch ij; V i,tis the effective value of the voltage at node i at time t; V j,t is the effective value of the voltage at node j at time t.

[0091] In order to ensure the safe operation of the pure renewable energy power system, it is necessary to constrain the voltage of each node and the current and power of each branch, that is, to construct safe operation constraints based on node voltage constraints, branch current constraints and transmission power constraints. In a preferred embodiment, the safe operation constraints include:

[0092]

[0093] in, is the lower limit of the voltage at node i; is the upper voltage limit of node i; is the lower limit value matrix of branch ij current; is the upper limit value matrix of branch ij current; S ij,max is the upper limit of the transmission power of branch ij; P ij,t is the active power transmitted by branch ij at time t; Q ij,t is the reactive power transmitted by branch ij at time t.

[0094] For step S3 and step S4, under the constraints of the wind turbine output constraint, photovoltaic generator output constraint, energy storage operation constraint, DC channel operation constraint, power flow constraint and safe operation constraint constructed above, the objective function is solved to generate the wind turbine output, photovoltaic generator output, energy storage active absorption power and DC transmission power of the pure new energy power system when the total operation cost of the power system and the total voltage deviation of each node of the power grid are minimized, and then the wind turbine, photovoltaic generator, energy storage device and DC channel of the pure new energy power system are regulated.

[0095] By implementing the scheme of the present invention, the influence of energy storage control and DC regulation on the regulation of the pure renewable energy power system can be fully considered, thereby improving the stability of the operation of the pure renewable energy power system.

[0096] It should be added that in order to verify the impact of energy storage reactive control and DC regulation on the regulation of pure renewable energy power system, the present invention makes the following analysis.

[0097] Case 1 is set as the case where energy storage only participates in the active optimization of the pure renewable energy power system, and Case 2 is set as the case where energy storage participates in the active and reactive optimization of the pure renewable energy power system. In case 1, the network loss cost is 19.65, the cost of wind and solar abandonment is 6.77, the energy storage operation cost is 8.93, and the DC regulation cost is 7.28. That is, the total operation cost of the power system in case 1 is 42.63 for one day. In case 2, the various costs for one day are: network loss cost is 18.54, wind and solar abandonment cost is 6.67, energy storage operation cost is 9.23, and DC regulation cost is 7.25. That is, the total operation cost of the power system in case 2 is 41.69 for one day. It can be seen that compared with Case 1, the energy storage operation cost of Case 2 has increased due to the addition of energy storage reactive power control, but the network loss cost and wind and solar power abandonment cost have been significantly reduced, indicating that optimizing the reactive power control of the system through the remaining capacity of energy storage can not only improve the system's absorption of new energy, but also reduce the line loss cost when the input power in the system increases, thereby reducing the total operating cost of the power system.

[0098] In case 2, appropriate economic and safety weight coefficients are selected to make the total system cost the same as that in case 1. The average node voltage deviation and safety margin of the two are compared as follows: Figure 3 and Figure 4 As shown, under the premise of the same total system operating cost, Case 2 uses energy storage to control the reactive power of the system, which makes the overall average voltage deviation significantly smaller than that of Case 1, significantly increases the system node voltage safety margin, and improves the system voltage stability to a certain extent.

[0099] Based on the above method embodiment, the present invention provides a corresponding device embodiment.

[0100] like Figure 5 As shown, an embodiment of the present invention provides a pure renewable energy power system control device taking into account energy storage control, including: a data acquisition module, a model and constraint condition construction module, a model solving module and a control module;

[0101] The data acquisition module is used to acquire basic data of the pure new energy power system; wherein the basic data includes: grid node data, grid branch data, wind turbine power data, photovoltaic power data, energy storage device power data, energy storage device load data, and DC channel performance data;

[0102] The model and constraint condition construction module is used to construct the objective function of the pure new energy power system control model based on the basic data, with the total operation cost of the power system and the total voltage deviation of each node of the power grid as the comprehensive minimum as the goal; and construct the wind turbine output constraint, photovoltaic generator output constraint, energy storage operation constraint, DC channel operation constraint, power flow constraint and safe operation constraint of the objective function based on the basic data;

[0103] The model solving module is used to solve the objective function under the constraints of wind turbine output constraints, photovoltaic generator output constraints, energy storage operation constraints, DC channel operation constraints, power flow constraints and safe operation constraints, and generate the wind turbine output, photovoltaic generator output, energy storage active absorption power and DC transmission power of the pure new energy power system when the total operation cost of the power system and the total voltage deviation of each node of the power grid are minimized;

[0104] The control module is used to control the wind turbine generator set, photovoltaic generator set, energy storage device and DC channel of the pure new energy power system according to the output of the wind turbine generator set, photovoltaic generator set, energy storage active absorption power and DC transmission power of the pure new energy power system.

[0105] It should be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0106] Those skilled in the art can clearly understand that for the sake of convenience and brevity, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0107] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for regulating a pure renewable energy power system taking into account energy storage control, characterized in that: include: Obtaining basic data of a pure renewable energy power system; wherein the basic data includes: grid node data, grid branch data, wind turbine power data, photovoltaic power data, energy storage device power data, energy storage device load data, and DC channel performance data; According to the basic data, the objective function of the pure new energy power system control model is constructed with the goal of minimizing the total operating cost of the power system and the total voltage deviation of each node of the power grid; and the wind turbine output constraint, photovoltaic generator output constraint, energy storage operation constraint, DC channel operation constraint, power flow constraint and safe operation constraint of the objective function are constructed based on the basic data; Under the constraints of wind turbine output constraints, photovoltaic generator output constraints, energy storage operation constraints, DC channel operation constraints, power flow constraints and safe operation constraints, the objective function is solved to generate the wind turbine output, photovoltaic generator output, energy storage active absorption power and DC transmission power of the pure new energy power system when the total operation cost of the power system and the total voltage deviation of each node of the power grid are minimized; The wind turbines, photovoltaic generators, energy storage devices and DC channels of the pure renewable energy power system are regulated according to the output of the wind turbines, photovoltaic generators, active energy absorption power and DC transmission power of the pure renewable energy power system.

2. A method for regulating a pure renewable energy power system taking into account energy storage control as claimed in claim 1, characterized in that: The grid node data includes: the total number of grid nodes, the voltage reference value of each node, the upper voltage limit of each node, and the lower voltage limit of each node; The power grid branch data includes: resistance values ​​of each branch, reactance values ​​of each branch, upper limit value matrix of each branch current, lower limit value matrix of each branch current and upper limit value of each branch transmission power; The wind turbine generator power data includes: the upper limit of actual active power injected by the wind turbine into each node, the lower limit of actual active power injected by the wind turbine into each node, the upper limit of actual reactive power injected by the wind turbine into each node, the lower limit of actual reactive power injected by the wind turbine into each node and the power factor angle of the wind turbine converter; The power data of the photovoltaic power generation group includes: the upper limit of the actual active power injected by photovoltaic into each node, the lower limit of the actual active power injected by photovoltaic into each node, the upper limit of the actual reactive power injected by photovoltaic into each node, the lower limit of the actual reactive power injected by photovoltaic into each node and the power factor angle of the photovoltaic converter; The energy storage device power data includes: the maximum active power absorbed and released by each node energy storage, the maximum reactive power released by each node energy storage, the minimum reactive power released by each node energy storage, the maximum reactive power absorbed by each node energy storage, the minimum reactive power absorbed by each node energy storage, the maximum value of the energy storage converter power factor, and the minimum value of the energy storage converter power factor; The energy storage device load data includes: the rated capacity of each node energy storage, the initial charge of each node energy storage, the efficiency of each node energy storage absorbing power and the efficiency of each node energy storage releasing power; The DC channel performance data includes: an upper limit of DC channel capacity, a lower limit of DC channel capacity, a maximum ramp-up rate of DC transmission power, a maximum ramp-down rate of DC transmission power, and a minimum DC constant operation time.

3. A method for regulating and controlling a pure renewable energy power system taking into account energy storage control as claimed in claim 2, characterized in that: The objective function is specifically: min F = γ1F1 + γ2F2; Among them, F is the objective function of the pure renewable energy power system control model; F1 is the total operating cost of the power system; F2 is the total voltage deviation of each node in the power grid; γ1 is the weight coefficient of the power system economic index; γ2 is the weight coefficient of the power system security index; g 1,t is the network loss of the system at time t; g 2,t is the amount of wind and solar power abandoned at time t; g 3,t is the interaction power between energy storage and grid at time t; g 4,t is the DC regulation value of the system at time t; T is the dispatching period; N is the total number of grid nodes; V i,t is the effective value of the voltage at node i at time t; V i,N is the voltage reference value of node i; c1 is the network loss cost coefficient; c2 is the wind and solar abandonment penalty coefficient; c3 is the energy storage operation cost coefficient; c4 is the DC regulation cost coefficient; I ij,t is the effective value of the current in branch ij at time t; R ij is the resistance value of branch ij; is the wind turbine power connected to node i at time t; is the actual active power injected into node i by the wind turbine at time t; is the photovoltaic power connected to node i at time t; is the actual active power injected into node i by photovoltaic at time t; is the active absorbed power of energy storage at node i at time t; is the active released power of energy storage at node i at time t; is the DC transmission power at time t; Δt represents the time interval; is the DC transmission power at time t-1.

4. A method for regulating a pure renewable energy power system taking into account energy storage control as claimed in claim 3, characterized in that: The wind turbine generator set output constraint includes: in, is the actual active power injected into node i by the wind turbine at time t; is the lower limit of the actual active power injected by the wind turbine into node i; is the upper limit of the actual active power injected by the wind turbine into node i; is the actual reactive power injected by the wind turbine into node i at time t; is the lower limit of the actual reactive power injected by the wind turbine into node i; is the upper limit of the actual reactive power injected by the wind turbine into node i; is the power factor angle of the wind turbine converter at node i.

5. A method for regulating a pure renewable energy power system taking into account energy storage control as claimed in claim 4, characterized in that: The photovoltaic power generation group output constraint includes: in, is the actual active power injected into node i by photovoltaic at time t; is the lower limit of the actual active power injected into the photovoltaic node i; is the upper limit of the actual active power injected into the photovoltaic node i; is the actual reactive power injected into node i by photovoltaic at time t; is the lower limit of the actual reactive power injected into the photovoltaic node i; is the upper limit of the actual reactive power injected into the photovoltaic node i; is the power factor angle of the photovoltaic converter at node i.

6. A method for regulating and controlling a pure renewable energy power system taking into account energy storage control as claimed in claim 5, characterized in that: The energy storage operation constraints include: in, is the active absorbed power of energy storage at node i at time t; is the active released power of energy storage at node i at time t; is the maximum active power absorbed and released by the energy storage at node i; is the minimum reactive power absorbed by the energy storage at node i; is the maximum reactive power absorbed by the energy storage at node i; is the reactive absorption power of energy storage at node i at time t; is the reactive power released by the energy storage of node i at time t; is the maximum value of the power factor of the energy storage converter at node i; is the minimum value of the power factor of the energy storage converter at node i; is the state of absorption and release of power of energy storage at node i at time t, 1 represents release power and 0 represents absorption power; is the rated capacity of energy storage at node i; E i,0 is the initial charge of energy storage at node i; E i,t is the energy storage charge of node i in scheduling at time t; is the minimum charge of energy storage for node i; is the maximum charge of energy storage for node i; The efficiency of energy storage absorbing power for node i; is the efficiency of energy storage and power release at node i; T is the scheduling period.

7. A method for regulating and controlling a pure renewable energy power system taking into account energy storage control as claimed in claim 6, characterized in that: The DC channel operation constraints include: in, is the DC transmission power at time t; is the lower limit of DC channel capacity; is the upper limit of DC channel capacity; DR DC UR is the maximum ramp-up rate of DC transmission power; DC is the maximum downslope rate of DC transmission power; Indicates whether the DC power is adjusted at time t, using a Boolean value; v is the minimum constant operating time of the DC.

8. A method for regulating a pure renewable energy power system taking into account energy storage control as claimed in claim 7, characterized in that: The power flow constraints include: in, is the active power injected into node i at time t; is the reactive power injected into node i at time t; is the active load of node i at time t; is the reactive load of node i at time t; A btn , A bfn Represents the power flow relationship between nodes i and j in the system. When power flows from node i to node j, A btn is 1; when power flows from node j to node i, A bfn I ij,t is the effective value of the current in branch ij at time t; P ij,t is the active power transmitted by branch ij at time t; Q ij,t is the reactive power transmitted by branch ij at time t; R ij is the resistance value of branch ij; X ij is the reactance value of branch ij; V i,t is the effective value of the voltage at node i at time t; V j,t is the effective value of the voltage at node j at time t.

9. A method for regulating and controlling a pure renewable energy power system taking into account energy storage control as claimed in claim 8, characterized in that: The safety operation constraints include: Among them, V i min is the lower limit of node i voltage; V i max is the upper voltage limit of node i; is the lower limit value matrix of branch ij current; is the upper limit value matrix of branch ij current; S ij,max is the upper limit of the transmission power of branch ij; P ij,t is the active power transmitted by branch ij at time t; Q ij,t is the reactive power transmitted by branch ij at time t.

10. A pure new energy power system control device taking into account energy storage control, characterized in that: include: Data acquisition module, model and constraint condition construction module, model solving module and control module; The data acquisition module is used to acquire basic data of the pure new energy power system; wherein the basic data includes: grid node data, grid branch data, wind turbine power data, photovoltaic power data, energy storage device power data, energy storage device load data, and DC channel performance data; The model and constraint condition construction module is used to construct the objective function of the pure new energy power system control model based on the basic data, with the total operation cost of the power system and the total voltage deviation of each node of the power grid as the comprehensive minimum as the goal; and construct the wind turbine output constraint, photovoltaic generator output constraint, energy storage operation constraint, DC channel operation constraint, power flow constraint and safe operation constraint of the objective function based on the basic data; The model solving module is used to solve the objective function under the constraints of wind turbine output constraints, photovoltaic generator output constraints, energy storage operation constraints, DC channel operation constraints, power flow constraints and safe operation constraints, and generate the wind turbine output, photovoltaic generator output, energy storage active absorption power and DC transmission power of the pure new energy power system when the total operation cost of the power system and the total voltage deviation of each node of the power grid are minimized; The control module is used to control the wind turbine generator set, photovoltaic generator set, energy storage device and DC channel of the pure new energy power system according to the output of the wind turbine generator set, photovoltaic generator set, energy storage active absorption power and DC transmission power of the pure new energy power system.

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