Regulation and control method and apparatus for 100% renewable energy power system and considering energy storage control

Abstract

Disclosed in the present invention are a regulation and control method and apparatus for a 100% renewable energy power system and considering energy storage control. The method comprises: acquiring basic data of a 100% renewable energy power system; on the basis of the basic data, with the objective of comprehensively minimizing the total operating cost of the power system and the total voltage deviation of nodes in a power grid, constructing an objective function for a regulation and control model of the 100% renewable energy power system, and wind turbine generator set output constraints, photovoltaic generator set output constraints, energy storage operation constraints, direct-current channel operation constraints, power flow constraints and secure operation constraints of the objective function; solving the objective function under the constraints, so as to generate a wind turbine generator set output, a photovoltaic generator set output, the active power absorption of energy storage and a direct-current transmission power of the 100% renewable energy power system when the total operating cost of the power system and the total voltage deviation of the nodes in the power grid are comprehensively minimized; and regulating and controlling the 100% renewable energy power system. By means of implementing the present invention, the voltage stability of a 100% renewable energy power system can be improved.

Description

A method and device for regulating a pure renewable energy power system that incorporates energy storage control Technical Field

[0001] This invention relates to the field of power technology, and in particular to a method and apparatus for regulating a pure new energy power system that takes into account energy storage control. Background Technology

[0002] Vigorously developing new energy power generation such as wind and solar power to gradually replace traditional fossil fuel units is an important way to accelerate the construction of new power systems and promote the green and low-carbon transformation of energy. Against this backdrop, small-area power systems can fully utilize local resources to build a coordinated development pattern of source-grid-load-storage operation, achieving 100% renewable energy power supply within the region. However, the operation and control of a 100% renewable energy power system differs significantly from the existing power grid. The uncertainty of renewable energy output makes it difficult to guarantee the balance of active power under safe operating conditions, potentially leading to renewable energy power shortages or wind and solar curtailment. For 100% renewable energy power systems located far from load centers and without synchronous power source support, their grid strength is lower, and their voltage stability margin and dynamic voltage support capacity are significantly reduced compared to power systems dominated by traditional synchronous power sources, resulting in prominent voltage stability issues. Summary of the Invention

[0003] This invention provides a method and apparatus for regulating a pure renewable energy power system that takes into account energy storage control. It can effectively reduce the average voltage deviation of the system and increase the safety margin of the system's node voltage 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 regulation method for a pure renewable energy power system that takes into account energy storage control, comprising:

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

[0006] Based on the aforementioned basic data, an objective function for the regulation and control model of a pure renewable energy power system is constructed with the goal of minimizing the total operating cost of the power system and the total voltage deviation of each node in the power grid. Furthermore, based on the aforementioned basic data, constraints on the output of wind turbine generators, output of photovoltaic generators, energy storage operation, DC channel operation, power flow, and safe operation are constructed for the objective function.

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

[0008] The wind turbine generators, photovoltaic generators, energy storage devices, and DC transmission channels of the pure new energy power system are regulated based on the output of the wind turbine generators, the output of the photovoltaic generators, the active power absorbed by the energy storage, and the DC transmission power.

[0009] Furthermore, the power grid node data includes: the total number of power 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: the resistance value of each branch, the reactance value of each branch, the upper limit value matrix of the current of each branch, the lower limit value matrix of the current of each branch, and the upper limit value of the transmission power of each branch.

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

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

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

[0014] The load data of the energy storage device includes: the rated capacity of energy storage at each node, the initial charge of energy storage at each node, the efficiency of energy storage power absorption at each node, and the efficiency of energy storage power release at each node.

[0015] The DC channel performance data includes: DC channel capacity upper limit, DC channel capacity lower limit, maximum DC transmission power upslope rate, maximum DC transmission power downslope rate, and minimum constant DC operating time.

[0016] Furthermore, the objective function is specifically:

[0017] minF = γ1F1 + γ2F2;

[0018] Where 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 at each node of the power grid; γ1 is the weighting coefficient of the power system economic indicators; γ2 is the weighting coefficient of the power system security indicators; g 1,t Let g be the network loss of the system at time t; 2,t g represents the amount of wind and solar power curtailment at time t; 3,t Let g be the energy storage and grid interaction power at time t; 4,t V represents the DC regulation at time t; T is the dispatch period; N is the total number of grid nodes; V i,t V represents the effective voltage value of node i at time t. i,N Here is the voltage reference value for node i; c1 is the network loss cost coefficient; c2 is the wind and solar curtailment penalty coefficient; c3 is the energy storage operation cost coefficient; c4 is the DC regulation cost coefficient; I ij,t R is the effective value of the branch current ij at time t; ij Let be the resistance value of branch ij; Let be the power of the wind turbine connected to node i at time t; Let t be the actual active power injected into node i by the wind turbine; Let be the photovoltaic power of node i connected at time t; Let be the actual active power injected into photovoltaic node i at time t; Let be the active power absorbed by node i at time t; Let be the active power released from the energy stored at node i at time t; Let be the DC transmission power at time t; Δt represents the time interval. Let be the DC transmission power at time t-1.

[0019] Furthermore, the output constraint of the wind turbine generator set includes:

[0020] in, Let t be the actual active power injected into node i by the wind turbine; The lower limit of the actual active power injected into node i of the wind turbine; The upper limit of the actual active power injected into node i of the wind turbine; Let be the actual reactive power injected into node i by the wind turbine at time t; The lower limit of the actual reactive power injected into node i of the wind turbine; The upper limit of the actual reactive power injected into node i of the wind turbine; Let be the power factor angle of the wind turbine converter at node i.

[0021] Furthermore, the output constraint of the photovoltaic generator set includes:

[0022] in, Let be the actual active power injected into photovoltaic node i at time t; This represents the lower limit of the actual active power of photovoltaic injection node i; This represents the upper limit of the actual active power of photovoltaic injection node i; Let t be the actual reactive power injected into node i by the photovoltaic system; This represents the lower limit of the actual reactive power at photovoltaic injection node i; This represents the upper limit of the actual reactive power of photovoltaic injection node i; Let be the power factor angle of the photovoltaic converter at node i.

[0023] Furthermore, the energy storage operation constraints include:

[0024] E i,t (0)=E i,0 ;

[0025] in, Let be the active power absorbed by node i at time t; Let be the active power released from the energy stored at node i at time t; The maximum active power absorbed and released by the energy storage at node i; The minimum reactive power absorbed by the energy storage at node i; The maximum reactive power absorbed by the energy storage at node i; Let be the reactive power absorbed by node i at time t; Let be the reactive power released from the energy stored at node i at time t; The maximum value of the power factor of the energy storage converter at node i; The minimum power factor of the energy storage converter at node i; Let t represent the state of the absorbed and released power of the energy stored at node i at time t, where 1 represents the released power and 0 represents the absorbed power. The rated capacity for energy storage for node i; E i,0 The initial charge of energy stored at node i; E i,t Let t be the energy stored at node i during scheduling; The minimum charge amount stored for node i; The maximum charge stored for node i; The efficiency of energy storage and power absorption for node i; The efficiency of energy storage and power release at node i; T is the scheduling period.

[0026] Furthermore, the DC channel operating constraints include:

[0027] in, Let be the DC transmission power at time t; This is the lower limit of the DC channel capacity; This represents the upper limit of DC channel capacity; DR DC UR is the maximum upslope rate of DC transmission power. DC This represents the maximum downslope rate of DC transmission power. Indicates whether DC power regulation is performed at time t, using Boolean values; τ is the minimum constant operating time of DC.

[0028] Furthermore, the power flow constraint includes:

[0029] in, Let t be the active power injected into node i at time t; Let t be the reactive power injected into node i at time t; Let be the active load of node i at time t; Let A be the reactive load of node i at time t; btn A bfn This represents the power flow relationship between nodes i and j in the system. When power flows from node i to node j, A btn A is 1; when power flows from node j to node i, A bfn =1; I ij,t P represents the effective value of the branch current ij at time t; ij,t Q represents the active power transmitted by branch ij at time t; ij,t R is the reactive power transmitted by branch ij at time t; ij X represents the resistance value of branch ij; ij V is the reactance value of branch ij; i,t V represents the effective voltage value of node i at time t. j,t Let be the effective voltage value of node j at time t.

[0030] Furthermore, the safety operation constraints include:

[0031] in, This represents the lower limit of the voltage at node i. This represents the upper limit of the voltage at node i. This is the matrix representing the lower limit values ​​of the branch current ij; S is the matrix representing the upper limit values ​​of the branch current ij; ij,max P represents the upper limit of the transmission power of branch ij; ij,t Q represents the active power transmitted by branch ij at time t; ij,t Let be the reactive power transmitted by branch ij at time t.

[0032] Based on the above method embodiments, the present invention provides corresponding apparatus embodiments;

[0033] One embodiment of the present invention provides a control device for a pure new energy power system that takes energy storage control into account, including: a data acquisition module, a model and constraint construction module, a model solving module, and a control module;

[0034] 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 generator power data, energy storage device power data, energy storage device load data, and DC channel performance data;

[0035] The model and constraint construction module is used to construct an objective function for the pure new energy power system control model based on the basic data, with the goal of minimizing the total operating cost of the power system and the total voltage deviation of each node in the power grid. Based on the basic data, the module also constructs 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 objective function.

[0036] The model solving module is used to solve the objective function under the constraints of wind turbine output, photovoltaic generator output, energy storage operation, DC channel operation, power flow, and safe operation, and generate the wind turbine output, photovoltaic generator output, energy storage active power absorption power, and DC transmission power of the pure new energy power system when the total operating cost of the power system and the total voltage deviation of each node of the power grid are minimized.

[0037] The control module is used to control the wind turbine generator, photovoltaic generator, energy storage device and DC channel of the pure new energy power system according to the output of the wind turbine generator, the output of the photovoltaic generator, the active power absorbed by the energy storage and the DC transmission power.

[0038] The following benefits can be obtained by implementing the present invention:

[0039] This invention provides a method and apparatus for regulating a pure renewable energy power system that incorporates energy storage control. The method constructs an objective function for the regulation model of the pure renewable energy power system based on fundamental data of the system, along with corresponding constraints on wind turbine output, photovoltaic generator output, energy storage operation, DC transmission line operation, power flow, and safety operation. Under these constraints, the objective function is solved to generate the wind turbine output, photovoltaic generator output, active power absorption of energy storage, and DC transmission power of the pure renewable energy power system when the total operating cost of the power system and the total voltage deviation at each node of the grid are minimized. Then, the wind turbine output, photovoltaic generator output, active power absorption of energy storage, and DC transmission power of the pure renewable energy power system are regulated based on these parameters. By constructing an objective function for the regulation model of the pure renewable energy power system that integrates the total operating cost of the power system and the total voltage deviation at each node of the grid, the average voltage deviation of the system is effectively reduced while decreasing the total operating cost, increasing the voltage safety margin at each node and thus improving voltage stability. Attached Figure Description

[0040] Figure 1 is a flowchart illustrating a method for regulating a pure new energy power system that takes energy storage control into account, according to an embodiment of the present invention.

[0041] Figure 2 is a control system model of a pure new energy power system provided in an embodiment of the present invention.

[0042] Figure 3 is a curve showing the average voltage deviation of the system according to an embodiment of the present invention.

[0043] Figure 4 is a diagram of the system node voltage safety margin provided in an embodiment of the present invention.

[0044] Figure 5 is a schematic diagram of the structure of a pure new energy power system control device considering energy storage control according to an embodiment of the present invention. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Figure 1 shows a method for regulating a pure renewable energy power system that takes energy storage control into account, according to an embodiment of the present invention, comprising:

[0047] Step S1: Obtain 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 generator power data, energy storage device power data, energy storage device load data, and DC channel performance data;

[0048] Step S2: Based on the aforementioned basic data, construct the objective function of the pure new energy power system control model with the goal of minimizing the total operating cost of the power system and the total voltage deviation of each node in the power grid; and 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 objective function based on the aforementioned basic data.

[0049] Step S3: Under the constraints of wind turbine output, photovoltaic generator output, energy storage operation, DC channel operation, power flow, and safe operation, solve the objective function to generate the wind turbine output, photovoltaic generator output, energy storage active power absorption, and DC transmission power of the pure new energy power system when the total operating cost of the power system and the total voltage deviation of each node of the power grid are minimized.

[0050] Step S4: Adjust the wind turbine generator, photovoltaic generator, energy storage device and DC channel of the pure new energy power system according to the output of the wind turbine generator, the output of the photovoltaic generator, the active power absorbed by the energy storage and the DC transmission power.

[0051] It should be noted that before performing the above steps, a pure renewable energy power system model as shown in Figure 2 needs to be constructed. This model, in addition to including only renewable energy output equipment, also considers energy storage control and DC transmission characteristics. As shown in Figure 2, this pure renewable energy power system model includes wind power plants, photovoltaic power plants, and energy storage devices connected to the AC network. The pure renewable energy power system model achieves power transmission with the external AC power grid through a DC channel; the AC network includes local loads. In this model, the main power sources are the output from wind power plants and photovoltaic power plants.

[0052] The control of the pure new energy power system is realized based on the constructed pure new energy power system model.

[0053] For step S1, acquiring basic data of the pure new energy power system. In a preferred embodiment, 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 grid branch data includes: the resistance value of each branch, the reactance value of each branch, the upper current limit matrix of each branch, the lower current limit matrix of each branch, and the upper transmission power limit value of each branch; the wind turbine generator power data includes: the upper limit of the actual active power injected by the wind turbine into each node, the lower limit of the actual active power injected by the wind turbine into each node, the upper limit of the actual reactive power injected by the wind turbine into each node, the lower limit of the actual reactive power injected by the wind turbine into each node, and the power factor angle of the wind turbine converter; the photovoltaic generator power data includes: the upper limit of the actual active power injected by the photovoltaic into each node, the lower limit of the actual active power injected by the photovoltaic into each node, the upper limit of the actual reactive power injected by the photovoltaic into each node, and the upper limit of the actual reactive power injected by the photovoltaic into each node. The data includes: the lower limit of actual reactive power at each node and the power factor angle of the photovoltaic converter; power data of energy storage devices, including: the maximum active power absorbed and released by energy storage at each node, the maximum reactive power released by energy storage at each node, the minimum reactive power released by energy storage at each node, the maximum reactive power absorbed by energy storage at each node, the minimum reactive power absorbed by energy storage at each node, the maximum and minimum power factors of the energy storage converter; load data of energy storage devices, including: the rated capacity of energy storage at each node, the initial charge of energy storage at each node, the efficiency of energy storage power absorption at each node, and the efficiency of energy storage power release at each node; and DC channel performance data, including: the upper limit of DC channel capacity, the lower limit of DC channel capacity, the maximum upslope rate of DC transmission power, the maximum downslope rate of DC transmission power, and the minimum constant operating time of DC.

[0054] For step S2, based on the basic data obtained in step S1, and taking into account the economy and security of power grid operation, 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 in the power grid. Among them, the total operating cost of the power system takes into account the grid loss cost, wind and solar curtailment cost, energy storage operation cost and DC regulation cost.

[0055] In a preferred embodiment, the objective function is specifically:

[0056] minF = γ1F1 + γ2F2;

[0057] Where 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 at each node of the power grid; γ1 is the weighting coefficient of the power system economic indicators; γ2 is the weighting coefficient of the power system security indicators; g 1,t Let g be the network loss of the system at time t; 2,tg represents the amount of wind and solar power curtailment at time t; 3,t Let g be the energy storage and grid interaction power at time t; 4,t V represents the DC regulation at time t; T is the scheduling period, which is 24h in this invention; N is the total number of grid nodes; V i,t V represents the effective voltage value of node i at time t. i,N Here is the voltage reference value for node i; c1 is the network loss cost coefficient; c2 is the wind and solar curtailment penalty coefficient; c3 is the energy storage operation cost coefficient; c4 is the DC regulation cost coefficient; I ij,t R is the effective value of the branch current ij at time t; ij Let be the resistance value of branch ij; Let be the power of the wind turbine connected to node i at time t; Let t be the actual active power injected into node i by the wind turbine; Let be the photovoltaic power of node i connected at time t; Let be the actual active power injected into photovoltaic node i at time t; Let be the active power absorbed by node i at time t; Let be the active power released from the energy stored at node i at time t; Let be the DC transmission power at time t; Δt represents the time interval. Let be the DC transmission power at time t-1.

[0058] It should be noted that, in this invention, The form represents the DC transmission power at time t, i.e., the physical quantity; The form represents the DC transmission power value at time t, that is, the specific physical quantity. The other parameters can be represented by these two forms, which will not be elaborated here.

[0059] It should be noted that, since the two components F1 and F2 of the objective function F have different dimensions, a linear weighting method is used when minimizing the objective function, and the relative importance of the economic index F1 and the safety index F2 in the pure energy power system is characterized by the magnitude of the weight coefficients γ1 and γ2.

[0060] Furthermore, based on the pure new energy power system model, and taking into full account the operating characteristics of wind turbine generators, photovoltaic generators, energy storage devices, and DC channels, the following constraints are constructed for the objective function: wind turbine generator output constraints, photovoltaic generator output constraints, energy storage operation constraints, DC channel operation constraints, power flow constraints, and safe operation constraints.

[0061] The output of a wind turbine generator set mainly considers the constraints on its active and reactive power output. In a preferred embodiment, the output constraints of the wind turbine generator set include:

[0062] in, Let t be the actual active power injected into node i by the wind turbine; The lower limit of the actual active power injected into node i of the wind turbine; The upper limit of the actual active power injected into node i of the wind turbine; Let be the actual reactive power injected into node i by the wind turbine at time t; The lower limit of the actual reactive power injected into node i of the wind turbine; The upper limit of the actual reactive power injected into node i of the wind turbine; The power factor angle of the wind turbine converter at node i. Take 0.9.

[0063] The output of a photovoltaic (PV) generator set mainly considers the constraints on its active and reactive power output. In a preferred embodiment, the output constraints of the PV generator set include:

[0064] in, Let be the actual active power injected into photovoltaic node i at time t; This represents the lower limit of the actual active power of photovoltaic injection node i; This represents the upper limit of the actual active power of photovoltaic injection node i; Let t be the actual reactive power injected into node i by the photovoltaic system; This represents the lower limit of the actual reactive power at photovoltaic injection node i; This represents the upper limit of the actual reactive power of photovoltaic injection node i; Let i be the power factor angle of the photovoltaic converter at node i. The value is 0.95.

[0065] For energy storage devices, certain operational constraints must be met during operation. These mainly include constraints on energy absorption and release power, energy storage capacity, and ensuring that the capacity remains the same at the beginning and end of the scheduling cycle. Based on these considerations, constraints conducive to the cyclic scheduling of energy storage are constructed. In a preferred embodiment, the energy storage operational constraints include:

[0066] E i,t (0)=E i,0 ;

[0067] in, Let be the active power absorbed by node i at time t; Let be the active power released from the energy stored at node i at time t; The maximum active power absorbed and released by the energy storage at node i; The minimum reactive power absorbed by the energy storage at node i; The maximum reactive power absorbed by the energy storage at node i; Let be the reactive power absorbed by node i at time t; Let be the reactive power released from the energy stored at node i at time t; The maximum value of the power factor of the energy storage converter at node i; The minimum power factor of the energy storage converter at node i; Let t represent the state of the absorbed and released power of the energy stored at node i at time t, where 1 represents the released power and 0 represents the absorbed power. The rated capacity for energy storage for node i; E i,0 The initial charge of energy stored at node i; E i,t Let t be the energy stored at node i during scheduling; The minimum charge amount stored for node i; The maximum charge stored for node i; The efficiency of energy storage and power absorption for node i; The efficiency of energy storage and power release at node i; T is the scheduling period.

[0068] For DC channels, which serve as the medium for power exchange between pure renewable energy power systems and the outside world, power exchange is primarily conducted via flexible DC transmission. When transmitting power through a DC channel, its power transmission curve is limited by the channel's capacity and operating mode. Based on these limitations, DC channel operating constraints are constructed. In a preferred embodiment, the DC channel operating constraints include:

[0069] in, Let be the DC transmission power at time t; This is the lower limit of the DC channel capacity; This represents the upper limit of DC channel capacity; DR DC UR is the maximum upslope rate of DC transmission power. DC This represents the maximum downslope rate of DC transmission power. This indicates whether DC power regulation is performed at time t, using Boolean values; τ is the minimum constant operating time of DC. It should be noted that... This is a 0-1 variable, representing whether DC power regulation is performed at time t. If DC power regulation is performed at time t, then... If the DC power is not regulated at time t, then... =0; This means that for any time t+τ greater than or equal to T, the following condition must be met.

[0070] In addition to the constraints mentioned above, it is also necessary to consider the power flow constraints that the pure new energy power system must meet during its overall power flow operation and the safety operation constraints that ensure the safe operation of the pure new energy power system.

[0071] A power flow model using the Distflow expression is used to construct power flow constraints. In a preferred embodiment, the power flow constraints include:

[0072] in, Let t be the active power injected into node i at time t; Let t be the reactive power injected into node i at time t; Let be the active load of node i at time t; Let A be the reactive load of node i at time t; btn A bfn This represents the power flow relationship between nodes i and j in the system. When power flows from node i to node j, A btn A is 1; when power flows from node j to node i, A bfn =1; I ij,t P represents the effective value of the branch current ij at time t; ij,t Q represents the active power transmitted by branch ij at time t; ij,t R is the reactive power transmitted by branch ij at time t; ij X represents the resistance value of branch ij; ij V is the reactance value of branch ij; i,t V represents the effective voltage value of node i at time t. j,t Let be the effective voltage value of node j at time t.

[0073] To ensure the safe operation of a pure renewable energy power system, it is necessary to constrain the voltage at each node and the current and power of each branch, i.e., 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:

[0074] in, This represents the lower limit of the voltage at node i. This represents the upper limit of the voltage at node i. This is the matrix representing the lower limit values ​​of the branch current ij; S is the matrix representing the upper limit values ​​of the branch current ij; ij,max P represents the upper limit of the transmission power of branch ij; ij,t Q represents the active power transmitted by branch ij at time t; ij,t Let be the reactive power transmitted by branch ij at time t.

[0075] For steps S3 and S4, under the constraints of the wind turbine output, photovoltaic generator output, energy storage operation, DC channel operation, power flow, and safe operation constructed above, the objective function is solved to generate the wind turbine output, photovoltaic generator output, energy storage active power absorption, and DC transmission power of the pure new energy power system when the total operating cost of the power system and the total voltage deviation of each node of the grid are minimized. Then, the wind turbine, photovoltaic generator, energy storage device, and DC channel of the pure new energy power system are regulated.

[0076] By implementing the solution of this invention, the impact of energy storage control and DC regulation on the regulation of pure new energy power systems can be fully considered, thereby improving the stability of the operation of pure new energy power systems.

[0077] It should be added that, in order to verify the impact of energy storage reactive power control and DC regulation on the regulation of pure new energy power systems, the present invention makes the following analysis.

[0078] Case 1 illustrates the scenario where energy storage only participates in the active power optimization of a pure renewable energy power system, while Case 2 illustrates the scenario where energy storage participates in both active and reactive power optimization of a pure renewable energy power system. Under Case 1, the grid loss cost for one day is 19.65, wind and solar curtailment cost is 6.77, energy storage operating cost is 8.93, and DC regulation cost is 7.28, resulting in a total power system operating cost of 42.63 for one day under Case 1. Under Case 2, the costs for one day are: grid loss cost is 18.54, wind and solar curtailment cost is 6.67, energy storage operating cost is 9.23, and DC regulation cost is 7.25, resulting in a total power system operating cost of 41.69 for one day under Case 2. It can be seen that, compared with Case 1, Case 2 has increased its energy storage operating cost due to the addition of energy storage reactive power control, but the grid loss cost and wind and solar curtailment cost are significantly reduced. This shows that optimizing the reactive power control of the system through the remaining energy storage capacity can not only improve the system's absorption of new energy, but also reduce line loss costs when the input power in the system increases, thereby reducing the total operating cost of the power system.

[0079] In Case 2, appropriate economic and safety weighting coefficients were selected to make the total system cost the same as in Case 1. The average node voltage deviation and safety margin of the two are compared as shown in Figure 3 and Figure 4, respectively. It can be seen that under the premise of the same total system operating cost, Case 2, through energy storage to control the reactive power of the system, makes the overall average voltage deviation significantly smaller than that of Case 1, the system node voltage safety margin significantly increased, and the voltage stability of the system is improved to a certain extent.

[0080] Based on the above method embodiments, the present invention provides corresponding apparatus embodiments.

[0081] As shown in Figure 5, an embodiment of the present invention provides a control device for a pure new energy power system that takes energy storage control into account, including: a data acquisition module, a model and constraint construction module, a model solving module, and a control module;

[0082] 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 generator power data, energy storage device power data, energy storage device load data, and DC channel performance data;

[0083] The model and constraint construction module is used to construct an objective function for the pure new energy power system control model based on the basic data, with the goal of minimizing the total operating cost of the power system and the total voltage deviation of each node in the power grid. Based on the basic data, the module also constructs 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 objective function.

[0084] The model solving module is used to solve the objective function under the constraints of wind turbine output, photovoltaic generator output, energy storage operation, DC channel operation, power flow, and safe operation, and generate the wind turbine output, photovoltaic generator output, energy storage active power absorption power, and DC transmission power of the pure new energy power system when the total operating cost of the power system and the total voltage deviation of each node of the power grid are minimized.

[0085] The control module is used to control the wind turbine generator, photovoltaic generator, energy storage device and DC channel of the pure new energy power system according to the output of the wind turbine generator, the output of the photovoltaic generator, the active power absorbed by the energy storage and the DC transmission power.

[0086] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0087] Those skilled in the art will clearly understand that, for convenience and brevity, the specific working process of the device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0088] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and 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 that takes into account energy storage control, characterized in that, include: Acquire basic data for a pure renewable energy power system; wherein, the basic data includes: grid node data, grid branch data, wind turbine power data, photovoltaic generator power data, energy storage device power data, energy storage device load data, and DC channel performance data; Based on the aforementioned basic data, an objective function for the regulation and control model of a pure renewable energy power system is constructed with the goal of minimizing the total operating cost of the power system and the total voltage deviation of each node in the power grid. Furthermore, based on the aforementioned basic data, constraints on the output of wind turbine generators, output of photovoltaic generators, energy storage operation, DC channel operation, power flow, and safe operation are constructed for the objective function. Under the constraints of wind turbine output, photovoltaic generator output, energy storage operation, DC channel operation, power flow, and safe operation, the objective function is solved to generate the wind turbine output, photovoltaic generator output, energy storage active power absorption, and DC transmission power of a pure new energy power system when the total operating cost of the power system and the total voltage deviation of each node of the grid are minimized. The wind turbine generators, photovoltaic generators, energy storage devices, and DC transmission channels of the pure new energy power system are regulated based on the output of the wind turbine generators, the output of the photovoltaic generators, the active power absorbed by the energy storage, and the DC transmission power.

2. The method for regulating a pure new energy power system considering energy storage control as described in claim 1, characterized in that, The power grid node data includes: the total number of power 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: the resistance value of each branch, the reactance value of each branch, the upper limit value matrix of the current of each branch, the lower limit value matrix of the current of each branch, and the upper limit value of the transmission power of each branch. The power data of the wind turbine generator set includes: the upper limit of the actual active power injected into each node, the lower limit of the actual active power injected into each node, the upper limit of the actual reactive power injected into each node, the lower limit of the actual reactive power injected into each node, and the power factor angle of the wind turbine converter. The photovoltaic generator power data includes: the upper limit of the actual active power injected into each node, the lower limit of the actual active power injected into each node, the upper limit of the actual reactive power injected into each node, the lower limit of the actual reactive power injected into each node, and the power factor angle of the photovoltaic converter. The power data of the energy storage device includes: the maximum active power absorbed and released by each node, the maximum reactive power released by each node, the minimum reactive power released by each node, the maximum reactive power absorbed by each node, the minimum reactive power absorbed by each node, the maximum value of the power factor of the energy storage converter, and the minimum value of the power factor of the energy storage converter. The load data of the energy storage device includes: the rated capacity of energy storage at each node, the initial charge of energy storage at each node, the efficiency of energy storage power absorption at each node, and the efficiency of energy storage power release at each node. The DC channel performance data includes: DC channel capacity upper limit, DC channel capacity lower limit, maximum DC transmission power upslope rate, maximum DC transmission power downslope rate, and minimum constant DC operating time.

3. The method for regulating a pure new energy power system considering energy storage control as described in claim 2, characterized in that, The objective function is specifically: min F = γ1F1 + γ2F2; Where 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 at each node of the power grid; γ1 is the weighting coefficient of the power system economic indicators; γ2 is the weighting coefficient of the power system security indicators; g 1,t Let g be the network loss of the system at time t; 2,t g represents the amount of wind and solar power curtailment at time t; 3,t Let g be the energy storage and grid interaction power at time t; 4,t V represents the DC regulation at time t; T is the dispatch period; N is the total number of grid nodes; V i,t V represents the effective voltage value of node i at time t. i,N Here is the voltage reference value for node i; c1 is the network loss cost coefficient; c2 is the wind and solar curtailment penalty coefficient; c3 is the energy storage operation cost coefficient; c4 is the DC regulation cost coefficient; I ij,t R is the effective value of the branch current ij at time t; ij Let be the resistance value of branch ij; Let be the power of the wind turbine connected to node i at time t; Let t be the actual active power injected into node i by the wind turbine; Let be the photovoltaic power of node i connected at time t; Let be the actual active power injected into photovoltaic node i at time t; Let be the active power absorbed by node i at time t; Let be the active power released from the energy stored at node i at time t; Let be the DC transmission power at time t; Δt represents the time interval. Let be the DC transmission power at time t-1.

4. The method for regulating a pure new energy power system considering energy storage control as described in claim 3, characterized in that, The output constraints of the wind turbine generator set include: in, Let t be the actual active power injected into node i by the wind turbine; The lower limit of the actual active power injected into node i of the wind turbine; The upper limit of the actual active power injected into node i of the wind turbine; Let be the actual reactive power injected into node i by the wind turbine at time t; The lower limit of the actual reactive power injected into node i of the wind turbine; The upper limit of the actual reactive power injected into node i of the wind turbine; Let be the power factor angle of the wind turbine converter at node i.

5. The method for regulating a pure new energy power system considering energy storage control as described in claim 4, characterized in that, The output constraints of the photovoltaic generator set include: in, Let be the actual active power injected into photovoltaic node i at time t; This represents the lower limit of the actual active power of photovoltaic injection node i; This represents the upper limit of the actual active power of photovoltaic injection node i; Let t be the actual reactive power injected into node i by the photovoltaic system; This represents the lower limit of the actual reactive power at photovoltaic injection node i; This represents the upper limit of the actual reactive power of photovoltaic injection node i; Let be the power factor angle of the photovoltaic converter at node i.

6. The method for regulating a pure new energy power system considering energy storage control as described in claim 5, characterized in that, The energy storage operation constraints include: E i,t (0)=E i,0 ; in, Let be the active power absorbed by node i at time t; Let be the active power released from the energy stored at node i at time t; The maximum active power absorbed and released by the energy storage at node i; The minimum reactive power absorbed by the energy storage at node i; The maximum reactive power absorbed by the energy storage at node i; Let be the reactive power absorbed by node i at time t; Let be the reactive power released from the energy stored at node i at time t; The maximum value of the power factor of the energy storage converter at node i; The minimum power factor of the energy storage converter at node i; Let t represent the state of the absorbed and released power of the energy stored at node i at time t, where 1 represents the released power and 0 represents the absorbed power. The rated capacity for energy storage for node i; E i,0 The initial charge of energy stored at node i; E i,t Let t be the energy stored at node i during scheduling; The minimum charge amount stored for node i; The maximum charge stored for node i; The efficiency of energy storage and power absorption for node i; The efficiency of energy storage and power release at node i; T is the scheduling period.

7. A method for regulating a pure new energy power system considering energy storage control as described in claim 6, characterized in that, The DC channel operating constraints include: in, Let be the DC transmission power at time t; This is the lower limit of the DC channel capacity; This represents the upper limit of DC channel capacity; DR DC UR is the maximum upslope rate of DC transmission power. DC This represents the maximum downslope rate of DC transmission power. Indicates whether DC power regulation is performed at time t, using Boolean values; τ is the minimum constant operating time of DC.

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

9. A method for regulating a pure new energy power system considering energy storage control as described in claim 8, characterized in that, The safety operation constraints include: in, This represents the lower limit of the voltage at node i. This represents the upper limit of the voltage at node i. This is the matrix representing the lower limit values ​​of the branch current ij; S is the matrix representing the upper limit values ​​of the branch current ij; ij,max P represents the upper limit of the transmission power of branch ij; ij,t Q represents the active power transmitted by branch ij at time t; ij,t Let be the reactive power transmitted by branch ij at time t.

10. A control device for a pure new energy power system that incorporates energy storage control, characterized in that, include: The module includes a data acquisition module, a model and constraint construction module, a model solving module, and a 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 generator power data, energy storage device power data, energy storage device load data, and DC channel performance data; The model and constraint construction module is used to construct an objective function for the pure new energy power system control model based on the basic data, with the goal of minimizing the total operating cost of the power system and the total voltage deviation of each node in the power grid. Based on the basic data, the module also constructs 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 objective function. The model solving module is used to solve the objective function under the constraints of wind turbine output, photovoltaic generator output, energy storage operation, DC channel operation, power flow, and safe operation, and generate the wind turbine output, photovoltaic generator output, energy storage active power absorption power, and DC transmission power of the pure new energy power system when the total operating 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, photovoltaic generator, energy storage device and DC channel of the pure new energy power system according to the output of the wind turbine generator, the output of the photovoltaic generator, the active power absorbed by the energy storage and the DC transmission power.

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