Scheduling method and system for power system containing pumped storage power station

Abstract

The invention provides a scheduling method and system for a power system containing a pumped storage power station, and the method comprises the steps: building a peak clipping and valley filling benefit model of the pumped storage power station according to the peak regulation characteristics of the pumped storage power station; according to the peak clipping and valley filling benefit model of the pumped storage power station, analyzing the operation environment of the pumped storage power station, and establishing a comprehensive scheduling strategy of the power system; according to the comprehensive dispatching strategy of the power system, an economic dispatching model of a hybrid system is established, and the hybrid system comprises a thermal power generating unit, a hydroelectric generating unit and pumped storage; and solving the economic dispatching model by using an improved ant colony algorithm to obtain an optimal dispatching scheme of the power system containing the pumped storage power station. Factors such as power generation cost, water pumping cost, system loss and power market price are comprehensively considered, the overall operation cost is remarkably reduced, the economical efficiency and reliability of system operation are improved, application and development of the water pumping energy storage technology can be promoted, the challenge of energy structure transformation can be coped with, and the increase of future power requirements can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of power system dispatching, and more specifically, to a dispatching method and system for a power system including a pumped storage power station. Background Art

[0002] With the rapid development of the global economy and the continuous progress of society, the demand for electricity has shown a trend of sustained growth. As an important infrastructure of modern society, the safety, stability and economic operation of the power system are of great significance to economic and social development. However, the volatility and uncertainty of electricity demand have brought great challenges to the operation of the power system. In this context, how to effectively carry out the economic dispatch of the power system, reduce operating costs, and improve power supply reliability and grid stability has become a hot issue in current power system research.

[0003] As an important energy storage technology, pumped storage power stations play an important role in balancing power supply and demand, regulating grid load, and ensuring safe and stable operation of power systems due to their large capacity, high efficiency, and rapid response. Pumped storage power stations use cheap electricity to pump water to the upper reservoir to store energy during the low-power demand period, and release hydropower to generate electricity during the peak power demand period. This can not only smooth the power load curve and reduce the peak-to-valley difference of the power grid, but also improve the operating efficiency and economy of the power system. Therefore, the research and development of economic dispatch methods for pumped storage power stations is of great significance to achieving efficient, economical and sustainable operation of the power system.

[0004] The operating costs of the power system mainly include power generation costs, transmission loss costs, and dispatching costs. Through reasonable economic dispatch, the configuration of power generation resources can be optimized and the overall power generation cost can be reduced. The characteristics of pumped storage power stations, which store energy during off-peak periods and generate electricity during peak periods, give them unique advantages in reducing the peak-to-valley difference of the power system and smoothing the load curve. By optimizing the dispatch of pumped storage power stations, the dependence on expensive fuel power generation during peak periods can be effectively reduced, reducing the overall power generation cost. At the same time, by simulating and analyzing the effects of different dispatching strategies, theoretical guidance and decision support can be provided for the actual operation of the power system.

[0005] In summary, researching and developing economic dispatch methods that consider pumped-storage power station systems can not only optimize the operating costs of power systems and improve the stability and economy of power grids, but also promote the application and development of pumped-storage technology, meet the challenges of energy structure transformation, and meet the growth of future electricity demand. However, there are few methods in the prior art that use the operating characteristics of pumped-storage power stations to perform comprehensive optimization and dispatch of power systems. Therefore, a dispatch method and system for power systems containing pumped-storage power stations are needed to provide new ideas for the economic dispatch of power systems and the efficient use of pumped-storage power stations. Summary of the invention

[0006] In order to solve the deficiencies in the prior art, the present invention provides a dispatching method and system for an electric power system including a pumped-storage power station. By taking into account the peak-shaving and valley-filling benefits of the pumped-storage power station and the operating environment of the pumped-storage power station, an economic dispatching model of the hybrid system is established, and an improved ant colony algorithm is proposed.

[0007] The present invention adopts the following technical solution.

[0008] A first aspect of the present invention provides a dispatching method for a power system including a pumped storage power station, characterized in that:

[0009] Step 1, taking into account the peak load characteristics of the pumped storage power station, a peak load reduction and valley filling benefit model of the pumped storage power station is established;

[0010] Step 2, based on the peak load shaving and valley filling benefit model of the pumped storage power station in step 1, and analyzing the operating environment of the pumped storage power station, a comprehensive dispatching strategy for the power system is established;

[0011] Step 3, according to the comprehensive dispatch strategy of the power system, an economic dispatch model of a hybrid system is established, wherein the hybrid system includes thermal power units, hydropower units and pumped storage;

[0012] Step 4: Use the improved ant colony algorithm to solve the economic dispatch model in step 3 to obtain the optimal dispatch plan for the power system containing the pumped storage power station.

[0013] Preferably, in step 1, the peak shaving and valley filling benefit model of the pumped storage power station includes: coal saving benefit, energy storage benefit and economic benefit.

[0014] Preferably, in step 2, establishing a comprehensive dispatching strategy for the power system further includes: studying the peak-shaving characteristics of different power generation modes, including the peak-shaving characteristics of thermal power units and the peak-shaving characteristics of hydropower units.

[0015] Preferably, in step 3, an economic dispatch model of the hybrid system is established with the goal of minimizing the electricity purchase cost, which is expressed by the following formula:

[0016]

[0017] Where:

[0018] T is the total number of system optimization periods;

[0019] I is the serial number of the system generator set;

[0020] p i (t) is the active power of unit i in time period t;

[0021] f i [p i(t)] represents the fee function that the power grid needs to pay when unit i operates in time period t.

[0022] Preferably, in step 3, the economic dispatch model of the hybrid system needs to satisfy power balance constraints, line transmission power constraints, spinning reserve capacity and unit power constraints.

[0023] Preferably, the line transmission power constraint is expressed by the following formula:

[0024]

[0025] Where:

[0026] p k,max is the stable transmission limit of the k-th hop line;

[0027] p j,met (t) is the injected power of the jth node at time t;

[0028] S j,k The sensitivity of the injected power at the jth node to the power flow of the kth jump line;

[0029] n is the number of nodes that have an impact on the k-th jump line power flow;

[0030] The constraint on spinning reserve capacity is expressed as follows,

[0031]

[0032] Where:

[0033] p B,min Spinning spare capacity for the system;

[0034] p i .max is the upper limit of the unit output;

[0035] P D (t) is the total load of the system in time period t;

[0036] u i (t) is the voltage of the i-th node at time t;

[0037] l is the number of nodes.

[0038] Preferably, step 4 comprises:

[0039] Step 4.1, set the initial pheromone concentration, generate a group of ants, and randomly distribute them on each node; each ant selects the next node based on the pheromone and heuristic information;

[0040] Step 4.2, after the ant completes the path, it updates the pheromone according to the path quality;

[0041] Step 4.3, improve the role of heuristic information in the ant colony algorithm, so that ants rely more on heuristic information when selecting paths, and obtain the improved path selection probability;

[0042] Step 4.4, introduce the pheromone global optimal update mechanism, so that the pheromone update depends on both the local search results and the global optimal path, and obtain the improved pheromone update method.

[0043] Preferably, the improved path selection probability is expressed by the following formula:

[0044]

[0045] Where:

[0046] H ij is the enhanced heuristic information of path (i, j);

[0047] γ is the importance parameter for enhancing heuristic information;

[0048] P ij (t) is the probability of an ant moving from node i to node j;

[0049] τ ij (t) is the pheromone concentration on the path from node i to node j;

[0050] η ij (t) is the heuristic information from node i to node j;

[0051] α is a parameter of pheromone importance;

[0052] β is a parameter of the importance of heuristic information;

[0053] Allowed represents the next set of nodes that the ant can choose.

[0054] Preferably, the improved pheromone updating method is expressed by the following formula:

[0055]

[0056] Where:

[0057] τ ij (t) is the pheromone concentration on the path from node i to node j;

[0058] Δτ ij (t) is the amount of pheromone left by the ant on the path (i, j) in time t;

[0059] ρ is the pheromone volatility coefficient;

[0060] represents the pheromone increment on the global optimal path at time t, which is defined as:

[0061]

[0062] Where:

[0063] Q is a constant;

[0064] L best is the length of the global optimal path found so far.

[0065] A second aspect of the present invention provides a dispatching system for a power system including a pumped storage power station, and a dispatching method for a power system including a pumped storage power station is implemented, comprising:

[0066] Benefit analysis module, used to establish a peak-shaving and valley-filling benefit model for pumped-storage power stations;

[0067] Comprehensive strategy module, used to analyze the operating environment of pumped storage power stations and establish comprehensive dispatch strategies for power systems;

[0068] An economic dispatch module, used to establish an economic dispatch model of a hybrid system, wherein the hybrid system includes thermal power units, hydropower units and pumped storage;

[0069] The model solving module is used to solve the economic dispatch model and generate the optimal dispatch plan for the power system including the pumped storage power station.

[0070] Compared with the prior art, the beneficial effects of the present invention include at least:

[0071] (1) The present invention establishes a scheduling model based on optimization theory, comprehensively considering factors such as power generation cost, pumping cost, system loss and electricity market price, significantly reducing the overall operating cost and improving the economy and reliability of system operation.

[0072] (2) The present invention improves the ant colony algorithm, adopts heuristic information, and designs a reasonable path selection probability formula, thereby increasing the evolution speed, reducing the size of the ant colony, and reducing the time spent on the search process.

[0073] (3) The present invention can promote the application and development of pumped storage technology, meet the challenges of energy structure transformation, and meet the growth of future electricity demand. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 It is a power rate balance diagram provided according to an application example of the present invention;

[0075] Figure 2 It is a load and unit output curve provided according to the application example of the present invention;

[0076] Figure 3 It is a comparison curve before and after load optimization provided according to the application example of the present invention;

[0077] Figure 4 It is a flow chart of a dispatching method for a power system including a pumped storage power station provided in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0078] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the scope of protection of the present invention.

[0079] The present invention provides a dispatching method and system for a power system including a pumped storage power station, aiming to optimize the operating cost and efficiency of the power system. As an important energy storage technology, a pumped storage power station stores energy by pumping water to an upper reservoir when the power demand is low, and releases energy to generate electricity when the power demand is peak, thereby balancing the supply and demand of electricity and improving the stability and economy of the power grid. The present invention first analyzes the operating principle of a pumped storage power station and its role in the power system, and then establishes an economic dispatching model based on optimization theory, which comprehensively considers factors such as power generation cost, pumping cost, system loss and power market price. The effectiveness and superiority of the proposed method are verified through simulation analysis under different scenarios. The results show that, under the comprehensive consideration of the pumped storage system, the economic dispatching strategy of the power system can significantly reduce the overall operating cost and improve the economy and reliability of the system operation. This study provides a theoretical basis and practical guidance for the large-scale application of pumped storage technology in future power systems.

[0080] like Figure 4 As shown, embodiment 1 of the present invention provides a dispatching method for a power system including a pumped storage power station, comprising the following steps:

[0081] Step 1: Analyze the benefits of peak load shifting of pumped storage power stations, including: Pumped storage power stations are currently an extremely effective peak load shifting power source, with the characteristics of rapid start and stop and flexible operation, and are usually used for peak power supply or handling load mutations. The peak load shifting function of pumped storage power stations brings many benefits to the entire system, mainly reflected in coal saving benefits, energy storage benefits and economic benefits.

[0082] Pumped storage power stations use cheap or surplus electricity to pump water for energy storage during low-demand periods, and release hydropower to generate electricity during peak periods, reducing reliance on high-cost fuel power generation. During peak demand periods, high-cost coal-fired power units are usually started to meet the additional electricity demand. The peak-shaving function of pumped storage power stations can reduce the start-up frequency and operation time of coal-fired power units, thereby reducing coal consumption. Coal-fired power units are usually less efficient when operating at partial load, and are most efficient when operating close to full load. The peak-shaving and valley-filling function of pumped storage power stations can smooth the power load, allowing coal-fired power units to operate closer to their optimal efficiency points, improving overall power generation efficiency and further reducing coal consumption. Since the coal combustion process of coal-fired power units produces a large amount of pollutants such as carbon dioxide, sulfur oxides and nitrogen oxides, by reducing coal consumption, pumped storage power stations reduce the emission of these pollutants to a certain extent, alleviate environmental pollution, and have significant environmental protection benefits.

[0083] As an important energy storage device in the power system, pumped storage power stations can play the role of peak load shifting and valley filling in the power system. During the period of low power demand, excess power is used for pumped storage; during the period of peak power demand, power is provided by releasing water for power generation to balance power supply and demand. This peak load shifting and valley filling function can effectively smooth the power load curve, reduce load fluctuations, and enhance the stability and reliability of the power grid. With the large-scale access of renewable energy such as wind power and solar energy, the volatility and uncertainty faced by the power system have increased. Pumped storage power stations can pump water for energy storage during the period of excess renewable energy generation, and release water for power generation during the period of insufficient renewable energy generation, effectively addressing the volatility of renewable energy, improving the utilization rate of renewable energy, and promoting the development of clean energy. Pumped storage power stations have the ability to respond quickly, and can quickly provide emergency power support when emergencies occur in the power system or when the load fluctuates violently. In addition, pumped storage power stations can also participate in the frequency regulation service of the power system, and maintain the frequency stability of the power system by quickly adjusting the output to ensure the safe operation of the power grid.

[0084] Pumped-storage power stations use cheap electricity to pump water for energy storage during off-peak hours, and generate electricity by releasing water during peak hours, reducing reliance on high-cost power generation methods, thereby reducing the overall operating cost of the power system. By rationally dispatching pumped-storage power stations, the allocation of power generation resources can be optimized to maximize economic benefits. The peak-shaving and valley-filling function of pumped-storage power stations can smooth out price fluctuations in the electricity market, reduce the pressure of rising electricity prices during peak hours, and improve the stability of the electricity market. In addition, by purchasing electricity to pump water during low-price periods and selling electricity to generate electricity during peak-price periods, pumped-storage power stations can obtain considerable economic benefits and enhance their market competitiveness. By peak-shaving and valley-filling, pumped-storage power stations provide the regulation capacity required by the electricity market, which helps to smooth out price fluctuations in the electricity market, maintain market order, and ensure the smooth operation of the electricity market. At the same time, pumped-storage power stations can also participate in the auxiliary service market of the electricity market, provide frequency regulation, standby and other services, and obtain additional economic benefits.

[0085] Step 2: Establish a comprehensive dispatching strategy for the power system based on the peak-shaving characteristics of different power generation methods, including: the continuous diversification of power generation methods in the power grid, coordinated operation to meet the power load demand in the power system, and research on the peak-shaving characteristics of different power generation methods, including the peak-shaving characteristics of thermal power units, the peak-shaving characteristics of hydropower units, and the peak-shaving characteristics of pumped-storage units.

[0086] Step 2.1, analyze the diversified power generation methods in the power grid.

[0087] Coal-fired power is a traditional base load power source with the characteristics of stability and reliability. However, coal-fired power has poor peak-shaving capacity and heavy pollution, which does not meet modern environmental protection requirements. The start-up and shutdown and load adjustment time of coal-fired power units are long, which is not suitable for rapid response to load changes. Hydropower is an ideal peak-shaving power source with the characteristics of flexible regulation and rapid start-up and shutdown. In particular, large reservoir hydropower stations with regulation capabilities can flexibly dispatch output according to power demand and balance power loads. Wind power and photovoltaic power generation are the main renewable energy power generation methods. Wind power and photovoltaic power generation are characterized by volatility and uncontrollability and rely on natural conditions. Despite their low operating costs and high environmental benefits, their intermittent and instability pose challenges to the dispatch and stability of the power grid.

[0088] Step 2.2, study the peak-shaving characteristics of different power generation methods.

[0089] Thermal power units include coal-fired power and natural gas power units, which have the following peak-shaving characteristics: Limited peak-shaving capacity: Coal-fired power units have weak peak-shaving capacity, and start-up, shutdown and load adjustment take a long time, which is not suitable for frequent peak-shaving. Natural gas units have strong peak-shaving capacity and can adjust output quickly, but the fuel cost is high. Economic considerations: Thermal power units have higher operating efficiency during high-load periods and lower operating efficiency during low-load periods. Frequent peak-shaving will increase operating costs and equipment wear. Environmental factors: During the peak-shaving process, the efficiency fluctuations of thermal power units will lead to changes in pollutant emissions, which puts greater pressure on environmental protection.

[0090] Hydropower units include conventional hydropower and pumped storage power stations, which have the following peak-shaving characteristics: Flexible regulation: Hydropower units can start and stop quickly and adjust output, which is suitable for load regulation and frequency regulation. The regulation capacity of large reservoir hydropower stations is particularly strong, which can smooth the power load curve. Environmental benefits: There is no pollutant emission during hydropower generation, which has significant environmental benefits and is an ideal clean energy peak-shaving power source. Resource dependence: The regulation capacity of hydropower is limited by water resources, and the peak-shaving capacity will decrease in dry and dry seasons.

[0091] Pumped storage power stations are one of the most effective peak-shaving power sources at present, with the following peak-shaving characteristics: Rapid start and stop: Pumped storage power stations can be started and stopped within a few minutes, quickly responding to changes in the load of the power system, and have extremely high peak-shaving capabilities. Flexible operation: By pumping water to store energy during off-peak hours and releasing water to generate electricity during peak hours, pumped storage power stations can smooth the power load and reduce load fluctuations. Energy storage benefits: Pumped storage power stations effectively utilize off-peak electricity, reduce peak power demand, and reduce the overall operating cost of the power system. Environmentally friendly: Pumped storage power stations do not emit pollutants during the power generation process, which has significant environmental benefits.

[0092] Step 2.3: Analyze the operating environment of the pumped storage power station

[0093] Grid load characteristics: The load characteristics of modern power grids show distinct peak and valley characteristics, with higher electricity demand during the day and night, and lower electricity demand late at night. With the development of social economy and the improvement of living standards, the demand for electricity continues to grow, and the gap between load peaks and valleys is also widening. Pumped storage power stations can effectively balance the power load and improve the operating efficiency and stability of the power grid by shaving peaks and filling valleys.

[0094] Access to renewable energy: The access to large-scale wind power and photovoltaic power generation has increased the load volatility and uncertainty of the power grid. Pumped storage power stations can pump water for energy storage during periods of excess wind power and photovoltaic power generation, and release water for power generation during periods of insufficient wind power and photovoltaic power generation, effectively addressing the volatility of renewable energy, improving the utilization rate of renewable energy, and promoting the development of clean energy.

[0095] Power market environment: In the power market environment, power prices fluctuate greatly with supply and demand. Pumped storage power stations can maximize economic benefits by purchasing electricity to pump water during low-price periods and selling electricity to generate electricity during peak-price periods. Reasonable use of power market price fluctuations and optimization of the dispatching strategy of pumped storage power stations can further improve the economic efficiency of the power system.

[0096] Technological progress and policy support: With the advancement of energy storage technology and the increase in policy support, the application prospects of pumped storage power stations in power systems are broader. Government policy support and capital investment will help promote the construction and operation of pumped storage power stations and improve their economy and competitiveness. At the same time, the development of advanced scheduling technology and optimization models can further improve the operating efficiency and regulation capacity of pumped storage power stations.

[0097] Step 2.4, coordinate operation to meet the power load demand in the power system and establish a comprehensive dispatching strategy.

[0098] The power generation methods in the power system are diversified, and it is necessary to comprehensively consider the peak-shaving characteristics of various generators and formulate scientific dispatching strategies. Through optimized dispatching, the advantages of various generators can be fully utilized to achieve efficient and stable operation of the power system. As an important peak-shaving power source, pumped storage power stations play a key role in comprehensive dispatching.

[0099] Specifically, the comprehensive scheduling strategy requires the following:

[0100] Balance of power supply and demand: In the power system, the balance of power supply and demand is crucial. By rationally dispatching pumped storage power stations, energy can be stored during off-peak hours and generated during peak hours, balancing power supply and demand, reducing load fluctuations, and improving the stability and reliability of the power grid. At the same time, the rapid response capability of pumped storage power stations can be used to cope with sudden load changes and power shortages, ensuring the safety of power supply.

[0101] Improve system economy: The application of pumped storage power stations in power systems can effectively reduce system operating costs. By using cheap electricity to pump water for energy storage during off-peak hours and reducing the demand for high-cost electricity by releasing water for power generation during peak hours, the overall operating cost of the power system can be significantly reduced. Reasonable use of power market price fluctuations and optimization of dispatch strategies can further improve the economy of the power system and maximize economic benefits.

[0102] In summary, the operating environment of pumped-storage power stations in modern power systems is complex and changeable, involving the coordinated operation of multiple power generation methods. By deeply studying the peak-shaving characteristics of different power generation methods and formulating scientific dispatching strategies, the peak-shaving and valley-filling benefits of pumped-storage power stations can be fully utilized to achieve efficient, stable and economical operation of the power system. In the context of grid load characteristics, access to diversified power generation methods, power market environment, technological progress and policy support, pumped-storage power stations, as an important peak-shaving power source, will play a more important role in the future power system. By continuously optimizing and improving the operating benefits of pumped-storage power stations, we can make important contributions to achieving a green, smart and sustainable energy future.

[0103] Step 3: Establish an economic dispatch model for the hybrid system, specifically including: by comparing with the economic dispatch model of the traditional power system, establish an economic dispatch model for the hybrid system including thermal power units, hydropower units and pumped storage.

[0104] Step 3.1: The traditional economic dispatch of power system is to achieve the economic dispatch of power system by following the principle of overall optimization of power system and taking the minimum power generation cost or operation cost as the objective function, under the premise of ensuring the safety, stability and reliability of power system.

[0105] The mathematical model of traditional economic dispatch is established and expressed as the following formula:

[0106]

[0107] Where, T is the total number of system optimization periods; I is the sequence number of system generator sets; p i (t) is the active power of unit i in period t; x i (t) is the continuous start-up and shutdown time of unit i in period l; u i (t) is the state of unit i in time period t, u i (t) = 1 means running state, u i (t) = 0 means shutdown state; C i [p i (t)] represents the power generation cost of unit i in period t; S i [x i (t),u i (t)] is the start-stop cost from period t-1 to period t when the unit status changes; p D (t) is the system load in period t; p D.B.C.min Minimum iF. Spinning reserve: p D.B.D.min is the minimum negative spinning reserve.

[0108] From the above model, we can see that traditional economic dispatch is based on the perspective of power plants, and the various losses in the actual power generation and peak-shaving process are used as indicators as the basis for dispatch. Therefore, the peak-shaving power dispatch discussed here is mainly for thermal power units and pumped storage units, and is converted into coordinated operation of water and fire peak-shaving.

[0109] Step 3.2: The power grid, based on its own interests, strives to meet the power grid's demand for electricity with the minimum expenditure, while ensuring that national production and living electricity consumption are not affected. Therefore, a peak-shaving economic dispatch model for the power system is established with the goal of minimizing the purchase cost of electricity.

[0110]

[0111] Where, T is the total number of system optimization periods; I is the sequence number of system generator sets; p i (t) is the active power of unit i in period t; f i [p i (t)] represents the fee function that the power grid needs to pay when unit i operates in time period t.

[0112] Step 3.3, during the operation of the entire system, in addition to meeting the constraints of unit operation, grid dispatchers also need to consider various conditions for stable operation of the system when conducting grid dispatch to ensure timely supply of electricity and safe operation of the grid. The main constraints are system stable operation constraints and unit characteristic parameter constraints.

[0113] Power balance constraint: During the entire dispatch balance period, the output power of all units in the system must be consistent with the system load demand, which can be expressed as follows:

[0114]

[0115] In the formula, G F ,G p ,G N ,G W They are the thermal core unit set, pumped storage unit set, nuclear power unit set and hydropower unit set in the hybrid power system respectively; P F,i (t), P P,i (t)P N,i (t)P W,i (t) is the specific output of thermal power unit i in time period t; P D (t) is the total load of the system in time period t.

[0116] The line transmission power constraint is expressed as follows:

[0117]

[0118] Where pk,max is the stable transmission limit of the k-th jump line; p j,met (t) is the injected power of the jth node at time t; S j,k is the sensitivity of the j-th node injection power to the k-th jump line power flow, and n is the number of nodes that affect the k-th jump line power flow.

[0119] The constraint on spinning reserve capacity is expressed as follows,

[0120]

[0121] In the formula, p B,min is the system rotating reserve capacity, mainly including load reserve and accident reserve, and is generally taken as 7% to 15%, where l is the number of nodes.

[0122] The unit power constraint is expressed as follows:

[0123] p i.min ≤p i (t)≤p i.max

[0124] In the formula, p i.min is the lower limit of the unit output, generally the minimum technical output; p i .max is the upper limit of the unit output, generally the rated power of the unit.

[0125] Step 4: Use the improved ant colony algorithm to solve the economic dispatch model in step 3 and obtain the optimal dispatch plan for the pumped storage power station, which specifically includes: analyzing the commonly used optimization algorithms for economic dispatch, and proposing an improved ant colony algorithm by studying the shortcomings of the traditional ant colony algorithm due to the use of random selection strategies, slow evolution speed, large ant colony size, and long search process time.

[0126] Ant Colony Optimization (ACO) is a group intelligence optimization algorithm based on simulating the foraging behavior of ants. Its basic idea comes from the process of ant colonies in nature cooperating with each other to find the shortest path through pheromone. The basic principles of the ant colony algorithm include the pheromone mechanism (ants leave pheromones on the path during their walking, and other ants can sense the pheromones and tend to choose the path with higher pheromone concentration. The concentration of pheromones decays over time), heuristic information (when choosing a path, ants not only rely on pheromones, but also consider the heuristic information of the current path, that is, the feasibility or attractiveness of the path), and probabilistic selection mechanism (ants probabilistically choose a path based on the combination of pheromone concentration and heuristic information, thereby achieving path optimization).

[0127] Step 4.1, set the initial pheromone concentration, generate a group of ants, and randomly distribute them on each node. Each ant selects the next node based on the pheromone and heuristic information, and the probability formula for selection is:

[0128]

[0129] Where, ·P ij (t): The probability of an ant moving from node i to node j. τ ij (t): pheromone concentration on the path from node i to node j. η ij (t): Heuristic information from node i to node j, usually the feasibility or attractiveness of the path. α: Parameter of pheromone importance. β: Parameter of heuristic information importance. allowed: The set of next nodes that the ant can choose.

[0130] Step 4.2: After the ant completes the path, it updates the pheromone according to the path quality. The pheromone update formula is:

[0131] τ ij (t+1)=(1-ρ)·τ ij (t)+Δτ ij (t)

[0132] Where, ρ: pheromone volatility coefficient (0 <rho<1).Δτ ij (i): The amount of pheromone left by the ant on the path (i, j) in time t, which is usually related to the length or cost of the path.

[0133] If there are m ants, then:

[0134]

[0135] In the formula, is the amount of pheromone left by the kth ant at time t, usually defined as:

[0136]

[0137] In the formula, Q is a constant, L k is the path length or path cost traversed by ant k.

[0138] Step 4.3, in order to speed up the evolution, the role of heuristic information can be enhanced so that ants can rely more on heuristic information when choosing paths. Heuristic information is usually related to the specific characteristics of the problem, and stronger heuristic information can be designed based on the characteristics of the problem.

[0139] The improved path selection probability formula is:

[0140]

[0141] Among them, H ij is the enhanced heuristic information of path (i, j), and γ is the importance parameter of the enhanced heuristic information.

[0142] In step 4.4, in order to avoid premature convergence and stagnation, a pheromone global optimal update mechanism can be introduced, so that the pheromone update not only depends on the local search results, but also refers to the global optimal path.

[0143] The improved pheromone update formula is:

[0144]

[0145] In the formula, represents the pheromone increment on the global optimal path at time t, which is defined as:

[0146]

[0147] Where, L best is the length of the global optimal path found so far.

[0148] Embodiment 2 of the present invention provides a dispatching system for a power system including a pumped-storage power station, and runs the dispatching method for a power system including a pumped-storage power station described in Embodiment 1 of the present invention, including:

[0149] Benefit analysis module, used to establish a peak-shaving and valley-filling benefit model for pumped-storage power stations;

[0150] Comprehensive strategy module, used to analyze the operating environment of pumped storage power stations and establish comprehensive dispatch strategies for power systems;

[0151] An economic dispatch module, used to establish an economic dispatch model of a hybrid system, wherein the hybrid system includes thermal power units, hydropower units and pumped storage;

[0152] The model solving module is used to solve the economic dispatch model and generate the optimal dispatch plan for the power system including the pumped storage power station.

[0153] Application examples:

[0154] In order to further clearly introduce the technical solution of the present invention and the beneficial technical effects brought about by it, the following application examples are introduced. Specifically, the immune ant colony algorithm applied to the economic dispatch of the power system is programmed based on MATLAB / Simulink, and the simulation system uses a hybrid power generation system consisting of 2 thermal power plants, 1 nuclear power plant, 1 hydropower station, and 1 pumped storage station to supply power to a certain area.

[0155] In order to simplify the algorithm solution, the peak of hydropower unit regulation is not considered, that is, only the flood season is considered. Then the improved ant colony algorithm proposed in this paper is used to optimize the calculation of the computing power system.

[0156] Figure 1 This is a power rate balance diagram, which shows the power changes of different power types within 24 hours a day. The colors in the figure represent different types of power sources. The blue part represents hydropower. The red part represents thermal power. The yellow part represents pumped storage power. The purple part represents pumped storage power. The black hollow circles and lines represent the total load of the system. The following points can be analyzed from the figure: the total load has obvious peak-to-valley changes within 24 hours. The load gradually increases in the morning, reaches a peak at noon, and then begins to decline in the afternoon. There is another small peak in the evening, and the load is lower at night. Hydropower power is relatively stable and does not change much in a day. Thermal power increases during periods of high load and decreases during periods of low load, but the overall change is relatively slow. Pumped storage power (yellow) increases during peak load periods to help meet peak load demand. Pumped storage power (purple) appears during low load periods, indicating that water is pumped to the upper reservoir to store energy when the load is low. Pumped storage power stations play a significant role in balancing the supply and demand of electricity. They optimize the operation of the power system by storing energy during low load periods and releasing energy during peak load periods. This scheduling method not only smoothes the load curve, but also improves the economy and stability of the system.

[0157] Figure 2 The load and unit output curves show the load and output curves of different types of power sources in the power system within 24 hours. The colors and symbols in the figure represent different power sources and load conditions: the blue star mark indicates the total load. The orange circular mark indicates the hydropower power. The yellow diamond mark indicates the thermal power. The purple plus sign indicates the power change of pumped storage, including power generation and pumping. The following points can be seen from the figure: the total load has obvious peak and valley changes in a day, gradually rising in the morning, reaching a peak at noon, and then starting to decline in the afternoon, with a secondary peak in the evening, and the load is lower at night. The output power of hydropower is relatively stable, basically maintaining at a constant level, with almost no change. This shows that hydropower stations usually operate as base load power sources. The output power of thermal power increases during periods of high load and decreases during periods of low load. Thermal power undertakes more power generation tasks during peak load periods, indicating that thermal power is flexibly adjusted to cope with load fluctuations. The power of pumped storage is negative during the low load period, indicating that it is pumping water for energy storage during this period; it is positive during the peak load period, indicating that it is generating power and releasing energy during this period. Pumped storage plays a key role in balancing electricity supply and demand. It optimizes the operation of the power system by pumping water to store energy during low load periods and generating electricity during peak load periods.

[0158] Figure 3This is a comparison curve before and after load optimization. The following points can be analyzed from the figure: the load curve has obvious peak-to-valley changes. The load gradually rises in the morning, reaches a peak at noon, begins to decline in the afternoon, has a secondary peak in the evening, and is lower at night. The load fluctuates greatly during certain periods, especially during peak hours, when the load rises and falls sharply. The optimized load curve is smoother than before optimization, and the peak-to-valley difference is reduced. The peaks during the peak load period are reduced, and the valleys during the low load period are filled, which shows that the load of the power system is more balanced after optimization. Through load optimization, the load of the power system during peak hours is reduced, reducing the pressure of peak load on the power system. During the low load period, the load is increased, indicating that the low-valley power is used for pumped energy storage or other means of load shifting. The overall load curve tends to be smooth, indicating that the operation of the power system is more stable and the large load fluctuations are reduced.

[0159] Compared with the prior art, the beneficial effects of the present invention include at least:

[0160] (1) The present invention establishes a scheduling model based on optimization theory, comprehensively considering factors such as power generation cost, pumping cost, system loss and electricity market price, significantly reducing the overall operating cost and improving the economy and reliability of system operation.

[0161] (2) The present invention improves the ant colony algorithm, adopts heuristic information, and designs a reasonable path selection probability formula, thereby increasing the evolution speed, reducing the size of the ant colony, and reducing the time spent on the search process.

[0162] (3) The present invention can promote the application and development of pumped storage technology, meet the challenges of energy structure transformation, and meet the growth of future electricity demand.

[0163] The present disclosure may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0164] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A dispatching method for a power system including a pumped storage power station, characterized in that: The following steps are involved: Step 1, taking into account the peak load characteristics of the pumped storage power station, a peak load reduction and valley filling benefit model of the pumped storage power station is established; Step 2, based on the peak load shaving and valley filling benefit model of the pumped storage power station in step 1, and analyzing the operating environment of the pumped storage power station, a comprehensive dispatching strategy for the power system is established; Step 3, according to the comprehensive dispatch strategy of the power system, an economic dispatch model of a hybrid system is established, wherein the hybrid system includes thermal power units, hydropower units and pumped storage; Step 4: Use the improved ant colony algorithm to solve the economic dispatch model in step 3 to obtain the optimal dispatch plan for the power system containing the pumped storage power station.

2. The dispatching method of a power system including a pumped storage power station according to claim 1, characterized in that: In step 1, the peak-shaving and valley-filling benefit model of the pumped-storage power station includes: coal-saving benefit, energy storage benefit and economic benefit.

3. The dispatching method of a power system including a pumped storage power station according to claim 1, characterized in that: In step 2, establishing a comprehensive dispatching strategy for the power system also includes: studying the peak-shaving characteristics of different power generation methods, including the peak-shaving characteristics of thermal power units and the peak-shaving characteristics of hydropower units.

4. The dispatching method of a power system including a pumped storage power station according to claim 1, characterized in that: In step 3, with the goal of minimizing the electricity purchase cost, an economic dispatch model of the hybrid system is established, which is expressed as the following formula: Where: T is the total number of system optimization periods; I is the serial number of the system generator set; p i (t) is the active power of unit i in time period t; f i [p i (t)] represents the fee function that the power grid needs to pay when unit i operates in time period t.

5. The dispatching method of a power system including a pumped storage power station according to claim 1, characterized in that: In step 3, the economic dispatch model of the hybrid system needs to meet the power balance constraints, line transmission power constraints, spinning reserve capacity and unit power constraints.

6. The dispatching method for a power system including a pumped storage power station according to claim 5, characterized in that: The line transmission power constraint is expressed as follows: Where: p k,max is the stable transmission limit of the k-th hop line; p j,met (t) is the injected power of the jth node at time t; S j,k The sensitivity of the injected power at the jth node to the power flow of the kth jump line; n is the number of nodes that have an impact on the k-th jump line power flow; The constraint on spinning reserve capacity is expressed as follows, Where: p B,min Spinning spare capacity for the system; p i .max is the upper limit of the unit output; P D (t) is the total load of the system in time period t; u i (t) is the voltage of the i-th node at time t; l is the number of nodes.

7. The dispatching method of a power system including a pumped storage power station according to claim 1, characterized in that: Step 4 includes: Step 4.1, set the initial pheromone concentration, generate a group of ants, and randomly distribute them on each node; each ant selects the next node based on the pheromone and heuristic information; Step 4.2, after the ant completes the path, it updates the pheromone according to the path quality; Step 4.3, improve the role of heuristic information in the ant colony algorithm, so that ants rely more on heuristic information when selecting paths, and obtain the improved path selection probability; Step 4.4, introduce the pheromone global optimal update mechanism, so that the pheromone update depends on both the local search results and the global optimal path, and obtain the improved pheromone update method.

8. The dispatching method for a power system including a pumped storage power station according to claim 7, characterized in that: The improved path selection probability is expressed as follows: Where: H ij is the enhanced heuristic information of path (i, j); γ is the importance parameter for enhancing heuristic information; P ij (t) is the probability of an ant moving from node i to node j; τ ij (t) is the pheromone concentration on the path from node i to node j; η ij (t) is the heuristic information from node i to node j; α is a parameter of pheromone importance; β is a parameter of the importance of heuristic information; Allowed represents the next set of nodes that the ant can choose.

9. The dispatching method of the power system including the pumped storage power station according to claim 7, characterized in that: The improved pheromone update method is expressed by the following formula: Where: τ ij (t) is the pheromone concentration on the path from node i to node j; Δτ ij (t) is the amount of pheromone left by the ant on the path (i, j) in time t; ρ is the pheromone volatility coefficient; represents the pheromone increment on the global optimal path at time t, which is defined as: Where: Q is a constant; L best is the length of the global optimal path found so far.

10. A dispatching system for a power system including a pumped storage power station, running the dispatching method for a power system including a pumped storage power station according to any one of claims 1 to 9, characterized in that: include: Benefit analysis module, used to establish a peak-shaving and valley-filling benefit model for pumped-storage power stations; Comprehensive strategy module, used to analyze the operating environment of pumped storage power stations and establish comprehensive dispatch strategies for power systems; An economic dispatch module, used to establish an economic dispatch model of a hybrid system, wherein the hybrid system includes thermal power units, hydropower units and pumped storage; The model solving module is used to solve the economic dispatch model and generate the optimal dispatch plan for the power system including the pumped storage power station.

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