Power system source network load storage flexibility resource adjustment capability assessment method and device

Abstract

The invention provides a power system source network load storage flexibility resource adjustment capability evaluation method and device, and the method comprises the following steps: constructing a flexibility resource adjustment model, according to the total load of the system, the variable coefficient, the new energy output, the nuclear power base load and the flexible resource adjustment model, a residual load interval, a maximum climbing demand, an adjustment power interval and maximum climbing power are obtained through calculation; comparing the residual load interval with the regulation power interval to evaluate the power regulation capability of the source network load storage of the power system; and comparing the maximum climbing demand with the maximum climbing power to evaluate the climbing ability of the power system source network load storage. The power system source network load storage flexibility resource adjustment capability assessment method and device are used for assessing the power adjustment capability and the gradeability of the power system, the operation risk of the power system can be identified, the assessment result is specific and quantitative, an optimization direction is provided for flexible resource configuration, and the applicability is high.

Description

Technical Field

[0001] The present invention relates to the technical field of power system source-grid-load-storage dispatching, and in particular to a method and device for evaluating the regulation capability of power system source-grid-load-storage flexibility resources. Background Art

[0002] The key to addressing global climate change and achieving sustainable development lies in the green and low-carbon transformation of energy. Countries around the world have successively established carbon neutrality goals that are in line with their national conditions. Building a new power system is an important measure for China to achieve clean energy utilization. In the new power system, the penetration rate of renewable energy such as wind power and photovoltaics continues to increase, increasing the risk of safe and stable operation, and more flexibility adjustment needs have emerged. The structural contradiction of power supply and insufficient system peak-shaving capacity are the core issues restricting the development of renewable energy. Therefore, it is necessary to fully tap the adjustment potential of various flexible resources of source, grid, load and storage to cope with the randomness, volatility and intermittency of new energy output. Clarifying the adjustment capacity of different flexible resources and evaluating the overall adjustment capacity are of great significance to the safe development of the new power system.

[0003] In traditional power systems, power sources are mainly thermal power units and hydropower units with controllable output, which have strong load tracking and regulation performance. However, with the continuous development of large-scale wind and solar renewable energy generation and distributed power sources, the proportion of power sources with insufficient regulation capabilities and strong output uncertainty in the power structure has increased significantly. The safety and stability needs of new power systems that cannot be met by simply relying on the flexibility transformation of thermal power are beginning to emerge. Flexibility resources with a wider range of types and stronger regulation performance are needed to ensure the real-time dynamic supply and demand balance and safety and stability of the power system. Improving flexibility is a key way for new power systems to cope with volatility and uncertainty, and has received widespread attention from scholars at home and abroad.

[0004] The flexibility of the power system is provided by various regulating resources, which are distributed in various links of the power supply side, the grid side, the load side, and the energy storage side. The flexibility resources on the power supply side mainly include the flexibility transformation of coal-fired power and hydropower with regulating performance; the sources of flexibility resources on the grid side include interconnection, flexible transmission, microgrids, etc.; the flexibility resources on the load side mainly include adjustable loads, electric vehicle and vehicle-grid coordination, etc.; the flexibility resources on the energy storage side are represented by new energy storage and pumped storage. However, the current development of flexibility resources lags behind the random and volatile power sources such as wind power and photovoltaic power generation, and it is difficult to meet the requirements of the development of a high proportion of new energy power systems. The utilization rate of new energy has declined to varying degrees in various places. In the future, as the penetration rate of new energy increases, the pressure on system regulation and operation will continue to increase.

[0005] There are obvious differences in the technical characteristics of various resources providing flexibility, and the economic costs are also different. Although the deep peak regulation and fast start-stop technology of traditional thermal power units has strong regulation capabilities, it is often accompanied by high operating costs and emissions. Improved flexibility on the grid side, such as smart grid technology, can significantly improve the intelligence and automation level of the grid, but the initial investment is large and the long-term benefits are significant. The flexibility resources on the load side have the characteristics of fast response speed and flexible regulation, and can incentivize user participation through market mechanisms, but their economic costs are greatly affected by user willingness and behavior patterns. As an important supplement to flexibility, the energy storage side has various technical types and significant cost differences. Different energy storage methods have their own advantages and disadvantages in terms of capacity, efficiency, life and environmental impact. Existing research mainly considers the regulatory role of different flexibility resources on the energy system, but it is impossible to characterize the rich regulation capacity.

[0006] In the process of improving the flexibility of the power system, it is necessary to comprehensively consider the technical characteristics and economic costs of various resources and formulate scientific and reasonable planning and scheduling strategies. Fully consider the feasibility and necessity, avoid excessive disorderly development, and follow the principles of complementary advantages, moderate advance, and overall coordination to improve the flexibility of the system in an all-round, efficient, and most economical way, and transition from "source follows load" to "source, grid, load, and storage" coordinated development. The basic premise for achieving this goal is to accurately and scientifically evaluate the flexibility resource regulation capacity of the existing power system. Sources, grids, loads, and storage have different flexibility characteristics, and the overall regulation capacity is not a simple linear addition and subtraction. A set of scientific evaluation methods and equipment need to be designed.

[0007] In summary, existing research has recognized the importance of flexibility to new power systems and analyzed the technical characteristics, economic level, and regulatory role of different flexible resources. The combination of multiple flexible resources can achieve complementary advantages, maximize system flexibility, and enhance renewable energy carrying capacity. There are many types and quantities of flexible resources, and existing technologies have not studied the evaluation method of the regulation capacity of source-grid-load-storage flexible resources. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a method and device for evaluating the power regulation capability and climbing capability of an electric power system, which can identify the operating risks of the electric power system, make the evaluation results specific and quantified, provide optimization direction for the allocation of flexible resources, and has strong applicability.

[0009] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: A method for evaluating the regulation capability of power system source-grid-load-storage flexibility resources, comprising the following steps:

[0010] Obtain the operating parameters, variable coefficient, total system load, new energy output and nuclear power base load of the power system source, grid, load and storage;

[0011] Constructing a flexibility resource regulation model according to the operating parameters, wherein the flexibility resource regulation model includes an energy production regulation model, an energy transmission network regulation model, an energy consumption regulation model and an energy storage regulation model;

[0012] The energy production regulation model includes an output power lower limit, an output power upper limit and a nominal ramp upper limit;

[0013] The energy transmission network regulation model includes a transmission line power cap;

[0014] The energy consumption regulation model includes a maximum transfer amount of transferable load and a maximum reduction amount of interruptible load;

[0015] The energy storage regulation model includes a charging power upper limit and a discharging power upper limit;

[0016] Obtaining a residual load lower limit and a residual load upper limit according to the total system load, the variable coefficient, the new energy output, the nuclear power base load and the transmission line power upper limit;

[0017] Obtaining a remaining load interval and a maximum climbing requirement according to the remaining load lower limit and the remaining load upper limit;

[0018] The upper limit of the regulated power is obtained according to the variable coefficient, the upper limit of the output power, the maximum transfer amount of the transferable load, the maximum reduction amount of the interruptible load and the upper limit of the discharge power; the lower limit of the regulated power is obtained according to the variable coefficient, the lower limit of the output power, the maximum transfer amount of the transferable load and the upper limit of the charging power;

[0019] Obtaining an adjustment power range according to the adjustment power upper limit and the adjustment power lower limit;

[0020] Obtaining a maximum climbing power according to the variable coefficient, the output power upper limit, the nominal climbing upper limit and the discharge power upper limit;

[0021] Comparing the remaining load interval with the regulated power interval to evaluate the power regulation capability of the power system source, grid, load and storage;

[0022] The maximum climbing demand and the maximum climbing power are compared to evaluate the climbing capability of the power system source, grid, load and storage.

[0023] Furthermore, evaluating the power regulation capability of the power system source, grid, load and storage includes:

[0024] When the remaining load interval is within the adjustment power interval, the power of the power system source, grid, load and storage can be adjusted;

[0025] When the remaining load lower limit is lower than the adjustment power lower limit, the power downward adjustment space of the power system source, grid, load and storage is scarce;

[0026] When the upper limit of the remaining load is higher than the upper limit of the regulated power, the power upward regulation space of the power system source, grid, load and storage is in short supply.

[0027] Furthermore, the upper limit of the regulated power is 10% higher than the upper limit of the residual load, and the lower limit of the regulated power is 5% lower than the lower limit of the residual load.

[0028] Furthermore, when the maximum climbing power is not lower than the maximum climbing demand, the power system source, grid, load and storage have climbing flexibility.

[0029] Furthermore, the maximum climbing power is more than twice the maximum climbing requirement.

[0030] Further, the operating parameters include operating status, rated capacity, minimum output percentage, maximum output percentage, landslide limit percentage, climbing limit percentage, minimum continuous operation time, minimum continuous shutdown time and typical daily distributed power;

[0031] The energy production regulation model includes a first coal-electricity regulation model, a second coal-electricity regulation model, a gas-electricity regulation model and a hydroelectricity regulation model;

[0032] The first coal-fired power regulation model, the second coal-fired power regulation model and the gas-fired power regulation model all include output power constraints, ramp constraints and operating state constraints;

[0033] The hydropower regulation model includes output power constraints and total output power constraints;

[0034] Obtaining the output power lower limit according to the operating state, the rated capacity and the minimum output percentage;

[0035] Obtaining the output power upper limit according to the operating state, the rated capacity and the maximum output percentage;

[0036] Obtaining a nominal landslide upper limit according to the landslide limit percentage and the rated capacity;

[0037] Obtaining the nominal climbing upper limit according to the climbing limit percentage and the rated capacity;

[0038] The output power constraint is obtained according to the output power lower limit and the output power upper limit; the total output power constraint is obtained according to the output power constraint and the typical daily allocated power;

[0039] Obtaining the climbing constraint according to the nominal landslide upper limit and the nominal climbing upper limit;

[0040] The operation state constraint is obtained according to the operation state, the minimum continuous operation time and the minimum continuous shutdown time.

[0041] Further, the energy transmission network regulation model includes transmission line power constraints;

[0042] Obtaining a lower limit of power of the transmission line according to the rated capacity and the minimum output percentage;

[0043] Obtaining the power upper limit of the transmission line according to the rated capacity and the maximum output percentage;

[0044] The transmission line power constraint is obtained according to the transmission line power lower limit and the transmission line power upper limit.

[0045] Furthermore, the operating parameters also include a maximum transfer ratio of transferable loads and a maximum reduction ratio of interruptible loads;

[0046] The energy consumption regulation model includes a transferable flexible load model and an interruptible flexible load model;

[0047] The transferable flexible load model includes a total transferable load constraint and a transferable load transfer amount constraint; the interruptible flexible load model includes an interruptible load reduction amount constraint; the transferable load transfer amount constraint includes a transferable load transfer-in amount constraint and a transferable load transfer-out amount constraint;

[0048] According to the maximum transfer ratio of the transferable load and the total load of the system, a maximum transfer-in amount of the transferable load and a maximum transfer-out amount of the transferable load are obtained;

[0049] Obtaining the transferable load transfer amount constraint according to the maximum transferable load transfer amount;

[0050] Obtaining the transferable load transfer-out amount constraint according to the maximum transferable load transfer-out amount;

[0051] Obtaining the total amount constraint of the transferable load according to the transferable load transfer-in amount constraint and the transferable load transfer-out amount constraint;

[0052] Obtaining a maximum interruptible load reduction amount according to the maximum interruptible load reduction ratio and the system total load;

[0053] The interruptible load reduction amount constraint is obtained according to the interruptible load maximum reduction amount.

[0054] Furthermore, the operating parameters also include charge and discharge efficiency, minimum charge limit, maximum charge limit, minimum discharge limit, maximum discharge limit, minimum capacity limit, maximum capacity limit, charge state and discharge state;

[0055] The energy storage regulation model includes an energy storage capacity model, a charging power constraint, a discharging power constraint, a charging and discharging state constraint, and a storage capacity balance constraint;

[0056] Obtaining a charging power lower limit according to the charging state and the minimum charging limit;

[0057] Obtaining a charging power upper limit according to the charging state and the maximum charging limit;

[0058] Obtaining a lower limit of discharge power according to the discharge state and the minimum discharge limit;

[0059] Obtaining a discharge power upper limit according to the discharge state and the maximum discharge limit;

[0060] Obtaining the charging power constraint according to the charging power lower limit and the charging power upper limit;

[0061] Obtaining the discharge power constraint according to the discharge power lower limit and the discharge power upper limit;

[0062] Obtaining the charge and discharge state constraint according to the charge state and the discharge state;

[0063] Obtaining the power storage balance constraint according to the minimum capacity limit and the maximum capacity limit;

[0064] The energy storage capacity model is obtained according to the charging and discharging efficiency, the charging power constraint, the discharging power constraint and the storage capacity balance constraint.

[0065] A device for implementing the power system source-grid-load-storage flexibility resource regulation capability evaluation method, comprising a modeling unit, a calculation unit and an evaluation unit;

[0066] The modeling unit:

[0067] Used to obtain the operating parameters of the power system source, grid, load and storage, the variable coefficient, the total system load, the new energy output and the nuclear power base load;

[0068] Used to construct the flexibility resource adjustment model according to the operating parameters;

[0069] The computing unit:

[0070] Used to obtain a lower limit and an upper limit of the residual load according to the total system load, the variable coefficient, the new energy output, the nuclear power base load and the upper limit of the transmission line power;

[0071] Used to obtain a residual load range and a maximum climbing requirement according to the residual load lower limit and the residual load upper limit;

[0072] Used to obtain an upper limit of the regulated power according to the variable coefficient, the upper limit of the output power, the maximum transfer amount of the transferable load, the maximum reduction amount of the interruptible load and the upper limit of the discharge power; used to obtain a lower limit of the regulated power according to the variable coefficient, the lower limit of the output power, the maximum transfer amount of the transferable load and the upper limit of the charging power;

[0073] Used to obtain an adjustment power range according to the adjustment power upper limit and the adjustment power lower limit;

[0074] Used to obtain the maximum climbing power according to the variable coefficient, the output power upper limit, the nominal climbing upper limit and the discharge power upper limit;

[0075] The evaluation unit:

[0076] Used to compare the remaining load interval and the regulated power interval to evaluate the power regulation capability of the power system source, grid, load and storage;

[0077] Used to compare the maximum climbing demand and the maximum climbing power to evaluate the climbing capability of the power system source, grid, load and storage.

[0078] Compared with the prior art, the present invention has the following beneficial effects:

[0079] 1. The present invention establishes various types of flexibility resource regulation models, starting from the significant differences in regulation capabilities of different flexibility resources, and taking into account the operating characteristics of the power system and the regulation characteristics of various types of flexibility resources, in order to give full play to the advantages of source-grid-load-storage complementarity, proposes a flexibility resource regulation capability evaluation method that can evaluate the power regulation capability and ramping capability of the power system respectively, which can meet the evaluation needs of different types and quantities of flexibility resources;

[0080] 2. The present invention evaluates the power regulation capability of the power system source, grid, load and storage by comparing the remaining load interval and the regulation power interval, and evaluates the climbing capability of the power system source, grid, load and storage by comparing the maximum climbing demand and the maximum climbing power. The evaluation results are concretized and quantified, providing optimization direction for flexible resource allocation, ensuring safe, stable and reliable power supply while achieving clean and efficient energy utilization.

[0081] 3. The method for evaluating the regulation capability of the power system source, grid, load and storage flexibility resources proposed in the present invention can determine the power adjustable range and climbing capability of the flexibility resources, and identify the operating risks of the power system; it provides a new theoretical framework for the rational evaluation of the system regulation performance, and has important reference value for the construction of new power systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] Figure 1It is a flow chart of the method for evaluating the adjustment capability of the power system source-grid-load-storage flexibility resources of the present invention;

[0083] Figure 2 It is a schematic diagram of the principle of the method for evaluating the adjustment capability of the power system source-grid-load-storage flexibility resources of the present invention;

[0084] Figure 3 The installed capacity and annual utilization hours of various resources in the calculation example of the present invention;

[0085] Figure 4 is the typical daily load and the power of wind power and photovoltaic power in the calculation example of the present invention;

[0086] Figure 5 It is a schematic diagram of the residual load in the calculation example of the present invention;

[0087] Figure 6 The adjustment capability of various types of flexibility resources in the calculation example of the present invention;

[0088] Figure 7 is the adjustment power interval and the residual load interval in the calculation example of the present invention;

[0089] Figure 8 It is the adjustment power range of the flexibility resources of different schemes in the calculation example of the present invention. DETAILED DESCRIPTION

[0090] It is worth noting that the methods used in the present invention are all conventional methods unless otherwise specified; the raw materials and devices used are all conventional commercially available products, and their sources are not specifically limited unless otherwise specified.

[0091] The new power system has an increasing demand for flexible resources to cope with the volatility and uncertainty of renewable energy. The embodiment of the present invention provides a method for evaluating the regulation capability of power system source-grid-load-storage flexibility resources, including the following steps:

[0092] Obtain the operating parameters, variable coefficient, total system load, new energy output and nuclear power base load of the power system source, grid, load and storage;

[0093] Constructing a flexibility resource regulation model according to the operation parameters, the flexibility resource regulation model includes an energy production regulation model, an energy transmission network regulation model, an energy consumption regulation model and an energy storage regulation model;

[0094] The energy production regulation model includes the output power lower limit, output power upper limit and nominal ramp upper limit;

[0095] The energy transmission network regulation model includes transmission line power capping;

[0096] The energy consumption regulation model includes the maximum transfer amount of transferable load and the maximum reduction amount of interruptible load;

[0097] The energy storage regulation model includes a charging power cap and a discharging power cap;

[0098] The lower limit and upper limit of residual load are obtained according to the total system load, variable coefficient, new energy output, nuclear power base load and transmission line power limit;

[0099] Obtain the remaining load range and the maximum climbing requirement according to the remaining load lower limit and the remaining load upper limit;

[0100] Due to the uncertainty of new energy (such as wind power, photovoltaic power, etc.), the net load curve of new energy will also fluctuate. Nuclear power as base load hardly participates in intraday regulation. Energy transmission network (such as transmission line) is usually determined by the receiving end according to demand, and the regulation capacity is limited. Therefore, the total system load is deducted from the output of new energy, and then further deducted from the nuclear power base load and transmission line load to get the residual load, which is filled by other resources in the power system source, grid, load and storage; the residual load is:

[0101]

[0102] In the formula, is the residual load at time t, is the total system load at time t, P WT,t is the wind power output at time t, P PV,t is the photovoltaic output at time t, P NP,t is the nuclear power base load at time t, is the total power of the transmission line at time t, l is the transmission line number, and L is the total number of transmission lines;

[0103] In order to ensure the safe operation of the system, it is necessary to use the residual load lower limit and the upper limit of residual load Determined range Characterizing the residual load means obtaining the residual load interval, considering the variable coefficient. At this time, the variable coefficient is the fluctuation deviation of the output of new energy. The fluctuation deviation of the output of new energy includes the fluctuation deviation of wind power output and the fluctuation deviation of photovoltaic output. Then:

[0104]

[0105]

[0106] In the formula, is the lower limit of the residual load at time t, is the upper limit of the residual load at time t, δ WT is the fluctuation deviation of wind power output, δ PV is the fluctuation deviation of photovoltaic output;

[0107] In addition, the overall power of the flexible resource needs to track the fluctuation of the remaining load to meet the hourly ramp power demand and hourly landslide power demand. Since the ramping and landslide processes are similar, only the ramping capacity needs to be analyzed. The maximum ramping demand is:

[0108]

[0109] In the formula, ΔL flex is the maximum climbing requirement, max is the maximum value function, is the lower limit of the residual load at time (t-1).

[0110] The upper limit of the regulated power is obtained according to the variable coefficient, the upper limit of the output power, the maximum transfer amount of the transferable load, the maximum reduction amount of the interruptible load and the upper limit of the discharge power; the lower limit of the regulated power is obtained according to the variable coefficient, the lower limit of the output power, the maximum transfer amount of the transferable load and the upper limit of the charging power;

[0111] Taking into account the operating characteristics of various types of flexible resources, the upper limit of the regulation power is determined by the maximum output power of the energy production part, i.e. the upper limit of the output power (the maximum power of coal-fired power units, the maximum power of flexible coal-fired power units, the maximum power of gas-fired power units, and the maximum power of hydropower units), the maximum power of the energy consumption part, i.e. the maximum transfer amount of transferable loads and the maximum reduction amount of interruptible loads, and the maximum discharge power of the energy storage part, i.e. the maximum discharge power of energy storage. However, it is also necessary to consider the actual operation of the power system. Not every flexible resource can exert its regulation capacity in every period of time. For example, when coal-fired power units are undergoing planned maintenance and shutdown, they cannot provide regulation services; when they are in the heating season, the regulation capacity of coal-fired power units decreases; after flexibility transformation, the regulation capacity of coal-fired power units is improved, but the above situation also exists; gas-fired power units are similar to coal-fired power units; the regulation of hydropower units is limited by the water allocation plan; the transfer amount of transferable loads and interruptible loads cannot last for too long;

[0112] When applying, it is necessary to consider adjusting the variable coefficient of the credibility coefficient. Adjusting the credibility coefficient includes adjusting the credibility coefficient upward and adjusting the credibility coefficient downward. Then:

[0113]

[0114]

[0115] In the formula, To adjust the power limit, Adjust the credibility factor upward for coal-fired power units. is the upper limit of the output power of the i-th coal-fired power unit, i is the serial number of the coal-fired power unit, I is the total number of coal-fired power units, is the output power upper limit of the jth flexible coal-fired power unit, j is the serial number of the flexible coal-fired power unit, J is the total number of flexible coal-fired power units, Adjust the credibility factor upward for the gas-generator unit. is the upper limit of the output power of the mth gas-generator unit, m is the sequence number of the gas-generator unit, M is the total number of gas-generator units, Adjust the credibility factor upward for the hydropower unit. is the upper limit of the output power of the kth hydropower unit, k is the sequence number of the gas-generating unit, K is the total number of gas-generating units, Adjust the credibility factor upward for transferable loads, is the maximum transfer amount of the transferable load, Adjust the reliability factor upward for interruptible loads, is the maximum interruptible load reduction, Adjust the reliability factor upward for the energy storage unit. is the upper limit of discharge power, P t flex To adjust the power lower limit, ρ CP Adjust the credibility factor downward for coal-fired power units. is the lower limit of the output power of the i-th coal-fired power unit, is the lower limit of the output power of the jth flexible coal-fired power unit, ρ GP Adjust the credibility factor downward for the gas-generator unit. is the lower limit of the output power of the mth gas-generator unit, ρ HP Adjust the credibility factor downward for the hydropower unit. is the lower limit of the output power of the kth hydropower unit, ρ TFL Adjust the credibility factor downward for transferable load, ρ ES Adjust the reliability factor downward for the energy storage unit. The upper limit of charging power.

[0116] The adjustment power range is obtained according to the adjustment power upper limit and the adjustment power lower limit, that is, the adjustment power range is

[0117] The maximum climbing power is obtained according to the variable coefficient, the output power upper limit, the nominal climbing upper limit and the discharge power upper limit; since gas-fired power units, hydropower units and energy storage units can reach the rated power in a very short time, the climbing power of gas-fired power units, hydropower units and energy storage units can all be considered as the rated installed capacity, that is, the output power upper limit (gas-fired power units and power units) or the discharge power upper limit (energy storage units). After comprehensively considering these factors, the maximum climbing power is determined by the nominal climbing upper limit of the coal-fired power unit, the nominal climbing upper limit of the flexible modified coal-fired power unit, the output power upper limit of the gas-fired power unit, the output power upper limit of the hydropower unit, and the discharge power upper limit of the energy storage unit. However, the climbing of flexible resources is subject to certain restrictions, such as: when in the maximum power state, the flexible resources cannot provide climbing; when the energy storage unit has no storage capacity, it cannot provide climbing. The variable coefficient of the climbing credibility coefficient is introduced to correct the actual climbing capacity of various types of flexible resources, which is used to eliminate the situations where the unit is under maintenance, full power, full power, etc. The overall climbing power of the flexible resources, that is, the maximum climbing power, is:

[0118]

[0119] Where ΔP flex is the maximum climbing power, σ CP is the climbing reliability coefficient of the coal-fired power unit, is the nominal ramp limit of the i-th coal-fired power unit, is the nominal ramp limit of the jth flexible coal-fired power unit, σ GP is the climbing reliability coefficient of the gas-fired generator set, σ HP is the climbing reliability coefficient of the hydropower unit, σ ES is the climbing reliability coefficient of the energy storage unit;

[0120] Compare the remaining load range and the regulated power range to evaluate the power regulation capability of the power system source, grid, load and storage;

[0121] Compare the maximum climbing demand and the maximum climbing power to evaluate the climbing capability of the power system source, grid, load and storage.

[0122] The evaluation of the coordinated regulation capability of flexible resources including source, grid, load and storage needs to include multiple dimensions: regulation direction, regulation rate and regulation depth, which can be reflected by the regulation power range and maximum climbing power after the combination of flexible resources. The regulation power range and maximum climbing power can be obtained by separately modeling the regulation models of flexible resources, and the residual load range and maximum climbing demand can be obtained by combining the total system load, variable coefficient, new energy output and nuclear power base load. The power regulation capability of the source, grid, load and storage of the power system can be evaluated by comparing the regulation power range and the residual load range, and the climbing capability of the source, grid, load and storage of the power system can be evaluated by comparing the maximum climbing demand and the maximum climbing power.

[0123] Evaluating the power regulation capability of the power system source, grid, load and storage includes: comparing the remaining load range The power adjustment range is

[0124] When the remaining load interval is within the adjustment power interval, that is, the adjustment power interval at least envelops the remaining load interval, the power of the power system source, grid, load and storage can be adjusted; when When the supply is less than the demand, it will lead to the problem of power supply security; when When supply exceeds demand, it leads to problems in absorbing renewable energy.

[0125] Preferably, the power cap is adjusted Above the upper limit of residual load It can be considered that the power system source, grid, load and storage have strong safety and reliability. Such regulation capability can effectively cope with load fluctuations, ensure the stability of power supply, and adjust the power lower limit to be 5% lower than the remaining load lower limit. At this time, the power system source, grid, load and storage have sufficient new energy absorption capacity.

[0126] When the lower limit of the remaining load is lower than the lower limit of the regulated power, the power downward regulation space of the power system source, grid, load and storage is limited;

[0127] When the upper limit of the remaining load is higher than the upper limit of the regulated power, there is limited room for upward regulation of power in the power system's source, grid, load and storage.

[0128] Compare the maximum climbing requirement ΔL flex and maximum climbing power ΔP flex When the maximum climbing power is not less than the maximum climbing demand, the power system source, grid, load and storage have climbing flexibility.

[0129] Preferably, the maximum ramp power is more than twice the maximum ramp demand, with sufficient ramp flexibility to cope with the fluctuations in the power system's source, grid, load, and storage loads and renewable energy. It should be noted that when the installed capacity of wind turbines and photovoltaic units increases, more ramp demands will be created, and the flexibility of coal-fired power units can be modified to increase the ramp capacity of the power system's source, grid, load, and storage.

[0130] When constructing the energy production regulation model, the operating parameters include operating status, rated capacity, minimum output percentage, maximum output percentage, landslide limit percentage, climbing limit percentage, minimum continuous operation time, minimum continuous shutdown time and typical daily allocated power;

[0131] The energy production regulation model includes the first coal-fired power regulation model, the second coal-fired power regulation model, the gas-fired power regulation model and the hydropower regulation model; the first coal-fired power regulation model is for coal-fired power units, the second coal-fired power regulation model is for flexible transformation coal-fired power units, the gas-fired power regulation model is for gas-fired power units, and the hydropower regulation model is for hydropower units;

[0132] The first coal-fired power regulation model, the second coal-fired power regulation model and the gas-fired power regulation model all include output power constraints, ramp constraints and operating state constraints;

[0133] The hydropower regulation model includes output power constraints and total output power constraints;

[0134] Obtain the lower limit of output power according to the operating status, rated capacity and minimum output percentage;

[0135] Obtain output power cap based on operating status, rated capacity and maximum output percentage;

[0136] Obtain the nominal landslide limit based on the landslide limit percentage and rated capacity;

[0137] Obtain the nominal climbing upper limit according to the climbing limit percentage and the rated capacity;

[0138] The output power constraint is obtained according to the output power lower limit and the output power upper limit; the total output power constraint is obtained according to the output power constraint and the typical daily allocated power;

[0139] Obtain climbing constraints according to the nominal landslide upper limit and the nominal climbing upper limit;

[0140] Get the operating state constraints based on the operating state, minimum continuous operating time, and minimum continuous shutdown time.

[0141] Coal-fired power units have large unit capacity and stable operation, but the minimum output of coal-fired power units that have not undergone flexibility transformation remains high, the ramp rate is slow, and the start and stop time is long. The first coal-fired power regulation model is:

[0142]

[0143] In the formula, u i,t is the operating status of the i-th coal-fired power unit at time t, with a value of 0 or 1, 0 for shutdown and 1 for operation. is the minimum output percentage of the i-th coal-fired power unit, is the maximum output percentage of the i-th coal-fired power unit, and Indicates the adjustable range of coal-fired power units, for is the lower limit of the output power of the i-th coal-fired power unit, for is the upper limit of the output power of the i-th coal-fired power unit, C CP,i is the rated installed capacity of the i-th coal-fired power unit, indicating the maximum adjustable output of the power system source, grid, load and storage. is the landslide limit percentage of the i-th coal-fired power unit, is the ramp limit percentage of the i-th coal-fired power unit, (PCP,i,t -P CP,i,t-1 ) is the nominal ramp power of the i-th coal-fired power unit at time t, for That is, the nominal ramp limit of the i-th coal-fired power unit, t is time, τ is any time, is the minimum continuous operation time of the i-th coal-fired power unit, is the minimum continuous shutdown time of the i-th coal-fired power unit;

[0144] The flexible transformation of coal-fired power units has great economic advantages and will be the main supplier of flexibility. The minimum output of the flexible transformation coal-fired power units is reduced, the ramp rate is increased, and the start-up time is shortened. The regulation model of the flexible transformation coal-fired power units, that is, the second coal-fired power regulation model, is:

[0145]

[0146]

[0147] In the formula, is the operating status of the jth flexible coal-fired power unit at time t, with a value of 0 or 1, 0 for shutdown and 1 for operation. is the minimum output percentage of the jth flexible coal-fired power unit, is the maximum output percentage of the jth flexible coal-fired power unit, and Indicates the adjustable range of flexible transformation of coal-fired power units, for That is, the lower limit of the output power of the jth flexible coal-fired power unit, for That is, the upper limit of the output power of the jth flexible coal-fired power unit, is the rated installed capacity of the jth flexible coal-fired power unit, which represents the maximum adjustable output of the power system source, grid, load and storage. is the landslide limit percentage of the jth flexible modified coal-fired power unit, is the ramp limit percentage of the jth flexible coal-fired power unit, is the nominal ramp power of the jth flexible coal-fired power unit at time t, for This is the nominal ramp limit of the jth flexible coal-fired power unit, is the minimum continuous operation time of the jth flexible coal-fired power unit, The minimum shutdown duration of the jth flexible coal-fired power unit;

[0148] Gas-fired power units have a larger adjustment range, faster adjustment rate, and shorter start-up and shutdown time than coal-fired power units. The flexibility adjustment model of gas-fired power units, i.e., the gas-fired power adjustment model, is similar to that of coal-fired power units. The gas-fired power adjustment model is:

[0149]

[0150] In the formula, u m,t is the operating status of the mth gas-generator unit at time t, with a value of 0 or 1, 0 for shutdown and 1 for operation. is the minimum output percentage of the mth gas generator set, is the maximum output percentage of the mth gas generator set, and Indicates the adjustable range of the gas-electric unit. for That is the lower limit of the output power of the mth gas-generator unit, for That is, the upper limit of the output power of the mth gas-generator unit, C GP,m is the rated installed capacity of the mth gas-fired generator set, indicating the maximum adjustable output of the power system source, grid, load and storage. is the landslide limit percentage of the mth gas-fired generator unit, is the climbing limit percentage of the mth gas generator set, (P GP,m,t -P GP,m,t-1 ) is the nominal climbing power of the mth gas generator set at time t, for This is the nominal climbing limit of the mth gas generator set. is the minimum continuous operation time of the mth gas-generator unit, is the minimum continuous shutdown time of the mth gas-generator unit;

[0151] Hydropower units have strong regulation capabilities, and the ramp and start-stop rates are very fast. The power generation capacity of hydropower units is related to the amount of water coming in, and there are seasonal differences. It is necessary to arrange the water allocation of adjustable hydropower from a long-term scale throughout the year. The flexibility regulation model of hydropower units, that is, the hydropower regulation model, is:

[0152]

[0153] In the formula, is the minimum output percentage of the kth hydropower unit, C HP,k is the rated installed capacity of the kth hydropower unit, P HP,k,t is the output power of the kth hydropower unit at time t, is the maximum output percentage of the kth hydropower unit, T is the total operating time, for That is the lower limit of the output power of the kth hydropower unit, for That is, the upper limit of the output power of the kth hydropower unit, E HP,k is the typical daily allocated power of the k-th hydropower unit, indicating the typical daily power allocated to the k-th hydropower unit by the dispatcher according to the annual power generation plan;

[0154] Nuclear power units usually operate at full power as base load, and occupying power generation space will increase the system peak load pressure and lead to wind and solar power abandonment problems. Due to its slow regulation rate, flexibility regulation modeling is not performed.

[0155] When constructing the energy consumption regulation model, the operating parameters also include rated capacity, minimum output percentage and maximum output percentage, and the energy transmission network regulation model includes transmission line power constraints;

[0156] Obtain the lower power limit of the transmission line according to the rated capacity and the minimum output percentage;

[0157] Obtain the power cap of the transmission line based on the rated capacity and the percentage of maximum output;

[0158] The power constraint of the transmission line is obtained according to the lower power limit of the transmission line and the upper power limit of the transmission line.

[0159] The power of the transmission line is mainly determined by the receiving end. When the local power generation at the receiving end cannot meet its load, the sending end realizes the cross-regional optimal allocation of electric energy through the energy transmission network (in this embodiment, through the transmission line). The transmission line can improve the security capacity of the receiving end area and increase the space for renewable energy consumption in the sending end area. The energy transmission network regulation model is:

[0160]

[0161] In the formula, is the minimum output percentage of the lth transmission line, C TL,l is the rated capacity of the lth transmission line, P TL,l,t is the power of the lth transmission line at time t, is the maximum output percentage of the lth transmission line, is the upper limit of the power of the lth transmission line.

[0162] When constructing the energy consumption regulation model, the operating parameters also include the maximum transfer ratio of the transferable load and the maximum reduction ratio of the interruptible load;

[0163] The energy consumption regulation model includes the transferable flexible load model and the interruptible flexible load model;

[0164] The transferable flexible load model includes the total transferable load constraint and the transferable load transfer amount constraint; the interruptible flexible load model includes the interruptible load reduction amount constraint; the transferable load transfer amount constraint includes the transferable load transfer-in amount constraint and the transferable load transfer-out amount constraint;

[0165] According to the maximum transfer ratio of the transferable load and the total load of the system, the maximum transfer-in amount of the transferable load and the maximum transfer-out amount of the transferable load are obtained;

[0166] Obtaining the transfer amount constraint of the transferable load according to the maximum transfer amount of the transferable load;

[0167] Obtaining the transfer-out amount constraint of the transferable load according to the maximum transfer-out amount of the transferable load;

[0168] Obtain the total amount constraint of transferable load according to the transferable load input constraint and the transferable load output constraint;

[0169] The maximum interruptible load reduction amount is obtained according to the maximum interruptible load reduction ratio and the total system load;

[0170] The interruptible load reduction amount constraint is obtained according to the interruptible load maximum reduction amount.

[0171] Flexible loads participating in demand response can be divided into transferable flexible loads (TFL) and interruptible flexible loads (IFL). Transferable loads can change the time of electricity consumption, such as charging electric vehicles. Interruptible loads can reduce electricity consumption during peak load periods, such as industrial manufacturers. The regulation characteristics of flexible loads are incentive guidance and fast response. The energy consumption regulation model constructed for flexible loads is:

[0172]

[0173] In the formula, is the transferable load at time t, is the transferable load at time t, is the maximum transfer ratio of the transferable load, is the total system load at time t, L IFL,t is the reduction amount of interruptible load at time t, is the maximum reduction ratio of interruptible load, for is the maximum transfer amount of the transferable load, for That is the maximum reduction in interruptible load;

[0174] When constructing the energy storage regulation model, the operating parameters also include charge and discharge efficiency, minimum charge limit, maximum charge limit, minimum discharge limit, maximum discharge limit, minimum capacity limit, maximum capacity limit, charge state, and discharge state;

[0175] The energy storage regulation model includes energy storage capacity model, charging power constraint, discharging power constraint, charging and discharging state constraint and storage capacity balance constraint;

[0176] Obtaining a lower limit of charging power according to the charging state and the minimum charging limit;

[0177] Obtain the upper limit of charging power according to the charging state and the maximum charging limit;

[0178] Obtaining a lower limit of discharge power according to a discharge state and a minimum discharge limit;

[0179] Obtaining a discharge power upper limit according to a discharge state and a maximum discharge limit;

[0180] Obtaining a charging power constraint according to a charging power lower limit and a charging power upper limit;

[0181] Obtaining a discharge power constraint according to a discharge power lower limit and a discharge power upper limit;

[0182] Obtaining charging and discharging state constraints according to the charging state and the discharging state;

[0183] Obtaining a storage capacity balance constraint according to a minimum capacity limit and a maximum capacity limit;

[0184] The energy storage capacity model is obtained according to the charging and discharging efficiency, charging power constraint, discharging power constraint and storage capacity balance constraint.

[0185] The storage capacity of the energy storage unit is determined by the storage capacity at the previous moment and the charge and discharge capacity at this moment. The energy storage unit needs to meet the charging power constraint, the discharging power constraint, the charge and discharge state constraint, and the storage capacity balance constraint. The energy storage unit includes electrochemical energy storage and pumped storage. The regulation characteristics of electrochemical energy storage are fast regulation, short duration, and small scale, and the regulation characteristics of pumped storage are fast regulation, short duration, and large scale. The modeling of electrochemical energy storage and pumped storage is similar and can be combined, that is, the energy storage regulation model is:

[0186]

[0187] C ES,1 =C ES,24 ;

[0188] In the formula, C ES,t is the storage capacity of the energy storage unit at time t, which determines the subsequent regulation capacity of the energy storage unit, η ES is the charging and discharging efficiency of the energy storage unit, is the charging efficiency of the energy storage unit at time t, is the discharge efficiency of the energy storage unit at time t, is the charging operation status of the energy storage unit at time t, with a value of 0 or 1, 0 means charging, and 1 means not charging. is the minimum charging limit of the energy storage unit, is the maximum charging limit of the energy storage unit, is the discharge operation state of the energy storage unit at time t, and the value is 0 or 1, 0 means discharge, and 1 means no discharge. is the minimum discharge limit of the energy storage unit, is the maximum discharge limit of the energy storage unit, is the minimum capacity limit of the energy storage unit, is the maximum capacity limit of the energy storage unit, for This is the upper limit of charging power. for That is the upper limit of discharge power, C ES,1 is the storage capacity of the energy storage unit in the initial period of the day, C ES,24 The amount of electricity stored in the energy storage unit at the end of the day;

[0189] Based on the above flexible resource adjustment model, the upper and lower limits of the adjustment power are expressed as:

[0190]

[0191] The maximum climbing power is expressed as:

[0192]

[0193] Calculation example

[0194] This paper takes the power system source, grid, load and storage of a certain region in northern China as an example for calculation and analysis. The region has excellent wind and solar resources, and the installed capacity of renewable energy accounts for more than 60% of the total installed capacity, becoming the main power source of the power system. Improving the flexibility of the power system has become the key to promoting the consumption of new energy. By the end of 2023, the total installed capacity in the region will be 104.1GW. The installed capacity of various resources is as follows: Figure 3 The flexibility of the power system in the region, including source, grid, load and storage, mainly relies on coal-fired power, gas-fired power, hydropower and energy storage.

[0195] The output range of coal-fired power units is usually 50%-100%, and the ramp rate (ramp limit percentage) is 50%. After flexibility transformation, the minimum output of coal-fired power units can be reduced to 30%, and the ramp rate can reach 100%. The output range of gas-fired power units is usually 20%-100%. The output range of hydropower is 0-100%. The demand response capacity of flexible loads is calculated as 3% of the maximum power load (total system load). The output range of energy storage units is -100%-100%, but the duration is 3-5 hours. The credibility coefficient is determined based on the historical operation data of the power system.

[0196] A day in 2023 when the output power of wind turbines and photovoltaic units fluctuated greatly was selected as a typical day. The load (total system load) and wind power (wind power output) and photovoltaic (photovoltaic output) on the typical day are as follows: Figure 4 . According to forecasting experience, the fluctuation deviation of wind power output and photovoltaic output are both 0.2. The total system load curve in the region is relatively flat, with a low peak-to-valley difference. However, the installed capacity of wind power and photovoltaic power is high, and the maximum output of new energy during the day can reach 46% of the total system load, and the minimum output reaches 28% of the total system load. The maximum output and minimum output of new energy (wind power and photovoltaic power) differ by 18%, requiring sufficient flexibility resources to adjust. For the convenience of analysis, the average data of equipment or units are used as operating parameters for analysis.

[0197] (1) Evaluate the power regulation capability of the power system in the region

[0198] The remaining load can be obtained by deducting the wind power output, photovoltaic output and total power of the transmission line from the total system load (there are no nuclear power units installed in the area, and the nuclear power base load is 0), such as Figure 5 (In the figure, wind power represents wind power output, photovoltaic represents photovoltaic output, and Eastward transmission represents the total power of the transmission line.) The blue area in the figure is the remaining load, which is the part that needs to be filled by flexible resources. The remaining load range is [12.52, 26.68] GW.

[0199] According to the obtained operating parameters, the flexible resource regulation model can calculate: the coal-fired power regulation range calculated by the first coal-fired power regulation model and the second coal-fired power regulation model is [14.45, 28.89] GW; the gas-fired power regulation range calculated by the gas-fired power regulation model is [0.01, 0.04] GW; the hydropower regulation range calculated by the hydropower regulation model is [0, 0.27] GW; the electrochemical energy storage regulation range is [-0.21, 0.21] GW and the pumped storage regulation range is [-0.6, 0.6] GW calculated by the energy storage regulation model; the flexible load regulation range calculated by the energy consumption regulation model is [-1.16, 1.16] GW. In summary, the regulation power range that can be provided by the flexible resources in this region is [12.48, 31.17] GW. The larger the right end point value of the adjustment power range, i.e., the upper limit of the adjustment power, the stronger the upward adjustment capability of the power system in the region; the smaller the left end point value of the adjustment power range, i.e., the lower limit of the adjustment power, the stronger the downward adjustment capability of the power system in the region. Figure 6 .

[0200] The regulation capabilities of various flexible resources in the power system, including source, grid, load and storage, are summarized to obtain the regulation power range, and the regulation power range is compared with the remaining load range. The envelope of the regulation power range to the remaining load range is as follows: Figure 7 As can be seen from the figure, the adjustment power range can basically form an envelope for the remaining load range. 31.17>26.68 means that the upper limit of the adjustment power is greater than the upper limit of the remaining load, and the power system source, grid, load and storage have ample upward adjustment space. However, 12.48<12.52 means that the lower limit of the adjustment power is slightly less than the lower limit of the remaining load, and the power system source, grid, load and storage have limited downward adjustment space.

[0201] In general, the safety and reliability of the power system can be evaluated by the relationship between the upper limit of the regulation power and the upper limit of the remaining load. If the upper limit of the regulation power can exceed 10% of the upper limit of the remaining load, then it can be considered that the power system has strong safety and reliability, because such regulation capability can effectively cope with load fluctuations and ensure the stability of power supply. In this example, an analysis was conducted on a regional power system. The upper limit of the remaining load of the regional power system is 26.68GW. In order to ensure the safety and reliability of the power system, the upper limit of the regulation power needs to reach 29.35GW. By comparison, it is found that the upper limit of the regulation power of the source-grid-load-storage flexibility resources in the regional power system is 31.17GW, which has exceeded the actual regulation demand. From this data, the regional power system has sufficient capacity to support peak load demand, so there is no risk of power supply. This guarantee of safety and reliability is mainly due to the sufficient coal-fired power units in the region. These coal-fired power units play a key role in the power system, and their contribution to the upper limit of the regulation power accounts for as much as 92.68%. This fully demonstrates the important role of coal-fired power units in ensuring power supply. With the cooperation of flexible resources such as flexible loads and energy storage units, the power system in this region has strong regulation capabilities and safety guarantees when dealing with peak loads.

[0202] In addition, the power system also pays great attention to the consumption of new energy such as wind power and photovoltaics, reduces resource waste, improves the efficiency of clean energy utilization, and thus reduces carbon emissions from the power system. The power system's ability to absorb new energy is evaluated by adjusting the relationship between the lower limit of power and the lower limit of residual load. If the lower limit of the adjusted power is lower than 5% of the lower limit of the residual load, then the power system can be considered to have sufficient capacity to absorb new energy. In this example, the lower limit of the residual load of the regional power system is 12.52GW. In order to reduce the problems of wind and solar power abandonment, the lower limit of the adjusted power shall not exceed 11.89GW. By comparison, it is found that the lower limit of the adjusted power of the source-grid-load-storage flexibility resources in the regional power system is 12.48GW, which is slightly higher than the given reference value of 11.89GW. This means that when the power of new energy fluctuates greatly, the system may face certain risks of wind and solar power abandonment. Figure 8 The size of the yellow area indicates the risk of wind and solar power abandonment. According to the actual situation, the utilization rate of wind power in the region will be only 93.2% and the utilization rate of photovoltaic power will be only 96.6% in 2023. This further verifies the accuracy of the assessment model.

[0203] (2) Evaluate the ramping capability of the power system in the region

[0204] See also Figure 5At 16:00, compared with 15:00, the total load of the power system surged, and the wind power output and photovoltaic output decreased at the same time. The power system had a large ramp demand, requiring various flexible resources to increase output to meet the load demand. At 16:00, the maximum ramp demand of the remaining load was about 5GW.

[0205] The flexibility resource regulation model can be used to calculate that the nominal ramping limit of coal-fired power units is 9.63GW. The nominal ramping limit of gas-fired power units is 0.02GW. The nominal ramping limit of hydropower units is 0.13GW. The nominal ramping limit of electrochemical energy storage units is 0.11GW. The nominal ramping limit of pumped storage units is 0.3GW. The nominal ramping limit of flexible loads is 0.58GW. In summary, the maximum ramping power that the flexibility resources in the region can provide is 10.77GW.

[0206] The current flexibility resource ramping capacity is more than twice the system ramping demand, and there is sufficient ramping flexibility to cope with power system load and new energy fluctuations. It should be noted that when the installed capacity of wind turbines and photovoltaic units increases further, more ramping demands will be brought. Coal-fired power units can be modified to increase the ramping capacity of the power system.

[0207] In summary, the flexibility characteristics of the power system source, grid, load and storage in this region are as follows: in the adjustment range, the upper limit of the adjustment power exceeds the actual adjustment demand, indicating that it is safe and reliable, and can effectively cope with load fluctuations and ensure the stability of power supply. However, the lower limit of the adjustment power is slightly higher than the given reference value, and there is pressure to absorb new energy, especially when the power fluctuations of new energy such as wind power output and photovoltaic output are large, wind and light abandonment may occur. In terms of climbing power, it has sufficient climbing capacity to cope with load and new energy fluctuations. In view of the above situation, in order to achieve cleaner and more efficient energy utilization, it is necessary to further optimize the configuration of flexible resources, improve the absorption capacity of new energy, and expand the lower limit of adjustment power. The following are some possible solutions:

[0208] Option 1: Stimulate the potential of flexible load response and increase the demand response capability from 3% to 4% of the maximum power load (total system load).

[0209] Option 2: Improve the charging capacity of the energy storage unit and increase the layout scale of the energy storage unit by 1GW.

[0210] Option 3: Carry out flexibility transformation on coal-fired power units, with the scale of transformation to be 20% of installed capacity.

[0211] Option 4: Comprehensively adopt the above three options to comprehensively improve the regulation capacity of the power system from three aspects: encouraging flexible loads, promoting energy storage layout, and implementing flexibility transformation.

[0212] The adjustment power range of flexibility resources in different solutions is as follows: Figure 8 As shown in the figure. As can be seen from the figure, encouraging flexible loads, promoting energy storage layout, and implementing flexibility transformation have all expanded the lower limit of regulation power and increased the power system's ability to absorb wind power and photovoltaics, but the effects are different. After continuing to tap the potential of flexible load response, Scheme 1 has significantly increased the downward regulation capacity, but there is still a small risk of wind and photovoltaic abandonment. After increasing the scale of energy storage layout, Scheme 2 stores wind power and photovoltaics, and there is almost no risk of wind and photovoltaic abandonment, which significantly improves the system's downward regulation capacity. After Scheme 3 carries out flexibility transformation of coal-fired power, it greatly expands the lower limit of regulation power and can achieve full absorption of wind power and photovoltaics. After taking the above three measures at the same time, Scheme 4 has the maximum adjustable power range of the power system. The ample flexibility increases the safety and reliability of the system, reduces operation risks, and can carry more wind power and photovoltaics, which is conducive to the rapid development of wind power and photovoltaics.

[0213] Analysis of the region shows that the existing flexibility resources can basically meet the regulation needs of the power system, but it still faces a certain risk of wind and solar power abandonment. Studies have shown that by encouraging flexible loads, promoting energy storage layout, and implementing flexibility transformation, the regulation capacity of the power system can be significantly improved and the space for renewable energy consumption can be expanded. However, different technical solutions have different effects in the process of improving regulation capacity, and the most significant effect is the flexibility transformation of coal-fired power. With the continuous increase in the penetration rate of new energy, enhancing system flexibility has become an inevitable choice. In the short term, it is recommended to improve the system regulation capacity through the flexibility transformation of coal-fired power units; in the long term, the flexibility of the system should be ensured by large-scale deployment of energy storage facilities. Through these measures, the sustainable development of the power system can be effectively promoted and the efficient use of clean energy can be achieved.

[0214] This embodiment also provides a device for implementing a method for evaluating the regulation capability of power system source-grid-load-storage flexibility resources, including a modeling unit, a calculation unit, and an evaluation unit;

[0215] Modeling unit:

[0216] Used to obtain the operating parameters, variable coefficient, total system load, new energy output and nuclear power base load of the power system source, grid, load and storage;

[0217] Used to build a flexibility resource adjustment model based on operating parameters;

[0218] Computational Unit:

[0219] Used to obtain the lower limit and upper limit of residual load according to the total system load, variable coefficient, new energy output, nuclear power base load and transmission line power limit;

[0220] Used to obtain the remaining load range and the maximum climbing requirement according to the remaining load lower limit and the remaining load upper limit;

[0221] Used to obtain the upper limit of the regulated power according to the variable coefficient, the upper limit of the output power, the maximum transfer amount of the transferable load, the maximum reduction amount of the interruptible load and the upper limit of the discharge power; used to obtain the lower limit of the regulated power according to the variable coefficient, the lower limit of the output power, the maximum transfer amount of the transferable load and the upper limit of the charging power;

[0222] Used to obtain an adjustment power range according to an adjustment power upper limit and an adjustment power lower limit;

[0223] Used to obtain the maximum climbing power according to the variable coefficient, the output power upper limit, the nominal climbing upper limit and the discharge power upper limit;

[0224] Assessment Unit:

[0225] Used to compare the remaining load range and the regulated power range to evaluate the power regulation capability of the power system source, grid, load and storage;

[0226] Used to compare the maximum climbing demand and the maximum climbing power to evaluate the climbing capability of the power system source, grid, load and storage.

[0227] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A method for evaluating the regulation capability of power system source-grid-load-storage flexibility resources, characterized in that: The following steps are involved: Obtain the operating parameters, variable coefficient, total system load, new energy output and nuclear power base load of the power system source, grid, load and storage; Constructing a flexibility resource regulation model according to the operating parameters, the flexibility resource regulation model includes an energy production regulation model, an energy transmission network regulation model, an energy consumption regulation model and an energy storage regulation model; the energy production regulation model includes an output power lower limit, an output power upper limit and a nominal climbing upper limit; The energy transmission network regulation model includes the upper limit of the power of the transmission line; the energy consumption regulation model includes the maximum transfer amount of the transferable load and the maximum reduction amount of the interruptible load; the energy storage regulation model includes the upper limit of the charging power and the upper limit of the discharging power; Obtaining a residual load lower limit and a residual load upper limit according to the total system load, the variable coefficient, the new energy output, the nuclear power base load and the transmission line power upper limit; Obtaining a remaining load interval and a maximum climbing requirement according to the remaining load lower limit and the remaining load upper limit; Obtaining an upper limit of regulated power according to the variable coefficient, the upper limit of output power, the maximum transfer amount of the transferable load, the maximum reduction amount of the interruptible load and the upper limit of discharge power; Obtaining a lower limit of the adjustment power according to the variable coefficient, the lower limit of the output power, the maximum transfer amount of the transferable load and the upper limit of the charging power; Obtaining an adjustment power range according to the adjustment power upper limit and the adjustment power lower limit; Obtaining a maximum climbing power according to the variable coefficient, the output power upper limit, the nominal climbing upper limit and the discharge power upper limit; Comparing the remaining load interval with the regulated power interval to evaluate the power regulation capability of the power system source, grid, load and storage; The maximum climbing demand and the maximum climbing power are compared to evaluate the climbing capability of the power system source, grid, load and storage.

2. The method for evaluating the flexibility resource regulation capability of power system source, grid, load and storage according to claim 1 is characterized in that: The power regulation capability of the power system source, grid, load and storage is evaluated including: When the remaining load interval is within the adjustment power interval, the power of the power system source, grid, load and storage can be adjusted; When the remaining load lower limit is lower than the adjustment power lower limit, the power downward adjustment space of the power system source, grid, load and storage is scarce; When the upper limit of the remaining load is higher than the upper limit of the regulated power, the power upward regulation space of the power system source, grid, load and storage is in short supply.

3. The method for evaluating the adjustment capability of power system source-grid-load-storage flexibility resources according to claim 2 is characterized in that: The upper limit of the regulated power is 10% higher than the upper limit of the residual load, and the lower limit of the regulated power is 5% lower than the lower limit of the residual load.

4. The method for evaluating the adjustment capability of power system source-grid-load-storage flexibility resources according to claim 1 is characterized in that: When the maximum climbing power is not lower than the maximum climbing demand, the power system source, grid, load and storage have climbing flexibility.

5. The method for evaluating the adjustment capability of power system source-grid-load-storage flexibility resources according to claim 4 is characterized in that: The maximum climbing power is more than twice the maximum climbing requirement.

6. The method for evaluating the flexibility resource regulation capability of power system source, grid, load and storage according to claim 1 is characterized in that: The operating parameters include operating status, rated capacity, minimum output percentage, maximum output percentage, landslide limit percentage, climbing limit percentage, minimum continuous operating time, minimum continuous shutdown time and typical daily power distribution; The energy production regulation model includes a first coal-electricity regulation model, a second coal-electricity regulation model, a gas-electricity regulation model and a hydroelectricity regulation model; The first coal-fired power regulation model, the second coal-fired power regulation model and the gas-fired power regulation model all include output power constraints, ramp constraints and operating state constraints; The hydropower regulation model includes output power constraints and total output power constraints; Obtaining the output power lower limit according to the operating state, the rated capacity and the minimum output percentage; Obtaining the output power upper limit according to the operating state, the rated capacity and the maximum output percentage; Obtaining a nominal landslide upper limit according to the landslide limit percentage and the rated capacity; Obtaining the nominal climbing upper limit according to the climbing limit percentage and the rated capacity; Obtaining the output power constraint according to the output power lower limit and the output power upper limit; Obtaining the total output power constraint according to the output power constraint and the typical daily allocated power; Obtaining the climbing constraint according to the nominal landslide upper limit and the nominal climbing upper limit; The operation state constraint is obtained according to the operation state, the minimum continuous operation time and the minimum continuous shutdown time.

7. The method for evaluating the adjustment capability of power system source-grid-load-storage flexibility resources according to claim 6 is characterized in that: The energy transmission network regulation model includes transmission line power constraints; Obtaining a lower limit of power of the transmission line according to the rated capacity and the minimum output percentage; Obtaining the power upper limit of the transmission line according to the rated capacity and the maximum output percentage; The transmission line power constraint is obtained according to the transmission line power lower limit and the transmission line power upper limit.

8. The method for evaluating the adjustment capability of power system source-grid-load-storage flexibility resources according to claim 6 is characterized in that: The operating parameters also include a maximum transfer ratio of transferable load and a maximum reduction ratio of interruptible load; The energy consumption regulation model includes a transferable flexible load model and an interruptible flexible load model; The transferable flexible load model includes a total transferable load constraint and a transferable load transfer amount constraint; the interruptible flexible load model includes an interruptible load reduction amount constraint; the transferable load transfer amount constraint includes a transferable load transfer-in amount constraint and a transferable load transfer-out amount constraint; According to the maximum transfer ratio of the transferable load and the total load of the system, a maximum transfer-in amount of the transferable load and a maximum transfer-out amount of the transferable load are obtained; Obtaining the transferable load transfer amount constraint according to the maximum transferable load transfer amount; Obtaining the transferable load transfer-out amount constraint according to the maximum transferable load transfer-out amount; Obtaining the total amount constraint of the transferable load according to the transferable load transfer-in amount constraint and the transferable load transfer-out amount constraint; Obtaining a maximum interruptible load reduction amount according to the maximum interruptible load reduction ratio and the system total load; The interruptible load reduction amount constraint is obtained according to the interruptible load maximum reduction amount.

9. The method for evaluating the adjustment capability of power system source-grid-load-storage flexibility resources according to claim 6 is characterized in that: The operating parameters also include charge and discharge efficiency, minimum charge limit, maximum charge limit, minimum discharge limit, maximum discharge limit, minimum capacity limit, maximum capacity limit, charge state and discharge state; The energy storage regulation model includes an energy storage capacity model, a charging power constraint, a discharging power constraint, a charging and discharging state constraint, and a storage capacity balance constraint; Obtaining a charging power lower limit according to the charging state and the minimum charging limit; Obtaining a charging power upper limit according to the charging state and the maximum charging limit; Obtaining a lower limit of discharge power according to the discharge state and the minimum discharge limit; Obtaining a discharge power upper limit according to the discharge state and the maximum discharge limit; Obtaining the charging power constraint according to the charging power lower limit and the charging power upper limit; Obtaining the discharge power constraint according to the discharge power lower limit and the discharge power upper limit; Obtaining the charge and discharge state constraint according to the charge state and the discharge state; Obtaining the power storage balance constraint according to the minimum capacity limit and the maximum capacity limit; The energy storage capacity model is obtained according to the charging and discharging efficiency, the charging power constraint, the discharging power constraint and the storage capacity balance constraint.

10. A device for implementing the method for evaluating the adjustment capability of power system source-grid-load-storage flexibility resources according to any one of claims 1 to 9, characterized in that: It includes modeling unit, calculation unit and evaluation unit; The modeling unit: Used to obtain the operating parameters of the power system source, grid, load and storage, the variable coefficient, the total system load, the new energy output and the nuclear power base load; Used to construct the flexibility resource adjustment model according to the operating parameters; The computing unit: Used to obtain a lower limit and an upper limit of the residual load according to the total system load, the variable coefficient, the new energy output, the nuclear power base load and the upper limit of the transmission line power; Used to obtain a residual load range and a maximum climbing requirement according to the residual load lower limit and the residual load upper limit; Used to obtain an upper limit of regulated power according to the variable coefficient, the upper limit of output power, the maximum transfer amount of the transferable load, the maximum reduction amount of the interruptible load and the upper limit of discharge power; Used to obtain the lower limit of the adjustment power according to the variable coefficient, the lower limit of the output power, the maximum transfer amount of the transferable load and the upper limit of the charging power; Used to obtain an adjustment power range according to the adjustment power upper limit and the adjustment power lower limit; Used to obtain the maximum climbing power according to the variable coefficient, the output power upper limit, the nominal climbing upper limit and the discharge power upper limit; The evaluation unit: Used to compare the remaining load interval and the regulated power interval to evaluate the power regulation capability of the power system source, grid, load and storage; Used to compare the maximum climbing demand and the maximum climbing power to evaluate the climbing capability of the power system source, grid, load and storage.

Images