A photovoltaic-solar thermal combined power generation coordination planning method and system

Abstract

The present invention relates to a coordinated planning method and system for photovoltaic-thermal combined power generation. The method comprises: determining the output power of photovoltaic and solar thermal power stations to a receiving end via a DC transmission channel based on the channel capacity of the DC transmission channel; obtaining the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the thermal storage system in the solar thermal power station based on the output power and a pre-established coordinated planning model; and planning photovoltaic-thermal combined power generation using the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the thermal storage system in the solar thermal power station as a coordinated planning scheme. The technical solution provided by the present invention can complement the advantages of photovoltaic and solar thermal power generation, minimize generalized load fluctuations, and improve the stability and safety of power grid operation.

Description

Technical Field

[0001] The present invention relates to the technical field of power system planning, and in particular to a method and system for coordinated planning of photovoltaic-solar thermal combined power generation. Background Art

[0002] With the gradual depletion of fossil fuels like coal and oil, traditional thermal power generation is increasingly facing fuel shortages. Therefore, new renewable energy sources are urgently needed to replace traditional power generation methods. As one of the cleanest and most direct forms of renewable energy in the world today, the rational planning and utilization of solar power generation is a key measure to achieving my country's energy conservation and emission reduction goals.

[0003] Currently, solar power generation is primarily divided into two methods: photovoltaic power generation and concentrated solar thermal power generation. However, the output of large-scale photovoltaic power generation is characterized by randomness and intermittence, increasing the uncertainty and insecurity of grid operation. While concentrated solar thermal power generation can improve output stability, it faces high investment costs and a high cost per kilowatt-hour. Therefore, a coordinated planning method for combined photovoltaic and concentrated solar thermal power generation bases is urgently needed. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to make the advantages of photovoltaic power generation and solar thermal power generation complement each other, achieve the purpose of minimizing generalized load fluctuations, and improve the stability and safety of power grid operation.

[0005] The purpose of the present invention is achieved by adopting the following technical solutions:

[0006] A photovoltaic-solar thermal power generation coordinated planning method, wherein the improvement is that the method comprises:

[0007] Determine the output power of the photovoltaic power station and the solar thermal power station to the receiving end through the DC transmission channel based on the channel capacity of the DC transmission channel;

[0008] Based on the external power transmission and the pre-established coordination planning model, the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station are obtained;

[0009] The photovoltaic-thermal combined power generation is planned using the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station and the capacity of the heat storage system in the solar thermal power station as a coordinated planning scheme.

[0010] Preferably, determining the output power of the photovoltaic power station and the solar thermal power station to the receiving end through the DC transmission channel according to the channel capacity of the DC transmission channel includes:

[0011] According to the channel capacity of the DC transmission channel, determine the daily duration T1 during which the DC transmission channel operates at the minimum transmission power and the daily duration T2 during which the DC transmission channel operates at the maximum transmission power;

[0012] Starting from time 0 every day, the photovoltaic power station and the solar thermal power station output the external power to the receiving end through the DC transmission channel at the minimum external power, and the duration is the said duration T1. After the photovoltaic power station and the solar thermal power station output the external power to the receiving end through the DC transmission channel at the minimum external power, the photovoltaic power station and the solar thermal power station output the external power to the receiving end through the DC transmission channel at the maximum external power, and the duration is the said duration T2. ​​The external power output of the photovoltaic power station and the solar thermal power station to the receiving end through the DC transmission channel corresponding to each time of the day is obtained.

[0013] Furthermore, determining, based on the channel capacity of the DC transmission channel, a daily duration T1 during which the DC transmission channel operates at a minimum transmission power and a daily duration T2 during which the DC transmission channel operates at a maximum transmission power, includes:

[0014] The following formula is used to solve the duration T1 of the DC transmission channel operating at the minimum transmission power and the duration T2 of the DC transmission channel operating at the maximum transmission power:

[0015]

[0016] Among them, P DC1 is the minimum output power of the DC output channel, P DC2 is the maximum external power of the DC transmission channel, C DC is the channel capacity of the DC transmission channel, T DC It is the preset annual operating time of the DC transmission channel.

[0017] Preferably, obtaining the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station based on the external power transmission and a pre-established coordinated planning model includes:

[0018] Bringing the external power into a pre-established coordination planning model;

[0019] Optimizing the coordinated planning model to obtain the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station;

[0020] The coordinated planning model includes an objective function and constraint conditions constructed with the goal of minimizing generalized load fluctuations; the objective function is determined according to the external power.

[0021] Preferably, the pre-established coordination planning model is determined as follows:

[0022]

[0023]

[0024] Where T is the planning period, t∈T, P l (t) is the power load demand in the power system at time t, P PV (t) is the output power of the photovoltaic power station at time t, P CSP (t) is the output power of the CSP station at time t, P DC (t) is the transmission power of the DC transmission channel at time t, P local (t) is the power consumption of the local load at time t, P G (t) is the output power of the conventional unit at time t, P EENS (t) is the power loss of the power system at time t, C PV is the installed capacity of the photovoltaic power station, C CSP is the installed capacity of the CSP station, C G is the installed capacity of conventional units, C TES,min is the lower limit of the heat value of the heat storage system in the CSP station, C TES (t) is the cumulative heat stored in the thermal storage system of the CSP station at time t, C TES,max The upper limit of the calorific value of the heat storage system in the CSP station is the capacity of the heat storage system in the CSP station.

[0025] Furthermore, the output power P of the photovoltaic power station at time t is determined by the following formula: PV (t):

[0026]

[0027] Among them, C PV is the installed capacity of the photovoltaic power station, f PV is the loss coefficient of the photovoltaic power station, Ir(t) is the actual light radiation intensity at time t, Ir ref is the light radiation intensity under standard test conditions, α is the power temperature coefficient of the photovoltaic power station, T(t) is the actual ambient temperature at time t, T ref is the ambient temperature under standard test conditions.

[0028] Furthermore, the output power P of the CSP station at time t is determined by the following formula: CSP (t):

[0029] P CSP (t) = Q PB (t)η PB

[0030] Among them, Q PB(t) is the heat entering the power generation system of the CSP station at time t, η PB The efficiency of the power generation system.

[0031] Furthermore, the heat Q entering the power generation system of the CSP station at time t is determined as follows: PB (t):

[0032] Q PB (t) = Q SF (t)±Q TES (t)

[0033] Q SF (t) = A × DNI (t) × η

[0034] Among them, Q SF (t) is the heat received by the concentrating solar collector system in the CSP station at time t, Q TES (t) is the amount of heat stored / released by the thermal storage system in the CSP plant at time t, A is the mirror field area, DNI(t) is the light radiation intensity at time t, and η is the photothermal conversion efficiency.

[0035] Furthermore, the cumulative amount of heat C stored in the heat storage system of the CSP power station at time t is TES (t) Determine based on the state of the heat storage system at the previous moment:

[0036] When the heat storage system is storing heat at time t-1 and has not reached the upper limit of the heat storage system capacity, the cumulative heat stored in the heat storage system at time t C is determined by the following formula: TES (t):

[0037] C TES (t) = C TES (t-1)·(1-γ)+η ch Q TES (t-1)

[0038] When the heat storage system is storing heat at time t-1 and has reached the upper limit of the heat storage system capacity, the cumulative heat stored in the heat storage system at time t C is determined by the following formula: TES (t):

[0039] C TES (t) = C TES (t-1)·(1-γ)

[0040] When the heat storage system releases heat at time t-1 and does not reach the lower limit of the heat storage system's calorific value, the cumulative heat stored in the heat storage system at time t is determined by the following formula: TES (t):

[0041] C TES (t) = C TES (t-1)·(1-γ)-η disQ TES (t-1)

[0042] When the heat storage system releases heat at time t-1 and has reached the lower limit of the heat storage system's calorific value, the cumulative heat stored in the heat storage system at time t is determined by the following formula: TES (t):

[0043] C TES (t) = C TES (t-1)·(1-γ)

[0044] Among them, C TES (t-1) is the cumulative heat stored in the heat storage system at time t-1, γ is the dissipation coefficient of the heat storage system, η ch is the heat storage efficiency, η dis is the heat release efficiency, Q TES (t-1) is the amount of heat stored / released by the heat storage system at time t-1.

[0045] A photovoltaic-solar thermal combined power generation coordination planning system, wherein the improvement is that the system comprises:

[0046] A determination unit, configured to determine the transmission power outputted by the photovoltaic power station and the solar thermal power station to the receiving end through the DC transmission channel according to the channel capacity of the DC transmission channel;

[0047] A calculation unit, configured to obtain the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station based on the external power transmission and a pre-established coordination planning model;

[0048] A planning unit is used to plan photovoltaic-thermal combined power generation using the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station and the capacity of the heat storage system in the solar thermal power station as a coordinated planning scheme.

[0049] Compared with the closest prior art, the present invention has the following beneficial effects:

[0050] The technical solution provided by the present invention determines the output power of the photovoltaic power station and the solar thermal power station to the receiving end through the DC transmission channel based on the channel capacity of the DC transmission channel; based on the output power and a pre-established coordinated planning model, the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station are obtained; and the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station are used as the coordinated planning scheme to plan photovoltaic-solar thermal combined power generation. Based on the technical solution provided by the present invention, the installed capacity of photovoltaic power generation and solar thermal power generation, as well as the capacity of the heat storage system, can be coordinated and planned, so that the advantages of photovoltaic power generation and solar thermal power generation are complementary, the generalized load fluctuation is minimized, the stability and safety of power grid operation are improved, and the long-term operation requirements of the system are met for safe and economical operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a flow chart of a coordinated planning method for a photovoltaic-solar thermal combined power generation base provided by the present invention;

[0052] Figure 2 This is a graph showing the output characteristics of each unit in a typical 24-hour day in a photovoltaic-thermal combined power generation base provided by an embodiment of the present invention;

[0053] Figure 3 This is a heat change curve diagram of the heat storage system in a typical 24-hour solar thermal power station provided by an embodiment of the present invention;

[0054] Figure 4 This is a schematic diagram of the structure of a coordinated planning system for a photovoltaic-solar-thermal combined power generation base provided by the present invention. DETAILED DESCRIPTION

[0055] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0057] The present invention provides a photovoltaic-thermal combined power generation coordination planning method, such as Figure 1 As shown, including:

[0058] 101. Determine the output power of the photovoltaic power station and the solar thermal power station to the receiving end through the DC transmission channel based on the channel capacity of the DC transmission channel;

[0059] 102. Based on the external power transmission and the pre-established coordination planning model, obtain the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station;

[0060] 103. The photovoltaic-solar thermal power generation is planned using the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station and the capacity of the heat storage system in the solar thermal power station as a coordinated planning scheme.

[0061] The step of determining the output power of the photovoltaic power station and the solar thermal power station to the receiving end through the DC transmission channel according to the channel capacity of the DC transmission channel includes:

[0062] According to the channel capacity of the DC transmission channel, determine the daily duration T1 during which the DC transmission channel operates at the minimum transmission power and the daily duration T2 during which the DC transmission channel operates at the maximum transmission power;

[0063] Starting from time 0 every day, the photovoltaic power station and the solar thermal power station output the external power to the receiving end through the DC transmission channel at the minimum external power, and the duration is the said duration T1. After the photovoltaic power station and the solar thermal power station output the external power to the receiving end through the DC transmission channel at the minimum external power, the photovoltaic power station and the solar thermal power station output the external power to the receiving end through the DC transmission channel at the maximum external power, and the duration is the said duration T2. ​​The external power output of the photovoltaic power station and the solar thermal power station to the receiving end through the DC transmission channel corresponding to each time of the day is obtained.

[0064] The determining, based on the channel capacity of the DC transmission channel, the duration T1 during which the DC transmission channel operates at the minimum transmission power and the duration T2 during which the DC transmission channel operates at the maximum transmission power each day includes:

[0065] The following formula is used to solve the duration T1 of the DC transmission channel operating at the minimum transmission power and the duration T2 of the DC transmission channel operating at the maximum transmission power:

[0066]

[0067] Among them, P DC1 is the minimum transmission power of the DC transmission channel, P DC2 is the maximum external power of the DC transmission channel, C DC is the channel capacity of the DC transmission channel, T DC It is the preset annual operating time of the DC transmission channel.

[0068] The method of obtaining the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station based on the external power transmission and the pre-established coordinated planning model includes:

[0069] Bringing the external power into a pre-established coordination planning model;

[0070] Optimizing the coordinated planning model to obtain the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station;

[0071] The coordinated planning model includes an objective function and constraint conditions constructed with the goal of minimizing generalized load fluctuations; the objective function is determined according to the external power.

[0072] Taking the photovoltaic power station and the solar thermal power station as negative loads, the photovoltaic power station, the solar thermal power station and the conventional power load are generalized loads. The output power P of the generalized load at time t is determined as follows:g,l (t):

[0073] P g,l (t) = P l (t)-P PV (t)-P CSP (t) (1)

[0074] Determine the average value P of the generalized load output power at time t by the following formula g,l,avg (t):

[0075]

[0076] The objective function is to minimize the generalized load fluctuation, that is:

[0077]

[0078] Substituting equations (1) and (2) into equation (3), we can obtain the objective function:

[0079]

[0080] The coordinated planning model is composed of the objective function and constraints, wherein the constraints include: system power balance constraints, power demand constraints of conventional power loads, photovoltaic power station operation constraints, solar thermal power station operation constraints, conventional unit operation constraints, and thermal storage system capacity constraints;

[0081] The system power balance constraint is: P DC (t)+P local (t) = P G (t)+P CSP (t)+P PV (t)+P EENS (t);

[0082] The power demand constraint of the conventional power load is: P l (t) = P DC (t)+P local (t);

[0083] The photovoltaic power station operation constraint is: 0≤P PV (t)≤C PV ;

[0084] The operation constraint of the CSP plant is: 0≤P CSP (t)≤C CSP ;

[0085] The conventional unit operation constraint is: 0≤P G (t)≤C G ;

[0086] The capacity constraint of the heat storage system is: C TES,min ≤C TES (t)≤C TES,max ;

[0087] Therefore, the pre-established coordination planning model is determined as follows:

[0088]

[0089]

[0090] Where T is the planning period, t∈T, P l (t) is the power load demand in the power system at time t, P PV (t) is the output power of the photovoltaic power station at time t, P CSP (t) is the output power of the CSP station at time t, P DC (t) is the DC transmission power at time t, P local (t) is the power consumption of the local load at time t, P G (t) is the output power of the conventional unit at time t, P EENS (t) is the power loss of the power system at time t, C PV is the installed capacity of the photovoltaic power station, C CSP is the installed capacity of the CSP station, C G is the installed capacity of conventional units, C TES,min is the lower limit of the heat value of the heat storage system in the CSP station, C TES (t) is the cumulative heat stored in the thermal storage system of the CSP station at time t, C TES,max The upper limit of the calorific value of the heat storage system in the CSP station is the capacity of the heat storage system in the CSP station.

[0091] The conventional units include thermal power units and hydropower units.

[0092] Determine the output power P of the photovoltaic power station at time t by the following formula PV (t):

[0093]

[0094] Among them, C PV is the installed capacity of the photovoltaic power station, f PV is the loss coefficient of the photovoltaic power station, Ir(t) is the actual light radiation intensity at time t, Ir ref is the light radiation intensity under standard test conditions, α is the power temperature coefficient of the photovoltaic power station, T(t) is the actual ambient temperature at time t, T ref is the ambient temperature under standard test conditions, f PV =0.87, Irref =1000kW / m 2 / year,α=0.0046,T ref =25℃;

[0095] Determine the output power P of the CSP station at time t by the following formula: CSP (t):

[0096] P CSP (t) = Q PB (t)η PB

[0097] Among them, Q PB (t) is the heat entering the power generation system of the CSP station at time t, η PB The efficiency of the power generation system.

[0098] The photovoltaic power station includes a heat storage system, a power generation system and a concentrated heat collection system. The power generation system can specifically adopt a steam turbine generator.

[0099] The heat Q entering the power generation system of the CSP station at time t is determined by the following formula: PB (t):

[0100] Q PB (t) = Q SF (t)±Q TES (t)

[0101] Q SF (t) = A × DNI (t) × η

[0102] Among them, Q SF (t) is the heat received by the concentrating solar collector system in the CSP station at time t, Q TES (t) is the amount of heat stored / released by the thermal storage system in the CSP plant at time t, A is the mirror field area, DNI(t) is the light radiation intensity at time t, and η is the photothermal conversion efficiency.

[0103] The cumulative amount of heat C stored in the heat storage system of the CSP station at time t TES (t) Determine based on the state of the heat storage system at the previous moment:

[0104] When the heat storage system is storing heat at time t-1 and has not reached the upper limit of the heat storage system capacity, the cumulative heat stored in the heat storage system at time t C is determined by the following formula: TES (t):

[0105] C TES (t) = C TES (t-1)·(1-γ)+η ch Q TES (t-1)

[0106] When the heat storage system is storing heat at time t-1 and has reached the upper limit of the heat storage system capacity, the cumulative heat stored in the heat storage system at time t C is determined by the following formula: TES (t):

[0107] C TES (t) = C TES (t-1)·(1-γ)

[0108] When the heat storage system releases heat at time t-1 and does not reach the lower limit of the heat storage system's calorific value, the cumulative heat stored in the heat storage system at time t is determined by the following formula: TES (t):

[0109] C TES (t) = C TES (t-1)·(1-γ)-η dis Q TES (t-1)

[0110] When the heat storage system releases heat at time t-1 and has reached the lower limit of the heat storage system's calorific value, the cumulative heat stored in the heat storage system at time t is determined by the following formula: TES (t):

[0111] C TES (t) = C TES (t-1)·(1-γ)

[0112] Among them, C TES (t-1) is the cumulative heat stored in the heat storage system at time t-1, γ is the dissipation coefficient of the heat storage system, η ch is the heat storage efficiency, η dis is the heat release efficiency, Q TES (t-1) is the amount of heat stored / released by the heat storage system at time t-1.

[0113] The working process of the heat storage system is as follows: in the heat storage stage, the low-temperature heat storage medium is pumped out of the tank by a pump and absorbs heat to increase its temperature; in the heat release stage, the high-temperature heat storage medium is pumped out and enters the steam generation system to heat the feed water, generating steam to drive the steam turbine to do work. Among them, heat storage and heat release are mutually exclusive.

[0114] In the embodiment provided by the present invention, the installed capacity of the photovoltaic power station in the photovoltaic-thermal combined power generation base, the installed capacity of the thermal power station and the capacity of the heat storage system in the thermal power station are unknown, and the capacity C of the DC transmission channel is unknown. DC The preset annual operating time of the DC transmission channel is 8 million kilowatts. DC For 5200 hours, the power consumption of the local load is P localThe installed capacity of photovoltaic power station in the photovoltaic-solar thermal power generation base obtained by using the pre-established coordinated planning model is 2300MW, the installed capacity of solar thermal power station is 7700MW, and the generalized load fluctuation is 23441. Figure 2 The following figure shows the output characteristics of each unit in a typical 24-hour day at a photovoltaic-solar combined power generation base. In a combined power generation base, the total base output meets the power requirements of local load consumption and the power required for DC transmission. For PV power plants, their output is generally proportional to the daily irradiation. At night, when there is no output, there is no load regulation capability. For CSP plants, between midnight and 10 a.m., the output of the steam turbine units is provided by the thermal storage system. However, due to load demand, the CSP units do not need to operate at full capacity, but instead increase their output based on load conditions. During periods of sufficient irradiation, the CSP plant stores heat. Although output increases appropriately based on the DC transmission plan, its own output is adaptively reduced because some power is met by the PV plant, demonstrating its excellent regulation characteristics. At night, the PV plant has no power output, and the load demand is fully met by the CSP plant and conventional units. The CSP plant's output relies solely on the heat stored in the thermal storage system during the daytime period of sufficient irradiation. During peak evening load demand, the CSP plant operates at full capacity to ensure system power balance. For traditional units, due to their limited total installed capacity, which is only about 20% of the total capacity, they cannot fully rely on traditional units to meet the load demand. In addition, considering that the adjustable range is small, the adjustment cost is low, and the system operates more economically, the output of traditional units at each moment does not change much, except at night, when the photovoltaic output is zero. The output of the solar thermal unit alone is not enough to meet the load demand, and the traditional units will appropriately increase their output.

[0115] like Figure 3 As shown in the figure, the heat storage system in a typical 24-hour solar thermal power station heat change curve is as follows. For the heat storage system, from 0 to 10 o'clock, in addition to the dissipation of the system itself, there is also heat release consumption by the heat storage system to supply the steam turbine unit of the solar thermal power station, so its heat decreases hour by hour; after 11 o'clock, the heat storage system begins to store excess heat, and its heat increases again. Moreover, since the heat storage rate is related to the solar irradiation, it can be seen that the capacity of the heat storage system is slow at the beginning, and the heat storage rate gradually increases as it enters noon. However, due to the sudden drop in solar irradiation around 5 pm, the heat of the heat storage system remains almost unchanged. As the sun sets, the irradiation gradually decreases, which also reduces the heat storage rate. At night, the heat storage system needs to release heat to supply the steam turbine unit of the solar thermal power station for power generation, and has its own dissipation process, so its heat continues to decrease.

[0116] Based on the same concept of the above method, the present invention also provides a photovoltaic-thermal combined power generation coordination planning system, such as Figure 4 As shown, including:

[0117] A determination unit, configured to determine the transmission power outputted by the photovoltaic power station and the solar thermal power station to the receiving end through the DC transmission channel according to the channel capacity of the DC transmission channel;

[0118] A calculation unit, configured to obtain the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station based on the external power transmission and a pre-established coordination planning model;

[0119] A planning unit is used to plan photovoltaic-thermal combined power generation using the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station and the capacity of the heat storage system in the solar thermal power station as a coordinated planning scheme.

[0120] The determining unit includes:

[0121] a determination module, configured to determine, based on the channel capacity of the DC transmission channel, a daily duration T1 during which the DC transmission channel operates at a minimum transmission power and a daily duration T2 during which the DC transmission channel operates at a maximum transmission power;

[0122] The acquisition module is used to obtain the external power output by the photovoltaic power station and the solar thermal power station to the receiving end through the DC transmission channel at the minimum external power starting from time 0 every day, and the duration is the said duration T1. After the photovoltaic power station and the solar thermal power station output the external power to the receiving end through the DC transmission channel at the minimum external power, the photovoltaic power station and the solar thermal power station output the external power to the receiving end through the DC transmission channel at the maximum external power, and the duration is the said duration T2, and obtain the external power output by the photovoltaic power station and the solar thermal power station to the receiving end through the DC transmission channel corresponding to each time of the day.

[0123] The determination module is specifically used to solve the daily duration T1 of the DC transmission channel operating at the minimum transmission power and the daily duration T2 of the DC transmission channel operating at the maximum transmission power according to the following formula:

[0124]

[0125] Among them, P DC1 is the minimum transmission power of the DC transmission channel, P DC2 is the maximum external power of the DC transmission channel, C DC is the channel capacity of the DC transmission channel, T DC It is the preset annual operating time of the DC transmission channel.

[0126] The computing unit comprises:

[0127] A first calculation module is used to bring the external power into a pre-established coordination planning model;

[0128] A second calculation module is used to optimize the coordinated planning model to obtain the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station;

[0129] The coordinated planning model includes an objective function and constraint conditions constructed with the goal of minimizing generalized load fluctuations; the objective function is determined according to the external power.

[0130] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0131] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0132] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0133] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A photovoltaic-solar thermal power generation coordinated planning method, characterized in that: The method comprises: According to the channel capacity of the DC transmission channel, determine the duration T1 during which the DC transmission channel operates at the minimum transmission power and the duration T2 during which the DC transmission channel operates at the maximum transmission power; starting from time 0 each day, the photovoltaic power station and the solar thermal power station output the transmission power to the receiving end through the DC transmission channel at the minimum transmission power for a duration of the said duration T1; after the photovoltaic power station and the solar thermal power station output the transmission power to the receiving end through the DC transmission channel at the minimum transmission power, the photovoltaic power station and the solar thermal power station output the transmission power to the receiving end through the DC transmission channel at the maximum transmission power for a duration of the said duration T2, and obtain the transmission power output by the photovoltaic power station and the solar thermal power station to the receiving end through the DC transmission channel corresponding to each time of the day; Based on the external power transmission and the pre-established coordination planning model, the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station are obtained; Planning photovoltaic-thermal combined power generation using the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station as a coordinated planning scheme; Among them, the coordinated planning model includes an objective function and constraints constructed with the goal of minimizing generalized load fluctuations; the objective function is determined based on the external power; the generalized load includes photovoltaic power stations, solar thermal power stations and conventional power loads, and the photovoltaic power stations and the solar thermal power stations serve as negative loads.

2. The method according to claim 1, wherein The determining, based on the channel capacity of the DC transmission channel, the duration T1 during which the DC transmission channel operates at the minimum transmission power and the duration T2 during which the DC transmission channel operates at the maximum transmission power each day includes: The following formula is used to solve the duration T1 of the DC transmission channel operating at the minimum transmission power and the duration T2 of the DC transmission channel operating at the maximum transmission power: Among them, P DC1 is the minimum transmission power of the DC transmission channel, P DC2 is the maximum external power of the DC transmission channel, C DC is the channel capacity of the DC transmission channel, T DC It is the preset annual operating time of the DC transmission channel.

3. The method according to claim 1, wherein The method of obtaining the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station based on the external power transmission and the pre-established coordinated planning model includes: Bringing the external power into a pre-established coordination planning model; The coordinated planning model is optimized and calculated to obtain the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station.

4. The method according to claim 1, wherein The pre-established coordination planning model is determined as follows: Where T is the planning period, t∈T, P l (t) is the power load demand in the power system at time t, P PV (t) is the output power of the photovoltaic power station at time t, P CSP (t) is the output power of the CSP station at time t, P DC (t) is the DC transmission power at time t, P local (t) is the power consumption of the local load at time t, P G (t) is the output power of the conventional unit at time t, P EENS (t) is the power loss of the power system at time t, C PV is the installed capacity of the photovoltaic power station, C CSP is the installed capacity of the CSP station, C G is the installed capacity of conventional units, C TES,min is the lower limit of the heat value of the heat storage system in the CSP station, C TES (t) is the cumulative heat stored in the thermal storage system of the CSP station at time t, C TES,max The upper limit of the calorific value of the heat storage system in the CSP station is the capacity of the heat storage system in the CSP station.

5. The method according to claim 4, wherein Determine the output power P of the photovoltaic power station at time t by the following formula PV (t): Among them, C PV is the installed capacity of the photovoltaic power station, f PV is the loss coefficient of the photovoltaic power station, Ir(t) is the actual light radiation intensity at time t, Ir ref is the light radiation intensity under standard test conditions, α is the power temperature coefficient of the photovoltaic power station, T(t) is the actual ambient temperature at time t, T ref is the ambient temperature under standard test conditions.

6. The method according to claim 4, wherein Determine the output power P of the CSP station at time t by the following formula: CSP (t): P CSP (t)=Q PB (t)η PB Among them, Q PB (t) is the heat entering the power generation system of the CSP station at time t, η PB The efficiency of the power generation system.

7. The method according to claim 6, wherein The heat Q entering the power generation system of the CSP station at time t is determined by the following formula: PB (t): Q PB (t)=Q SF (t)±Q TES (t) Q SF (t)=A×DNI(t)×η Among them, Q SF (t) is the heat received by the concentrating solar collector system in the CSP station at time t, Q TES (t) is the amount of heat stored / released by the thermal storage system in the CSP plant at time t, A is the mirror field area, DNI(t) is the light radiation intensity at time t, and η is the photothermal conversion efficiency.

8. The method according to claim 4, wherein The cumulative amount of heat C stored in the heat storage system of the CSP station at time t TES (t) Determine based on the state of the heat storage system at the previous moment: When the heat storage system is storing heat at time t-1 and has not reached the upper limit of the heat storage system capacity, the cumulative heat stored in the heat storage system at time t C is determined by the following formula: TES (t): C TES (t)=C TES (t-1)·(1-γ)+η ch ·Q TES (t-1) When the heat storage system is storing heat at time t-1 and has reached the upper limit of the heat storage system capacity, the cumulative heat stored in the heat storage system at time t C is determined by the following formula: TES (t): C TES (t)=C TES (t-1)·(1-γ) When the heat storage system releases heat at time t-1 and does not reach the lower limit of the heat storage system's calorific value, the cumulative heat stored in the heat storage system at time t is determined by the following formula: TES (t): C TES (t)=C TES (t-1)·(1-γ)-η dis ·Q TES (t-1) When the heat storage system releases heat at time t-1 and has reached the lower limit of the heat storage system's calorific value, the cumulative heat stored in the heat storage system at time t is determined by the following formula: TES (t): C TES (t)=C TES (t-1)·(1-γ) Among them, C TES (t-1) is the cumulative heat stored in the heat storage system at time t-1, γ is the dissipation coefficient of the heat storage system, η ch is the heat storage efficiency, η dis is the heat release efficiency, Q TES (t-1) is the amount of heat stored / released by the heat storage system at time t-1.

9. A photovoltaic-solar thermal power generation coordination planning system, characterized in that: The system comprises: a determining unit, configured to determine, based on the channel capacity of the DC transmission channel, a daily duration T1 during which the DC transmission channel operates at a minimum transmission power and a daily duration T2 during which the DC transmission channel operates at a maximum transmission power; starting from time 0 each day, the photovoltaic power station and the solar thermal power station output the transmission power to the receiving end through the DC transmission channel at the minimum transmission power for a duration of T1; after the photovoltaic power station and the solar thermal power station output the transmission power to the receiving end through the DC transmission channel at the minimum transmission power, the photovoltaic power station and the solar thermal power station output the transmission power to the receiving end through the DC transmission channel at the maximum transmission power for a duration of T2; and obtain the transmission power output by the photovoltaic power station and the solar thermal power station to the receiving end through the DC transmission channel corresponding to each time of the day; A calculation unit, configured to obtain the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station based on the external power transmission and a pre-established coordination planning model; a planning unit, configured to plan photovoltaic-thermal combined power generation using the installed capacity of the photovoltaic power station, the installed capacity of the solar thermal power station, and the capacity of the heat storage system in the solar thermal power station as a coordinated planning scheme; Among them, the coordinated planning model includes an objective function and constraints constructed with the goal of minimizing generalized load fluctuations; the objective function is determined based on the external power; the generalized load includes photovoltaic power stations, solar thermal power stations and conventional power loads, and the photovoltaic power stations and the solar thermal power stations serve as negative loads.

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