Hybrid power station power supply ratio range calculation method

Abstract

The invention discloses a hybrid power station power supply ratio range calculation method, which comprises a first stage and a second stage: in the first stage, the capacity of diesel generating sets is calculated, a basic power supply is designed according to a user load data scheme, and the rated capacity and the number of the diesel generating sets are selected; in the second stage, the matching range of the wind and light storage power source capacity is calculated and selected, the matching range of the new energy wind power generation power, the photovoltaic power generation power, the energy storage system power and the charge capacity is calculated according to the function requirements and resource conditions of the whole station, and coordinated optimization can be carried out in the calculation range; the method has the advantages that a demonstration basis, constraint conditions and a visual and flexible selection range are provided for a hybrid power station power supply scheme, and the design efficiency and accuracy are improved; advantages of a traditional power supply and a new energy power supply are fully combined, and power supply flexibility and reliability and economic, energy-saving and environment-friendly levels are comprehensively improved.

Description

Technical Field

[0001] The invention relates to coordinated optimization of a hybrid power capacity solution, in particular to a method for calculating a power ratio range of a new energy hybrid power station, and belongs to the field of design calculation of new energy power stations. Background Art

[0002] Many domestic and foreign engineering projects and various camps are often located in areas far away from the power grid. Users widely use off-grid power stations to solve the power supply and use problems in isolated scenarios. Diesel generator sets, with their advantages of black start capability, reliable power supply, flexible operation, fast start-up, and low cost, will remain the first choice for basic power equipment for users in this market for a long time. With the development of energy transformation, users further require full use of local resources, the introduction of clean new energy such as wind power and photovoltaics to achieve energy conservation and environmental protection, reduce emissions, and configure energy storage systems accordingly to expand power station functions and improve power supply reliability and power quality. A hybrid power station composed of wind, solar, storage and diesel requires planning of the power supply combination and reasonable matching of power supply capacity. The capacity ratio must be adapted to the load scale curve, power supply control strategy, parallel wiring scheme or switching method, otherwise it will lead to excessive waste or insufficient capacity, and even unfavorable situations such as reverse power backflow of diesel generator sets and system voltage instability.

[0003] Therefore, the capacity ratio analysis of hybrid power sources needs to comprehensively consider various aspects such as load target demand, basic power supply guarantee, local resource conditions, expected functions and coordination, mature market products, etc., and establish a normative calculation method based on the load operation rules and new energy conditions of off-grid island scenarios to provide a selection range of power supply parameters. When the analysis links are incomplete, the basis is insufficient, and the calculation method is inappropriate, it may affect the one-sided technical functions and waste of resources in the power station design, or the overall function of the power station may have bottlenecks. Summary of the invention

[0004] The purpose of the present invention is to provide a method for calculating the power supply ratio range of a hybrid power station, through the calibration and calculation of various indicators such as steady-state capacity, peak capacity, voltage drop, active overload, single-step loading rate, and steady-state load rate, the capacity of a diesel generator set is selected to make it a basic power source, so as to meet the requirements of black start, reliable support for basic load, bearing the impact of large load start-up, flexible operation mode, and cost reduction; a method for calculating the wind, light, and storage capacity ratio is provided, and the requirements of power station operation mode change, peak load regulation function, charging reservation, and emergency endurance are combined into the calculation steps, so that the power supply capacity ratio meets the needs of economic operation, load peak regulation, energy storage charging guarantee, and emergency endurance of key loads within the station; the power range and charge capacity range of wind power generation, photovoltaic power generation, and energy storage system are provided, and the design and selection are made within the calculation range, and the corresponding power supply control strategy, parallel wiring scheme, and switching mode are selected accordingly, so as to reduce capacity waste or shortage, and prevent the reverse power backflow of the diesel generator set, and the inability to maintain the bus voltage and power station stability, thereby improving the level of economic energy saving and emission reduction and environmental protection.

[0005] The technical solution of the present invention is: The calculation method of the power supply ratio range of the hybrid power station includes the first stage and the second stage; The first stage is the capacity calculation of diesel generator sets. The basic power supply is designed according to the user load data plan, and the rated capacity and number of diesel generator sets are selected. The second stage is the capacity calculation of wind, solar and energy storage power. According to the functional requirements and resource conditions of the whole station, the matching range of new energy wind power generation power, photovoltaic power generation power, energy storage system power and load capacity is calculated. The wind, solar and energy storage power can be coordinated and optimized within the design value range to improve the reliability, economy and energy conservation and environmental protection level of the power station operation. The calculation method is suitable for two situations: the first situation is to design a wind, solar, and energy storage power source based on an existing diesel generator power station; the second situation is a completely new design of a wind, solar, and energy storage diesel hybrid power station; when in the first situation, directly enter the second stage calculation; when in the second situation, first perform the first stage calculation, and then perform the second stage calculation.

[0006] The first stage: diesel generator capacity calculation, specifically includes the following steps: Step 1.1: According to the user load data plan, calculate the minimum capacity value of the diesel generator set - S G1 , S G2 , S G3 , S G4 , S G5 , S G6 , respectively satisfying the steady-state capacity S G1 , peak capacity S G2 , voltage drop S G3 , Active overload SG4 , single-step loading rate S G5 , steady-state load rate S G6 The requirements for various indicators; the calculation method is as follows; Meet the steady-state capacity:

[0007] Meeting peak capacity:

[0008] Meet the voltage drop:

[0009] Satisfy active overload:

[0010] Meet the single-step loading rate:

[0011] Meet the steady-state load rate: ; Step 1.2: Take the maximum value SGmax of the results in step 1.1;

[0012] Step 1.3: Select the single-unit product specifications and number N of diesel generator sets. Under the premise of ensuring that the total rated capacity Ssum of the diesel generator sets is not less than SGmax, select the diesel generator set solution to minimize Ssum, that is: .

[0013] The second stage: Calculation of wind, solar and energy storage capacity The wind, solar and energy storage power sources include wind power generation, photovoltaic power generation and energy storage system power sources; based on the rated capacity Sg, rated power factor PFg and number N of diesel generator sets, the matching capacity design range of wind, solar and energy storage power sources is calculated according to user load data, diesel generator set operation mode and local wind and solar resource conditions; Since off-grid power stations have a basic normal load level, and there will be different degrees of load peak and valley changes at different stages of each year and between day and night, the total power balance is first calculated between the power system and the load system, and the peak power balance is achieved by combining the peak load process analysis, and finally the wind, solar and storage power capacity matching plan is comprehensively calculated; the power and power change cycle of the power source and load is analyzed in 24 hours per year and day; The specific steps include: Step 2.1: Load active power calculation The user planning data or operation statistics are: annual maximum expected load Spk, average load power factor PFa, average load rate Ra; calculate in sequence: annual average daily active load power Ld, average active load power Pd, peak active load power Fd, expressed as: Ld=Spk*PFa*Ra*24h; Pd=Ld / 24h=Spk*PFa*Ra; Fd=Pd / Ra=Spk*PFa; Step 2.2: Calculation of diesel generator set operation mode (1) Normal operation mode: at least one diesel generator set is used as a reliability standby, and the operating output power is mainly economic power. The ratio of economic power to rated power is Cr. Calculate in sequence: the average daily active load Lg, the economic power Pgj of the diesel generator set, and the rated power Pg, expressed as: Lg = (N-1) * Sg * PFg * Cr * 24h; Pgj = (N-1) * Sg * PFg * Cr; Pg = (N-1) * Sg * PFg; (2) Maximum operation mode: All diesel generator sets are running, and the following are calculated in sequence: the average daily active load Lg2, economic power Pgj2, and rated power Pg2, expressed as: Lg2=N*Sg*PFg*Cr*24h, Pgj2=N*Sg*PFg*Cr, Pg2=N*Sg*PFg; (3) Minimum operation mode: Only one diesel generator set is running, and the calculations are as follows: the average daily active load Lg3, economic power Pgj3, and rated power Pg3, expressed as: Lg3=Sg*PFg*Cr*24h; Pgj3=Sg*PFg*Cr; Pg3=Sg*PFg; Step 2.3: Calculate the design range of the energy storage system charge capacity Eb According to the daily average active load Ld and the daily average active load Lg borne by the diesel generator set in normal operation, the difference Ld-Lg is calculated, and the difference is taken as zero when it is negative; when wind and solar power are not considered, the energy storage system is required to bear the difference peak load ratio Tb, and the remaining peak load is borne by wind and solar power, the difference between the rated power and economic power of the operating unit, and the activation of the standby diesel generator set; assuming that the energy storage system charge capacity utilization rate is i, then Eb≥(Ld-Lg)*Tb / i; and Eb should not be greater than the difference between the daily average active load Ld and the daily average active load Lg3 borne by the diesel generator set in the minimum operation mode, that is, Eb≤(Ld-Lg3)*Tb / i; the result is expressed as: Max((Ld-Lg)*Tb / i, 0)≤Eb≤(Ld-Lg3)*Tb / i; Step 2.4: Calculate the power shortage during peak load period During the peak load period, the operation mode and output level of the diesel generator set are adjusted according to whether the wind, solar and storage power sources are sufficient; the normal operation mode power gap △F=Fd-Pgj; the maximum operation mode power gap △F2=Fd-Pgj2; the minimum operation mode power gap △F3=Fd-Pgj3; the power gap is borne by the wind, solar and storage power sources, the difference between the rated power and the economic power of the operating unit, and the use of the standby diesel generator set; in order to avoid excessive investment, the minimum operation mode of the diesel generator set with a low probability is not considered; Step 2.5: Calculate the total power range of wind, solar and energy storage The total power of wind, solar and storage power is expressed as Pwpb=(Pw*f+Pp*g+Pb*m)*Ts; Considering the power output fluctuation in normal operation mode or the fluctuation of diesel generator sets within a certain range, there is no need to start the standby diesel generator set, and the wind, solar and storage power supply makes up for the power difference of the diesel generator set fluctuation. For this purpose, the fluctuation coefficient k≥1 is increased to correct △F to get k*△F; Pwpb≥k*△F is designed when the wind, solar and storage simultaneous rate Ts=1 is the maximum; In order to avoid excessive waste of wind, solar and storage scale, Pwpb should be taken at a lower value; When Ts is low, the peak load is transferred to the diesel generator set; Step 2.6: Select the energy storage system power Pb The energy storage system converts electric energy through a bidirectional converter, taking into account the consistency of charging power and discharging power values; the energy storage system independently performs short-term peak regulation for power shortages, and when the discharge output coefficient is m, the power Pb range of the energy storage system is △F2 / m≤Pb≤k*△F / m; when designing the value, it is coordinated with the design of wind and solar power sources, and a comprehensive balance is struck between using a relatively low value to reduce investment costs and using a relatively large value to facilitate the economic operation of the peak-shaving diesel generator set; Step 2.7: Calculate wind power generation Pw During the peak load period at night or when photovoltaic power is insufficient, wind power generation and energy storage systems are used to peak the power supply gap of diesel generator sets; the annual average wind energy utilization probability V, the wind turbine output rate f, when wind energy is sufficient, the energy storage system discharge output coefficient m is m1 when a lower value is selected, and when m is m2 when a higher value is selected, the maximum is 1; then the wind power generation power Pw range is: (△F2-Pb*m1) / V / f≤Pw≤(k*△F-Pb*m2) / V / f, and the coordination with the energy storage system and photovoltaic power is considered when selecting the value; if the hybrid power station plan does not consider the use of wind energy, Pw can be set to 0, and the photovoltaic storage power design can be increased accordingly to meet the power supply requirements; Step 2.8: Calculate photovoltaic power generation Pp Considering the situation of no wind during the peak load period, the photovoltaic power generation and energy storage system are used to peak the power supply gap of the diesel generator set; the annual average sunlight peak probability U, the photovoltaic output rate g, when the photovoltaic is sufficient, the energy storage system discharge output coefficient m is selected as a lower value when m is m1, and a higher value when m is m2, and the maximum is 1; then the photovoltaic power generation power Pp range is (△F2-Pb*m1) / U / g≤Pp≤(k*△F-Pb*m2) / U / g; if the hybrid power station plan does not consider the use of photovoltaics, then let Pp=0, and increase the wind storage power design accordingly to meet the power supply requirements; The total power of wind, solar and energy storage is Pwpb=(Pw*f+Pp*g+Pb*m)*Ts. Take the maximum value of Ts, which is 1. Verify whether Pwpb≥k*△F in step 2.5 is satisfied. Step 2.9: Determine the energy storage system charge capacity Eb When wind power generation alone charges the energy storage system, the expected value of the amount of electricity that can be charged within time t is Eb1≥Pw*V*f*t / i; when photovoltaic power generation alone charges the energy storage system, the expected value of the amount of electricity that can be charged within time t is Eb2≥Pp*U*g*t / i; in order to meet the needs of frequent load peak regulation, the energy storage system charge capacity Eb should satisfy Eb≥Max(Eb1, Eb2); and the final range of Eb is determined jointly with Max((Ld-Lg)*Tb / i, 0)≤Eb≤(Ld-Lg3)*Tb / i in step 2.3, and the Pb value obtained in step 2.6 is combined to select the energy storage system charge capacity Eb value within this range; Step 2.10: Calculate the charging capacity of the energy storage system during peak hours During the peak load period, the active load power Fd, the power system is tight, and if the economic power and normal operation mode of the diesel generator set cannot guarantee charging, the rated power and maximum operation mode are used. Considering the fixed time periods when wind and solar are different, the expected total active power of diesel, wind and solar as the power source is: Pgwp=Pg2+Min(Pw*V*f,Pp*U*g); it is required to have the ability to charge the energy storage system at any time in each daily cycle, and the charging guarantee capacity coefficient n is expressed as: n=(Pg2+Min(Pw*V*f,Pp*U*g)-Fd) / Pb; if n>1, it means that the power supply still has margin when charging at full power; if n≤0, it means that the power supply does not have the expected margin and does not have the charging guarantee capability, and it is necessary to return to steps 2.6 to 2.9 to re-coordinate the adjustment and optimization of wind, solar and storage power Pw, Pp, Pb and charge capacity Eb within the value range; Step 2.11: Emergency endurance test In extreme cases, when all diesel generator sets fail, the wind, solar and energy storage power sources will independently support the critical load Pkey of the entire station; the expected power of wind, solar and energy storage is Pwpb'=Pb*m+Min(Pw*V*f,Pp*U*g), and the critical load Pkey is not greater than Pwpb'; the expected endurance time of the critical load is Tc1 and Tc2: when the wind, solar and energy storage power sources support the critical load, and Min(Pw*V*f,Pp*U*g) is less than Pkey, Tc1=Eb*i / (Pkey-Min(Pw*V*f,Pp*U*g)); when the wind and solar power sources are insufficient and the energy storage system independently bears the critical load, Tc2=Eb*i / Pkey; to improve the emergency endurance capability, return to steps 2.6 to 2.9, adjust within the value range of wind, solar and energy storage power and load capacity, and coordinate and optimize.

[0014] Through the above steps, a power structure capacity matching scheme for the hybrid power station is obtained, including the total capacity Ssum of the diesel generator set and the specifications and number of each unit, the wind power generation power Pw, the photovoltaic power generation power Pp, the energy storage system power Pb and the charge capacity Eb.

[0015] According to the new energy hybrid power station power supply plan, the energy-saving and environmental protection effects are calculated and analyzed.

[0016] The basic parameters include: the average annual load of the power station is 365*Ld; the average annual wind energy utilization hours Hw; the average annual sunshine hours Hp; the carbon dioxide emission rate of the diesel generator set is E; the diesel density D; the fuel consumption rate Y, the fuel consumption deviation coefficient of the operating mode l; the diesel cost C; When all loads are powered by diesel generators without wind and solar power, the average annual diesel consumption is 365*Ld*Y*l / D liters, and the annual fuel cost is C*365*Ld*Y*l / D yuan; the annual carbon dioxide emissions are E*365*Ld*Y*l / D tons; When the wind-solar-storage-diesel hybrid power station is in operation, the average annual power generation is: wind power is Pw*V*f*Hw, photovoltaic power is Pp*U*g*Hp; the total wind and solar power generation W1=Pw*V*f*Hw+Pp*U*g*Hp; the average annual fuel savings are W1*Y*l / D ten thousand liters, the annual fuel consumption cost savings are C*W1*Y*l / D ten thousand yuan, and the annual carbon dioxide emissions are reduced by E*W1*Y*l / D tons.

[0017] The beneficial effects of the present invention are: (1) Through the calibration and calculation of various indicators such as steady-state capacity, peak capacity, voltage drop, active overload, single-step loading rate, and steady-state loading rate, the capacity of the diesel generator set is selected so that it can be used as the basic power source to meet the requirements of black start, reliable support for basic load, bearing the impact of large load start-up, flexible operation mode, and cost reduction; (2) Provide a calculation method for the ratio of wind, solar and energy storage capacity, combining the requirements of power station operation mode changes, peak load regulation, charging reserve, and emergency endurance into the calculation steps, so that the power capacity ratio meets the needs of economic operation within the station, load peak regulation, energy storage charging guarantee, and emergency endurance of key loads; (3) Provide the power range and charge capacity range of wind power generation, photovoltaic power generation, and energy storage systems, design and select within the calculation range, and select the appropriate power control strategy, parallel wiring scheme, and switching method accordingly, so as to reduce capacity waste or shortage, prevent reverse power backflow of diesel generator sets, and fail to maintain bus voltage and power station stability, and improve economic energy saving and emission reduction and environmental protection levels.

[0018] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a flow chart of a method for calculating a power supply ratio range of a hybrid power station according to an embodiment of the present invention; DETAILED DESCRIPTION

[0020] The preferred embodiments of the present invention are described below. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. Example

[0021] like Figure 1 As shown in the figure, the calculation method of the power supply ratio range of the hybrid power station includes the first stage and the second stage: The first stage is the capacity calculation of diesel generator sets. The basic power supply is designed according to the user load data plan, and the rated capacity and number of diesel generator sets are selected. The second stage is the capacity calculation of wind, solar and energy storage power. According to the functional requirements and resource conditions of the whole station, the matching range of new energy wind power generation power, photovoltaic power generation power, energy storage system power and load capacity is calculated. Among them, the wind, solar and energy storage power sources are coordinated and optimized within the design value range to improve the reliability, economy and energy conservation and environmental protection level of the power station operation. The calculation method is suitable for two situations: the first situation is to match and design a wind-solar-storage power source on the basis of an existing diesel generator power station; the second situation is a completely new design of a wind-solar-storage-diesel hybrid power station; when in the first situation, directly enter the second stage calculation; when in the second situation, first perform the first stage calculation, and then perform the second stage calculation; The first stage: diesel generator capacity calculation The calculation method and formula provided by the patent technology under review "Emergency Power Station Capacity Verification Programming Calculation Method" (application publication number CN 117574616A, application publication date 2024.02.20) are adopted, which specifically includes the following steps: Step 1.1: According to the user load data plan, calculate the minimum capacity value of the diesel generator set - S G1 , S G2 , S G3 , S G4 , S G5 , S G6 , respectively satisfying the steady-state capacity S G1 , peak capacity S G2 , voltage drop S G3 , Active overload S G4 , single-step loading rate S G5 , steady-state load rate S G6 The requirements for various indicators; the calculation method is as follows; Meet the steady-state capacity:

[0022] Meeting peak capacity:

[0023] Meet the voltage drop:

[0024] Satisfy active overload:

[0025] Meet the single-step loading rate:

[0026] Meet the steady-state load rate:

[0027] This embodiment calculates S based on the user load data table and the requirements that the voltage drop does not exceed 20% and the steady-state load rate does not exceed 75%. G1 , S G2 , S G3 , S G4 , S G5 , S G6 The values ​​are 4821, 5784, 4892, 5920, 4704, 5624 (in kVA); Step 1.2: Take the maximum value SGmax of the results in step 1.1;

[0028] Calculated value of SGmax in this embodiment: SGmax=Max(4821,5784,4892,5920,4704,5624)=5920kVA; Step 1.3: Select the single-unit product specifications (rated capacity Sg, rated power factor PFg) and number N of diesel generator sets. Under the premise of ensuring that the total rated capacity Ssum of the diesel generator sets is not less than SGmax, select the diesel generator set solution to minimize Ssum, that is:

[0029] This embodiment refers to the diesel generator set products on the market, selects a single unit with a rated capacity of 2000kVA, a rated power factor of 0.8, and a quantity of 3 units; then the total capacity of the diesel generator set is Ssum=6000kVA, which is greater than SGmax=5920kVA, meeting the requirements; Phase 2: Calculation of wind, solar and energy storage capacity The wind, solar and energy storage power sources include wind power generation, photovoltaic power generation and energy storage system power sources; based on the rated capacity Sg, rated power factor PFg and number N of diesel generator sets, the matching capacity design range of wind, solar and energy storage power sources is calculated according to user load data, diesel generator set operation mode and local wind and solar resource conditions; Off-grid power stations have a basic normal load level, and there will be different degrees of load peak and valley changes at different stages of each year and between day and night. Therefore, between the power supply system and the load system, the total power balance is first calculated, and the peak power balance is achieved by combining the peak load process analysis. Finally, the wind, solar and storage power capacity matching plan is comprehensively calculated; the power and power change cycle of the power supply and load is analyzed in 24 hours per year and day; Step 2.1: Load active power calculation The user planning data or operation statistics are: annual maximum expected load Spk, average load power factor PFa, average load rate Ra; calculate in sequence: annual average daily active load power Ld, average active load power Pd, peak active load power Fd, expressed as: Ld=Spk*PFa*Ra*24h; Pd=Ld / 24h=Spk*PFa*Ra; Fd=Pd / Ra=Spk*PFa; The user data of this embodiment is Spk=4900kVA, PFa=0.85, Ra=60%; the calculation results are Ld=59976kWh; Pd=2499kW; Fd=4165kW; Step 2.2: Calculation of diesel generator set operation mode (1) Normal operation mode: at least one diesel generator set is used as a reliability standby, and the operating output power is mainly economic power. The ratio of economic power to rated power is Cr. Calculate in sequence: the average daily active load Lg, the economic power Pgj of the diesel generator set, and the rated power Pg, expressed as: Lg = (N-1) * Sg * PFg * Cr * 24h; Pgj = (N-1) * Sg * PFg * Cr; Pg = (N-1) * Sg * PFg; This embodiment has three diesel generator sets, two of which are working and one is on standby; Cr=0.75; the calculation results are Lg=57600kWh, Pgj=2400kW, Pg=3200kW; (2) Maximum operation mode: All diesel generator sets are running, and the following are calculated in sequence: the average daily active load Lg2, economic power Pgj2, and rated power Pg2, expressed as: Lg2=N*Sg*PFg*Cr*24h, Pgj2=N*Sg*PFg*Cr, Pg2=N*Sg*PFg; The calculation results of this embodiment are Lg2=86400kWh, Pgj2=3600kW, Pg2=4800kW; (3) Minimum operation mode: Only one diesel generator set is running, and the calculations are as follows: the average daily active load Lg3, economic power Pgj3, and rated power Pg3, expressed as: Lg3=Sg*PFg*Cr*24h; Pgj3=Sg*PFg*Cr; Pg3=Sg*PFg; The calculation results of this embodiment are Lg3=28800kWh, Pgj3=1200kW, Pg3=1600kW; Step 2.3: Calculate the design range of the energy storage system charge capacity Eb According to the daily average active load Ld and the daily average active load Lg that the diesel generator set can bear in normal operation, the difference Ld-Lg is calculated (the difference is taken as zero when it is negative); when wind and solar power are not considered, the energy storage system is required to bear the difference peak load ratio Tb, and the remaining peak load is borne by wind and solar power, the difference between the rated power and economic power of the operating unit, and the activation of the standby diesel generator set; assuming that the energy storage system charge capacity utilization rate is i, then Eb≥(Ld-Lg)*Tb / i; and Eb should not be greater than the difference between the daily average active load Ld and the daily average active load Lg3 borne by the diesel generator set in the minimum operation mode, that is, Eb≤(Ld-Lg3)*Tb / i; the result is expressed as: Max((Ld-Lg)*Tb / i, 0)≤Eb≤(Ld-Lg3)*Tb / i; In this embodiment, based on Ld=59976kWh, Lg=57600kWh, the difference is calculated as Ld-Lg=2376kWh; the peak load ratio Tb=10%, the charge capacity utilization rate i=70%; the charge capacity calculation result is 339kWh≤Eb≤4454kWh; Step 2.4: Calculate the power shortage during peak load period During the peak load period, the operation mode and output level of the diesel generator set are adjusted according to whether the wind, solar and storage power sources are sufficient; the normal operation mode power gap △F=Fd-Pgj; the maximum operation mode power gap △F2=Fd-Pgj2; the minimum operation mode power gap △F3=Fd-Pgj3; the power gap is borne by the wind, solar and storage power sources, the difference between the rated power and the economic power of the operating unit, and the use of the standby diesel generator set; in order to avoid excessive investment, the minimum operation mode of the diesel generator set with a low probability is not considered; The power shortage calculation of this embodiment is: normal operation mode △F=1765kW, maximum operation mode △F2=565kW, minimum operation mode △F3=2965kW; Step 2.5: Calculate the total power range of wind, solar and energy storage The total power of wind, solar and storage power is expressed as Pwpb=(Pw*f+Pp*g+Pb*m)*Ts (see steps 2.6 to 2.8); Considering the power output fluctuations in normal operation or the fluctuations of diesel generator sets within a certain range, there is no need to start the standby diesel generator set. The wind, solar and storage power supplies make up for the power difference of the diesel generator set fluctuations. For this purpose, the fluctuation coefficient k≥1 is increased to correct △F to obtain k*△F; Pwpb≥k*△F is designed when the wind, solar and storage simultaneous rate Ts=1 (maximum); In order to avoid excessive waste of wind, solar and storage scale, Pwpb should be taken at a lower value; when Ts is low, the peak load is transferred to the diesel generator set; In this embodiment, k=1.2, and the calculation result is that Pwpb should be no less than 2118kW; Step 2.6: Select the energy storage system power Pb The energy storage system converts electric energy through a bidirectional converter, taking into account the consistency of charging power and discharging power values; the energy storage system independently performs short-term peak regulation for power shortages, and when the discharge output coefficient is m, the power Pb range of the energy storage system is △F2 / m≤Pb≤k*△F / m; when designing the value, it is coordinated with the design of wind and solar power sources, and a comprehensive balance is struck between using a relatively low value to reduce investment costs and using a relatively large value to facilitate the economic operation of the peak-shaving diesel generator set; In this embodiment, m=1, the energy storage system power is 565kW≤Pb≤2118kW, and a lower value is adopted, and Pb=1000kW is selected; Step 2.7: Calculate wind power generation Pw During the peak load period at night or when photovoltaic power is insufficient, wind power generation and energy storage systems are used to peak the power supply gap of diesel generator sets; the annual average wind energy utilization probability V, the wind turbine output rate f, when wind energy is sufficient, the energy storage system discharge output coefficient m is m1, select a lower value (smaller peak-shaving gap), and select a higher value (larger peak-shaving gap) when m is m2, and the maximum is 1; then the wind power generation power Pw range is: (△F2-Pb*m1) / V / f≤Pw≤(k*△F-Pb*m2) / V / f, and the coordination with the energy storage system and photovoltaic power is considered when selecting the value; if the hybrid power station plan does not consider the use of wind energy, Pw can be set to 0, and the photovoltaic storage power design can be increased accordingly to meet the power supply requirements; In this embodiment, the average annual wind energy utilization probability V=0.62 is obtained or estimated based on user data, the wind turbine output rate f=0.75, and m1=m2=0.2 is taken; the calculation range of Pw is: 785kW≤Pw≤4125kW, and the lower value is Pw=800kW; Step 2.8: Calculate the photovoltaic power generation power Pp Considering the situation of no wind during the peak load period, photovoltaic power generation and energy storage system are used to peak the power supply gap of diesel generator sets; the annual average sunshine peak probability U, photovoltaic output rate g, when photovoltaic is sufficient, the energy storage system discharge output coefficient m is m1, select a lower value (smaller peak-shaving gap), and select a higher value (larger peak-shaving gap) when m is m2, and the maximum is 1; then the photovoltaic power generation power Pp range is (△F2-Pb*m1) / U / g≤Pp≤(k*△F-Pb*m2) / U / g; if the hybrid power station plan does not consider the use of photovoltaics, Pp can be set to 0, and the wind storage power design can be increased accordingly to meet the power supply requirements; The total power of wind, solar and energy storage is Pwpb=(Pw*f+Pp*g+Pb*m)*Ts. Take the maximum value of Ts (the maximum value is 1) and verify whether Pwpb≥k*△F in step 2.5 is satisfied; In this embodiment, the annual average sunshine peak probability U=0.67 is obtained or estimated based on user data, the photovoltaic output rate g=0.75, and m1=m2=0.2 is taken; the Pp calculation range is: 726kW≤Pw≤3817kW, and the lower value is Pw=750kW; the total wind-solar-storage power Pwpb=2163kW>2118kW is calculated, which meets the requirement of Pwpb≥k*△F=2118kW in step 2.5; Step 2.9: Determine the energy storage system charge capacity Eb When wind power generation alone charges the energy storage system, the expected value of the amount of electricity that can be charged within time t is Eb1≥Pw*V*f*t / i; when photovoltaic power generation alone charges the energy storage system, the expected value of the amount of electricity that can be charged within time t is Eb2≥Pp*U*g*t / i; in order to meet the needs of frequent load peak regulation, the energy storage system charge capacity Eb should satisfy Eb≥Max(Eb1, Eb2); and the final range of Eb is determined jointly with Max((Ld-Lg)*Tb / i, 0)≤Eb≤(Ld-Lg3)*Tb / i in step 2.3, and the Pb value obtained in step 2.6 is combined to select the energy storage system charge capacity Eb value within this range; In this embodiment, t=3h is designed, and Eb1≥1593kWh and Eb2≥1615kWh are calculated. The larger one is selected, and Eb≥1615kWh. Combined with 339kWh≤Eb≤4454kWh in step 2.3, the final result is 1615kWh≤Eb≤4454kWh. According to the result of step 2.6, Pb=1000kW, Eb=2000kWh can be selected. Step 2.10: Calculate the charging capacity of the energy storage system during peak hours During the peak load period, the active load power Fd, the power system is tight, and if the economic power and normal operation mode of the diesel generator set cannot guarantee charging, the rated power and maximum operation mode are used. Considering the fixed period (night) when the wind and solar are different, the expected total active power of the diesel, wind and solar as the power source is: Pgwp=Pg2+Min(Pw*V*f,Pp*U*g); it is required to have the ability to charge the energy storage system at any time in each daily cycle, and the charging guarantee capacity coefficient n is expressed as: n=(Pg2+Min(Pw*V*f,Pp*U*g)-Fd) / Pb; if n>1, it means that the power supply still has margin when charging at full power; if n≤0, it means that the power supply does not have the expected margin and does not have the charging guarantee capability, and it is necessary to return to steps 2.6 to 2.9 to re-coordinate the adjustment and optimization of the wind, solar and storage power Pw, Pp, Pb and the charge capacity Eb within the value range; The charging guarantee capability coefficient n of this embodiment is required to be no less than 0.5; the calculated value n=(4800+Min(372,377)-4165) / 1000=1.01>0.5, which meets the requirement; Step 2.11: Emergency endurance test In extreme cases, when all diesel generator sets fail, the wind, solar and energy storage power sources will independently support the critical load Pkey of the entire station; the expected power of wind, solar and energy storage is Pwpb'=Pb*m+Min(Pw*V*f,Pp*U*g), and the critical load Pkey is not greater than Pwpb'; the expected endurance time of the critical load is Tc1 and Tc2: when the wind, solar and energy storage power sources support the critical load, and Min(Pw*V*f,Pp*U*g) is less than Pkey, Tc1=Eb*i / (Pkey-Min(Pw*V*f,Pp*U*g)); when the wind and solar power sources are insufficient and the energy storage system independently bears the critical load, Tc2=Eb*i / Pkey; to improve the emergency endurance capability, return to steps 2.6 to 2.9, adjust within the range of wind, solar and energy storage power and load capacity, and coordinate and optimize.

[0030] In this embodiment, Pkey=720kW; Min(Pw*V*f,Pp*U*g)=372, Pwpb'=1372kW; the calculated wind-solar-storage emergency endurance time is Tc1=4 hours; the independent emergency endurance time of the energy storage system is Tc2=1.95 hours.

[0031] Through the above steps, a power structure capacity matching scheme for the hybrid power station is obtained, in which the total capacity of the diesel generator set Ssum=6000kVA, composed of 3 2000kVA units, wind power generation power Pw=800kW, photovoltaic power generation power Pp=750kW, energy storage system power Pb=1000kW and charge capacity Eb=2000kWh.

[0032] According to the new energy hybrid power station power supply plan, the energy-saving and environmental protection effects are calculated and analyzed.

[0033] The basic parameters include: the average annual load of the power station is 365*Ld; the average annual wind energy utilization hours Hw; the average annual sunshine hours Hp; the carbon dioxide emission rate of the diesel generator set is E (kg / L diesel); the diesel density D (kg / L); the fuel consumption rate Y (kg / kWh), the fuel consumption deviation coefficient of the operating mode l; the diesel cost C (yuan / L); When all loads are powered by diesel generators (without wind and solar power), the average annual diesel consumption is 365*Ld*Y*l / D (liters), and the annual fuel cost is C*365*Ld*Y*l / D (yuan); the annual carbon dioxide emissions are E*365*Ld*Y*l / D (tons); When the wind, solar, storage and diesel hybrid power station is in operation, the average annual power generation is: wind power is Pw*V*f*Hw, photovoltaic power is Pp*U*g*Hp; the total wind and solar power generation W1=Pw*V*f*Hw+Pp*U*g*Hp; the average annual fuel saving is W1*Y*l / D (10,000 liters), the annual fuel consumption cost saving is C*W1*Y*l / D (10,000 yuan), and the annual carbon dioxide emission reduction is E*W1*Y*l / D (tons).

[0034] The specific data calculation and analysis of the energy saving and emission reduction effect of this embodiment are as follows: Specific values ​​of basic parameters: 365*Ld=21891.24MWh; Hw=5400h; Hp=3200h; E=2.63 (kg / L diesel); D=0.84 (kg / L); Y=0.2 (kg / kWh), l=1.12; C=7.6 (yuan / L); the calculation results are as follows: Diesel generator power station (without wind and solar power): annual diesel consumption is 5.838 million liters, fuel cost is 44.366 million yuan, and carbon dioxide emissions are 15,353 tons; Energy saving and emission reduction effect of hybrid power station: According to the power generation of new energy (wind power 2008.8MWh, photovoltaic power 1206MWh, wind and solar power total 3215MWh), the annual fuel saving is 857,000 liters, the fuel consumption cost is saved by 652,000 yuan, and the carbon dioxide emissions are reduced by 2255 tons.

Claims

1. A method for calculating the power ratio range of a hybrid power station, characterized in that: It includes the first and second phases; The first stage is to calculate the capacity of diesel generator sets, design the basic power supply according to the user load data scheme, and select the rated capacity and number of diesel generator sets; The second stage is the calculation of wind, solar and energy storage power capacity. According to the functional requirements and resource conditions of the entire station, the matching range of new energy wind power generation power, photovoltaic power generation power, energy storage system power and load capacity is calculated.

2. The method for calculating the power supply ratio range of a hybrid power station according to claim 1, characterized in that: The calculation method is suitable for two situations: the first situation is to design a wind, solar, and energy storage power source based on an existing diesel generator power station; the second situation is a completely new design of a wind, solar, and energy storage diesel hybrid power station; when in the first situation, directly enter the second stage calculation; when in the second situation, first perform the first stage calculation, and then perform the second stage calculation.

3. The method for calculating the power supply ratio range of a hybrid power station according to claim 1, characterized in that: The first stage is the capacity calculation of the diesel generator set, which specifically includes the following steps: Step 1.1: According to the user load data plan, calculate the minimum capacity value of the diesel generator set - S G1 , S G2 , S G3 , S G4 , S G5 , S G6 , respectively satisfying the steady-state capacity S G1 , peak capacity S G2 , voltage drop S G3 , Active overload S G4 , single-step loading rate S G5 , steady-state load rate S G6 The requirements for various indicators; the calculation method is as follows; Meet the steady-state capacity: ， Meeting peak capacity: ， Meet the voltage drop: ， Satisfy active overload: ， Meet the single-step loading rate: ， Meet the steady-state load rate: ； Step 1.2: Take the maximum value SGmax of the results in step 1.1; ， Step 1.3: Select the single-unit product specifications and number N of diesel generator sets. Under the premise of ensuring that the total rated capacity Ssum of the diesel generator sets is not less than SGmax, select the diesel generator set solution to minimize Ssum, that is: 。 4. The method for calculating the power supply ratio range of a hybrid power station according to claim 1, characterized in that: The second stage is the calculation of wind, solar and energy storage capacity; The wind, solar and energy storage power sources include wind power generation, photovoltaic power generation and energy storage system power sources; based on the rated capacity Sg, rated power factor PFg and number N of diesel generator sets, the matching capacity design range of wind, solar and energy storage power sources is calculated according to user load data, diesel generator set operation mode and local wind and solar resource conditions; Off-grid power stations have a basic normal load level, and there will be different degrees of load peak and trough changes at different stages of each year and between day and night. Therefore, between the power supply system and the load system, the total power balance is calculated first, and the peak power balance is achieved in combination with the peak-shaving process analysis. Finally, a comprehensive calculation is made to match the capacity of wind, solar and power storage sources. The power and power change cycle of the power supply and load is analyzed in annual and daily 24-hour cycles.

5. The method for calculating the power supply ratio range of a hybrid power station according to claim 4, characterized in that: The wind-solar-energy storage power capacity calculation specifically includes the following steps: Step 2.1: Load active power calculation The user planning data or operation statistics are: annual maximum expected load Spk, average load power factor PFa, average load rate Ra; calculate in sequence: annual average daily active load power Ld, average active load power Pd, peak active load power Fd, expressed as: Ld=Spk*PFa*Ra*24h; Pd=Ld / 24h=Spk*PFa*Ra; Fd=Pd / Ra=Spk*PFa; Step 2.2: Calculation of diesel generator set operation mode (1) Normal operation mode: at least one diesel generator set is used as a reliability standby, and the operating output power is mainly economic power. The ratio of economic power to rated power is Cr. Calculate in sequence: the average daily active load Lg, the economic power Pgj of the diesel generator set, and the rated power Pg, expressed as: Lg = (N-1) * Sg * PFg * Cr * 24h; Pgj = (N-1) * Sg * PFg * Cr; Pg = (N-1) * Sg * PFg; (2) Maximum operation mode: All diesel generator sets are running, and the following are calculated in sequence: the average daily active load Lg2, economic power Pgj2, and rated power Pg2, expressed as: Lg2=N*Sg*PFg*Cr*24h, Pgj2=N*Sg*PFg*Cr, Pg2=N*Sg*PFg; (3) Minimum operation mode: Only one diesel generator set is running, and the calculations are as follows: the average daily active load Lg3, economic power Pgj3, and rated power Pg3, expressed as: Lg3=Sg*PFg*Cr*24h; Pgj3=Sg*PFg*Cr; Pg3=Sg*PFg; Step 2.3: Calculate the design range of the energy storage system charge capacity Eb According to the daily average active load Ld and the daily average active load Lg that the diesel generator set can bear in normal operation, the difference Ld-Lg is calculated, and the difference is taken as zero when it is negative; when wind and solar power are not considered, the energy storage system is required to bear the difference peak load ratio Tb, and the remaining peak load is borne by wind and solar power, the difference between the rated power and economic power of the operating unit, and the activation of the standby diesel generator set; assuming that the energy storage system charge capacity utilization rate is i, then Eb≥(Ld-Lg)*Tb / i; and Eb should not be greater than the difference between the daily average active load Ld and the daily average active load Lg3 borne by the diesel generator set in the minimum operation mode, that is, Eb≤(Ld-Lg3)*Tb / i; the result is expressed as: Max((Ld-Lg)*Tb / i, 0)≤Eb≤(Ld-Lg3)*Tb / i; Step 2.4: Calculate the power shortage during peak load period During the peak load period, the operation mode and output level of the diesel generator set are adjusted according to whether the wind, solar and storage power sources are sufficient; the normal operation mode power gap △F=Fd-Pgj; the maximum operation mode power gap △F2=Fd-Pgj2; the minimum operation mode power gap △F3=Fd-Pgj3; the power gap is borne by the wind, solar and storage power sources, the difference between the rated power and the economic power of the operating unit, and the use of the standby diesel generator set; in order to avoid excessive investment, the minimum operation mode of the diesel generator set with a low probability is not considered; Step 2.5: Calculate the total power range of wind, solar and energy storage The total power of wind, solar and storage power is expressed as Pwpb=(Pw*f+Pp*g+Pb*m)*Ts; Considering the power output fluctuation in normal operation mode or the fluctuation of diesel generator sets within a certain range, there is no need to start the standby diesel generator set, and the wind, solar and storage power supply makes up for the power difference of the diesel generator set fluctuation. For this purpose, the fluctuation coefficient k≥1 is increased to correct △F to get k*△F; Pwpb≥k*△F is designed when the wind, solar and storage simultaneous rate Ts=1 is the maximum; In order to avoid excessive waste of wind, solar and storage scale, Pwpb should be taken at a lower value; When Ts is low, the peak load is transferred to the diesel generator set; Step 2.6: Select the energy storage system power Pb The energy storage system converts electric energy through a bidirectional converter, taking into account the consistency of charging power and discharging power values; the energy storage system independently performs short-term peak regulation for power shortages, and when the discharge output coefficient is m, the power Pb range of the energy storage system is △F2 / m≤Pb≤k*△F / m; when designing the value, it is coordinated with the design of wind and solar power sources, and a comprehensive balance is struck between using a relatively low value to reduce investment costs and using a relatively large value to facilitate the economic operation of the peak-shaving diesel generator set; Step 2.7: Calculate wind power generation Pw During the peak load period at night or when photovoltaic power is insufficient, wind power generation and energy storage systems are used to peak the power supply gap of diesel generator sets; the annual average wind energy utilization probability V, the wind turbine output rate f, when wind energy is sufficient, the energy storage system discharge output coefficient m is selected as a lower value when m is m1, and a higher value when m is m2, with a maximum of 1; then the wind power generation power Pw range is: (△F2-Pb*m1) / V / f≤Pw≤(k*△F-Pb*m2) / V / f, and the coordination with the energy storage system and photovoltaic power is considered when selecting the value; if the hybrid power station plan does not consider the use of wind energy, then set Pw=0, and increase the photovoltaic storage power design accordingly to meet the power supply requirements; Step 2.8: Calculate photovoltaic power generation Pp Considering the situation of no wind during the peak load period, the photovoltaic power generation and energy storage system are used to peak the power supply gap of the diesel generator set; the annual average sunlight peak probability U, the photovoltaic output rate g, when the photovoltaic is sufficient, the energy storage system discharge output coefficient m is selected as a lower value when m is m1, and a higher value when m is m2, and the maximum is 1; then the photovoltaic power generation power Pp range is (△F2-Pb*m1) / U / g≤Pp≤(k*△F-Pb*m2) / U / g; if the hybrid power station plan does not consider the use of photovoltaics, then let Pp=0, and increase the wind storage power design accordingly to meet the power supply requirements; The total power of wind, solar and storage is Pwpb=(Pw*f+Pp*g+Pb*m)*Ts. Take the maximum value of Ts, which is 1. Verify whether Pwpb≥k*△F in step 2.5 is satisfied. Step 2.9: Determine the energy storage system charge capacity Eb When wind power generation alone charges the energy storage system, the expected value of the amount of electricity that can be charged within time t is Eb1≥Pw*V*f*t / i; when photovoltaic power generation alone charges the energy storage system, the expected value of the amount of electricity that can be charged within time t is Eb2≥Pp*U*g*t / i; in order to meet the needs of frequent load peak regulation, the energy storage system charge capacity Eb should satisfy Eb≥Max(Eb1, Eb2); and the final range of Eb is determined jointly with Max((Ld-Lg)*Tb / i, 0)≤Eb≤(Ld-Lg3)*Tb / i in step 2.3, and the Pb value obtained in step 2.6 is combined to select the energy storage system charge capacity Eb value within this range; Step 2.10: Calculate the charging capacity of the energy storage system during peak hours During the peak load period, the active load power Fd, the power system is tight, and if the economic power and normal operation mode of the diesel generator set cannot guarantee charging, the rated power and maximum operation mode are used. Considering the fixed time periods when wind and solar are different, the expected total active power of diesel, wind and solar as the power source is: Pgwp=Pg2+Min(Pw*V*f,Pp*U*g); it is required to have the ability to charge the energy storage system at any time in each daily cycle, and the charging guarantee capacity coefficient n is expressed as: n=(Pg2+Min(Pw*V*f,Pp*U*g)-Fd) / Pb; if n>1, it means that the power supply still has margin when charging at full power; if n≤0, it means that the power supply does not have the expected margin and does not have the charging guarantee capability, and it is necessary to return to steps 2.6 to 2.9 to re-coordinate the adjustment and optimization of wind, solar and storage power Pw, Pp, Pb and charge capacity Eb within the value range; Step 2.11: Emergency endurance test In extreme cases, when all diesel generator sets fail, the wind, solar and energy storage power sources will independently support the critical load Pkey of the entire station; the expected power of wind, solar and energy storage is Pwpb'=Pb*m+Min(Pw*V*f,Pp*U*g), and the critical load Pkey is not greater than Pwpb'; the expected endurance time of the critical load is Tc1 and Tc2: when the wind, solar and energy storage power sources support the critical load, and Min(Pw*V*f,Pp*U*g) is less than Pkey, Tc1=Eb*i / (Pkey-Min(Pw*V*f,Pp*U*g)); when the wind and solar power sources are insufficient and the energy storage system independently bears the critical load, Tc2=Eb*i / Pkey; if you want to improve the emergency endurance capability, return to steps 2.6 to 2.9, adjust within the value range of wind, solar and energy storage power and load capacity, and coordinate and optimize.

6. The method for calculating the power supply ratio range of a hybrid power station according to claim 1, characterized in that: A power structure capacity matching scheme of a hybrid power station is obtained by the calculation method, including the total capacity Ssum of diesel generator sets and the specifications and number of single machines, wind power generation power Pw, photovoltaic power generation power Pp, energy storage system power Pb and charge capacity Eb.

7. The method for calculating the power supply ratio range of a hybrid power station according to claim 1, characterized in that: According to the new energy hybrid power station power supply plan, the energy-saving and environmental protection effects are calculated and analyzed, including the following contents: The basic parameters include: the average annual load of the power station is 365*Ld; the average annual wind energy utilization hours Hw; the average annual sunshine hours Hp; the carbon dioxide emission rate of the diesel generator set is E; the diesel density D; the fuel consumption rate Y, the fuel consumption deviation coefficient of the operating mode l; the diesel cost C; When all loads are powered by diesel generators without wind and solar power, the average annual diesel consumption is 365*Ld*Y*l / D liters, and the annual fuel cost is C*365*Ld*Y*l / D yuan; the annual carbon dioxide emissions are E*365*Ld*Y*l / D tons; When the wind, solar, storage and diesel hybrid power station is in operation, the average annual power generation is: wind power is Pw*V*f*Hw, photovoltaic power is Pp*U*g*Hp; the total wind and solar power generation W1=Pw*V*f*Hw+Pp*U*g*Hp; the average annual fuel savings are W1*Y*l / D ten thousand liters, the annual fuel consumption cost savings are C*W1*Y*l / D ten thousand yuan, and the annual carbon dioxide emissions are reduced by E*W1*Y*l / D tons.

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