Photovoltaic and energy storage coupled power generation optimization calculation method and system

Abstract

The present invention provides a method and system for optimizing the calculation of power generation coupled with photovoltaic and energy storage, and relates to the technical field of photovoltaic power generation optimization calculation. The method includes: obtaining measurement data; dividing the measurement data into time periods according to a preset cycle; calibrating the attributes of each divided time period according to the operating state of the power system; judging the priority strategy adopted in the current valley time period according to the remaining available power in the valley time period; calculating the output data of the photovoltaic system in each time period according to the attributes and strategies of each time period; calculating the output data of the energy storage system in each time period according to the attributes of the time period; calculating the output data at the transformer bus corresponding to the photovoltaic grid connection and the output data at the photovoltaic grid connection point according to the output data of the photovoltaic system and the output data of the energy storage system. The method and system of the present invention can significantly improve the calculation efficiency and calculation accuracy, and provide reliable data support for the operation of photovoltaic and energy storage systems.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic power generation optimization calculation, and in particular to a photovoltaic and energy storage coupled power generation optimization calculation method and system. Background Art

[0002] At present, the annual power generation and sales of photovoltaic power generation are different due to the inconsistent natural conditions (geographic location, weather conditions) in various regions. Photovoltaic equipment and energy storage equipment will produce different degrees of loss over time, which will also affect the total amount of power generation. Since photovoltaic energy storage power generation systems have limitations such as energy storage system capacity, i.e., the maximum power on the grid, as well as the volatility of photovoltaic system power generation, a single calculation method cannot simulate all power generation situations. A method is needed to couple the two, simulate the performance of the entire system, and formulate charging strategies under different circumstances to achieve the optimization of power generation. Most of the existing calculation schemes are manual statistics of power generation over the years. The statistical dimensions are only the amount of electricity generated by the photovoltaic system and the amount of electricity input into the grid, and manual predictions are made, which has a large limitation on the calculation range. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0004] To this end, a first aspect of the present invention provides a method for optimizing the calculation of power generation by coupling photovoltaics with energy storage.

[0005] A second aspect of the present invention provides a photovoltaic and energy storage coupled power generation optimization calculation system.

[0006] The present invention provides a method for optimizing the calculation of power generation by coupling photovoltaic and energy storage, comprising:

[0007] Obtaining photovoltaic system measurement data and energy storage system measurement data;

[0008] Dividing the photovoltaic system measurement data into time periods according to a preset cycle;

[0009] According to the operation status of the power system, attribute calibration is performed on each divided time period, and the attribute calibration includes marking the current time period as a valley time period, a peak time period or a blank time period;

[0010] According to the remaining available power in the off-peak time period, determine the priority strategy adopted in the current off-peak time period, wherein the priority strategy includes an Internet access priority strategy and a charging priority strategy;

[0011] According to the attributes and strategies of each time period, the photovoltaic system output data in each time period is calculated respectively, wherein the photovoltaic system output data includes the photovoltaic system DC power generation, the photovoltaic system AC power generation, the amount of abandoned light and the photovoltaic system loss;

[0012] According to the time period attributes, the energy storage system output data is calculated for each time period, wherein the energy storage system output data includes the DC power, AC power, power ratio, power and loss of the energy storage system;

[0013] Calculate the output data of the transformer bus corresponding to the photovoltaic grid connection according to the output data of the photovoltaic system and the output data of the energy storage system. The output data of the transformer bus includes at least the transformer loss.

[0014] The output data at the photovoltaic grid connection point is calculated based on the photovoltaic system output data and the energy storage system output data. The output data at the grid connection point at least includes line loss and overall power station power.

[0015] The photovoltaic and energy storage coupled power generation optimization calculation method according to the above technical solution of the present invention may also have the following additional technical features:

[0016] In the above technical solution, the photovoltaic system measurement data includes the power actually generated by the photovoltaic system and the output power of the photovoltaic system;

[0017] The energy storage system measurement data includes factory acceptance test battery capacity, battery health status, contract year battery capacity, battery charging efficiency, battery discharging efficiency, battery operating loss, battery standby loss and DC limit power.

[0018] In the above technical solution, the attribute calibration of each divided time period according to the operating state of the power system includes:

[0019] According to the peak and valley time period information pre-divided by the power system, the attributes of each divided time period are judged. When the divided time period is in the peak time period of the power system, the time period is marked as the peak time period; when the divided time period is in the valley time period of the power system, the time period is marked as the valley time period; when the divided time period is in the remaining time periods of the power system except the peak time period and the valley time period, the time period is marked as the blank time period;

[0020] During peak hours, the energy storage system discharges and all the electricity generated by the photovoltaic system is connected to the grid;

[0021] When the time period is off-peak, the power generation of the photovoltaic system is prioritized to the grid or charging according to the set strategy;

[0022] When the time period is a blank period, the electricity generated by the photovoltaic system cannot be connected to the grid and is used to charge the energy storage system.

[0023] In the above technical solution, the priority strategy to be adopted in the current off-peak time period is determined according to the remaining available power in the off-peak time period, including:

[0024] Calculate the remaining available power during the off-peak period, that is, the total available power generated by the photovoltaic system from this period to the end of the off-peak period. If the total available power is greater than the power required to fully charge the battery, the grid-connection priority strategy is adopted during this period. If the total available power is less than the power required to fully charge the battery, the charging priority strategy is adopted during this period.

[0025] In the above technical solution, the step of determining the priority strategy to be adopted in the current off-peak time period according to the remaining available power in the off-peak time period further includes:

[0026] In the grid-connected priority strategy, the power output by the photovoltaic system is prioritized for grid-connected access. When the output power of the photovoltaic system exceeds the maximum grid-connected power, the excess power is used to charge the energy storage system, and the excess power that further exceeds the upper limit of the energy storage system's charging power is directly discarded. The charging process stops after the energy storage system is fully charged, and thereafter, all the output power of the photovoltaic system is used to grid-connected access, and the part that exceeds the maximum grid-connected power is discarded.

[0027] In the charging priority strategy, the power output by the photovoltaic system is used to charge the energy storage system according to a preset ratio. When the power output by the photovoltaic system is greater than the amount of power required to fully charge the battery, the excess is used to power the grid.

[0028] In the above technical solution, the photovoltaic system output data in each time period is calculated according to the attributes and strategies of each time period, including:

[0029] Calculate the DC power generation of the photovoltaic system based on the actual power generated by the photovoltaic system;

[0030] Calculate the AC power generation of the photovoltaic system based on the output power of the photovoltaic system and the amount of abandoned light;

[0031] For blank time periods:

[0032] The photovoltaic system has no output, and the amount of abandoned light is 0. The photovoltaic system loss is calculated based on the power consumed by the photovoltaic system from the grid when it is not loaded and the availability of the photovoltaic system;

[0033] For valley time period:

[0034] The photovoltaic system loss is 0;

[0035] When the grid-connected priority strategy is adopted, when the actual output power of the photovoltaic system is less than or equal to the sum of the maximum grid-connected power and the battery working loss, the amount of abandoned light is the part of the actual output power of the photovoltaic system that exceeds the sum of the maximum grid-connected power and the battery standby loss; when the actual output power of the photovoltaic system is greater than the sum of the maximum grid-connected power and the battery working loss, the amount of abandoned light is dynamically determined according to the battery power. Before the battery is fully charged, the battery charging power cannot exceed its maximum limit, and the excess is regarded as the amount of abandoned light;

[0036] When the charging priority strategy is adopted, when the battery is not fully charged, the abandoned light amount is the part of the actual output power of the photovoltaic system that exceeds the sum of the maximum charging power of the battery and the maximum online power; when the battery is fully charged, the abandoned light amount is the part of the actual output power of the photovoltaic system that exceeds the sum of the maximum online power and the battery standby loss;

[0037] For peak time periods:

[0038] The amount of abandoned light in the PV system is 0, and the PV system loss is calculated based on the power consumed by the PV system from the grid when it is not loaded and the PV system availability.

[0039] In the above technical solution, the energy storage system output data in each time period is calculated according to the time period attributes, including:

[0040] For blank time periods:

[0041] If the actual power generation of the photovoltaic system is still surplus after meeting the power demand of the station, the reactive power of the transformer and the working loss of the battery, the surplus will be used as the AC power of the energy storage system, and the DC power is the AC power multiplied by the battery charging efficiency; otherwise, the energy storage system will not work;

[0042] The amount of energy stored in the energy storage system in the current period is the amount of energy stored in the previous period plus the amount of charge stored in the current period or minus the amount of discharge stored in the current period;

[0043] When the energy storage system is working, the loss of the energy storage system is equal to the working loss of the battery; when the energy storage system is not working, the loss of the energy storage system is equal to the standby loss of the battery;

[0044] For valley time period:

[0045] When the grid-connected priority strategy is adopted, when the actual output power of the photovoltaic system is less than or equal to the sum of the maximum grid-connected power and the battery working loss, the energy storage system does not work, the AC power and DC power of the energy storage system are both 0, the power of the energy storage system remains unchanged, and the loss of the energy storage system is the battery standby loss; when the actual output power of the photovoltaic system is greater than the sum of the maximum grid-connected power and the battery working loss, the loss of the energy storage system is the battery working loss, the AC power of the energy storage system is the excess power after deducting the energy storage system loss and the maximum grid-connected power consumption from the actual output power of the photovoltaic system, and is not greater than the maximum charging power of the battery, and the DC power is the AC power multiplied by the battery charging efficiency;

[0046] When the charging priority strategy is adopted, the energy storage system works and the energy storage system loss is the battery working loss. When the power allocated to the grid is greater than the maximum online power, the AC power is the excess power after deducting the energy storage system loss and the maximum online power from the actual output power of the photovoltaic system; when the power allocated to the grid is not greater than the maximum online power, the AC power does not exceed the maximum charging power of the battery, and the proportion of each charge decreases according to the value set by the charging strategy; the DC power is the AC power multiplied by the battery charging efficiency;

[0047] For peak time periods:

[0048] The energy storage system discharges. During the discharge process, the AC power of the energy storage system is determined according to the maximum grid-connected power and battery loss, and the DC power is calculated according to the battery discharge efficiency. Before the battery is discharged to 0, the loss of the energy storage system is the battery working loss, and after the battery is discharged to 0, the loss of the energy storage system is the battery standby loss.

[0049] In the above technical solution, the output data at the transformer bus corresponding to photovoltaic grid connection is calculated according to the photovoltaic system output data and the energy storage system output data, including:

[0050] The total power of the energy storage system is the AC power of the energy storage system minus the battery operating loss;

[0051] The total power of the photovoltaic system is the AC power generated by the photovoltaic system;

[0052] When the photovoltaic system and the energy storage system need to be powered off the grid, the transformer loss is the reactive loss of the transformer; when the photovoltaic system or the energy storage system does not need to be powered off the grid, the active loss is calculated based on the total power of the energy storage system and the total power of the photovoltaic system, and the transformer loss is the sum of the reactive loss and the active loss.

[0053] In the above technical solution, the output data at the photovoltaic grid connection point is calculated according to the photovoltaic system output data and the energy storage system output data, including:

[0054] The total power of the energy storage system is the AC power of the energy storage system minus the battery operating loss;

[0055] The total power of the photovoltaic system is the AC power generated by the photovoltaic system;

[0056] When the photovoltaic and battery need to be powered off the grid, the line loss is 0; in other cases, the line loss is calculated based on the total power of the energy storage system, the total power of the photovoltaic system, and the transformer loss;

[0057] The total power of the power station is calculated based on the total power of the energy storage system, the total power of the photovoltaic system and the total loss, where the total loss includes station power consumption, line loss and transformer loss.

[0058] The present invention provides a photovoltaic and energy storage coupled power generation optimization calculation system, comprising:

[0059] A data input module is used to obtain photovoltaic system measurement data and energy storage system measurement data;

[0060] A data splitting module, used to divide the photovoltaic system measurement data into time periods according to a preset period;

[0061] An attribute calibration module is used to perform attribute calibration on each divided time period according to the operation status of the power system, wherein the attribute calibration includes marking the current time period as a valley time period, a peak time period or a blank time period;

[0062] A strategy judgment module, used to judge the priority strategy adopted in the current off-peak time period according to the remaining available power in the off-peak time period, wherein the priority strategy includes an Internet access priority strategy and a charging priority strategy;

[0063] A photovoltaic system calculation module is used to calculate the photovoltaic system output data in each time period according to the attributes and strategies of each time period, wherein the photovoltaic system output data includes the photovoltaic system DC power generation, the photovoltaic system AC power generation, the amount of abandoned light and the photovoltaic system loss;

[0064] The energy storage system calculation module is used to calculate the output data of the energy storage system in each time period according to the time period attributes, wherein the output data of the energy storage system includes the DC power, AC power, power ratio, power and loss of the energy storage system;

[0065] A bus calculation module, used to calculate the output data of the transformer bus corresponding to the photovoltaic grid-connected system according to the photovoltaic system output data and the energy storage system output data, and the output data of the transformer bus at least includes the transformer loss;

[0066] The grid connection point calculation module is used to calculate the output data at the photovoltaic grid connection point according to the photovoltaic system output data and the energy storage system output data. The output data at the grid connection point at least includes line loss and the overall power of the power station.

[0067] In summary, due to the adoption of the above technical features, the beneficial effects of the present invention are:

[0068] The present invention combines the basic hardware parameters of photovoltaic panel manufacturers to calculate the power generation situation throughout the year. Through daily power generation analysis, it solves the decision of whether the electricity generated in photovoltaic power generation should be transmitted to the power grid or stored locally. At the same time, it calculates the optimal value of total power generation, and provides photovoltaic operation and maintenance and energy storage operation and maintenance decisions based on the calculation process and actual power generation conditions.

[0069] The method and system of the present invention can significantly improve the computing efficiency, improve the computing dimension and improve the computing accuracy through intelligent computing. Compared with the traditional computing work that requires 3 people to complete the calculation of photovoltaic power sales strategy for one year in one month, the system of the present invention can calculate the situation for a whole year in 2 to 6 minutes.

[0070] Additional aspects and advantages of the present invention will become apparent from the following description or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0072] Figure 1 It is a flow chart of a method for optimizing calculation of power generation by coupling photovoltaic power generation with energy storage according to an embodiment of the present invention. DETAILED DESCRIPTION

[0073] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0074] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0075] Refer to the following Figure 1 The following describes a method for optimizing the calculation of power generation by coupling photovoltaic power generation with energy storage according to some embodiments of the present invention.

[0076] Some embodiments of the present application provide a method for optimizing calculation of power generation by coupling photovoltaics with energy storage.

[0077] like Figure 1 As shown, the first embodiment of the present invention proposes a method for optimizing the calculation of power generation of photovoltaic and energy storage coupling, including the following steps S1-S8.

[0078] S1. Obtaining photovoltaic system measurement data and energy storage system measurement data.

[0079] In some embodiments, the photovoltaic system measurement data includes the power actually generated by the photovoltaic system and the output power of the photovoltaic system. If the output power of the photovoltaic system is a negative value, it means that the photovoltaic system consumes power from the power grid when it is unloaded; the energy storage system measurement data includes the factory acceptance test battery capacity, battery health status, contract year battery capacity, battery charging efficiency, battery discharge efficiency, battery working loss, battery standby loss and DC limit power. In general, the photovoltaic system measurement data is measured and counted on an hourly basis, that is, the statistical period of the obtained photovoltaic system measurement data is one hour. The energy storage system measurement data is usually characteristic data provided by the manufacturer, in which the contract year battery capacity is equal to the factory acceptance test battery capacity multiplied by the battery health status. These measurement data can be input by designers or staff according to actual conditions, or directly imported through a data table; in a specific embodiment, a configuration file is formed after the measurement data is input, and the above-mentioned required measurement data is obtained by reading these configuration files.

[0080] It is understandable that the photovoltaic system in the present disclosure is mainly a photovoltaic power generation device, and the energy storage system is a battery for storing electrical energy. The high voltage, medium voltage and low voltage referred to in the present disclosure are relative concepts, that is, for a three-phase transformer in the system, it has three phases of high voltage, medium voltage and low voltage. The bus connected to the high voltage phase is the high voltage bus, and the bus connected to the medium voltage phase is the medium voltage bus. The voltage of the medium voltage bus is usually between 1 kV and 35 kV, and the voltage of the high voltage bus is above 35 kV.

[0081] In addition, in step S1, transformer data and other data can also be synchronously input for subsequent calculations. Transformer data includes reactive power, active power and rated capacity of each transformer; other data includes peak period data of the power system, station power consumption and availability of photovoltaic systems. It can be understood that the peak period data of the power system is the data on the division of the peak, valley and normal times of the power system based on the actual operation of the power system. The above transformer data and other data are also known data that can be directly obtained.

[0082] S2. Divide the photovoltaic system measurement data into time periods according to a preset cycle.

[0083] Specifically, the collection period of the photovoltaic system measurement data is divided into several time periods according to a smaller preset period, and the smaller preset period is subsequently calculated to obtain more accurate calculation data. In a specific embodiment, the preset period is 15 minutes, and the hourly photovoltaic system measurement data obtained in step S1 is divided into photovoltaic system measurement data every 15 minutes. Those skilled in the art can also set other preset periods for division, such as 10 minutes, 20 minutes or 30 minutes, etc. The smaller the preset period, the greater the calculation amount and the higher the calculation accuracy.

[0084] S3. According to the operation status of the power system, attribute calibration is performed on each divided time period, and the attribute calibration includes marking the current time period as a valley time period, a peak time period or a blank time period.

[0085] In some embodiments, step S3 includes:

[0086] According to the peak and valley time period information pre-divided by the power system, the attributes of each divided time period are judged. When the divided time period is in the peak time period of the power system, the time period is marked as the peak time period; when the divided time period is in the valley time period of the power system, the time period is marked as the valley time period; when the divided time period is in the remaining time periods of the power system except the peak time period and the valley time period, the time period is marked as the blank time period.

[0087] When the time period is the peak time period, the energy storage system discharges and all the electricity generated by the photovoltaic system is connected to the grid; when the time period is the valley time period, the power generated by the photovoltaic system is prioritized to be connected to the grid or charged according to the set strategy; when the time period is the blank time period, the electricity generated by the photovoltaic system cannot be connected to the grid and is used to charge the energy storage system.

[0088] S4. Determine the priority strategy to be adopted in the current off-peak time period according to the remaining available power in the off-peak time period, wherein the priority strategy includes an Internet access priority strategy and a charging priority strategy.

[0089] In some embodiments, step S4 includes: calculating the remaining available power during the valley time period, that is, the total available power emitted by the photovoltaic system from the time period to the end of the valley time period; if the total available power is greater than the power required to fully charge the battery, the time period adopts an Internet access priority strategy; if the total available power is less than the power required to fully charge the battery, the time period adopts a charging priority strategy.

[0090] In a specific embodiment, the method for calculating the amount of power required to fully charge the battery and the remaining available power during the off-peak period is as follows:

[0091] The amount of electricity required to fully charge the battery = battery capacity / charging efficiency + working loss * charging time;

[0092] The remaining available electricity during the off-peak period = PV system output power * PV system availability * off-peak period duration.

[0093] In a specific embodiment, the maximum online power may be calculated in step S4, and the maximum online power is the sum of the limited power, line loss, station power consumption and transformer loss.

[0094] In the grid-connected priority strategy, the power output by the photovoltaic system is prioritized for grid-connected access. When the output power of the photovoltaic system exceeds the maximum grid-connected power, the excess power is used to charge the energy storage system, and the excess power that further exceeds the upper limit of the energy storage system's charging power is directly discarded. The charging process stops after the energy storage system is fully charged, and thereafter, all the output power of the photovoltaic system is used to grid-connected access, and the part that exceeds the maximum grid-connected power is discarded.

[0095] In the charging priority strategy, the power output by the photovoltaic system is used to charge the energy storage system according to a preset ratio. When the power output by the photovoltaic system is greater than the amount of power required to fully charge the battery, the excess is used to power the grid.

[0096] S5. Calculate the output data of the photovoltaic system in each time period according to the attributes and strategies of each time period, wherein the output data of the photovoltaic system includes the direct current power generation of the photovoltaic system, the alternating current power generation of the photovoltaic system, the amount of abandoned light, and the loss of the photovoltaic system.

[0097] The calculation methods for the DC power generation of the photovoltaic system and the AC power generation of the photovoltaic system in each period are the same. The DC power generation of the photovoltaic system is calculated based on the actual power generated by the photovoltaic system; the AC power generation of the photovoltaic system is calculated based on the output power of the photovoltaic system and the amount of abandoned light.

[0098] Specifically, the DC power generation power of the photovoltaic system = the actual power generated by the photovoltaic system * the utilization rate of the photovoltaic system; the AC power generation power of the photovoltaic system = the output power of the photovoltaic system * the utilization rate of the photovoltaic system - the amount of abandoned light.

[0099] The remaining output data needs to be calculated based on the time period attributes.

[0100] In some embodiments, for the blank time period:

[0101] The photovoltaic system basically has no output. If there is any output, it is all used to charge the battery. When the photovoltaic system has no output, the amount of abandoned light is 0. The photovoltaic system loss can be calculated based on the power consumed by the photovoltaic system from the grid when it is not loaded and the availability of the photovoltaic system. At this time, the photovoltaic system loss is equal to the product of the power consumed by the photovoltaic system from the grid when it is not loaded and the availability of the photovoltaic system.

[0102] For valley time period:

[0103] At this time, the photovoltaic system generates electricity and the photovoltaic system loss is 0;

[0104] When the grid-connected priority strategy is adopted, when the actual output power of the photovoltaic system is less than or equal to the sum of the maximum grid-connected power and the battery working loss, all power is used to connect to the grid, and the battery is not charged. Only when the photovoltaic power generation exceeds the upper limit of the grid but is not enough to cover the battery working loss, the part above the upper limit of the grid will be abandoned. The abandoned light amount is the part of the actual output power of the photovoltaic system that exceeds the sum of the maximum grid-connected power and the battery standby loss. Among them, the actual output power of the photovoltaic system is the product of the actual power generated by the photovoltaic system and the availability of the photovoltaic system.

[0105] When the actual output power of the photovoltaic system is greater than the sum of the maximum online power and the battery working loss, the amount of abandoned light is dynamically determined according to the battery power. Before the battery is fully charged, the battery charging power cannot exceed its maximum limit, and the excess part is used as the abandoned light amount. Specifically, at this time, the online power reaches the upper limit, the excess power is used to charge the battery, and the rest is discarded. In this case, the calculation of the parameters is related to the battery power. Before the battery is fully charged, the battery charging power cannot exceed its maximum limit. The maximum battery charging power = DC limit power / battery charging efficiency + battery working loss. When the difference between the actual output power of the photovoltaic system and the maximum online power, that is, the excess power generation power is less than or equal to the maximum charging power of the battery, all the excess power generation power is used for charging, and the abandoned light amount is 0. When the difference between the actual output power of the photovoltaic system and the maximum online power is greater than the maximum charging power of the battery, the abandoned light amount is the difference between the excess power generation power and the maximum charging power of the battery. After the battery is fully charged, all the power that cannot be connected to the Internet is discarded, but the excess power generation power can bear the loss of the energy storage system, so at this time, the power after deducting the loss of the energy storage system from the excess power generation power can be used as the abandoned light amount.

[0106] When the charging priority strategy is adopted, when the battery is not fully charged, that is, the battery power is less than the battery capacity of the contract year, the amount of abandoned light is the part of the actual output power of the photovoltaic system that exceeds the sum of the maximum charging power of the battery and the maximum online power; specifically, it is necessary to judge whether the actual output power of the photovoltaic system has reached the maximum charging power of the battery: when the actual output power of the photovoltaic system is less than or equal to the maximum charging power of the battery, the amount of abandoned light is 0; when the actual output power of the photovoltaic system is greater than the maximum charging power of the battery, if the actual output power of the photovoltaic system minus the maximum charging power of the battery is still less than or equal to the maximum online power, the amount of abandoned light is 0, otherwise, the amount of abandoned light is the part of the actual output power of the photovoltaic system that exceeds the sum of the maximum charging power of the battery and the maximum online power.

[0107] When the battery is fully charged, the amount of abandoned light is the portion of the actual output power of the photovoltaic system that exceeds the sum of the maximum grid-connected power and the battery standby loss.

[0108] For peak time periods:

[0109] At this time, the photovoltaic system basically does not work, and the amount of abandoned light in the photovoltaic system is 0. If all the power generated is used to access the grid, the photovoltaic system loss is calculated based on the power consumed by the photovoltaic system from the grid when it is not loaded and the availability of the photovoltaic system.

[0110] S6. Calculate the output data of the energy storage system in each time period according to the time period attributes, wherein the output data of the energy storage system includes the DC power, AC power, power ratio, power and loss of the energy storage system.

[0111] In some embodiments, for the blank time period:

[0112] If the actual power generation of the photovoltaic system is still surplus after meeting the power consumption of the station, the reactive power of the transformer and the working loss of the battery, the surplus part will be used as the AC power of the energy storage system, and the DC power is the AC power multiplied by the battery charging efficiency; in other cases, the energy storage system does not work, the AC power and DC power of the energy storage system are both 0, the battery power remains unchanged, and the battery loss is the standby loss.

[0113] The amount of energy storage system in the current period is the amount of energy in the previous period plus the amount of charge in this period or minus the amount of discharge in this period. Specifically, a negative power number indicates that the energy storage system is charging, and a positive power number indicates that the energy storage system is discharging. The energy storage system's energy calculation is cumulative or cumulative, with an initial value of 0. When the battery DC or AC power is not zero, the amount of energy in each period is the amount of energy in the previous period plus or minus the amount of charge or discharge in this period. When the battery power is zero, the battery power remains unchanged.

[0114] The battery power percentage is the percentage of the battery power in this period to the total battery power.

[0115] When the energy storage system is working, the loss of the energy storage system is equal to the working loss of the battery; when the energy storage system is not working, the loss of the energy storage system is equal to the standby loss of the battery.

[0116] For valley time period:

[0117] When the grid-connected priority strategy is adopted, when the actual output power of the photovoltaic system is less than or equal to the sum of the maximum grid-connected power and the battery working loss, the energy storage system does not work, the AC power and DC power of the energy storage system are both 0, the power of the energy storage system remains unchanged, and the loss of the energy storage system is the battery standby loss. When the actual output power of the photovoltaic system is greater than the sum of the maximum grid-connected power and the battery working loss, the battery starts to charge, the loss of the energy storage system is the battery working loss, the AC power of the energy storage system is the excess power after deducting the energy storage system loss and the maximum grid-connected power consumption from the actual output power of the photovoltaic system, and is not greater than the maximum charging power of the battery, and the DC power is the AC power multiplied by the battery charging efficiency; the battery power calculation is the same as the blank time period; when the battery is fully charged, it is necessary to reverse the DC power of the energy storage system based on the battery capacity margin, and then reverse the AC power based on the charging efficiency. The calculation method is as follows:

[0118] The DC power of the energy storage system = (battery capacity in the contract year - battery power in the previous period) / preset cycle length;

[0119] The AC power of the energy storage system = the DC power of the energy storage system / battery charging efficiency.

[0120] When the charging priority strategy is adopted, the energy storage system works and the energy storage system loss is the battery working loss. In some embodiments, in order to reduce the impact on the power grid, a certain proportion (strategy percentage) of battery charging is allocated to the power grid at this time. The proportion can be set as needed. The specific calculation method is divided into two types according to the power size:

[0121] When the power allocated to the grid is greater than the maximum grid-connected power, the AC power of the energy storage system is the excess power after deducting the energy storage system loss and the maximum grid-connected power from the actual output power of the photovoltaic system; when the power allocated to the grid is not greater than the maximum grid-connected power, the AC power of the energy storage system does not exceed the maximum charging power of the battery, and the proportion of each charge decreases according to the value set by the charging strategy:

[0122] The AC power of the energy storage system = -min((actual output power of the photovoltaic system - battery working loss), maximum battery charging power)*(1-(strategy percentage*number of consecutive times of charging priority strategy)).

[0123] The calculation of the DC efficiency of the energy storage system, the power of the energy storage system, and the power percentage are the same as the above calculation method. Similarly, when the battery is fully charged, the AC power of the energy storage system should be determined by the remaining capacity of the battery.

[0124] For peak time periods:

[0125] The energy storage system discharges. During the discharge process, the AC power of the energy storage system is determined by the maximum grid-connected power and battery loss, that is, the AC power of the energy storage system is equal to the maximum grid-connected power minus the AC power generation power of the photovoltaic system plus the battery working loss. The DC power is calculated based on the battery discharge efficiency, that is, the DC power of the energy storage system is equal to the AC power of the energy storage system divided by the battery discharge efficiency. Before the battery is discharged to 0, the loss of the energy storage system is the battery working loss, and after the battery is discharged to 0, the loss of the energy storage system is the battery standby loss.

[0126] S7. Calculate the output data of the transformer bus corresponding to the photovoltaic grid connection according to the output data of the photovoltaic system and the output data of the energy storage system. The output data of the transformer bus at least includes transformer loss.

[0127] In some embodiments, step S7 includes:

[0128] The total power of the energy storage system is the AC power of the energy storage system minus the battery operating loss;

[0129] The total power of the photovoltaic system is the AC power generated by the photovoltaic system;

[0130] When the photovoltaic system and energy storage system need to be powered off the grid, the transformer loss is the reactive power loss of all transformers (the sum of the reactive power of the transformers).

[0131] When the photovoltaic system or energy storage system does not need to be powered off the grid, the active power loss is calculated based on the total power of the energy storage system and the total power of the photovoltaic system. The transformer loss is the sum of the reactive power loss and the active power loss. In a specific embodiment, the transformer loss is calculated as follows:

[0132] The loss of a single transformer = transformer reactive power loss + [(total power of energy storage system + total power of photovoltaic system) / number of transformers / transformer efficiency / transformer capacity]^2*transformer active power.

[0133] The overall transformer loss requires multiplying the loss of a single transformer by the number of transformers.

[0134] S8. Calculate output data at the photovoltaic grid connection point based on the photovoltaic system output data and the energy storage system output data. The output data at the grid connection point at least includes line loss and overall power station power.

[0135] In some embodiments, step S8 includes:

[0136] When the photovoltaic and battery need to be powered off the grid, the line loss is 0; in other cases, the line loss is calculated based on the total power of the energy storage system, the total power of the photovoltaic system, and the transformer loss; in a specific embodiment, the specific calculation method is as follows:

[0137] Line loss = [(total power of energy storage system + total power of photovoltaic system - transformer loss) / limited power]^2 * line loss at full power.

[0138] The total power of the power station is calculated based on the total power of the energy storage system, the total power of the photovoltaic system and the total loss, where the total loss includes station power consumption, line loss and transformer loss.

[0139] The total power of the power station = the total power of the energy storage system + the total power of the photovoltaic system - transformer loss - station power consumption - line loss.

[0140] It should be noted that, in the present disclosure, the online power refers to the data when the overall power of the power station is greater than 0, and the offline power refers to the data when the overall power is less than 0.

[0141] The second embodiment of the present invention proposes a photovoltaic and energy storage coupled power generation optimization calculation system, and on the basis of the first embodiment, includes: a data input module, a data splitting module, an attribute calibration module, a strategy judgment module, a photovoltaic system calculation module, an energy storage system calculation module, a bus calculation module and a grid connection point calculation module.

[0142] The data input module is used to obtain the measurement data of the photovoltaic system and the energy storage system;

[0143] The data splitting module is used to divide the photovoltaic system measurement data into time periods according to a preset period;

[0144] The attribute calibration module is used to perform attribute calibration on each divided time period according to the operation status of the power system, and the attribute calibration includes marking the current time period as a valley time period, a peak time period or a blank time period;

[0145] The strategy judgment module is used to judge the priority strategy adopted in the current off-peak time period according to the remaining available power in the off-peak time period, and the priority strategy includes an Internet access priority strategy and a charging priority strategy;

[0146] The photovoltaic system calculation module is used to calculate the photovoltaic system output data in each time period according to the attributes and strategies of each time period, wherein the photovoltaic system output data includes the photovoltaic system DC power generation, the photovoltaic system AC power generation, the amount of abandoned light and the photovoltaic system loss;

[0147] The energy storage system calculation module is used to calculate the energy storage system output data in each time period according to the time period attributes, wherein the energy storage system output data includes the DC power, AC power, power ratio, power and loss of the energy storage system;

[0148] The bus calculation module is used to calculate the output data of the transformer bus corresponding to the photovoltaic grid-connected system according to the output data of the photovoltaic system and the output data of the energy storage system. The output data of the transformer bus at least includes the transformer loss.

[0149] The grid connection point calculation module is used to calculate the output data at the photovoltaic grid connection point according to the photovoltaic system output data and the energy storage system output data. The output data at the grid connection point at least includes line loss and overall power station power.

[0150] In some embodiments, Python (programming language) combined with CEF (Express Exchange) technology can be used to write a calculation tool to form the system described in the above embodiment, automatically import the collected data into an Excel (table drawing tool) file, and then output the annual calculation results to a new Excel. At the same time, a calendar plug-in and a date curve can be added to the system to quickly locate a specific date for calculation analysis or data display.

[0151] In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0152] Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for optimizing the calculation of power generation of photovoltaic and energy storage coupling, characterized in that: include: Obtaining photovoltaic system measurement data and energy storage system measurement data; Dividing the photovoltaic system measurement data into time periods according to a preset cycle; According to the operation status of the power system, attribute calibration is performed on each divided time period, and the attribute calibration includes marking the current time period as a valley time period, a peak time period or a blank time period; According to the remaining available power in the off-peak time period, determine the priority strategy adopted in the current off-peak time period, wherein the priority strategy includes an Internet access priority strategy and a charging priority strategy; According to the attributes and strategies of each time period, the photovoltaic system output data in each time period is calculated respectively, wherein the photovoltaic system output data includes the photovoltaic system DC power generation, the photovoltaic system AC power generation, the amount of abandoned light and the photovoltaic system loss; According to the time period attributes, the energy storage system output data is calculated for each time period, wherein the energy storage system output data includes the DC power, AC power, power ratio, power and loss of the energy storage system; Calculate the output data of the transformer bus corresponding to the photovoltaic grid connection according to the output data of the photovoltaic system and the output data of the energy storage system. The output data of the transformer bus includes at least the transformer loss. Calculate the output data at the photovoltaic grid connection point based on the photovoltaic system output data and the energy storage system output data, where the output data at the grid connection point at least includes line loss and overall power station power; The method of calibrating the attributes of each divided time period according to the operating state of the power system includes: According to the peak and valley time period information pre-divided by the power system, the attributes of each divided time period are judged. When the divided time period is in the peak time period of the power system, the time period is marked as the peak time period; when the divided time period is in the valley time period of the power system, the time period is marked as the valley time period; when the divided time period is in the remaining time periods of the power system except the peak time period and the valley time period, the time period is marked as the blank time period; During peak hours, the energy storage system discharges and all the electricity generated by the photovoltaic system is connected to the grid; When the time period is off-peak, the power generation of the photovoltaic system is prioritized to the grid or charging according to the set strategy; Also, when the time period is a blank period, the electricity generated by the photovoltaic system cannot be connected to the grid and is used to charge the energy storage system; The determining of the priority strategy to be adopted in the current off-peak time period according to the remaining available power in the off-peak time period includes: Calculate the remaining available power during the off-peak period, that is, the total available power generated by the photovoltaic system from this period to the end of the off-peak period. If the total available power is greater than the power required to fully charge the battery, the grid-connection priority strategy is adopted during this period. If the total available power is less than the power required to fully charge the battery, the charging priority strategy is adopted during this period. In the grid-connected priority strategy, the power output by the photovoltaic system is prioritized for grid-connected access. When the output power of the photovoltaic system exceeds the maximum grid-connected power, the excess power is used to charge the energy storage system, and the excess power that further exceeds the upper limit of the energy storage system's charging power is directly discarded. The charging process stops after the energy storage system is fully charged, and thereafter, all the output power of the photovoltaic system is used to grid-connected access, and the part that exceeds the maximum grid-connected power is discarded. Also, in the charging priority strategy, the power output by the photovoltaic system is used to charge the energy storage system in priority according to a preset ratio. When the power output by the photovoltaic system is greater than the power required to fully charge the battery, the excess is used to power the grid; The photovoltaic system output data in each time period is calculated according to the attributes and strategies of each time period, including: Calculate the DC power generation of the photovoltaic system based on the actual power generated by the photovoltaic system; Calculate the AC power generation of the photovoltaic system based on the output power of the photovoltaic system and the amount of abandoned light; For blank time periods: The photovoltaic system has no output, and the amount of abandoned light is 0. The photovoltaic system loss is calculated based on the power consumed by the photovoltaic system from the grid when it is not loaded and the availability of the photovoltaic system; For valley time period: The photovoltaic system loss is 0; When the grid-connected priority strategy is adopted, when the actual output power of the photovoltaic system is less than or equal to the sum of the maximum grid-connected power and the battery working loss, the amount of abandoned light is the part of the actual output power of the photovoltaic system that exceeds the sum of the maximum grid-connected power and the battery standby loss; when the actual output power of the photovoltaic system is greater than the sum of the maximum grid-connected power and the battery working loss, the amount of abandoned light is dynamically determined according to the battery power. Before the battery is fully charged, the battery charging power cannot exceed its maximum limit, and the excess is regarded as the amount of abandoned light; When the charging priority strategy is adopted, when the battery is not fully charged, the abandoned light amount is the part of the actual output power of the photovoltaic system that exceeds the sum of the maximum charging power of the battery and the maximum online power; when the battery is fully charged, the abandoned light amount is the part of the actual output power of the photovoltaic system that exceeds the sum of the maximum online power and the battery standby loss; And, for peak time periods: The amount of abandoned light in the PV system is 0, and the PV system loss is calculated based on the power consumed by the PV system from the grid when it is not loaded and the availability of the PV system; The calculation of the energy storage system output data in each time period according to the time period attributes includes: For blank time periods: If the actual power generation of the photovoltaic system is still surplus after meeting the power demand of the station, the reactive power of the transformer and the working loss of the battery, the surplus will be used as the AC power of the energy storage system, and the DC power is the AC power multiplied by the battery charging efficiency; otherwise, the energy storage system will not work; The amount of energy stored in the energy storage system in the current period is the amount of energy stored in the previous period plus the amount of charge stored in the current period or minus the amount of discharge stored in the current period; When the energy storage system is working, the loss of the energy storage system is equal to the working loss of the battery; when the energy storage system is not working, the loss of the energy storage system is equal to the standby loss of the battery; For valley time period: When the grid-connected priority strategy is adopted, when the actual output power of the photovoltaic system is less than or equal to the sum of the maximum grid-connected power and the battery working loss, the energy storage system does not work, the AC power and DC power of the energy storage system are both 0, the power of the energy storage system remains unchanged, and the loss of the energy storage system is the battery standby loss; when the actual output power of the photovoltaic system is greater than the sum of the maximum grid-connected power and the battery working loss, the loss of the energy storage system is the battery working loss, the AC power of the energy storage system is the excess power after deducting the energy storage system loss and the maximum grid-connected power consumption from the actual output power of the photovoltaic system, and is not greater than the maximum charging power of the battery, and the DC power is the AC power multiplied by the battery charging efficiency; When the charging priority strategy is adopted, the energy storage system works and the energy storage system loss is the battery working loss. When the power allocated to the grid is greater than the maximum online power, the AC power is the excess power after deducting the energy storage system loss and the maximum online power from the actual output power of the photovoltaic system; when the power allocated to the grid is not greater than the maximum online power, the AC power does not exceed the maximum charging power of the battery, and the proportion of each charge decreases according to the value set by the charging strategy; the DC power is the AC power multiplied by the battery charging efficiency; And, for peak time periods: The energy storage system discharges. During the discharge process, the AC power of the energy storage system is determined by the maximum online power and battery loss, and the DC power is calculated based on the battery discharge efficiency. Before the battery is discharged to 0, the loss of the energy storage system is the battery working loss, and after the battery is discharged to 0, the loss of the energy storage system is the battery standby loss. The calculation of the output data at the transformer bus corresponding to the photovoltaic grid connection according to the photovoltaic system output data and the energy storage system output data includes: The total power of the energy storage system is the AC power of the energy storage system minus the battery operating loss; The total power of the photovoltaic system is the AC power generated by the photovoltaic system; Also, when the photovoltaic system and the energy storage system need to be powered off from the grid, the transformer loss is the reactive power loss of the transformer; when the photovoltaic system or the energy storage system does not need to be powered off from the grid, the active power loss is calculated based on the total power of the energy storage system and the total power of the photovoltaic system, and the transformer loss is the sum of the reactive power loss and the active power loss; The step of calculating the output data at the photovoltaic grid connection point according to the photovoltaic system output data and the energy storage system output data includes: The total power of the energy storage system is the AC power of the energy storage system minus the battery operating loss; The total power of the photovoltaic system is the AC power generated by the photovoltaic system; When the photovoltaic and battery need to be powered off the grid, the line loss is 0; in other cases, the line loss is calculated based on the total power of the energy storage system, the total power of the photovoltaic system, and the transformer loss; And, the total power of the power station is calculated based on the total power of the energy storage system, the total power of the photovoltaic system and the total loss, wherein the total loss includes station power consumption, line loss and transformer loss.

2. The method for optimizing the calculation of power generation of photovoltaic and energy storage coupling according to claim 1 is characterized in that: The photovoltaic system measurement data includes the power actually generated by the photovoltaic system and the output power of the photovoltaic system; The energy storage system measurement data includes factory acceptance test battery capacity, battery health status, contract year battery capacity, battery charging efficiency, battery discharging efficiency, battery operating loss, battery standby loss and DC limit power.

3. A photovoltaic and energy storage coupled power generation optimization calculation system, characterized in that: The method for optimizing the calculation of power generation of photovoltaic and energy storage coupling according to claim 1 or 2 comprises: A data input module is used to obtain photovoltaic system measurement data and energy storage system measurement data; A data splitting module, used for dividing the photovoltaic system measurement data into time periods according to a preset period; An attribute calibration module is used to perform attribute calibration on each divided time period according to the operation status of the power system, wherein the attribute calibration includes marking the current time period as a valley time period, a peak time period or a blank time period; A strategy judgment module, used to judge the priority strategy adopted in the current off-peak time period according to the remaining available power in the off-peak time period, wherein the priority strategy includes an Internet access priority strategy and a charging priority strategy; A photovoltaic system calculation module is used to calculate the photovoltaic system output data in each time period according to the attributes and strategies of each time period, wherein the photovoltaic system output data includes the photovoltaic system DC power generation, the photovoltaic system AC power generation, the amount of abandoned light and the photovoltaic system loss; The energy storage system calculation module is used to calculate the output data of the energy storage system in each time period according to the time period attributes, wherein the output data of the energy storage system includes the DC power, AC power, power ratio, power and loss of the energy storage system; A bus calculation module, used to calculate the output data of the transformer bus corresponding to the photovoltaic grid-connected system according to the photovoltaic system output data and the energy storage system output data, and the output data of the transformer bus at least includes the transformer loss; The grid connection point calculation module is used to calculate the output data at the photovoltaic grid connection point according to the photovoltaic system output data and the energy storage system output data. The output data at the grid connection point at least includes line loss and the overall power of the power station.

Images