Household intelligent photovoltaic system based on lithium battery energy storage

Abstract

The invention relates to the technical field of photovoltaic systems, in particular to a household intelligent photovoltaic system based on lithium battery energy storage, which comprises a data processing module, a control module and a communication module, the data processing module is used for acquiring related data of the battery and the photovoltaic panel and transmitting the related data to the control module; the control module obtains an overall energy efficiency index according to related data of the battery and the photovoltaic panel and transmits the overall energy efficiency index to the communication module; and the communication module transmits the overall energy efficiency index to a user side. The overall energy efficiency index is obtained, the system can execute simple electric quantity distribution, the actual energy efficiency of the system can be evaluated more comprehensively, and the energy utilization strategy is optimized.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic systems, and in particular to a household intelligent photovoltaic system based on lithium battery energy storage. Background Art

[0002] The photovoltaic system is a household energy management system that integrates solar power generation and energy storage functions. It converts solar energy into electrical energy through photovoltaic panels. The system gives priority to supplying household loads, and the remaining electricity is stored in lithium batteries for power supply at night or when there is insufficient light. The system can intelligently control the charging and discharging process of lithium batteries to optimize the utilization of electricity, extend battery life, reduce the household's dependence on the power grid, achieve energy conservation and consumption reduction, and reduce electricity costs.

[0003] The application document with publication number CN104052150A discloses an intelligent home energy efficiency management system for a household distributed photovoltaic power generation system, including: a distributed photovoltaic power generation system, a wireless communication system and an energy efficiency management system. The power generated by the distributed photovoltaic power generation system is used to power household electrical loads, charge batteries or be transmitted to the power grid. The wireless communication system includes the functions of power collection and remote control. The power generation information of the distributed photovoltaic power generation system, the battery power information and the power consumption information of each electrical appliance are transmitted to the energy efficiency management system through a ZigBee module. After analysis, the optimal power consumption plan is obtained and the power consumption time of each electrical appliance is determined. The switch control command of the electrical appliance is transmitted to the control module of each electrical appliance through the ZigBee module, and remote control of the electrical appliance is achieved by triggering a relay.

[0004] Existing technologies are limited to basic power supply, charging and grid feedback control, and lack analysis of the overall energy efficiency of the system. Summary of the invention

[0005] The purpose of the present invention is to provide a method for energy efficiency analysis. In view of the above-mentioned shortcomings, a household intelligent photovoltaic system based on lithium battery energy storage is proposed.

[0006] The present invention adopts the following technical solution: A household intelligent photovoltaic system based on lithium battery energy storage, the system comprising a data processing module, a control module and a communication module; the data processing module is used to obtain relevant data of the battery and the photovoltaic panel, and transmit it to the control module; the larger the value of the overall energy efficiency index, the higher the overall efficiency of the household intelligent photovoltaic system; The communication module transmits the overall energy efficiency index to the user end; The relevant data of the battery and the photovoltaic panel include relevant data of photovoltaic power generation, battery charging and discharging efficiency, battery power status, and battery charging and discharging power.

[0007] Optionally, the data processing module includes a battery management submodule, a data analysis submodule, a household load detection submodule, an information storage submodule, a photovoltaic panel detection submodule, a meteorological analysis submodule and a battery detection submodule; the battery management submodule is used to analyze and obtain the current battery power state and the current battery health state, and transmit them to the control module and the data analysis submodule; the data analysis submodule obtains the charging and discharging efficiency under the battery power state and the charging and discharging efficiency under the battery health state according to the current battery power state and the current battery health state, and transmits them to the control module; the household load detection submodule is used to detect and obtain the household load power, and transmit it to the control module; the information storage submodule is used to store the temperature coefficient, the area of ​​the photovoltaic panel, the reference temperature of the photovoltaic panel, the minimum allowable battery power state and the maximum discharge power of the battery when fully charged, and transmit them to the control module; the photovoltaic panel detection submodule is used to detect and obtain the current temperature of the photovoltaic panel, the current light intensity and the current incident angle of the photovoltaic panel, and transmit them to the control module; the meteorological analysis submodule is used to analyze and The cloud layer influence factor is obtained and transmitted to the control module; the battery detection submodule is used to detect and obtain the current charging current, the current discharging current and the current battery voltage, and transmit them to the control module; the control module obtains the carrying power influence coefficient according to the maximum discharge power of the battery in the fully charged state, the current battery power state and the current battery health state, obtains the battery charging and discharging power factor according to the charging and discharging efficiency in the battery health state, the current charging current, the current discharging current, the current battery voltage, the carrying power influence coefficient, the current battery power state and the minimum power state allowed by the battery, obtains the temperature-related efficiency index according to the temperature coefficient, the current temperature of the photovoltaic panel and the reference temperature of the photovoltaic panel, obtains the photovoltaic power generation power factor according to the area of ​​the photovoltaic panel, the current light intensity, the temperature-related efficiency index, the current temperature of the photovoltaic panel, the current light incident angle, the temperature coefficient, the reference temperature of the photovoltaic panel and the cloud layer influence factor, and obtains the overall energy efficiency index according to the photovoltaic power generation power factor, the charging and discharging efficiency in the battery power state, the battery charging and discharging power factor, the current battery health state and the household load power.

[0008] Optionally, the photovoltaic panel detection submodule includes a temperature detection unit, a light intensity detection unit and an angle detection unit; the temperature detection unit is used to detect the temperature and obtain the current temperature of the photovoltaic panel, and transmit it to the control module; the light intensity detection unit is used to detect the light intensity and obtain the current light intensity, and transmit it to the control module; the angle detection unit is used to detect the incident angle and obtain the current incident angle of the photovoltaic panel, and transmit it to the control module.

[0009] Optionally, the meteorological analysis submodule includes a cloud information acquisition unit and a cloud impact analysis unit; the cloud information acquisition unit is used to acquire current cloud information and transmit it to the cloud impact analysis unit; the cloud impact analysis unit obtains a cloud impact factor based on the current cloud information analysis and transmits it to the control module.

[0010] Optionally, the battery detection submodule includes a current detection unit and a voltage detection unit; the current detection unit is used to detect current and derive the current charging current and the current discharging current and transmit them to the control module; the voltage detection unit is used to detect voltage and derive the current battery voltage and transmit it to the control module.

[0011] Optionally, when the control module calculates the overall energy efficiency index, the following formula is satisfied: ; in, is the overall energy efficiency index, is the photovoltaic power factor, is the charge and discharge efficiency under the battery power state, is the current battery power status, is the battery charging and discharging power factor, is the current battery health status, For household load power.

[0012] The beneficial effects achieved by the present invention are: The overall energy efficiency index is obtained, so that the system can not only perform simple power allocation, but also more comprehensively evaluate the actual energy efficiency of the system and optimize the energy utilization strategy; Through the battery management submodule and battery detection submodule, the current charging and discharging efficiency and health status of the battery can be analyzed, and the load power influence coefficient and charging and discharging power factor can be calculated, so as to achieve smarter battery management, extend battery life, and optimize battery efficiency; The addition of photovoltaic panel detection submodule and meteorological analysis submodule can obtain and analyze photovoltaic panel temperature, light intensity, incident angle and cloud influence factors in real time, and obtain temperature-related efficiency indicators and photovoltaic power factor, so that the system can dynamically adjust photovoltaic power generation efficiency, thereby more accurately optimizing the photovoltaic power generation process; A household load detection submodule has been added to monitor household load power in real time and perform intelligent energy allocation based on overall energy efficiency indicators. This allows the system to perform more optimized power scheduling based on load demand and system energy efficiency status, thereby improving the overall utilization efficiency of the system.

[0013] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and description and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a structural diagram of the data processing module in the present invention; Figure 3 It is a schematic diagram of the structure of the photovoltaic panel detection submodule in the present invention; Figure 4 It is a structural schematic diagram of the meteorological analysis submodule in the present invention; Figure 5 It is a structural schematic diagram of the battery detection submodule in the present invention; Figure 6 is a relationship diagram of the present invention; Figure 7 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention; Figure 8 Schematic diagram of the structure of the optimal temperature analysis module in the second embodiment of the present invention; Fig. 9 This is a relationship diagram of the second embodiment of the present invention. DETAILED DESCRIPTION

[0015] The following is an explanation of the embodiments of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted according to actual dimensions. It is stated in advance. The following embodiments will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention.

[0016] Embodiment 1: This embodiment provides a household intelligent photovoltaic system based on lithium battery energy storage, combined with Figures 1 to 6 shown.

[0017] A household intelligent photovoltaic system based on lithium battery energy storage, the system comprising a data processing module, a control module and a communication module; the data processing module is used to obtain relevant data of the battery and the photovoltaic panel, and transmit it to the control module; the control module derives an overall energy efficiency index based on the relevant data of the battery and the photovoltaic panel, and transmits it to the communication module; the communication module transmits the overall energy efficiency index to the user end.

[0018] Optionally, the data processing module includes a battery management submodule, a data analysis submodule, a household load detection submodule, an information storage submodule, a photovoltaic panel detection submodule, a meteorological analysis submodule and a battery detection submodule; the battery management submodule is used to analyze and obtain the current battery power state and the current battery health state, and transmit them to the control module and the data analysis submodule; the data analysis submodule obtains the charging and discharging efficiency under the battery power state and the charging and discharging efficiency under the battery health state according to the current battery power state and the current battery health state, and transmits them to the control module; the household load detection submodule is used to detect and obtain the household load power, and transmit it to the control module; the information storage submodule is used to store the temperature coefficient, the area of ​​the photovoltaic panel, the reference temperature of the photovoltaic panel, the minimum allowable battery power state and the maximum discharge power of the battery when fully charged, and transmit them to the control module; the photovoltaic panel detection submodule is used to detect and obtain the current temperature of the photovoltaic panel, the current light intensity and the current incident angle of the photovoltaic panel, and transmit them to the control module; the meteorological analysis submodule is used to analyze and The cloud layer influence factor is obtained and transmitted to the control module; the battery detection submodule is used to detect and obtain the current charging current, the current discharging current and the current battery voltage, and transmit them to the control module; the control module obtains the carrying power influence coefficient according to the maximum discharge power of the battery in the fully charged state, the current battery power state and the current battery health state, obtains the battery charging and discharging power factor according to the charging and discharging efficiency in the battery health state, the current charging current, the current discharging current, the current battery voltage, the carrying power influence coefficient, the current battery power state and the minimum power state allowed by the battery, obtains the temperature-related efficiency index according to the temperature coefficient, the current temperature of the photovoltaic panel and the reference temperature of the photovoltaic panel, obtains the photovoltaic power generation power factor according to the area of ​​the photovoltaic panel, the current light intensity, the temperature-related efficiency index, the current temperature of the photovoltaic panel, the current light incident angle, the temperature coefficient, the reference temperature of the photovoltaic panel and the cloud layer influence factor, and obtains the overall energy efficiency index according to the photovoltaic power generation power factor, the charging and discharging efficiency in the battery power state, the battery charging and discharging power factor, the current battery health state and the household load power.

[0019] Optionally, the photovoltaic panel detection submodule includes a temperature detection unit, a light intensity detection unit and an angle detection unit; the temperature detection unit is used to detect the temperature and obtain the current temperature of the photovoltaic panel, and transmit it to the control module; the light intensity detection unit is used to detect the light intensity and obtain the current light intensity, and transmit it to the control module; the angle detection unit is used to detect the incident angle and obtain the current incident angle of the photovoltaic panel, and transmit it to the control module.

[0020] Optionally, the meteorological analysis submodule includes a cloud information acquisition unit and a cloud impact analysis unit; the cloud information acquisition unit is used to acquire current cloud information and transmit it to the cloud impact analysis unit; the cloud impact analysis unit obtains a cloud impact factor based on the current cloud information analysis and transmits it to the control module.

[0021] Optionally, the battery detection submodule includes a current detection unit and a voltage detection unit; the current detection unit is used to detect current and derive the current charging current and the current discharging current and transmit them to the control module; the voltage detection unit is used to detect voltage and derive the current battery voltage and transmit it to the control module.

[0022] Optionally, when the control module calculates the overall energy efficiency index, the following formula is satisfied: ; in, is the overall energy efficiency index, is the photovoltaic power factor, is the charge and discharge efficiency under the battery power state, is the current battery power status, is the battery charging and discharging power factor, is the current battery health status, For household load power.

[0023] Optionally, the control module satisfies the following formula when calculating: .

[0024] .

[0025] .

[0026] .

[0027] in, is the area of ​​the photovoltaic panel, is the current light intensity, is the temperature-related efficiency index, is the current temperature of the photovoltaic panel, is the current light incident angle, is the temperature coefficient, is the reference temperature of the photovoltaic panel, is the cloud influence factor; is the charge and discharge efficiency of the battery in a healthy state, is the current charging current, is the current discharge current, is the current battery voltage, is the load-carrying power influence coefficient, The minimum power state allowed by the battery; It is the maximum discharge power of the battery when it is fully charged.

[0028] When calculating the control module, refer to the following program code: import numpy as np import matplotlib.pyplot as plt # Constants and initial parameters (some assumed values ​​are used here, which need to be modified according to actual conditions in actual applications) S = 1000 # Photovoltaic panel area, unit: square meters G = lambda t: 800 # Solar irradiance (W / m^2), assumed to be a constant or function T_ref = 25 # Reference temperature, unit: Celsius beta_1 = 0.005 # Temperature coefficient beta_x = 0.004 # Temperature coefficient C_cloud = lambda t: 1 # Cloud layer impact factor, assumed to be 1 (no clouds) SOC_min = 0.2 # minimum battery state P_rated = 500 # Rated power # Time range t = np.linspace(0, 24, 100) # Assume the time of day (0 to 24 hours) # Simulate variable data (assuming some randomly varying data) SOC = np.clip(0.5 + 0.1 * np.sin(0.5 * t), SOC_min, 1.0) # Battery status is between 0.2 and 1 SOH = 0.9 # Battery health status, assumed to be constant T_pv = lambda t: T_ref + 10 * np.sin(0.1 * t) # Battery temperature fluctuates over time theta = lambda t: np.radians(45) # Assume the lighting angle is 45 degrees I_charge = lambda t: 10 # Charging current, assumed to be constant I_discharge = lambda t: 5 # discharge current, assumed to be constant V_bat = 12 # Battery voltage, unit: Volt # Calculate each formula # Efficiency factor η_mp(t) eta_mp = lambda t: 0.18 * (1 - beta_x * (T_pv(t) - T_ref)) # Photovoltaic power factor P_pv(t) P_pv = lambda t: S * G(t) * eta_mp(t) * (np.cos(theta(t)) * (1 -beta_1 * (T_pv(t) - T_ref))) * C_cloud(t) # Decay rate α alpha = lambda t: P_rated / (SOH * SOC) # Output power P_out(t) eta_out = lambda soh: 0.9 # Assume η_out is a constant P_out = lambda t: eta_out(SOH) * (I_charge(t) - I_discharge(t)) * V_bat * max(0.1 - alpha(t) * (SOC - SOC_min)) # Overall energy efficiency index E_out(t) E_out = lambda t: (P_pv(t) * eta_mp(t) * SOC + P_out(t) * SOH) / P_out(t) # Calculate the value of E_out(t) E_out_values ​​= np.array([E_out(time) for time in t]) Specifically, the larger the value of the overall energy efficiency index, the higher the overall efficiency and the better the energy efficiency performance. It can feedback the comprehensive coordination effect between photovoltaic power generation, battery energy storage, and load demand, and can help users grasp the energy utilization efficiency of the current system in real time. If the overall energy efficiency index is relatively low, users can adjust the scheduling strategy according to the data, optimize the timing of charging and discharging, and avoid over-discharging or over-charging of the battery; the current battery power state is expressed in percentage, and the current battery power state is an indicator of the current storage power of the battery; the current battery health state (SOH) is expressed in percentage, and the current battery health state is an indicator of the degree of battery aging; the current battery power state and the current battery health state can be detected and evaluated in real time by the BMS in the existing technology; the unit of household load power is watt; the charging and discharging efficiency under the battery power state is the charging and discharging efficiency that changes accordingly with the current battery power state, which is obtained by technical personnel in this field through experiments.

[0029] The unit of the area of ​​the photovoltaic panel is square meters; the unit of the current light intensity is watts per square meter; the unit of the current temperature of the photovoltaic panel is degrees Celsius; the reference temperature of the photovoltaic panel is the temperature under standard test conditions, which is usually set to 25 degrees Celsius; the current light incident angle refers to the angle between the light and the surface of the photovoltaic panel, which can be calculated by the solar altitude angle and the inclination angle of the photovoltaic panel; the temperature coefficient is a constant that characterizes the effect of temperature on photovoltaic efficiency. Those skilled in the art can query the factory parameters of the photovoltaic panel to find out that the value is usually set in the range of -0.0035 per degree Celsius to -0.0045 per degree Celsius. In this embodiment, the corresponding temperature coefficient can be selected as -0.004 per degree Celsius; the cloud layer influence factor has a value range of 0 to 1, 0 represents a cloudless environment, and 1 represents complete obstruction by clouds. Those skilled in the art obtain the current weather conditions through the meteorological network to determine the specific value of the cloud layer influence factor. In this embodiment, when the meteorological network shows partially cloudy, the cloud layer influence factor is set to 0.5, and when the meteorological network shows cloudy, the cloud layer influence factor is set to 0.8.

[0030] The charge and discharge efficiency under a healthy battery state is the charge and discharge efficiency that changes with the current battery health state, which is obtained by technical personnel in this field through experiments; the units of the current charging current and the current discharging current are both amperes; the unit of the current battery voltage is volts; the minimum allowable state of charge of the battery is obtained by technical personnel in this field by querying the corresponding factory parameters of the battery, and the general value range is between 10% and 20%.

[0031] The maximum discharge power of a battery when fully charged is measured in watts.

[0032] Regarding the “charge and discharge efficiency under the battery power state”, it can be understood as “the charge and discharge efficiency corresponding to the battery under a certain power state”. In this embodiment, the charge and discharge efficiency corresponding to the battery power state between greater than or equal to 0% and less than 10% is set to 80%, the charge and discharge efficiency corresponding to the battery power state between greater than or equal to 10% and less than 30% is set to 85%, the charge and discharge efficiency corresponding to the battery power state between greater than or equal to 30% and less than 90% is set to 90%, and the charge and discharge efficiency corresponding to the battery power state between greater than or equal to 90% and less than or equal to 100% is set to 85%; the overall charge and discharge efficiency of a battery close to 100% (i.e., the ratio of the electrical energy output during discharge to the electrical energy input during charging) is usually low. This is because although the efficiency of charging and discharging is relatively high, due to the battery being close to a fully charged state, the energy loss caused by factors such as internal resistance and incomplete chemical reaction will increase significantly; a battery close to 0% has a large energy loss during the charging and discharging process, so the overall charge and discharge efficiency is usually low.

[0033] Regarding the "charge and discharge efficiency under the battery health state", it can be understood as "the charge and discharge efficiency corresponding to the battery under a certain health state". In this embodiment, the charge and discharge efficiency corresponding to the battery health state less than 70% is set to 70%, the charge and discharge efficiency corresponding to the battery health state greater than or equal to 70% to less than 80% is 82%, the charge and discharge efficiency corresponding to the battery health state greater than or equal to 80% to less than 90% is 90%, the charge and discharge efficiency corresponding to the battery health state greater than or equal to 90% to less than 100% is 95%, and the charge and discharge efficiency corresponding to the battery health state of 100% is 97%. In general, the better the battery health state, the higher the charge and discharge efficiency. When the battery health state decreases, the charge and discharge efficiency will decrease accordingly, until the battery health state seriously deteriorates, the efficiency may drop to a lower level.

[0034] The above units are only examples, and those skilled in the art may set different units according to actual needs when implementing this solution.

[0035] This embodiment solves the problem that traditional photovoltaic systems are relatively simple, and calculates the overall energy efficiency index, so that the system can not only perform simple power distribution, but also more comprehensively evaluate the actual energy efficiency of the system and optimize energy utilization strategies.

[0036] Embodiment 2: This embodiment includes all the contents of Embodiment 1, and provides a household intelligent photovoltaic system based on lithium battery energy storage, combined with Figures 7 to 9 .

[0037] Those skilled in the art can judge whether the value of the overall energy efficiency index is too small by using the overall energy efficiency index. If it is too small, the optimal operating temperature of the corresponding battery can be calculated by using the second embodiment.

[0038] A household intelligent photovoltaic system based on lithium battery energy storage, the system also includes an optimal temperature analysis module; the optimal temperature analysis module is used to analyze and obtain the optimal operating temperature of the battery and transmit it to the communication module; the communication module transmits the optimal operating temperature of the battery to the user end.

[0039] Optionally, the optimal temperature analysis module includes a reference value storage submodule, an influence factor setting submodule and a calculation submodule; the reference value storage submodule is used to store the reference temperature of the battery and transmit it to the calculation submodule; the influence factor setting submodule is used to set the influence factor of the charge and discharge efficiency on the optimal operating temperature, the influence factor of the internal resistance on the optimal operating temperature and the influence factor of the capacity retention rate on the optimal operating temperature, and transmit them to the calculation submodule; the calculation submodule derives the optimal operating temperature of the battery based on the reference temperature of the battery, the influence factor of the charge and discharge efficiency on the optimal operating temperature, the influence factor of the internal resistance on the optimal operating temperature and the influence factor of the capacity retention rate on the optimal operating temperature, and transmits the optimal operating temperature of the battery to the communication module.

[0040] Optionally, when the calculation submodule calculates the optimal operating temperature of the battery, the following formula is satisfied: .

[0041] .

[0042] in, is the optimal operating temperature of the battery, is the reference temperature of the battery, is the factor affecting the charge and discharge efficiency on the optimal operating temperature, is the influence factor of internal resistance on the optimal operating temperature, is the factor affecting the capacity retention rate on the optimal operating temperature.

[0043] When the calculation submodule calculates, the following formula is satisfied: # Define parameters t_d_ref = 25 # Assumed reference temperature, unit: Celsius w_eta = 0.5 # Assuming the weight of charge and discharge efficiency w_r = 0.3 # Assuming the weight of the internal resistance w_c = 0.2 # Assuming the weight of capacity retention rate # Make sure the weights sum to 1 if not abs(w_eta + w_r + w_c - 1) < 1e-6: raise ValueError("The sum of weights w_eta, w_r, w_c must be 1") # Calculate the optimal operating temperature T_opt T_opt = t_d_ref - (w_eta * 0.008 + w_r * 0.15 + w_c * 0.0015) # Output results print("The optimal operating temperature of the battery T_opt is:", T_opt, "degrees Celsius") Specifically, the unit of the optimal operating temperature of the battery and the reference temperature of the battery are both degrees Celsius; the capacity retention rate is the proportion of the original rated capacity that can be retained by the battery after a period of time or a certain number of charge and discharge cycles. It reflects the degree of available capacity that can be retained by the battery after being used or stored for a period of time, and is an important indicator for measuring battery aging and life; the influence factor of the charge and discharge efficiency on the optimal operating temperature, the influence factor of the internal resistance on the optimal operating temperature, and the influence factor of the capacity retention rate on the optimal operating temperature are all pre-set in the system by technical personnel in this field according to actual needs. For example, when frequent energy interaction with the power grid is required, the charge and discharge efficiency is an important indicator. At this time, the corresponding value of the influence factor of the charge and discharge efficiency on the optimal operating temperature is the highest. For systems with high heat dissipation requirements and the need to maintain stable power output, the internal resistance is an important performance indicator. At this time, the corresponding value of the influence factor of the internal resistance on the optimal operating temperature is the highest. For systems that need to be used for a long time and pay attention to battery life, the capacity retention rate is a key parameter. At this time, the corresponding value of the influence factor of the capacity retention rate on the optimal operating temperature is the highest.

[0044] The above units are only examples, and those skilled in the art may set different units according to actual needs when implementing this solution.

[0045] This embodiment solves the problem of high maintenance costs of traditional photovoltaic systems. The calculation of the optimal operating temperature of the battery can prevent the battery from operating at too high or too low a temperature, thereby reducing the impact of temperature fluctuations on battery life. Through more intelligent temperature management, the battery capacity retention rate is improved and the attenuation rate is reduced, thereby extending the battery life, making the system operation more stable, and reducing the cost caused by battery replacement or maintenance.

[0046] The contents disclosed above are only preferred feasible embodiments of the present invention, and do not limit the protection scope of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention description and drawings are included in the protection scope of the present invention. In addition, the elements therein can be updated as technology develops.

Claims

1. A household intelligent photovoltaic system based on lithium battery energy storage, characterized in that: The system includes a data processing module, a control module and a communication module; The data processing module is used to obtain relevant data of the battery and the photovoltaic panel, and transmit it to the control module; The control module obtains the overall energy efficiency index based on the relevant data of the battery and the photovoltaic panel, and transmits it to the communication module; the larger the value of the overall energy efficiency index, the higher the overall efficiency of the home intelligent photovoltaic system; The communication module transmits the overall energy efficiency index to the user end; The relevant data of the battery and the photovoltaic panel include relevant data of photovoltaic power generation, battery charging and discharging efficiency, battery power status, and battery charging and discharging power.

2. A household intelligent photovoltaic system based on lithium battery energy storage as claimed in claim 1, characterized in that: The data processing module includes a battery management submodule, a data analysis submodule, a household load detection submodule, an information storage submodule, a photovoltaic panel detection submodule, a meteorological analysis submodule and a battery detection submodule; The battery management submodule is used to analyze and obtain the current battery power state and the current battery health state, and transmit them to the control module and the data analysis submodule; The data analysis submodule obtains the charge and discharge efficiency under the battery power state and the charge and discharge efficiency under the battery health state according to the current battery power state and the current battery health state, and transmits them to the control module; The household load detection submodule is used to detect and obtain household load power and transmit it to the control module; The information storage submodule is used to store the temperature coefficient, the area of ​​the photovoltaic panel, the reference temperature of the photovoltaic panel, the minimum power state allowed by the battery and the maximum discharge power of the battery when fully charged, and transmit them to the control module; The photovoltaic panel detection submodule is used to detect and obtain the current temperature of the photovoltaic panel, the current light intensity and the current incident angle of the photovoltaic panel, and transmit them to the control module; The meteorological analysis submodule is used to analyze and obtain cloud layer influence factors and transmit them to the control module; The battery detection submodule is used to detect and obtain the current charging current, the current discharging current and the current battery voltage, and transmit them to the control module; The control module derives a load-bearing power influence coefficient according to the maximum discharge power of the battery in a fully charged state, the current battery power state and the current battery health state; derives a battery charge and discharge power factor according to the charge and discharge efficiency in the battery health state, the current charge current, the current discharge current, the current battery voltage, the load-bearing power influence coefficient, the current battery power state and the minimum power state allowed by the battery; derives a temperature-related efficiency index according to the temperature coefficient, the current temperature of the photovoltaic panel and the reference temperature of the photovoltaic panel; derives a photovoltaic power generation power factor according to the area of ​​the photovoltaic panel, the current light intensity, the temperature-related efficiency index, the current temperature of the photovoltaic panel, the current light incident angle, the temperature coefficient, the reference temperature of the photovoltaic panel and the cloud influence factor; and derives an overall energy efficiency index according to the photovoltaic power generation power factor, the charge and discharge efficiency in the battery power state, the battery charge and discharge power factor, the current battery health state and the household load power.

3. A household intelligent photovoltaic system based on lithium battery energy storage as claimed in claim 2, characterized in that: The photovoltaic panel detection submodule includes a temperature detection unit, a light intensity detection unit and an angle detection unit; The temperature detection unit is used to detect the temperature and obtain the current temperature of the photovoltaic panel, and transmit it to the control module; The light intensity detection unit is used to detect the light intensity and obtain the current light intensity, and transmit it to the control module; The angle detection unit is used to detect the incident angle and obtain the current incident angle of the photovoltaic panel, and transmit it to the control module.

4. A household intelligent photovoltaic system based on lithium battery energy storage as claimed in claim 2, characterized in that: The meteorological analysis submodule includes a cloud information acquisition unit and a cloud impact analysis unit; The cloud layer information acquisition unit is used to acquire current cloud layer information and transmit it to the cloud layer impact analysis unit; The cloud layer impact analysis unit obtains a cloud layer impact factor based on current cloud layer information analysis and transmits the result to the control module.

5. A household intelligent photovoltaic system based on lithium battery energy storage as claimed in claim 2, characterized in that: The battery detection submodule includes a current detection unit and a voltage detection unit; The current detection unit is used to detect the current and obtain the current charging current and the current discharging current and transmit them to the control module; The voltage detection unit is used to detect the voltage and obtain the current battery voltage, and transmit it to the control module.

6. A household intelligent photovoltaic system based on lithium battery energy storage as claimed in claim 2, characterized in that: When the control module calculates the overall energy efficiency index, the following formula is satisfied: ； in, is the overall energy efficiency index, is the photovoltaic power factor, is the charge and discharge efficiency under the battery power state, is the current battery power status, is the battery charging and discharging power factor, is the current battery health status, For household load power.

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