Control method of intelligent energy storage power distribution cabinet based on photovoltaic power generation
By arranging sensors and control units in the intelligent energy storage distribution cabinet, a dynamic balance between photovoltaic power generation, energy storage power and load power consumption is achieved, and the problem that traditional distribution cabinets cannot adapt to distributed photovoltaic power generation is solved, the grid stability and energy utilization efficiency are improved, the battery life is extended, and the risk of failure is reduced.
Patent Information
- Application Number
- CN202510684237.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-26
- Publication Date
- 2025-06-24
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
When traditional distribution cabinets respond to the power grid connection of distributed photovoltaic power generation, they cannot meet the needs of deep integration of smart grids, lack adaptation to the characteristics of photovoltaic power generation, and cannot effectively store or feedback excess power, resulting in waste of energy, and have shortcomings in grid interaction response and fault diagnosis.
By arranging sensors at key locations of the intelligent energy storage distribution cabinet, collecting and transmitting data in real time, and using the control unit to conduct real-time analysis and decision-making, we can achieve dynamic balance between photovoltaic power generation, energy storage power and load power consumption, conduct charging and discharging management and grid interaction response, and establish a fault diagnosis and processing mechanism.
It significantly optimizes power distribution, improves grid stability, reduces energy loss, extends battery life, reduces the risk of failure expansion, and improves the operation and maintenance economy and reliability of distribution cabinets.
Smart Images
Figure CN120200383A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of power control, and specifically to a control method for an intelligent energy storage power distribution cabinet based on photovoltaic power generation. Background Art
[0002] In the context of the global energy transition, the development and utilization of renewable energy have become the key ways to solve the energy crisis and environmental pollution problems. As a highly potential clean energy technology, photovoltaic power generation, with its advantages of rich resources, wide distribution, and no pollution, has continuously expanded its application scale in the power supply field. With the continuous progress of technology and the gradual reduction of costs, the penetration rate of photovoltaic power generation in the power system is increasing day by day, becoming an important part of the power structure in many regions and injecting new impetus into the sustainable development of energy.
[0003] In the process of traditional power distribution cabinets dealing with the access of distributed photovoltaic power generation to the power grid, many insurmountable defects have emerged, unable to meet the requirements of the deep integration of distributed energy and smart grid. The design concept of traditional power distribution cabinets is relatively backward, with single functions and lack of targeted adaptation to the characteristics of photovoltaic power generation. In terms of power balance control, traditional power distribution cabinets lack an intelligent adjustment mechanism and cannot automatically adjust the charge and discharge state of the energy storage unit according to the real-time changes in photovoltaic power generation and load power consumption. When the photovoltaic power generation is greater than the load power consumption, traditional power distribution cabinets cannot effectively store or feed back the excess electric energy reasonably, resulting in energy waste. When the photovoltaic power generation is insufficient, they cannot obtain supplementary electric energy from the energy storage unit or the power grid in time, leading to unstable load power supply. In addition, traditional power distribution cabinets have obvious deficiencies in charge and discharge management, lacking fine monitoring and control of key parameters such as battery temperature, charge and discharge current, and voltage, which easily cause problems such as overcharging, over-discharging, overcurrent, and overheating of the battery, not only shortening the service life of the battery but also increasing the safety hazards of the power distribution cabinet. In terms of grid interaction response, there is a lack of effective information interaction and collaborative control ability between traditional power distribution cabinets and smart grids, and they cannot adjust their own operating states in time according to information such as grid dispatching instructions, real-time frequency, and voltage, making it difficult to meet the requirements of smart grids for flexible adjustment of distributed energy. Summary of the Invention
[0004] The objective of the present invention is to make up for the deficiencies of the prior art and provide a control method for an intelligent energy storage power distribution cabinet based on photovoltaic power generation. It can reasonably arrange various sensors at key positions of the intelligent energy storage power distribution cabinet, as well as in the photovoltaic power generation unit, energy storage unit, and load terminal, and accurately transmit real-time data to the control unit through wired or wireless communication methods. In terms of power balance control, the control unit analyzes the collected data in real time, makes reasonable charge and discharge decisions for the energy storage unit based on the relationship between photovoltaic power generation, energy storage power, and load power consumption, and realizes efficient power regulation by adjusting the maximum power point tracking circuit of the photovoltaic power generation unit, the charge and discharge current of the energy storage unit, and the output voltage and frequency of the inverter unit, ensuring the reasonable distribution of power among different units. Charge and discharge management monitors the current, voltage, and temperature during the charging and discharging processes in real time, sets corresponding protection mechanisms to extend the battery life. In terms of grid interaction response, it obtains information such as grid dispatching instructions, real-time frequency, and voltage by interacting with the smart grid, and adjusts the operating state of the intelligent energy storage power distribution cabinet according to this information to achieve functions such as peak shaving and valley filling, frequency and voltage regulation, and maintain the stable operation of the grid. The fault diagnosis and handling mechanism monitors the operating parameters in real time, compares them with the preset range. When abnormalities are found, it can quickly locate the fault position and type, and take corresponding handling measures to ensure the safe and stable operation of the power distribution cabinet.
[0005] To solve the above technical problems, the present invention provides the following technical solutions: A control method for an intelligent energy storage power distribution cabinet based on photovoltaic power generation, the method includes the following specific steps: Data acquisition and transmission: Install sensors at key positions of the intelligent energy storage power distribution cabinet to collect data, and transmit it through wired methods such as RS-485 and CAN bus, or wireless methods such as ZigBee, LoRa, and 4G / 5G. Power balance control: By comparing photovoltaic power generation, energy storage power, and load power consumption, control the charge and discharge of the energy storage unit according to the comparison result, and adjust the power of each unit by adjusting the MPPT circuit of the photovoltaic power generation unit, the charge and discharge current of the energy storage unit, and the output voltage and frequency of the inverter unit. Charge and discharge management: During the charge and discharge of the energy storage unit, monitor the current, voltage, and temperature in real time. When the upper limit is exceeded or specific conditions are met, adjust the charge and discharge power, and set overcharge, over-discharge, over-current, and overheat protection mechanisms to cut off the circuit. Grid interaction response: Use the communication unit to obtain smart grid dispatching instructions, frequency, and voltage information, and adjust the operating state of the power distribution cabinet according to the instructions, and automatically adjust the power of the power generation and energy storage units according to the changes in frequency and voltage. Fault diagnosis and handling: Monitor the operating parameters in real time and compare them with the preset range. When abnormalities occur, evaluate the fault risk based on sensor data and the state of the power distribution cabinet, and automatically repair or cut off the circuit for different faults and notify the operation and maintenance personnel.
[0006] Furthermore, in the data acquisition and transmission step, sensors are installed at key positions of the intelligent energy storage power distribution cabinet to collect data, including current sensors, voltage sensors, and power sensors for monitoring the output of the photovoltaic power generation unit, state of charge sensors, voltage sensors, and current sensors for detecting the state of the energy storage unit, and current sensors, voltage sensors, and power sensors for obtaining the electricity consumption of the load. At the same time, a communication unit is set up to establish a two-way communication link with the dispatching center and relevant monitoring nodes of the smart grid through wired or wireless communication protocols.
[0007] Even further, in the power balance control step, after the control unit receives the sensor data, it performs real-time analysis on the photovoltaic power generation, energy storage power, and load power consumption, compares the magnitude relationship between the photovoltaic power generation and the load power consumption, and determines whether the energy storage unit needs to participate in power regulation. When the photovoltaic power generation is greater than the load power consumption, if the energy storage unit is not full, the control unit controls the energy storage unit to start charging; if the energy storage unit is full, the excess electric energy is fed back to the grid. When the photovoltaic power generation is less than the load power consumption, if the energy storage unit has remaining power, the control unit controls the energy storage unit to discharge to supplement the insufficient electric energy; if the energy storage unit has insufficient power, it obtains electric energy from the grid. According to the charge and discharge state of the energy storage unit and the demand of the grid, the output powers of the photovoltaic power generation unit, the energy storage unit, and the inverter unit are dynamically adjusted. By controlling the maximum power point tracking circuit of the photovoltaic power generation unit, the power generation efficiency is optimized, and by adjusting the charge and discharge current of the energy storage unit, the energy storage speed is controlled.
[0008] Even further, in the power balance control step, according to the charge and discharge state of the energy storage unit and the demand of the grid, the output powers of the photovoltaic power generation unit, the energy storage unit, and the inverter unit are dynamically adjusted, and its dynamic adjustment formula is: , where is the output power of the photovoltaic power generation unit, which is calculated from the current and voltage measured by the current sensor and voltage sensor installed at the output end of the photovoltaic power generation unit, and the calculation formula is: , is the power consumption of the load, which is directly measured by the power sensor installed at the load end, is the influence coefficient, which is determined through experiments according to the characteristics of the energy storage unit and the control requirements of the power distribution cabinet, is the state of charge of the energy storage unit, is the intermediate state of charge of the energy storage unit, which is set to 0.5, is the grid demand regulation coefficient, is the equipment performance regulation coefficient, which is determined according to the performance decay of the photovoltaic power generation unit and the energy storage unit.
[0009] Furthermore, in the charge and discharge management step, during the charging process of the energy storage unit, the charging current, voltage, and temperature are monitored in real time. When the charging current exceeds the set upper limit value, the charging power is reduced. When the charging voltage reaches the set upper limit value, it is switched to the constant voltage charging mode until the charging current drops to the set cut-off value, and then the charging stops. At the same time, the charging strategy is adjusted according to the battery temperature. During the discharging process of the energy storage unit, the discharging current, voltage, and temperature are also monitored in real time. When the discharging current exceeds the set upper limit value, the discharging power is reduced. When the discharging voltage drops to the set lower limit value, the discharging stops. At the same time, overcharge, over-discharge, over-current, and overheat protection mechanisms for the battery are set. When an abnormal situation of the battery is detected, the charge and discharge circuit is immediately cut off.
[0010] Furthermore, in the grid interaction response step, data interaction is carried out with the smart grid through the communication unit to obtain the dispatching instructions, real-time frequency, and voltage information of the grid. According to the dispatching instructions of the grid, the operating state of the intelligent energy storage power distribution cabinet is adjusted. When the grid needs peak shaving and valley filling, the discharging power of the energy storage unit is increased during peak electricity consumption periods, and the charging power of the energy storage unit is increased during low electricity consumption periods. According to the real-time frequency and voltage changes of the grid, the output powers of the photovoltaic power generation unit and the energy storage unit are automatically adjusted to maintain the stable operation of the grid. When the grid frequency is too high, the power generation is reduced. When the grid frequency is too low, the power generation is increased. When the grid voltage is too high, the output voltage is reduced. When the grid voltage is too low, the output voltage is increased.
[0011] Furthermore, in the grid interaction response step, according to the dispatching instructions of the grid, the operating state of the intelligent energy storage power distribution cabinet is adjusted, and its calculation formula is: , where is the comprehensive regulation power, which is the total amount of the intelligent energy storage power distribution cabinet's response to grid changes and its own output power regulation, is the power that needs to be regulated due to grid frequency changes, is the power that needs to be regulated due to grid voltage changes, is the power that needs to be regulated due to other dispatching signal changes of the grid.
[0012] Furthermore, the is the power that needs to be regulated due to grid frequency changes, and its calculation formula is: , where is the frequency regulation coefficient, is the real-time frequency of the grid, which is obtained from the smart grid in real time through the communication unit, is the reference frequency of the grid, is a positive number used to avoid the denominator being zero, and is set to , is the power that needs to be adjusted due to changes in the grid voltage, and its calculation formula is: , where is the voltage regulation coefficient, is the real-time voltage of the power grid, which is obtained from the smart grid in real time through the communication unit, is the reference voltage of the power grid, is a positive number used to avoid a zero denominator, is the power that needs to be adjusted due to changes in other scheduling signals of the power grid, and its calculation formula is: , where is the other scheduling signal regulation coefficient, is the value of other scheduling signals of the power grid, which is obtained from the scheduling instructions received from the smart grid dispatching center, is the reference value of this scheduling signal, which is determined according to the normal operation requirements of the power grid and historical data statistics, is a positive number used to avoid a zero denominator.
[0013] Furthermore, in the fault diagnosis and processing steps, when abnormal, the fault risk is evaluated based on sensor data and the status of the power distribution cabinet, and its evaluation formula is: , where is the fault risk evaluation value, is the weight coefficient of the rd parameter, is the th actual parameter value measured by the sensor, which is measured in real time by various sensors installed in the power distribution cabinet, is the th reference value of the parameter, which is obtained by statistically analyzing the historical data during the normal operation of the equipment, is the number of parameters participating in the evaluation, which is determined according to the number of sensors installed for fault diagnosis, is the adjustment factor, which is obtained by analyzing and simulating historical fault data, is a very small positive number set artificially, used to avoid drastic fluctuations in the fault risk value caused by small parameter changes.
[0014] Compared with the prior art, the control method of the intelligent energy storage power distribution cabinet based on photovoltaic power generation has the following beneficial effects: 1. Through the two-way interaction mechanism between the intelligent energy storage power distribution cabinet and the smart grid, the present invention significantly optimizes the power distribution pattern. In the power balance control link, based on the real-time collected data of photovoltaic power generation, energy storage power, and load power consumption, it accurately decides the charging and discharging operations of the energy storage unit, effectively smooths the impact of the intermittency and volatility of photovoltaic power generation on the power grid, greatly improves the stability of the power grid. At the same time, it flexibly adjusts the output power of each unit based on the grid demand, ensures the efficient transmission and utilization of electric energy, reduces the loss of energy during transmission and distribution, significantly improves the energy utilization efficiency, and provides strong support for building an efficient and stable smart grid.
[0015] 2. By real-time monitoring the charging current, voltage, and temperature, dynamically adjusting the charging strategy according to the battery characteristic curve, and strictly controlling the discharge parameters during the discharge process, the present invention effectively avoids overcharging, over-discharging, over-current, and overheating of the battery, comprehensively protects the safety of the energy storage battery, and extends the service life of the battery. In addition, the perfect fault diagnosis and processing system can quickly and accurately monitor, locate, and handle various faults. Minor faults can be automatically repaired, while serious faults can cut off the circuit and alarm in time, greatly reducing the risk of fault expansion, reducing the downtime and maintenance cost of the power distribution cabinet, and improving the operation and maintenance economy and reliability of the entire power distribution cabinet.
[0016] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0018] Figure 1 It is a flowchart operation diagram of a control method for an intelligent energy storage power distribution cabinet based on photovoltaic power generation; Figure 2 It is a flowchart of a control method for an intelligent energy storage power distribution cabinet based on photovoltaic power generation. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0019] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention objective, the following will, in conjunction with the accompanying drawings and preferred embodiments, describe in detail the specific embodiments, structures, features, and their effects according to the present invention.
[0020] Example 1: In a remote area, a communication base station uses an intelligent energy storage power distribution cabinet based on the control method of the present invention to ensure stable power supply. The base station is equipped with a photovoltaic power generation unit with a power of 100 kWp, and the energy storage unit is a lithium iron phosphate battery pack with a capacity of 200 kWh.
[0021] Various sensors are installed at the photovoltaic power generation unit, the energy storage unit, and the communication base station load to collect power generation, energy storage, and power consumption data. These data are transmitted to the control unit through a wireless communication unit. At the same time, the control unit will evaluate the accuracy of the data. If data anomalies are found, they will be processed in a timely manner to ensure the accuracy of the power distribution cabinet control.
[0022] The control unit continuously compares the photovoltaic power generation, energy storage power, and base station load power consumption, and uses the dynamic power regulation formula to calculate the regulation power. Among them, is the output power of the photovoltaic power generation unit, which is calculated from the current and voltage measured by the current sensor and voltage sensor installed at the output end of the photovoltaic power generation unit . is the power consumption of the load, which is directly measured by the power sensor installed at the load end. is the influence coefficient, which is determined through experiments and simulations according to the characteristics of the energy storage unit and the control requirements of the power distribution cabinet. is the state of charge of the energy storage unit, which is calculated by using the ampere-hour integration method combined with the open-circuit voltage method. is the intermediate state of charge of the energy storage unit, which is artificially set to 0.5. is the grid demand regulation coefficient. Since the power grid coverage in this area is unstable, when the power grid resumes power supply, in order to preferentially use the grid power to supply power to the base station and charge the energy storage unit, is initially set to 0.6. This enables more active response to grid dispatching when the grid is powered, and adjusts the charge and discharge strategy of the energy storage unit. After the power grid resumes power supply, if it is found that the grid voltage fluctuates greatly, in order to reduce the impact on the energy storage unit and base station equipment, can be appropriately reduced to reduce the charging power of the energy storage unit and avoid damage to equipment caused by grid instability. If the grid operates stably, can be appropriately increased to accelerate the charging speed of the energy storage unit. is the equipment performance regulation coefficient. In the initial stage of equipment operation, according to the initial performance parameters of the photovoltaic power generation unit and the energy storage unit, the performance decay of the equipment during operation is estimated, and Initially set to 0.8. During the operation of the equipment, regularly monitor the equipment performance. If it is found that the power generation efficiency of the photovoltaic power generation unit decreases due to aging, for example, the power generation power decreases by 10% compared to the initial value, at this time, appropriately reduce , adjust the power regulation strategy to adapt to the change of equipment performance. If the energy storage unit is maintained or upgraded, resulting in improved performance, can be correspondingly increased. For example, in the case of continuous cloudy days, the photovoltaic power generation is low. Assume that at this time , , , calculated according to the above formula is -25 kW (the negative sign indicates that the energy storage unit needs to discharge). The energy storage unit discharges at a power of 25 kW to maintain the operation of the base station. When the energy storage power is too low, the control unit will adjust the power consumption of some non-critical equipment according to the importance of the base station equipment, and give priority to ensuring the operation of the core communication equipment.
[0023] During the charging process of the energy storage unit, monitor the charging current, voltage and temperature in real time. When the charging current exceeds the set upper limit value, reduce the charging power. When the charging voltage reaches the set upper limit value, switch to the constant voltage charging mode until the charging current drops to the set cut-off value and stop charging. At the same time, adjust the charging strategy according to the battery temperature. During the discharging process of the energy storage unit, also monitor the discharging current, voltage and temperature in real time. When the discharging current exceeds the set upper limit value, reduce the discharging power. When the discharging voltage drops to the set lower limit value, stop discharging. At the same time, set the overcharge, over-discharge, over-current and overheat protection mechanisms for the battery. When an abnormal situation of the battery is detected, immediately cut off the charging and discharging circuit.
[0024] The intelligent energy storage power distribution cabinet is connected to the power grid through the communication unit, receives the dispatching instructions, frequency and voltage information of the power grid, and calculates the regulation power using the comprehensive regulation power formula , where , , , , , are the regulation coefficients of frequency, voltage and other dispatching signals respectively. Considering that the power grid frequency fluctuation in this area is relatively large, in order to make the power distribution cabinet respond more sensitively to the frequency change, is initially set to 0.7. After the power grid resumes power supply, monitor the fluctuation of the power grid frequency in real time. If it is found that the fluctuation amplitude of the power grid frequency decreases, can be appropriately reduced to 0.6 to reduce unnecessary regulation actions. If the fluctuation amplitude of the frequency increases, can be increased to 0.8 to enhance the regulation effect of the energy storage system on the frequency. Since the base station equipment has high requirements for voltage stability, and the power grid voltage in this area fluctuates greatly, It is initially set to 0.8. According to the power grid voltage monitoring data, when the voltage deviation is small, such as within the range of, it can be appropriately reduced to 0.7. When the voltage deviation is large and exceeds it is increased to 0.9 to strengthen the voltage regulation of the power distribution cabinet. When the power grid resumes power supply, according to the requirement in the power grid dispatching order to preferentially use the power grid power to supply power to the base station and charge the energy storage unit, is initially set to 0.7. If the power grid dispatching order changes, for example, it is required to increase the discharge power of the energy storage unit during a specific period to support the power grid, can be increased to 0.8 according to the change range of the order, so that the system can respond more actively to the dispatching signal. If the change of the dispatching signal is small, can be appropriately reduced, and are the real-time frequency and voltage of the power grid, which are obtained from the smart grid in real time through the communication unit, and are the reference frequency and voltage of the power grid, which are determined according to the power grid standards of the region where it is located, and is the value of other dispatching signals of the power grid, which is obtained from the dispatching order received from the smart grid dispatching center, is the reference value of this dispatching signal, which is determined according to the normal operation requirements of the power grid and historical data statistics; is a very small positive number, which is artificially set to For example, during the peak electricity consumption period, the power grid issues a dispatching order requiring the energy storage unit to discharge. The power distribution cabinet responds quickly, increases the discharge power, and relieves the power supply pressure of the power grid. When the power grid frequency or voltage fluctuates, the power distribution cabinet automatically adjusts the operation parameters of the photovoltaic power generation and energy storage system to maintain the stability of the power grid. For example, during the peak electricity consumption period in summer, when the power grid frequency drops slightly, the power distribution cabinet increases the discharge power of the energy storage unit and at the same time appropriately increases the output power of the photovoltaic power generation unit to stabilize the power grid frequency.
[0025] The control unit monitors the operation status of the power distribution cabinet in real time, analyzes the collected parameters. Once a fault is detected, such as a component of the photovoltaic power generation unit is damaged, resulting in a decrease in the power generation power, the fault risk assessment formula is used to evaluate the fault risk. Among them, is the weight coefficient of the th parameter, is the actual parameter value measured by the th sensor, which is measured in real time by various sensors installed in the power distribution cabinet, is the The reference values of the parameters are obtained by statistically analyzing the historical data during the normal operation of the device or determined by referring to the technical specification of the device. n is the number of parameters participating in the evaluation, which is determined according to the number of sensors installed for fault diagnosis. k is the adjustment factor, which is determined to be 2 through the analysis and simulation of historical fault data. α is a positive number, which is artificially set to 0.1. For faults that can be self-repaired, such as a short interruption of the communication line, an automatic attempt is made to restore the connection. For faults that cannot be self-repaired, a fault alarm message is sent to the operation and maintenance center through the satellite communication unit, detailing the type and location of the fault so that the operation and maintenance personnel can handle it in a timely manner to ensure the normal operation of the base station.
[0026] Embodiment 2: In a residential community, an intelligent energy storage power distribution cabinet based on the control method of the present invention is installed. The community is equipped with multiple groups of photovoltaic power generation units, which are distributed on the roofs of public buildings in the community with a total power of 500 kWp. The energy storage unit uses a lithium-ion battery pack with a total capacity of 800 kWh.
[0027] Current, voltage, power, and temperature sensors are installed at the output end of the photovoltaic power generation unit, the energy storage unit, and each load line. These sensors collect data according to the set sampling period and transmit the data to the control unit of the intelligent energy storage power distribution cabinet through wireless communication technology. The control unit will monitor the data quality in real time according to the data accuracy evaluation mechanism to ensure the reliability of the collected data.
[0028] Current, voltage, power, and temperature sensors are installed at the output end of the photovoltaic power generation unit, the energy storage unit, and each load line. These sensors collect data according to the set sampling period and transmit the data to the control unit of the intelligent energy storage power distribution cabinet through wireless communication technology. The control unit will monitor the data quality in real time according to the data accuracy evaluation mechanism to ensure the reliability of the collected data.
[0029] The control unit compares the photovoltaic power generation, energy storage power, and community load power consumption in real time. When there is sufficient sunlight during the day, if the photovoltaic power generation is greater than the community load power consumption and the energy storage unit is not full, the energy storage unit starts to charge. If the energy storage unit is already full, the excess electric energy is fed back to the power grid. When the photovoltaic power generation is less than the load power consumption, the energy storage unit discharges to supplement the electric energy. For example, at noon on a sunny day, the photovoltaic power generation reaches 300 kW, the community load power consumption is 150 kW, and the SOC of the energy storage unit is 60%. At this time, the energy storage unit charges at a power of 100 kW. In the evening, the photovoltaic power generation drops to 50 kW, the community load power consumption rises to 200 kW, and the SOC of the energy storage unit is 80%. The energy storage unit discharges at a power of 150 kW and supplements 50 kW of electric energy from the power grid to ensure stable power supply in the community.
[0030] During the charging process of the energy storage unit, the charging current, voltage, and temperature are monitored in real time. When the charging current approaches the maximum charging current allowed by the battery, the charging power is automatically reduced. When the charging voltage reaches the upper limit value, it switches to the constant voltage charging mode. During discharging, if the discharging current is too large or the battery voltage is too low, the discharging is immediately stopped to protect the energy storage battery. For example, when the temperature of the energy storage battery is too high, the charging rate is appropriately reduced to prevent the battery from being damaged due to overheating.
[0031] The intelligent energy storage power distribution cabinet is connected to the power grid through the communication unit, and receives the dispatching instructions, frequency, and voltage information of the power grid. During peak electricity consumption periods, when the power grid issues a dispatching instruction for the energy storage unit to discharge, the power distribution cabinet responds quickly and increases the discharging power to relieve the power supply pressure of the power grid. When the power grid frequency or voltage fluctuates, the power distribution cabinet automatically adjusts the operating parameters of the photovoltaic power generation and energy storage system to maintain the stability of the power grid. For example, during the peak electricity consumption period in summer, when the power grid frequency slightly decreases, the power distribution cabinet increases the discharging power of the energy storage unit and at the same time appropriately increases the output power of the photovoltaic power generation unit to stabilize the power grid frequency.
[0032] The control unit continuously monitors the operating parameters of the power distribution cabinet. Once abnormal parameters are found, such as excessive current in a certain line, too high temperature of the energy storage unit, etc., it immediately starts the fault diagnosis program. According to the preset fault judgment logic and historical data, it quickly locates the fault position and type. For minor faults, such as abnormal signals from a certain sensor, the power distribution cabinet automatically calibrates or switches to a standby sensor. For serious faults, such as a short circuit in the energy storage unit, it immediately cuts off the relevant circuit and sends a fault alarm message to the maintenance personnel of the community property to notify them for repair.
[0033] The above is only a preferred embodiment of the present invention, and it is not intended to limit the present invention in any form. Although the present invention has been disclosed above with the preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to form an equivalent embodiment within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.
Claims
1. A control method for an intelligent energy storage power distribution cabinet based on photovoltaic power generation, characterized in that, The method includes the following specific steps: Data acquisition and transmission: Install sensors at key positions of the intelligent energy storage power distribution cabinet to collect data, and transmit the data through wired methods such as RS-485 and CAN buses or wireless methods such as ZigBee, LoRa, and 4G / 5G; Power balance control: Real-time analysis is carried out on the photovoltaic power generation, energy storage power, and load power consumption. The magnitude relationship between the photovoltaic power generation and the load power consumption is compared to determine whether the energy storage unit needs to participate in power regulation. When the photovoltaic power generation is greater than the load power consumption, if the energy storage unit is not fully charged, the energy storage unit is controlled to start charging. If the energy storage unit is fully charged, the excess electrical energy is fed back to the grid. When the photovoltaic power generation is less than the load power consumption, if the energy storage unit has remaining power, the energy storage unit is controlled to discharge to supplement the insufficient electrical energy. If the energy storage unit has insufficient power, electrical energy is obtained from the grid. According to the charge and discharge status of the energy storage unit and the requirements of the grid, the output powers of the photovoltaic power generation unit, energy storage unit, and inverter unit are dynamically adjusted. Its dynamic adjustment formula is: , where is the output power of the photovoltaic power generation unit, which is calculated from the current and voltage measured by the current sensor and voltage sensor installed at the output end of the photovoltaic power generation unit. The calculation formula is: , is the power consumption of the load, which is directly measured by the power sensor installed at the load end, is the influence coefficient, which is determined through experiments according to the characteristics of the energy storage unit and the control requirements of the power distribution cabinet, is the state of charge of the energy storage unit, is the intermediate state of charge of the energy storage unit, which is set to 0.5, is the grid demand regulation coefficient, is the equipment performance regulation coefficient, which is determined according to the performance degradation of the photovoltaic power generation unit and the energy storage unit. By controlling the maximum power point tracking circuit of the photovoltaic power generation unit, the power generation efficiency is optimized. By adjusting the charge and discharge current of the energy storage unit, the energy storage speed is controlled; Charge and discharge management: During the charge and discharge of the energy storage unit, monitor the current, voltage, and temperature in real time. When the upper limit is exceeded or specific conditions are met, adjust the charge and discharge power, and set overcharge, over-discharge, over-current, and overheat protection mechanisms to cut off the circuit; Grid interaction response: Use the communication unit to obtain the dispatching instructions, frequency, and voltage information of the smart grid, and adjust the operating state of the power distribution cabinet according to the instructions. Automatically adjust the power of the power generation and energy storage units according to the changes in frequency and voltage; Fault diagnosis and handling: Monitor the operating parameters in real time and compare them with the preset range. When an abnormality occurs, evaluate the fault risk based on the sensor data and the state of the power distribution cabinet, and automatically repair or cut off the circuit for different faults and notify the operation and maintenance personnel.
2. The control method of an intelligent energy storage power distribution cabinet based on photovoltaic power generation according to claim 1, wherein In the data acquisition and transmission step, install sensors at key positions of the intelligent energy storage power distribution cabinet to collect data, including current sensors, voltage sensors, and power sensors for monitoring the output of the photovoltaic power generation unit, state of charge sensors, voltage sensors, and current sensors for detecting the state of the energy storage unit, and current sensors, voltage sensors, and power sensors for obtaining the electricity consumption of the load. At the same time, set up a communication unit to establish a two-way communication link with the dispatching center and relevant monitoring nodes of the smart grid through wired or wireless communication protocols.
3. The control method of an intelligent energy storage power distribution cabinet based on photovoltaic power generation according to claim 1, wherein, In the charge and discharge management step, during the charging process of the energy storage unit, monitor the charging current, voltage, and temperature in real time. When the charging current exceeds the set upper limit value, reduce the charging power. When the charging voltage reaches the set upper limit value, switch to the constant voltage charging mode until the charging current drops to the set cut-off value and stop charging. At the same time, adjust the charging strategy according to the battery temperature. During the discharging process of the energy storage unit, also monitor the discharging current, voltage, and temperature in real time. When the discharging current exceeds the set upper limit value, reduce the discharging power. When the discharging voltage drops to the set lower limit value, stop discharging. At the same time, set the overcharge, over-discharge, over-current, and overheat protection mechanisms for the battery. When an abnormal situation of the battery is detected, immediately cut off the charge and discharge circuit.
4. The control method of an intelligent energy storage power distribution cabinet based on photovoltaic power generation according to claim 1, wherein, In the grid interaction response step, conduct data interaction with the smart grid through the communication unit to obtain the dispatching instructions, real-time frequency, and voltage information of the grid. According to the dispatching instructions of the grid, adjust the operating state of the intelligent energy storage power distribution cabinet. When the grid needs to cut peaks and fill valleys, increase the discharging power of the energy storage unit during peak electricity consumption periods and increase the charging power of the energy storage unit during low electricity consumption periods. Automatically adjust the output power of the photovoltaic power generation unit and the energy storage unit according to the real-time frequency and voltage changes of the grid to maintain the stable operation of the grid. When the grid frequency is too high, reduce the power generation power. When the grid frequency is too low, increase the power generation power. When the grid voltage is too high, reduce the output voltage. When the grid voltage is too low, increase the output voltage.
5. The control method of an intelligent energy storage power distribution cabinet based on photovoltaic power generation according to claim 4, wherein, In the grid interaction response step, according to the dispatching instructions of the grid, adjust the operating state of the intelligent energy storage power distribution cabinet, and its calculation formula is: , where is the comprehensive regulation power, which is the total amount of the intelligent energy storage power distribution cabinet's response to the grid change and its own output power regulation, is the power that needs to be regulated due to the change of the grid frequency, is the power that needs to be regulated due to the change of the grid voltage, is the power that needs to be regulated due to the change of other dispatching signals of the grid.
6. The control method of an intelligent energy storage power distribution cabinet based on photovoltaic power generation according to claim 5, characterized in that, The is the power that needs to be adjusted due to the change in the grid frequency, and its calculation formula is: Wherein, is the frequency adjustment coefficient, is the real-time frequency of the grid, which is obtained from the smart grid in real time through the communication unit, is the reference frequency of the grid, is a positive number used to avoid a zero denominator, and is set to , is the power that needs to be adjusted due to the change in the grid voltage, and its calculation formula is: , wherein, is the voltage adjustment coefficient, is the real-time voltage of the grid, which is obtained from the smart grid in real time through the communication unit, is the reference voltage of the grid, is a positive number used to avoid a zero denominator, is the power that needs to be adjusted due to the change in other scheduling signals of the grid, and its calculation formula is: , wherein, is the other scheduling signal adjustment coefficient, is the value of other scheduling signals of the grid, which is obtained from the scheduling instructions received from the smart grid dispatching center, is the reference value of this scheduling signal, which is determined according to the normal operation requirements of the grid and historical data statistics, is a positive number used to avoid a zero denominator.
7. The control method of an intelligent energy storage power distribution cabinet based on photovoltaic power generation according to claim 1, characterized in that, In the fault diagnosis and processing steps, the fault risk is evaluated based on the sensor data and the status of the power distribution cabinet when an abnormality occurs. The evaluation formula is: ,in, is the failure risk assessment value, For the The weight coefficient of the parameter, For the The actual parameter values measured by each sensor are obtained by real-time measurement of various sensors installed in the power distribution cabinet. For the The reference value of each parameter is obtained by statistically analyzing the historical data of the normal operation of the equipment. The number of parameters involved in the evaluation is determined by the number of sensors installed for fault diagnosis. is the adjustment factor, which is obtained by analyzing and simulating historical fault data. It is an extremely small positive number set artificially to avoid drastic fluctuations in the fault risk value caused by slight changes in parameters.