Energy monitoring comprehensive control system and control method for photovoltaic energy storage system in industrial park

Abstract

The invention relates to the technical field of photovoltaic power generation dispatching energy storage charging and discharging, in particular to an energy monitoring comprehensive control system and control method for a photovoltaic energy storage system in an industrial park. The system comprises a photovoltaic assembly, a grid-connected inverter, a photovoltaic grid-connected power distribution cabinet, an energy management system, an energy storage converter system, a battery management system, an energy storage unit and an electricity utilization load, the energy management system is connected with the photovoltaic grid-connected power distribution cabinet through an RS485 communication cable, and the electricity utilization load is connected with the energy management system through an RS485 communication cable. The method has the advantages of being simple in system and method, good in charging and discharging scheduling effect, capable of relieving power grid pressure and increasing photovoltaic power generation benefits and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic power generation scheduling, energy storage, charging and discharging. Specifically, it provides an energy monitoring integrated control system and control method for photovoltaic energy storage systems in industrial parks, which have a simple system, a simple method, good charging and discharging scheduling effect, reduce grid pressure, and increase photovoltaic power generation efficiency. Background Art

[0002] As we all know, with the continuous development of new energy technologies, photovoltaic power generation, as a clean and renewable form of energy, has attracted more and more attention. Due to the rapid development of photovoltaic power generation in recent years, a large amount of surplus electricity has been connected to the grid during the peak period of photovoltaic power generation at noon, which has had an impact on the municipal power grid and posed a threat to the security of the grid. Moreover, as many provinces and cities have adjusted the time-of-use electricity price structure for industry and commerce, and in order to encourage the self-generation and self-use of new energy electricity, the peak period of photovoltaic power generation is the valley period of the time-of-use period for industrial and commercial users, or even the deep valley period. Therefore, the economic benefits of photovoltaic power generation have been significantly reduced. Summary of the Invention

[0003] The purpose of the present invention is to address the deficiencies of the above-mentioned prior art and to provide an energy monitoring integrated control system and control method for an industrial park photovoltaic energy storage system with a simple system, simple method, good charging and discharging scheduling effect, reduced grid pressure, and increased photovoltaic power generation efficiency.

[0004] The technical solution adopted by the present invention to solve its technical problem is: An energy monitoring integrated control system for a photovoltaic energy storage system in an industrial park is characterized in that the system includes photovoltaic components, a grid-connected inverter, a photovoltaic grid-connected distribution cabinet, an energy management system, an energy storage converter system, a battery management system, an energy storage unit, and an electrical load. The photovoltaic components are connected to the grid-connected inverter for unidirectional power transmission, the grid-connected inverter is connected to the photovoltaic grid-connected distribution cabinet for unidirectional power transmission, the energy storage unit is connected to the battery management system for bidirectional power transmission, the battery management system is connected to the energy storage converter system for bidirectional power transmission, the energy storage converter system is connected to the energy management system for bidirectional power transmission, the photovoltaic grid-connected distribution cabinet for unidirectional power transmission and the energy management system for bidirectional power transmission are respectively connected to the power supply system and connected to the electrical load for power supply, the energy management system is connected to the photovoltaic grid-connected distribution cabinet via an RS485 communication cable, and the electrical load is connected to the energy management system via an RS485 communication cable.

[0005] The photovoltaic grid-connected distribution cabinet of the present invention is equipped with a power generation monitoring device, a power consumption monitoring device is installed in the power load, and a data calculation module is installed in the energy management system. The power generation monitoring device and the power consumption monitoring device monitor the power generation and power consumption respectively and transmit them to the data calculation module via an RS485 communication cable. The data calculation module calculates the maximum charging power of the energy storage inverter system in real time and charges the energy storage unit according to the maximum power.

[0006] An energy monitoring and integrated control method for a photovoltaic energy storage system in an industrial park is characterized in that the control method comprises the following steps: (1) System design: The photovoltaic module is connected to the grid-connected inverter for unidirectional transmission, the grid-connected inverter is connected to the photovoltaic grid-connected distribution cabinet for unidirectional transmission, the energy storage unit is connected to the battery management system for bidirectional transmission, the battery management system is connected to the energy storage converter system for bidirectional transmission, the energy storage converter system is connected to the energy management system for bidirectional transmission, the photovoltaic grid-connected distribution cabinet for unidirectional transmission and the energy management system for bidirectional transmission are respectively connected to the power supply system and connected to the power supply of the power load, the energy management system is connected to the photovoltaic grid-connected distribution cabinet through an RS485 communication cable, the power load is connected to the energy management system through an RS485 communication cable, a power generation monitoring device is installed in the photovoltaic grid-connected distribution cabinet, a power consumption monitoring device is installed in the power load, and a data calculation module is installed in the energy management system. The power generation and power consumption monitored by the power generation monitoring device and the power consumption monitoring device are respectively transmitted to the data calculation module through the RS485 communication cable. The data calculation module calculates the real-time maximum charging power of the energy storage converter system and charges the energy storage unit according to the maximum power; (2) Control steps: a. Design a preset charging time period and a preset discharging time period. The power generation monitoring device of the photovoltaic grid-connected distribution cabinet is used to monitor and record the real-time power generation of the photovoltaic system, and send the monitored data to the data calculation module of the energy management system (EMS) via RS485 within the preset time period. The power consumption monitoring device at the power load end is used to monitor and record the real-time power consumption of the industrial park, and send the monitored data to the data calculation module of the energy management system (EMS) via RS485 within the preset time period. It is required that the two real-time data sent by the power generation monitoring device and the power consumption monitoring device be sent to the data calculation module of the energy management system (EMS) synchronously and without delay; b. The data calculation module of the energy management system (EMS) collects two real-time data sent by the power generation monitoring device and the power consumption monitoring device during the preset charging period. The data calculation module performs arithmetic operations and logical judgments on the data to calculate the real-time maximum charging power. The delay shall not exceed 200 milliseconds and then send instructions to the energy storage converter system (PCS). The energy storage converter system (PCS) charges the energy storage unit according to the maximum power. During the preset charging period, the maximum charging power is: Transformer real-time power supply margin = transformer rated capacity - transformer load power consumption; Maximum charging power = real-time photovoltaic power generation + real-time transformer power supply margin; The data calculation module of the energy management system (EMS) collects real-time data transmitted by the power consumption monitoring device during a preset discharge period. The data calculation module performs arithmetic operations and logical judgments on the data to calculate the real-time maximum discharge power. With a delay of no more than 200 milliseconds, the module issues a command to the energy storage converter system (PCS). The PCS, in accordance with the command, discharges the energy stored in the energy storage unit to the industrial park for load use. The energy management system (EMS) described herein tracks photovoltaic power generation and load power consumption monitoring devices via RS485 wired communication, acquiring real-time data at the millisecond level, linking all real-time generated power of the photovoltaic system and the load rate of the industrial park's transformers. It then calculates the real-time maximum charging power of the energy storage system and the PCS, and charges the energy storage unit at that maximum power.

[0007] The battery management system (BMS) of the present invention monitors the voltage, current, and temperature of the energy storage unit during charging by the energy storage converter system (PCS). This ensures that if the voltage of the energy storage unit exceeds a set safety threshold, the charging circuit is automatically disconnected; if the charging current exceeds the set safety threshold, the charging current is limited or charging is stopped; and if the temperature exceeds the set safety threshold, the heat dissipation device is activated or charging is stopped. This prevents overcharging, which could affect the performance and lifespan of the energy storage unit, or even lead to safety accidents, by causing overvoltage, overcurrent, or excessive temperature. During the charging process, the charging mode (e.g., constant current charging, constant voltage charging, or trickle charging) is automatically switched based on the energy storage unit status to optimize charging efficiency. This ensures safe, efficient, and stable charging of the energy storage unit. When the discharge current exceeds the set safety threshold, the discharge current is limited to prevent overheating or damage to the energy storage unit. When the temperature exceeds the set safety threshold, the heat dissipation device is activated or the discharge power is limited to prevent thermal runaway. This prevents overdischarge from affecting the performance and lifespan of the energy storage unit, or even causing permanent loss of energy storage unit capacity. During the discharge process, the discharge mode is automatically switched based on the energy storage unit status to optimize discharge efficiency. Ensure that the energy storage unit discharges safely, efficiently and stably.

[0008] The two real-time data sent by the power generation monitoring device and the power consumption monitoring device described in the present invention are synchronized and have no delay. It is necessary to collect and process the real-time data, filter the initial data layer by layer, remove redundant information, and reduce network bandwidth occupancy; adopt dual-channel synchronous transmission: design independent transmission paths for the two types of data respectively to avoid data competition and congestion, realize parallel transmission of the two types of data, and improve transmission efficiency; add timestamps in data packets to ensure that the data center can accurately identify the arrival order and time relationship of the data; adopt multi-path routing: configure multiple network paths to achieve data load balancing and redundant transmission, improve network reliability and stability, and when a network path fails, it can automatically switch to other available paths to ensure the continuity of data transmission.

[0009] The present invention sets the preset charging time period as the valley period, and sets the preset discharging time period as the peak period.

[0010] The present invention adopts the above-mentioned system and method, and has the advantages of simple system, simple method, good charging and discharging scheduling effect, reduced power grid pressure, and increased photovoltaic power generation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a system schematic diagram of the present invention.

[0012] Figure 2 This is the energy monitoring integrated control network architecture diagram of the present invention.

[0013] Figure 3 This is a flow chart of the data calculation module of the present invention performing arithmetic operations and logical judgments on data.

[0014] Figure 4 This is the power generation curve of the photovoltaic system on a certain day in June. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings: As shown in the accompanying drawings, an energy monitoring integrated control system for a photovoltaic energy storage system in an industrial park is characterized in that the system includes photovoltaic modules, grid-connected inverters, photovoltaic grid-connected distribution cabinets, an energy management system, an energy storage converter system, a battery management system, an energy storage unit, and power loads. The photovoltaic modules are connected to the grid-connected inverter for unidirectional power transmission, the grid-connected inverter is connected to the photovoltaic grid-connected distribution cabinet for unidirectional power transmission, the energy storage unit is connected to the battery management system for bidirectional power transmission, the battery management system is connected to the energy storage converter system for bidirectional power transmission, the energy storage converter system is connected to the energy management system for bidirectional power transmission, the photovoltaic grid-connected distribution cabinet for unidirectional power transmission and the energy management system for bidirectional power transmission are respectively connected to the power supply system and connected to the power loads for power supply, the energy management system is connected to the photovoltaic grid-connected distribution cabinet via an RS485 communication cable, and the power loads are connected to the energy management system via an RS485 communication cable.

[0016] Furthermore, a power generation monitoring device is installed in the photovoltaic grid-connected distribution cabinet, a power consumption monitoring device is installed in the power load, and a data calculation module is installed in the energy management system. The power generation monitoring device and the power consumption monitoring device monitor the power generation and power consumption respectively transmitted to the data calculation module via the RS485 communication cable. The data calculation module calculates the real-time maximum charging power of the energy storage inverter system and charges the energy storage unit according to the maximum power.

[0017] An energy monitoring and integrated control method for a photovoltaic energy storage system in an industrial park is characterized in that the control method comprises the following steps: (1) System design: The photovoltaic module is connected to the grid-connected inverter for unidirectional transmission, the grid-connected inverter is connected to the photovoltaic grid-connected distribution cabinet for unidirectional transmission, the energy storage unit is connected to the battery management system for bidirectional transmission, the battery management system is connected to the energy storage converter system for bidirectional transmission, the energy storage converter system is connected to the energy management system for bidirectional transmission, the photovoltaic grid-connected distribution cabinet for unidirectional transmission and the energy management system for bidirectional transmission are respectively connected to the power supply system and connected to the power supply of the power load, the energy management system is connected to the photovoltaic grid-connected distribution cabinet through an RS485 communication cable, the power load is connected to the energy management system through an RS485 communication cable, a power generation monitoring device is installed in the photovoltaic grid-connected distribution cabinet, a power consumption monitoring device is installed in the power load, and a data calculation module is installed in the energy management system. The power generation and power consumption monitored by the power generation monitoring device and the power consumption monitoring device are respectively transmitted to the data calculation module through the RS485 communication cable. The data calculation module calculates the real-time maximum charging power of the energy storage converter system and charges the energy storage unit according to the maximum power; (2) Control steps: a. Design a preset charging time period and a preset discharging time period. The power generation monitoring device of the photovoltaic grid-connected distribution cabinet is used to monitor and record the real-time power generation of the photovoltaic system, and send the monitored data to the data calculation module of the energy management system (EMS) via RS485 within the preset time period. The power consumption monitoring device at the power load end is used to monitor and record the real-time power consumption of the industrial park, and send the monitored data to the data calculation module of the energy management system (EMS) via RS485 within the preset time period. It is required that the two real-time data sent by the power generation monitoring device and the power consumption monitoring device be sent to the data calculation module of the energy management system (EMS) synchronously and without delay; b. The data calculation module of the energy management system (EMS) collects two real-time data sent by the power generation monitoring device and the power consumption monitoring device during the preset charging period. The data calculation module performs arithmetic operations and logical judgments on the data to calculate the real-time maximum charging power. The delay shall not exceed 200 milliseconds and then send instructions to the energy storage converter system (PCS). The energy storage converter system (PCS) charges the energy storage unit according to the maximum power. During the preset charging period, the maximum charging power is: Transformer real-time power supply margin = transformer rated capacity - transformer load power consumption; Maximum charging power = real-time photovoltaic power generation + real-time transformer power supply margin; The data calculation module of the energy management system (EMS) collects real-time data transmitted by the power consumption monitoring device during a preset discharge period. The data calculation module performs arithmetic operations and logical judgments on the data to calculate the real-time maximum discharge power. With a delay of no more than 200 milliseconds, the module issues a command to the energy storage converter system (PCS). The PCS, in accordance with the command, discharges the energy stored in the energy storage unit to the industrial park for load use. The energy management system (EMS) described herein tracks photovoltaic power generation and load power consumption monitoring devices via RS485 wired communication, acquiring real-time data at the millisecond level, linking all real-time generated power of the photovoltaic system and the load rate of the industrial park's transformers. It then calculates the real-time maximum charging power of the energy storage system and the PCS, and charges the energy storage unit at that maximum power.

[0018] Furthermore, the battery management system (BMS) monitors the voltage, current, and temperature of the energy storage unit during charging by the power storage converter system (PCS). This ensures that if the voltage of the energy storage unit exceeds a set safety threshold, the charging circuit is automatically disconnected; if the charging current exceeds the set safety threshold, the charging current is limited or charging is stopped; and if the temperature exceeds the set safety threshold, the heat dissipation device is activated or charging is stopped. This prevents overcharging from causing overvoltage, overcurrent, or excessive temperature, which could affect the performance and lifespan of the energy storage unit or even lead to safety accidents. During the charging process, the charging mode (such as constant current charging, constant voltage charging, or trickle charging) is automatically switched based on the energy storage unit status to optimize charging efficiency. This ensures safe, efficient, and stable charging of the energy storage unit. If the discharge current exceeds the set safety threshold, the discharge current is limited to prevent overheating and damage to the energy storage unit. If the temperature exceeds the set safety threshold, the heat dissipation device is activated or the discharge power is limited to prevent thermal runaway. This prevents overdischarge from affecting the performance and lifespan of the energy storage unit or even causing permanent loss of energy storage unit capacity. During the discharge process, the discharge mode is automatically switched based on the energy storage unit status to optimize discharge efficiency. Ensure that the energy storage unit discharges safely, efficiently and stably.

[0019] Furthermore, the two real-time data sent by the power generation monitoring device and the power consumption monitoring device are synchronized and have no delay. It is necessary to collect and process the real-time data, filter the initial data layer by layer, remove redundant information, and reduce network bandwidth occupancy; adopt dual-channel synchronous transmission: design independent transmission paths for the two types of data to avoid data competition and congestion, realize parallel transmission of the two types of data, and improve transmission efficiency; add timestamps in data packets to ensure that the data center can accurately identify the arrival order and time relationship of the data; adopt multi-path routing: configure multiple network paths to achieve data load balancing and redundant transmission, improve network reliability and stability, and when a network path fails, it can automatically switch to other available paths to ensure the continuity of data transmission.

[0020] In actual use, the preset charging time period is set to the valley period, which may be 11:00-14:00, and the preset discharging time period is set to the peak period, which may be 17:00-21:00.

[0021] The data calculation module of the present invention performs arithmetic operations and logical judgments on data as follows: Figure 3 As shown: First, the photovoltaic system power generation monitoring data and the power load power monitoring data are transmitted to the energy management system (EMS). The clock judgment module in the energy management system (EMS) judges the time. The time is 11:00-14:00 for energy storage charging time, the time is 17:00-21:00 for energy storage discharge time, and the rest of the time is other time. After the time is 11:00-14:00, it enters the data calculation module to calculate the maximum charging power, and then charges the energy storage unit through the energy storage converter. The battery management system monitors the energy storage unit voltage, current, voltage and other parameters. The energy storage unit voltage, current, temperature and other parameters continue to pass within the safety threshold range. The energy storage AC device charges the energy storage unit. If the voltage, current, temperature and other parameters of the energy storage unit exceed the safety threshold range, the charging current is limited or charging is stopped. After 17:00-21:00, the data calculation module is entered to calculate the maximum discharge power. The energy storage unit discharges through the energy storage converter. The battery management system monitors the voltage, current, and other parameters of the energy storage unit. If the voltage, current, temperature and other parameters of the energy storage unit are within the safety threshold range, the energy storage unit continues to discharge through the energy storage AC device. If the voltage, current, temperature and other parameters of the energy storage unit exceed the safety threshold range, the discharge current is limited or discharge is stopped. The cycle is repeated at other times to enter the energy management system.

[0022] The above-mentioned photovoltaic modules are installed on the roof of the building. They are the basic units that directly convert the sun's light energy into DC electricity. They use the photovoltaic effect of photovoltaic cells to directly convert the sun's light energy into DC electricity.

[0023] Grid-connected inverters are the core equipment of photovoltaic power generation systems, responsible for converting direct current (DC) generated by solar photovoltaics into alternating current (AC). Inverters are electronic devices that convert the DC power generated by photovoltaic modules into AC power that meets grid requirements and transmits it to the power system, prioritizing power consumption in industrial parks. When the power generated by the photovoltaic modules exceeds the power consumption of the loads, the excess power can be returned to the utility grid. Inverters also provide multiple functions, such as maximum power point tracking (MPPT), grid monitoring, and fault protection, to ensure the stable operation and efficient power generation of photovoltaic power generation systems.

[0024] The photovoltaic grid-connected distribution cabinet is responsible for the important task of safely connecting the AC power output by the grid-connected inverter to the power grid. The photovoltaic grid-connected distribution cabinet is equipped with a real-time monitoring device for the photovoltaic system power generation. The real-time photovoltaic power generation can be obtained through the monitoring device of the photovoltaic grid-connected distribution cabinet.

[0025] The Energy Management System (EMS) is the "brain" of the energy storage system and the core control unit. It is responsible for optimizing energy storage, release, and scheduling to achieve efficient, safe, and economical operation of the system. The Energy Management System (EMS) tracks the monitoring devices of photovoltaic power generation and load power consumption via RS485 wired mode, obtains real-time data and obtains all real-time generated electricity of the photovoltaic system and the load rate of the industrial park transformer in millisecond linkage. It calculates the real-time maximum charging power of the energy storage system's energy storage converter system (PCS) and charges the energy storage unit at maximum power.

[0026] The power storage converter system (PCS) is the "bridge" between energy storage and the power grid. It is the core power electronic device of the energy storage system. It is responsible for realizing the efficient two-way energy conversion between the energy storage unit and the power grid or load. It is a key equipment for the grid-connected operation and flexible scheduling of the energy storage system.

[0027] The Battery Management System (BMS) is the guardian of the energy storage battery pack, responsible for ensuring safe, efficient, and reliable operation. Its performance directly impacts the safety, efficiency, and lifespan of the energy storage system. When the power converter system (PCS) charges the energy storage unit, the BMS monitors the voltage, current, temperature, and other conditions of the energy storage unit. This ensures that if the voltage of the energy storage unit exceeds a set safety threshold, the charging circuit is automatically disconnected; if the charging current exceeds a set safety threshold, the charging current is limited or charging is stopped; and if the temperature exceeds a set safety threshold, the cooling device is activated or charging is stopped. This prevents overcharging from causing overvoltage, overcurrent, or excessive temperature, which could affect the performance and lifespan of the energy storage unit and even lead to safety accidents. During the charging process, the BMS automatically switches charging modes (such as constant current, constant voltage, and trickle charging) based on the energy storage unit's status to optimize charging efficiency, ensuring safe, efficient, and stable charging of the energy storage unit.

[0028] The energy storage unit is the "heart" of the energy storage system, responsible for storing electrical energy and realizing charge and discharge cycles. It is the core carrier of the energy storage system, and its performance directly affects the efficiency, safety and economy of the energy storage system.

[0029] The power load refers to the equipment or devices that consume electricity in the industrial park. It converts electrical energy into other forms of energy (such as light energy, heat energy, mechanical energy, etc.) to meet various production and life needs. The power load side is equipped with a monitoring device to monitor the real-time power consumption of the power load. The load power consumption of the industrial park at the same time can be obtained through the power load monitoring device.

[0030] Industrial and commercial electricity consumption uses time-of-use pricing, primarily to balance electricity supply and demand and reduce overall electricity costs. Electricity cannot be stored on a large scale, and its production and consumption must be balanced in real time. Power resource consumption and power supply costs vary depending on the time of day. Peak periods, when electricity consumption is concentrated, experience tight supply and demand, leading to higher power costs. Meanwhile, off-peak periods, when electricity consumption is lower, have relatively lower costs. The time-of-use pricing mechanism, by setting electricity price levels for different time periods—peak, flat, and off-peak periods—encourages users to use less electricity during peak hours and more during off-peak hours. This balances electricity supply and demand, avoids power outages, and ensures normal electricity use for production and daily life.

[0031] Because traditional energy storage system control methods rely on peak-valley arbitrage—charging during off-peak hours and discharging during peak hours during the industrial and commercial time-of-use electricity price period—this presents a problem: industrial parks want to use high-power, energy-consuming equipment during off-peak hours to reduce electricity costs. This situation results in the simultaneous energy consumption of energy storage charging and high-power equipment operation, which puts pressure on the transformer. Increasing transformer capacity increases distribution infrastructure construction costs and long-term operating costs. While photovoltaic power generation systems can be considered as backup power supply capacity, their output varies with the weather and is not constant. Therefore, traditional methods cannot accurately grasp the power supply and demand situation in industrial parks. To ensure the security of the industrial park's power grid, a conservative approach of reducing charging power is generally adopted.

[0032] The above-mentioned energy monitoring and comprehensive control method can utilize the power supply and distribution facilities and photovoltaic power generation system of the industrial park, and work in conjunction with the energy storage system. It can maximize the use of the electricity of the photovoltaic power generation system and the transformer power supply surplus for the energy storage unit during the off-peak period of the industrial and commercial time-of-use electricity price period, and discharge the electricity of the energy storage unit to the industrial park during the peak period and peak period for use by the load.

[0033] This integrated energy monitoring and control method maximizes the industrial park's power supply capacity, enabling peak-valley arbitrage and providing low-cost, highly efficient electricity. It also improves the utilization rate of all energy supply facilities in the industrial park, maximizing the benefits of photovoltaic power generation and energy storage systems. It also reduces the impact of excess photovoltaic power flowing online during peak periods on the utility grid, improving the safety factor of the utility grid. Furthermore, during peak and peak periods of industrial and commercial time-of-use electricity pricing, the energy storage system can be used to supply power to industrial park loads, reducing pressure on the utility grid.

[0034] The above-mentioned energy monitoring and comprehensive control method helps to promote the consumption of new energy, improve the stability of the power system, promote the development of the new energy industry, attract more investment into the new energy field, further promote the innovation and development of new energy technologies, improve the overall utilization efficiency of the power system, reduce the investment and operating costs of the power grid, and reduce social resource waste.

[0035] For example, on a certain day in May in an industrial park in Shandong, 11:00-14:00 is the general industrial and commercial off-peak period, with an electricity price of 0.25 yuan / kWh; 17:00-20:00 is the general industrial and commercial peak period, with an electricity price of 1.2 yuan / kWh; 20:00-21:00 is the general industrial and commercial peak period, with an electricity price of 1 yuan / kWh. The industrial park is equipped with a 1000kVA distribution transformer, and the power load throughout the day is 800kW; the DC installed capacity of the photovoltaic power generation system is 1000kW, and the photovoltaic system generates 850kWh, 900kWh, and 850kWh from 11:00-12:00, 12:00-13:00, and 13:00-14:00 respectively. The electricity consumption of the park with and without the above-mentioned energy comprehensive control method is shown in Figure 2. The cost comparison is shown in the following table: Summary: The table above shows that without integrated energy control, the PV system operates in a traditional grid-connected mode of "self-generated for own use, with surplus power fed to the grid." Furthermore, because the load approaches the transformer capacity, adding energy storage is not feasible due to the lack of guaranteed energy storage charging capacity. The value of the industrial park's load electricity consumption during the seven hours of 11:00 AM to 2:00 PM and 5:00 PM to 9:00 PM is 4,290 yuan (610 + 3,680 yuan).

[0036] By implementing a comprehensive energy control approach, which fully utilizes the transformer's power reserve and the photovoltaic system's generation, the value of the load's electricity consumption over the same two time periods, seven hours, is 750 yuan. This approach can save the park 3,540 yuan (4,290 - 750 yuan) in electricity costs.

[0037] Under the above-mentioned all-day electricity consumption situation, photovoltaic power generation is fully utilized and there is no surplus electricity to be connected to the grid. Therefore, there will be no impact on the power supply grid, which reduces the pressure on the grid and improves the safety factor of the grid.

[0038] In addition, after adopting the comprehensive energy control method, the power generated by the photovoltaic system is fully stored during the noon period, and the surplus power is not sent back to the public power grid, which reduces the impact of the surplus power on the main power grid during the peak period of photovoltaic power generation and improves the safety factor of the main power grid; during the peak and peak periods of the industrial and commercial time-of-use electricity price period, the energy storage system is used to supply power to the power loads in the industrial park to reduce the power supply pressure of the main power grid.

[0039] Figure 4This is the power generation curve of the photovoltaic system on a certain day in June. Since the photovoltaic system is greatly affected by weather conditions, when a cloud passes by and briefly blocks the photovoltaic modules, the output power of the photovoltaic system will fluctuate greatly. Therefore, it is crucial that the two real-time data sent by the power generation monitoring device and the power consumption monitoring device are synchronized and without delay. Otherwise, the execution of this energy monitoring and integrated control method will be deviated.

[0040] The present invention adopts the above-mentioned system and method, and has the advantages of simple system, simple method, good charging and discharging scheduling effect, reduced power grid pressure, and increased photovoltaic power generation efficiency.

Claims

1. An integrated energy monitoring and control system for photovoltaic energy storage systems in industrial parks, characterized by The system includes photovoltaic components, grid-connected inverters, photovoltaic grid-connected distribution cabinets, energy management systems, energy storage converter systems, battery management systems, energy storage units, and power loads. The photovoltaic components are connected to the grid-connected inverters for unidirectional power transmission, the grid-connected inverters are connected to the photovoltaic grid-connected distribution cabinets for unidirectional power transmission, the energy storage units are connected to the battery management system for bidirectional power transmission, the battery management system is connected to the energy storage converter system for bidirectional power transmission, the energy storage converter system is connected to the energy management system for bidirectional power transmission, the photovoltaic grid-connected distribution cabinets for unidirectional power transmission and the energy management system for bidirectional power transmission are respectively connected to the power supply system and connected to the power loads for power supply, the energy management system is connected to the photovoltaic grid-connected distribution cabinets through an RS485 communication cable, and the power loads are connected to the energy management system through an RS485 communication cable.

2. The energy monitoring integrated control system of an industrial park photovoltaic energy storage system according to claim 1 is characterized in that A power generation monitoring device is installed in the photovoltaic grid-connected distribution cabinet, a power consumption monitoring device is installed in the power load, and a data calculation module is installed in the energy management system. The power generation monitoring device and the power consumption monitoring device monitor the power generation and power consumption respectively and transmit them to the data calculation module via RS485 communication cable. The data calculation module calculates the maximum charging power of the real-time energy storage inverter system and charges the energy storage unit according to the maximum power.

3. A comprehensive energy monitoring and control method for photovoltaic energy storage systems in industrial parks, characterized in that The steps of the control method are as follows: (1) System design: The photovoltaic module is connected to the grid-connected inverter for unidirectional transmission, the grid-connected inverter is connected to the photovoltaic grid-connected distribution cabinet for unidirectional transmission, the energy storage unit is connected to the battery management system for bidirectional transmission, the battery management system is connected to the energy storage converter system for bidirectional transmission, the energy storage converter system is connected to the energy management system for bidirectional transmission, the photovoltaic grid-connected distribution cabinet for unidirectional transmission and the energy management system for bidirectional transmission are respectively connected to the power supply system and connected to the power supply of the power load, the energy management system is connected to the photovoltaic grid-connected distribution cabinet through an RS485 communication cable, the power load is connected to the energy management system through an RS485 communication cable, a power generation monitoring device is installed in the photovoltaic grid-connected distribution cabinet, a power consumption monitoring device is installed in the power load, and a data calculation module is installed in the energy management system. The power generation and power consumption monitored by the power generation monitoring device and the power consumption monitoring device are respectively transmitted to the data calculation module through the RS485 communication cable. The data calculation module calculates the real-time maximum charging power of the energy storage converter system and charges the energy storage unit according to the maximum power; (2) Control steps: a. Design a preset charging time period and a preset discharging time period. The power generation monitoring device of the photovoltaic grid-connected distribution cabinet is used to monitor and record the real-time power generation of the photovoltaic system, and send the monitored data to the data calculation module of the energy management system (EMS) via RS485 within the preset time period. The power consumption monitoring device at the power load end is used to monitor and record the real-time power consumption of the industrial park, and send the monitored data to the data calculation module of the energy management system (EMS) via RS485 within the preset time period. It is required that the two real-time data sent by the power generation monitoring device and the power consumption monitoring device be sent to the data calculation module of the energy management system (EMS) synchronously and without delay; b. The data calculation module of the energy management system (EMS) collects two real-time data sent by the power generation monitoring device and the power consumption monitoring device during the preset charging period. The data calculation module performs arithmetic operations and logical judgments on the data to calculate the real-time maximum charging power. The delay shall not exceed 200 milliseconds and then send instructions to the energy storage converter system (PCS). The energy storage converter system (PCS) charges the energy storage unit according to the maximum power. During the preset charging period, the maximum charging power is: Transformer real-time power supply margin = transformer rated capacity - transformer load power consumption; Maximum charging power = real-time photovoltaic power generation + real-time transformer power supply margin; The data calculation module of the energy management system (EMS) collects real-time data sent by the power consumption monitoring device within the preset discharge period. The data calculation module performs arithmetic operations and logical judgments on the data, calculates the real-time maximum discharge power delay of no more than 200 milliseconds, and issues instructions to the energy storage AC system (PCS). The energy storage converter system (PCS) discharges the electric energy stored in the energy storage unit to the industrial park for use by the load in accordance with the issued instructions.

4. The energy monitoring and integrated control method for photovoltaic energy storage systems in industrial parks according to claim 3 is characterized in that The energy management system (EMS) tracks the monitoring devices of photovoltaic power generation and load power consumption through RS485 wired mode, obtains real-time data and obtains all real-time generated electricity of the photovoltaic system and the load rate of the industrial park transformer in millisecond linkage, calculates the real-time maximum charging power of the energy storage system energy storage converter system (PCS), and charges the energy storage unit according to the maximum power.

5. The energy monitoring and integrated control method for photovoltaic energy storage systems in industrial parks according to claim 3 is characterized in that When the PCS is charging the energy storage unit, the battery management system (BMS) monitors the voltage, current, temperature and other conditions of the energy storage unit to ensure that when the voltage of the energy storage unit exceeds the set safety threshold, the charging circuit is automatically cut off; when the charging current exceeds the set safety threshold, the charging current is limited or charging is stopped; when the temperature exceeds the set safety threshold, the heat dissipation device is activated or charging is stopped, so as to prevent overcharging from causing overvoltage, overcurrent, or high temperature, which may affect the performance and life of the energy storage unit and even cause safety accidents. During the charging process, the charging mode is automatically switched according to the status of the energy storage unit to optimize the charging efficiency and ensure the safe, efficient and stable charging of the energy storage unit. When the discharge current exceeds the set safety threshold, the discharge current can be limited to prevent the energy storage unit from overheating or damage. When the temperature exceeds the set safety threshold, the heat dissipation device is activated or the discharge power is limited to prevent thermal runaway. Over-discharge will not affect the performance and life of the energy storage unit, or even cause permanent loss of energy storage unit capacity. During the discharge process, the discharge mode is automatically switched according to the state of the energy storage unit to optimize the discharge efficiency and ensure that the energy storage unit discharges safely, efficiently and stably.

6. The energy monitoring and integrated control method for photovoltaic energy storage systems in industrial parks according to claim 3 is characterized in that The two real-time data sent by the power generation monitoring device and the power consumption monitoring device are synchronized and delay-free. It is necessary to collect and process the real-time data, filter the initial data layer by layer, remove redundant information, and reduce network bandwidth usage. Dual-channel synchronous transmission is adopted: independent transmission paths are designed for the two types of data to avoid data competition and congestion, achieve parallel transmission of the two types of data, and improve transmission efficiency. Timestamps are added to the data packets to ensure that the data center can accurately identify the arrival order and time relationship of the data. Adopt multi-path routing: Configure multiple network paths to achieve data load balancing and redundant transmission, improve network reliability and stability, and when a network path fails, it can automatically switch to other available paths to ensure the continuity of data transmission.

7. The energy monitoring and integrated control method for photovoltaic energy storage systems in industrial parks according to claim 3 is characterized in that The preset charging time period is set as the valley period, and the preset discharging time period is set as the peak period.

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