A home pv energy storage system provides a continuous supply of green electricity for households day and night, regardless of stepped electricity prices, saving on electricity expenses, and intelligently managing household energy to enjoy a comfortable quality of life. Excess electricity generated during the day is automatically stored for use by night, and in the event of a power outage, the system acts as a backup power source, ensuring the normal operation of lighting, security, appliances, underfloor heating, and water purification systems. The home energy storage system is like a mini energy storage station, whose operation is not affected by urban power supply pressure. During low electricity usage periods, the battery pack in the home energy storage system can charge itself for use during peak or power outage periods. In addition to serving as an emergency power source, the home energy storage system can also balance the electricity load and save on household electricity expenses.
Currently, there are two types of home energy storage systems: grid-connected and off-grid.
The grid-connected home energy storage system consists of five parts, including a solar panel array, grid-connected inverter, BMS management system, battery pack, and AC load. The system uses a hybrid power supply of photovoltaics and energy storage. When the mains electricity is normal, the photovoltaic grid-connected system and mains electricity supply power to the load; when the mains electricity is cut off, the energy storage system and photovoltaic grid-connected system supply power jointly.
The grid-connected home energy storage system is divided into three operating modes: mode one: photovoltaics provide energy storage and excess electricity to the grid; mode two: photovoltaics provide energy storage and part of the load to the user; mode three: photovoltaics provide only partial energy storage.
The off-grid home energy storage system is independent and has no electrical connection to the grid, so the entire system does not require a grid-connected inverter, and the photovoltaic inverter can meet the requirements. The off-grid home energy storage system is divided into three operating modes: mode one: photovoltaics provide energy storage and user electricity (sunny days); mode two: photovoltaics and energy storage batteries provide user electricity (cloudy days); mode three: energy storage batteries provide user electricity (evenings and rainy days).
The main energy storage equipment required at present is the BMS battery management system, photovoltaic grid-connected inverter, and energy storage inverter. Based on the above requirements for home energy storage equipment and in combination with the safety isolation characteristics of the photovoltaic system’s various unit circuits, Gkeners proposes a complete set of power supply solutions for the control unit.
As the core energy storage device of the system, batteries need to monitor their online status in real-time, hence the importance of BMS is self-evident. In the BMS system, the BCU module communicates with the BMU module in real-time through the CAN bus to obtain system parameters such as single-cell voltage, box temperature, and insulation resistance. The system also collects charging and discharging currents through current sensors, dynamically calculates SOC, and displays relevant data through the touch screen. After the BCU module analyzes the comprehensive information of the battery pack, the system conducts intelligent management through an independent CAN bus. At the same time, it can also achieve secondary protection of charging and discharging through a relay to ensure effective isolation of strong and weak electricity, meet the diversified safety control needs of customers, and ensure the stable and efficient operation of the system. The core of the BMS power supply solution for energy storage systems is the isolated voltage transformation. The solar PV components gather and flow electrical energy, which is converted into AC by the inverter after DC conversion. During the operation of the inverter, monitoring, control, and communication of the conversion process are also required to ensure that the inverter voltage meets the specified requirements. The monitoring unit can directly obtain power from the mains for this part. The PV grid-connected inverter, also known as a bidirectional energy storage inverter or an integrated inverter, is composed of AC-DC units, DC-DC units, control units, communication units, and transfer relay units. Bidirectional energy storage inverters are divided into two types of power supply equipment: one is powered by the mains and the other is powered by a battery panel.
The gradual scaling and popularization of home energy storage is a healthy and rational development trend for future global energy demand. Gkeners actively participates in the green development of energy technology, combining its own technological platform advantages and independent innovation capabilities to provide a complete set of power supply solutions for home energy storage systems, simplifying the circuit design of home energy storage systems, reducing the construction and maintenance costs of home systems, and comprehensively improving the stability, safety, and reliability of the system.