Energy conversion principle of residential energy storage system

Energy conversion during the charging process

Grid charging

When the residential energy storage system is connected to the grid, it can be charged during the low electricity price period. At this time, the AC power in the grid is converted into DC power suitable for the energy storage battery by the charger, and then stored in the energy storage battery. In this process, the energy conversion mainly involves the conversion of AC to DC power and the conversion of electrical energy to chemical energy.

The conversion of AC to DC power is achieved through the rectifier circuit in the charger. The rectifier circuit converts the AC power in the grid into DC power, and then adjusts the voltage and current to make it suitable for the charging requirements of the energy storage battery.

The conversion of electrical energy to chemical energy occurs inside the energy storage battery. Different types of energy storage batteries have different energy conversion principles. For example, lithium-ion batteries store and release electrical energy through the movement of lithium ions between the positive and negative electrodes. During charging, lithium ions are removed from the positive electrode and embedded in the negative electrode through the electrolyte, while electrons flow from the external circuit to the negative electrode to achieve the conversion of electrical energy to chemical energy.

Photovoltaic panel charging

For households with photovoltaic panels installed, residential energy storage systems can also be charged using the direct current generated by photovoltaic panels. Photovoltaic panels convert solar energy into direct current, which is then stored in energy storage batteries through inverters and chargers.

In this process, the conversion of solar energy to electrical energy is achieved through the photovoltaic effect. After absorbing sunlight, the semiconductor materials in photovoltaic panels generate electron-hole pairs. These electrons and holes are separated under the action of the electric field inside the semiconductor to form direct current. Then, the direct current is converted into direct current suitable for energy storage batteries through inverters and chargers and stored in energy storage batteries.

Energy conversion during discharge process

When the household needs electricity, the energy storage batteries in the residential energy storage system begin to discharge. During the discharge process, chemical energy is converted into electrical energy, and then converted into AC power through an inverter to supply household appliances.

The conversion of chemical energy to electrical energy inside the energy storage battery is the reverse process of the charging process. For example, in a lithium-ion battery, lithium ions are removed from the negative electrode during discharge and embedded in the positive electrode through the electrolyte, while electrons flow out of the negative electrode and flow to the positive electrode through the external circuit to form a current.

The inverter converts the DC power in the energy storage battery into AC power. The principle is to convert the DC power into a series of pulse width modulated (PWM) square wave signals through the rapid switching of electronic switches. After filtering, these square wave signals can be used to obtain AC power with the same frequency and voltage as the power grid, which can be used to supply household appliances.

Advantages of residential energy storage system

Improve energy utilization efficiency

The residential energy storage system can charge during the low electricity price period and discharge during the peak electricity price period, thereby reducing the household's electricity cost. At the same time, it can also store the excess electricity generated by the photovoltaic panels and use it at night or on cloudy days when the photovoltaic panels cannot generate electricity, thereby improving the utilization efficiency of solar energy.

Providing backup power

When the power grid is out, the residential energy storage system can serve as a backup power source to provide a continuous power supply to the family. This is essential to ensure the basic living needs of the family and the operation of important equipment.

Reduce dependence on the power grid

With the popularization of residential energy storage systems, families can gradually reduce their dependence on the power grid and achieve energy self-sufficiency. This can not only reduce the energy costs of the family, but also reduce the load on the power grid and improve the stability and reliability of the power grid.

From charging to discharging, the residential energy storage system realizes the storage and supply of electrical energy through a series of energy conversion processes. It provides families with an efficient and reliable energy solution, which helps promote energy transformation and sustainable development. With the continuous advancement of technology, the performance of residential energy storage systems will continue to improve, the cost will continue to decrease, and it is expected to be widely used in more families in the future.