The energy storage inverter can be said to be the latest generation of inverters on the market today. As the name implies, energy storage is to convert AC power into DC power and store it in the battery. When a power failure occurs, the inverter will convert the DC power in the battery.
It can be converted into alternating current, can provide two-way conversion between grid power and battery power, and can break through the limitation that photovoltaic inverter can only be used during the day, which is one of the important reasons why it is becoming more and more popular.
What are the functions and advantages of energy storage inverter
Break through the limitations of weather changes
Since the energy storage inverter can convert AC power into DC power and store it in the battery, and convert the DC power in the battery into AC power after power failure, this greatly reduces the impact of weather conditions on power generation stability. It can greatly improve the stability and quality of the power grid.
Higher power consumption efficiency
Compared with grid-connected photovoltaic inverters, energy storage inverter has higher power consumption efficiency, which can not only break through the limitations of weather conditions and time, solve the problems existing in grid-connected photovoltaic inverters, but also provide more stable , long-lasting power, avoiding the inconvenience and trouble caused by the failure of the power system, which is also an important reason why we choose this inverter.
In the case of a grid system failure, the energy storage inverter can directly convert the stored DC power into an AC power supply grid system, which is less affected by external factors, can greatly reduce electricity costs, and has high stability. When in the peak period of power consumption, the energy storage inverter will convert the solar direct current into alternating current and merge it into the grid use.
While in the low period of power consumption, the energy storage inverter will convert the alternating current in the grid. The storage of direct current can realize the two-way conversion of direct current and alternating current, and can provide a strong guarantee for power consumption when the power is cut off.
In addition to the above functions, the energy storage inverter can also provide more stable and pure current with less harmonic content for the power grid, which not only meets the trend and requirements of energy saving and emission reduction in today’s society, but also improves the stability and quality of the power grid.
All in all, energy storage inverter can break through the limitations of traditional photovoltaic inverters, provide high-quality electric energy for the grid system, and at the same time reduce electricity costs and improve electricity efficiency. These advantages and functions are also energy storage inverter. The premise and guarantee that the device can occupy a certain advantage in the market.
How does the inverter convert direct current into alternating current
In recent years, with the vigorous development of the photovoltaic industry, photovoltaic power generation systems have received more and more attention. As we all know, the photovoltaic power generation system is composed of components, inverters, brackets, cables and other parts.
They have a clear division of labor in the system, and each undertakes different tasks. The component is the most intuitive component, it can convert sunlight energy into direct current; the bracket plays the role of placing, installing and fixing the component; the cable is essential in the power transmission system.
Among them, the inverter, which can convert the direct current generated by photovoltaic modules into alternating current, is the “heart” of the photovoltaic system and controls the production efficiency of photovoltaic power plants. So, how does an inverter do this job? How well do different inverter conversions work?
Reasons affecting the conversion of energy storage inverter
What is direct current and alternating current
The job of the inverter is to convert the direct current generated by the photovoltaic array into alternating current.
Direct current (DC)
The direction of the direct current and voltage is the same, and the direction of the current is always the same.
Alternating current (AC)
The current direction and magnitude of alternating current will change periodically over time. DC power has great limitations in daily applications.
For example, the AC load of household appliances cannot be powered by DC power supply, and most of the power will be lost during long-distance transportation. Therefore, if photovoltaic power generation is to be widely used, an inverter that can convert the direct current it generates into alternating current is indispensable.
How to convert direct current into alternating current
While the PV array transmits DC power to the inverter, the DC power is quickly transferred back and forth through the inverter’s internals. In this process, the inverter forces the direct current to constantly change direction, creating a square-wave alternating current.
However, the square wave AC waveform is not smooth, and the voltage has been changing suddenly, which will seriously affect the life of electrical appliances.
Therefore, by speeding up the transmission speed, and through the sinusoidal pulse width modulation method (SPWM), the multiple pulses in each sinusoidal period are naturally or regularly modulated in width, so that these pulses are sequentially modulated to be equivalent to sinusoidal.
The pulse sequence of the wave forms a sinusoidal current output, so that the square wave alternating current is successfully transformed into a sinusoidal alternating current, and the purpose of converting direct current into alternating current is achieved.
The conversion efficiency of different inverters is different
Although inverters can convert DC power into AC power, the conversion efficiency varies. In most cases, factors such as the power loss of the internal components of the inverter will affect the conversion efficiency of the inverter, resulting in changes in the power generation revenue of the photovoltaic power station.
Taking a 500kW inverter as an example, under the same power, if the conversion efficiency of a high-quality inverter is 1% higher than that of an ordinary inverter, based on 4 hours of work per day, the high-quality inverter can generate nearly 20 degrees more per day electricity, then nearly 7,300 kilowatt-hours of electricity can be generated in one year, and 73,000 kilowatt-hours of electricity can be generated in ten years, which greatly improves power generation income.
What is distributed photovoltaic storage
As we all know, photovoltaic power generation is the process of converting solar energy into electrical energy, which is easily affected by environmental factors such as solar radiation intensity and temperature, and has characteristics such as volatility, intermittency, and instability.
On the other hand, with the continuous growth of grid-connected photovoltaic installed capacity, the demand for flexible and adjustable resources in the grid is becoming more and more urgent. For example, during peak periods of electricity consumption, the power grid is often overloaded with power supply. At this time, the help of energy storage is needed. The energy storage system is similar to a super-large power bank. It can store electrical energy and release it.
According to system differences, energy storage inverter are divided into hybrid inverters, AC-coupled energy storage inverter, off-grid energy storage inverter (more energy storage knowledge points, please look forward to subsequent updates), etc., among which , with the advantages of high integration and powerful functions, the hybrid inverter has become a wise choice.
The energy storage system is equivalent to an electric energy steward, who can choose the most cost-effective and stable electricity consumption method. For users, the distributed photovoltaic distribution and storage improves the self-consumption rate, and can also convert excess solar energy into electrical energy and store it.
For the public grid, if more and more distributed photovoltaics are configured with energy storage systems, the power supply pressure will be greatly reduced. Furthermore, if a system somewhere in the power grid fails suddenly, it will not cause a large-scale power outage. After all, the energy storage system will mobilize the electric energy in the battery.