Characteristics and functions of solar inverters

A solar inverter is a device that converts DC power in a solar battery into AC power. Inverter, also known as power regulator and power regulator, is an essential part of photovoltaic power generation system. The working circuit of the solar inverter must be a full-bridge circuit. Through a series of filtering and modulation in the full-bridge circuit, the load and electrical properties of the current are changed to achieve the purpose expected by the user. A common solar power generation system mainly consists of four parts, namely solar panels, charge controller, solar inverter and battery. The solar panel is a device that provides direct current and can convert solar energy into electrical energy; the charge controller is mainly responsible for controlling the conversion of energy; the solar inverter converts the direct current from the panel into alternating current for storage of the battery. The battery is mainly responsible for converting the energy. Alternating current is stored for human use. Solar inverters play a connecting role in the entire solar power generation system.

Features of solar inverters

The main features of solar inverters are centralized inversion and string inversion. The scale of solar power generation systems is generally very large. If one solar panel is used to correspond to one inverter, it will cause a waste of resources and is very unrealistic. Therefore, in actual production, solar inverters centrally invert the DC power generated by all panels and convert it into AC power. Therefore, the size of the solar inverter generally needs to adapt to the size of the panel. Therefore, a single solar inverter is obviously unable to meet this requirement. This leads to another characteristic of solar inverters, which are often used in strings. .

Functions of solar inverters

The inverter not only has the function of DC to AC conversion, but also has the function of maximizing the performance of solar cells and the function of system fault protection. In summary, it has automatic running and shutdown functions, ZUI high-power tracking control function, independent operation prevention function (for grid-connected systems), automatic voltage adjustment function (for grid-connected systems), DC detection function (for grid-connected systems), and DC grounding. Detection function (for grid-connected systems). Here is a brief introduction to the automatic running and shutdown functions and the maximum power tracking control function.

1. Automatic operation and shutdown function: After sunrise in the morning, the intensity of solar radiation gradually increases, and the output of the solar cell also increases. When the output power required for the inverter operation is reached, the inverter automatically starts running. After entering operation, the inverter will monitor the output of the solar cell modules at all times. As long as the output power of the solar cell modules is greater than the output power required for the inverter task, the inverter will continue to operate; it will stop until sunset, even if The inverter can also operate on rainy days. When the solar module output becomes smaller and the inverter output approaches 0, the inverter enters a standby state.
2. Maximum power tracking control function: The output of the solar cell module changes with the intensity of solar radiation and the temperature of the solar cell module itself (chip temperature). In addition, since the voltage of solar cell modules decreases as the current increases, there is an optimal working point that can obtain the maximum power. The intensity of solar radiation is changing, and obviously the optimal working point is also changing. Related to these changes, the task point of the solar cell module is always kept at the maximum power point, and the system always obtains the maximum power output from the solar cell module. This kind of control is the maximum power tracking control. The biggest feature of the inverter used in solar power generation systems is that it includes the maximum power point tracking (MPPT) function.