Inverter is the key equipment of solar PV system.
Solar cells convert light energy into direct current, and then through the inverter DC reverse into a 50 Hz, 230/400-volt three-phase or single-phase AC 230V.
The inverter in photovoltaic power generation systems use can be divided into independent power supply and grid pattern with two kinds. According modulation waveform can be divided into square wave inverter, step wave inverter, sine wave inverter and modular three-phase inverter. For the grid system for the inverter transformer can be divided according to whether the inverter transformer and transformerless inverters.
At present, use of photovoltaic systems on the market up to a centralized inverter, the so-called central inverters, that is, after a series of solar cells, reaching a high voltage direct current, through an inverter into alternating current. However, photovoltaic power plants, the solar cell module, partial shadow, different tilt angle and facing orientation, dirt, different degrees of aging, small cracks and different temperatures and photovoltaic panels and other easily cause the system mismatch leads to decreased output efficiency malpractice, which led to significantly lower overall power output, so the central inverters difficult to solve this problem.
To solve this problem, in recent years, the new architecture, “micro-inverters” and “mini-converter” is developed.
Both with each solar cell module micro inverter, through the power output of each module is optimized, so that the overall output power is maximized. Even if some panels affected shadows, dust cover, etc., the inverter power optimizer can still track the best local MPP (maximum power point), concerned to restore the loss of more than 57% of the generating capacity. Meanwhile, the power optimizer input voltage / current is converted to a different output voltage / current, in order to maximize energy transfer system.
The definition of micro inverter
Micro-inverter technology proposed to integrate directly with a single inverter PV modules for each PV module individually equipped with a AC-DC conversion function and a maximum power point tracking inverter module, the energy emitted directly into PV modules into AC power for AC load use or transfer to the grid.
When the battery plates can not have a good job, only this one will be affected. Other photovoltaic panels will be run in the best working condition, so that higher overall system efficiency, greater power output. In practice, if the string inverter fails, it will cause a few kilowatts of solar panels can not play a role in affecting the micro-inverter failure caused relatively small.
Advantages of micro inverter
1, try to improve the power generation capacity of each inverter module to track the maximum power, because of the maximum power point tracking single block assembly, can greatly improve the photovoltaic power generation system can be increased by 25%.
2, each row of photovoltaic panels by adjusting the voltage and current, until all balance, in order to avoid the system are mismatched.
3. In addition, each module includes a monitoring function, reduced system maintenance costs, more stable and reliable operation.
4, flexible configuration, you can install a photovoltaic cell size in the domestic financial market in accordance with the user
5, no high-voltage, more secure, easy to install, faster, and low maintenance cost of installation, installation service providers dependent reduction, to make solar power system can DIY by the user.
6, cost and central inverters cost compared fairly, or even lower