In the solar off-grid system, the photovoltaic controller is to store the electricity generated by the photovoltaic module in the storage battery after transformation. In addition, it also has the functions of protecting the storage battery and preventing the battery from overcharging. At present, there are two main technical routes of the solar charge controller: Maximum power point tracking (MPPT) and pulse width modulation (PWM), both of which have its advantages and disadvantages, so users can select according to different scenarios.
Central inverter: The power is between 100kW and 2500kW. With the development of power electronics technology, the string inverter is having an increasingly bigger market, and the central inverters below 500KW have already basically been eliminated from the market. The power device adopts high-current IGBT. The system topology adopts DC-AC first-level power electronic device to transform the full-bridge inverter. The latter stage is generally connected to the double-split power-frequency boost isolation transformer. The protection level is generally IP20. It has a large size and is vertically installed indoor.
Pure sine wave inverters output the true sine wave AC power which is the same as or even better than the power grid we use every day since there is no electromagnetic pollution. Pure sine wave inverters, with high efficiency, stable sine wave output and high frequency technology, are suitable for all kinds of loads, which can not only power any common electrical equipment (including phone, heater, etc.), but also run the sensitive electronics or appliances (like microwave, fridge, etc.).