How to choose the solar power inverter for your solar system?

       The load is divided into resistive load, inductive load and capacitive load according to the impedance property. Resistive load without phase difference between current and voltage is resistive load, such as rice cooker, bulb, electric furnace, electric iron, etc. Inductive load is when the current lags behind the voltage by one phase, the load is inductive load, such as the load with motor, transformer, relay, compressor, etc. of washing machine, air conditioner, refrigerator, water pump, range hood, etc. Capacitive load is current lead voltage a phase difference negative load is capacitive load, such as compensation capacitance, computer, television and other domestic use of switching power supply. The starting power of induction load such as motor is 5-7 times of rated power. When calculating the power of solar power inverter, the starting power of these loads should be taken into account.

      If the load is elevator or the like, it cannot be directly connected with the solar power inverter output terminal, because when the elevator is descending, the motor will reverse, which will generate a back EMF, and when entering the solar power inverter, it will damage the solar power inverter. If it is necessary to use the off grid system, it is recommended to add a frequency converter between the electric inverter and the elevator motor.

      There are two main types of electric inverter waveforms, one is sine wave electric inverter, the other is modified wave electric inverter. The modified sine wave inverter for home uses PWM PWM to generate the modified wave output. Due to the harmonic distortion of about 20%, it can not be equipped with inductive load such as air conditioner, but it can be equipped with resistive load such as electric lamp. The modified sine wave inverter for home adopts the non isolated coupling circuit, which has the advantages of simple device and high efficiency. The pure sine wave inverter for home is designed with isolation coupling circuit. The circuit is complex and the cost is high. It can connect any common electrical equipment (including TV, LCD, etc., especially the refrigerator and other inductive loads) without interference.

    The output power of the best power inverter is greater than that of the load. For the occasion of strict requirements, the output power is the sum of all load power. But for ordinary poor families, considering that all loads cannot be turned on at the same time, in order to save costs, the sum of load power can be multiplied by a coefficient of 0.7-0.9.