Patent ID: 7126294

Claim:
A method of controlling a photovoltaic inverter for variable-speed controlling a motor with solar cells as its power source comprising a step of starting up the motor by supplying a start-up power through the photovoltaic inverter from said solar cells while monitoring the output power and voltage of said solar cells, a step of storing the voltage value of the solar cells as a reference voltage (V BASE ) when the power of said solar cells reached the maximum power point in the process of accelerating the rotational speed of this motor for a given acceleration time, a step of continuing accelerating until the voltage of the solar cells shifts from said reference voltage (V BASE ) to a first voltage (V BASE −V OVER ) that is lower than said reference voltage by a previously set voltage (V OVER ), a step of, after the voltage of the solar cells reached the first voltage (V BASE −V OVER ), decelerating the speed of said motor for a given deceleration time until the voltage of the solar cells shifts from this voltage to said reference voltage (V BASE ), and a step of, after this deceleration operation is over, when the voltage of the solar cells is within the given allowable voltage regulation range (Hb) with reference to said reference voltage (V BASE ), controlling said photovoltaic inverter in such way that said motor may continue operating at the current speed.