METHOD FOR COMPENSATING POWER FACTOR WITHOUT SENSING INPUT VOLTAGE

摘要

PURPOSE: A method for compensating power factor without sensing input voltage is provided to estimate an input voltage and compensate the power factor by using each state of an input voltage and an output voltage. CONSTITUTION: A method for compensating power factor without sensing input voltage includes a zero point estimation process and a power factor compensation process. The zero point estimation process is to estimate a zero point of an input voltage by using any one of the input current and a final output error signal of a controller or a pulse width modulation signal applied to a switch to form a waveform of the same phase as the input voltage without sensing the input voltage. The power factor compensation process is to read data including waveform values of sine waves by using the estimated zero point as a reference point and utilize the waveform of the same phase as the input voltage as a signal necessary for compensation of the power factor.