Power factor correction converter
A power factor correction converter includes an output voltage error amplifier which functions as a proportioning device in a low-frequency range in order to stabilize the output voltage by feedback control and obtains a reference current amplitude value vm by multiplying an error ev between a desired output voltage value Vref and a detected output voltage value vo by a predetermined proportionality factor. A factor element multiplies the reference current amplitude value by a predetermined factor and adds the resulting value to a reference value to obtain a desired output voltage value. The factor element functions as a low-pass filter by changing the desired output voltage value Vref in accordance with the reference current amplitude value vm in a low-frequency range and reducing the factor value in a high-frequency range.
1. A power factor correction converter comprising:
a rectifier circuit arranged to rectify an alternating-current voltage received from an alternating-current input power supply;
a series circuit connected to a trailing portion of the rectifier circuit and an inductor and a switching element;
a rectifying and smoothing circuit connected in parallel with the switching element;
a switching control circuit arranged to on/off controls the switching element so that input current received from the alternating-current input power supply has a shape similar to a shape of the alternating-current voltage;
an input voltage detection circuit arranged to detect an input voltage received from the alternating-current input power supply;
an inductor current detection circuit arranged to detect current passing through the inductor; and
an output voltage detection circuit arranged to detect an output voltage of the rectifying and smoothing circuit; wherein
the switching control circuit defines, as a reference current amplitude value, a product of an output voltage error, the output voltage error being an error between a desired output voltage value and a value of the detected output voltage, and a value of the detected input voltage and controls the on-time of the switching element in accordance with a difference between the reference current amplitude value and current passing through the inductor; and
the switching control circuit includes an output voltage control value correction circuit arranged to correct one of the desired output voltage value and the output voltage error using a value proportional to the reference current amplitude value.
2. The power factor correction converter according to claim 1 , wherein
the switching control circuit and the output voltage control value correction circuit include a digital signal processor arranged to maintain a digital value corresponding to the desired output voltage value; and
the output voltage control value correction circuit is arranged to correct the digital value using the value proportional to the reference current amplitude value.