Power factor/harmonics correction circuitry and method thereof

A power factor/harmonic compensation circuitry for a power supply having a voltage input, said power supply includes a boost converter connected to the voltage input, the boost converter includes an inductance coil and a storage capacitor, and further including a power switch connected between the inductance coil and the storage capacitor, and a control circuit connected to the power switch for providing a switch control signal for the boost converter, said control circuit including an error compensation circuit which produces an error signal, a pulse width modulator compares the error signal to a ramp signal and provides the switch control signal during each switching cycle, said power factor/harmonic compensation module comprising:

• a non-linear ramp circuit produces the ramp signal which has an increasing slope over the switching cycle.

A power factor/harmonic correction module for a power supply having a rectifier adapted to be connected to an alternating current line, said power supply includes a boost converter connected to the output of the rectifier, the boost converter including an input circuit having a series connected inductance coil and an output circuit having a storage capacitor, and further including a power switch connected between the inductance coil and the storage capacitor, and a control circuit connected to the power switch for providing a switch control signal for the boost converter, said control circuit including a multiplier producing a signal by multiplying the rectified input voltage and the output voltage and subtracting a voltage representing the line current, an error amplifier integrates said signal from said multiplier to produce an error signal, a pulse width modulator compares the error signal to a modulated ramp signal and provides the switch control signal, said power factor/harmonic compensation module comprising:

• a modulated ramp circuit connected to the rectifier, said modulated ramp circuit receives an input voltage and adds a constant value that is proportional to the input voltage to a ramp signal to produce the modulated ramp signal;
• and
• a non-linear ramp circuit produces the ramp signal which has an increasing slope over a cycle.

A method for correcting power factor/harmonic distortion in a power supply having a voltage input, said power supply includes a boost converter connected to the voltage input, the boost converter including an inductance coil and a storage capacitor, and further including a power switch connected between the inductance coil and the storage capacitor, and a control circuit connected to the power switch for providing a switch control signal for the boost converter, said control circuit including an error compensation circuit which produces an error signal, a pulse width modulator compares the error signal to a modulated ramp signal and provides the switch control signal during each switching cycle, said method comprising the steps of:

• modulating a ramp signal to produce the modulated ramp signal by adding a constant value that is proportional to an input voltage of the voltage input to a ramp signal.

A method for correcting power factor/harmonic distortion in a power supply having a voltage input, said power supply includes a boost converter connected to the voltage input, the boost converter including an inductance coil and a storage capacitor, and further including a power switch connected between the inductance coil and the storage capacitor, and a control circuit connected to the power switch for providing a switch control signal for the boost converter, said control circuit including an error compensation circuit which produces an error signal, a pulse width modulator compares the error signal to a modulated ramp signal and provides the switch control signal during each switching cycle, said method comprising the steps of:

• producing the ramp signal to have an increasing slope over the switching cycle.

A method for correcting power factor/harmonic distortion in a power supply having a rectifier adapted to be connected to an alternating current line, said power supply includes a boost converter connected to the output of the rectifier, the boost converter including an input circuit having a series connected inductance coil and an output circuit having a storage capacitor, and further including a power switch connected between the inductance coil and the storage capacitor, and a control circuit connected to the power switch for providing a switch control signal for the boost converter, said control circuit including a multiplier producing a signal by multiplying the rectified input voltage and the output voltage and subtracting a voltage representing the line current, an error amplifier integrates said signal from said multiplier to produce an error signal, a pulse width modulator compares the error signal to a modulated ramp signal and provides the switch control signal, said method comprising the steps of:

• modulating a ramp signal to produce the modulated ramp signal by adding a constant value that is proportional to an input voltage of the voltage input to a ramp signal;
• and
• producing the ramp signal to have an increasing slope over the switching cycle.