Daikin Industries, Ltd.

Masakazu Katou

Keisuke Shimatani

Masafumi Hashimoto

Keiichi Yoshisaka

Ryou Nakamoto

Hirohito Maeda

Nobuki Kitano

Takeomi Ukai

Hironobu Mizobe

An increase in a ripple voltage of a capacitor in a smoothing circuit is prevented to achieve a compact capacitor and cost reduction for capacitors in an electric power supply circuit which performs PAM control using a switching element. An electric power supply circuit includes a bridge circuit for rectifying alternating current power, a smoothing circuit which has two capacitors serially connected to each other, and a PAM control section for turning a switching element on and off at a predetermined timing. The PAM control section includes a phase difference detection section which detects a phase shift of a PAM waveform based on a change in a voltage difference between the two capacitors, and a phase correction section which corrects the phase of the PAM waveform so that an input current has a sine waveform.

Electric power supply circuit and PAM control method for the same

An electric power supply circuit includes a switching element (S) for causing a short-circuit for output power of a diode bridge circuit (), a zero-cross detector section () for detecting a point at which an input voltage reaches a level equal to or lower than a reference level, a timer section () for starting a count upon the detection by the zero-cross detector section (), and a PAM waveform output section () for causing the switching element (S) to perform switching with a predetermined output timing so that a waveform of the input current is caused to approximate to a sine wave. The circuit further includes a correction section () for correcting, when a difference between a detection interval from detection to detection by the zero-cross detector section (), and an average value for detection intervals up to current detection occurs, an initial value of the count of the timer section () according to the difference.

Electric power supply circuit with PAM waveform correction

The power supply device according to the present invention converts alternating-current power into direct-current power, and supplies the direct-current power to a load. Further, the power supply device includes a buffer, a control section, a rectifier circuit, a smoothing circuit, and a switch. After a predetermined zero cross point is detected, the control section uses in common, over a predetermined period of the alternating-current power, predetermined parameters retained in the buffer in calculating a timing at which a PAM interrupt pulse is generated.

Power supply device

A boot capacitor that functions as an operating power supply for a high-arm-side transistor provided in an inverter has to be charged prior to normal operation of a motor. This operation of charging the boot capacitor is performed at a carrier frequency that is lower than a carrier frequency for the normal operation.

Inverter driven compressor operation method and compressor drive device

An electric power supply circuit includes a diode bridge circuit () for rectifying an alternating current, a switching element (S) for causing a short-circuit for output power of the diode bridge circuit (), and a PAM control section () for causing the switching element (S) to perform switching with a predetermined timing so that a waveform of an input current approximates to a sine wave. The PAM control section () outputs ON/OFF pulses so that five pulses are output for each zero-cross point and one of the five pulses located in center extends over the zero-cross point at any time.

Growing community of inventors

Osaka, Japan

Masakazu Katou