Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Hidehisa Tanaka

Yoshinori Takeoka

Koji Hamaoka

Tomonori Ouchiyama

Makoto Katayama

Katsumi Endo

Hidetoshi Nishihara

Shuichi Yakushi

Tatsuyuki Iizuka

Yuji Saiki

Yoshiaki Doyama

A motor driving device includes: brushless DC motor () that drives a load that fluctuates during one rotation; and driver () that applies a voltage to brushless DC motor () and drives brushless DC motor (). The motor driving device further includes speed accelerator () that determines the voltage to be applied by driver () so as to accelerate brushless DC motor () such that a speed change rate of a speed within one rotation from start of brushless DC motor () with respect to a speed at next one rotation remains within a predetermined value or less.

Motor driving device, as well as refrigerator and device for operating compressor in which said motor driving device is used

Phase correction unit () for outputting a commutation signal for switching a winding that allows a current to flow to brushless DC motor () and drive unit () for outputting a drive signal indicating supplying timing of electric power supplied to brushless DC motor () by inverter () based on the commutation signal output from phase correction unit () are provided so as to maintain a predetermined relation between a phase of a current flowing to a predetermined winding of brushless DC motor () and a phase of a voltage. Since brushless DC motor () is driven by a signal for holding the predetermined relation between the phase of the current and the phase of the voltage, the stability of drive under high-speed and high-load conditions is enhanced and a drive range is extended.

Motor drive device, and compressor and refrigerator using same

To present a motor drive control device capable of realizing high speed driving by a simple power feeding control method. The motor drive control device of the invention has a three-phase full bridge circuit for adjusting the feeding phase so as to invert the terminal voltage in feeding-off time, by cyclically repeating positive direction feeding period, non-feeding period, negative direction feeding period, and non-feeding period. In high speed driving, the phase is adjusted so as to invert the terminal voltage right after feeding-off, and if not reaching the desired rotating speed, the feeding time is shortened. As a result, the phase angle to the actual applied voltage can be advanced, and high seed rotation by weak-field system driving is realized.

Motor drive control device

A compressor includes a motor driven by a controller and having a rotor and a stator, a compressing unit driven by the motor in a hermetic container in which refrigerant is filled. Driving the motor at a low rpm, the controller practices a feedback control which determines a timing of turning on/off switching elements based on a signal detecting a position of the rotor, and when the motor is driven at a high rpm, the controller practices an open-loop control which outputs a given frequency and drives the motor synchronizing with the given frequency. This structure achieves a compressor working with a fewer noises in PWM driving.

Electric compressor

A rectangular wave or a waveform similar to the rectangular wave is output with an conductive angle no less than 120&#xb0; but no more than 150&#xb0; during low-speed operation, but output a rectangular wave, a sine wave or a waveform similar to them with an conductive angle no less than 130&#xb0; but under 180&#xb0; by changing the frequency only while maintaining the PWM duty constant at high-speed operation, making it possible to realize high-efficiency and low-noise operation at low-speed operation, secure stable high speed, and prevent peak current of effective current because the current waveform also comes closer to sine wave.

Growing community of inventors

Shiga, Japan

Hidehisa Tanaka