Abstract:
A motor drive control apparatus (1) according to the present invention includes: a three-phase rectifier (10) to rectify an AC voltage supplied from a three-phase AC source (6); a booster circuit (20) including a reactor (21), a switching element (22), and a backflow preventing element (23), to boost a DC bus voltage supplied from the three-phase rectifier (10); a smoothing capacitor (30) to smooth an output of the booster circuit (20); and an inverter circuit (40) to convert the DC bus voltage smoothed by the smoothing capacitor (30) into an AC voltage and supplying the AC voltage to a motor. During a starting operation of a boosting operation of the booster circuit (20) or a stopping operation of the boosting operation thereof, a rotation speed of the motor is fixed.
Abstract:
Phase correction unit (25) for outputting a commutation signal for switching a winding that allows a current to flow to brushless DC motor (4) and drive unit (16) for outputting a drive signal indicating supplying timing of electric power supplied to brushless DC motor (4) by inverter (3) based on the commutation signal output from phase correction unit (25) are provided so as to maintain a predetermined relation between a phase of a current flowing to a predetermined winding of brushless DC motor (4) and a phase of a voltage. Since brushless DC motor (4) 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.
Abstract:
The invention relates to a drive system with an energy accumulator and a method for operating a drive system, wherein an inverter supplies an electric motor, the inverter is supplied from a unipolar DC link voltage, an energy accumulator is connected in parallel to the inverter, in particular a film capacitor is connected in parallel to the inverter, the DC link voltage is generated by a DC/DC converter supplied by an AC/DC converter, in particular a rectifier, and in particular wherein an electric current can be supplied to the DC link by the DC/DC converter.
Abstract:
A three-phase regenerative drive (20) is operated based upon power from a single-phase AC source ( 12) and power from a DC source (14). The single-phase AC input power and the DC input power are converted to DC voltage on a DC bus (24) by a three-phase converter (22). DC power is provided from the DC bus (24) to a three-phase inverter having outputs connected to a motor (34). A controller (44) controls operation of the three-phase converter (22) based upon contribution factors of the AC and DC sources ( 12, 14) during motoring and regeneration. The controller (44) also controls an AC component of current from the DC source to reduce ripple current on the DC bus (24).
Abstract:
A refrigerator and a method of operating the same are disclosed. In the refrigerator and the method of operating the same, a voltage of an electric power input is measured and rectified through the half wave rectification or the full wave rectification in correspondence with the measured voltage, so that the refrigerator can be used without a voltage converting device when a voltage of the input power is changed. Therefore, the change or the modification of the circuit is not needed in order to use the refrigerator in other regions. Since components are compatible and utility of the components is improved, manufacturing costs can be reduced.
Abstract:
Systems and methods for synchronous operation of variable speed drives having active converters include extending the synchronous operation of an active converter to the AC mains voltage during complete line dropout. A phase angle control circuit includes a squaring amplifier, a first phase-lock loop circuit associated and a second phase-lock loop circuit. The squaring amplifier receives the AC power source and outputs a rectangular output signal to a pair of phase lock loop (PLL) circuits. The first PLL circuit with a first lag-lead filter is configured with a high cutoff frequency to provide the converter stage with a phase angle parameter; and the second phase-lock loop circuit including a second lag-lead filter configured to have a low cutoff frequency to provide the lag-lead filter the capability of storing the phase angle of the mains voltage during mains interruption.
Abstract:
The present invention provides a control apparatus for detecting at an early stage a short circuit between the terminals of an electrolytic capacitor, and detecting a short circuit between a load that is connected in parallel to the electrolytic capacitor, the apparatus performing appropriate processing before an adverse effect is inflicted on peripheral equipment. In the control apparatus (4), microcomputers (5, 6) switch on a second relay (84); an electrolytic capacitor (83) is gradually charged via a current-limiting resistor (85); a first voltage detection control for detecting a voltage between terminals of the electrolytic capacitor (83) is performed when a first set time period has elapsed after the second relay (84) has been switched on; and a second voltage detection control for detecting a voltage between the terminals of the electrolytic capacitor (83) is performed when a second set time period, which is longer than the first set time period, has elapsed after the second relay (84) has been switched on.
Abstract:
The control apparatus has a battery (B1) whose positive terminal is connected to a reactor (L1). The other end of the reactor is connected to a power line and ground through the transistors (Q1,Q2) respectively. The power line voltage is increased according to the motor drive state, by pulse width modulation (PWM) control of the transistors.