Abstract:
An inverter controller for driving a brushless DC motor, of which rotor is provided with permanent magnets, includes an inverter circuit, a position sensing circuit, a DC voltage sensor, and a conduction angle controller. The inverter circuit is connected to the brushless DC motor for driving this motor. The position sensing circuit senses a rotor position with respect to a stator from an induction voltage of the brushless DC motor. The DC voltage sensor senses a voltage value of a DC power voltage supplied to the inverter circuit. The conduction angle controller changes a conduction angle of the inverter circuit within a range less than 180 degrees in electric angles in response to a rate of change in the DC power voltage.
Abstract:
An inverter controller for driving a brushless DC motor, of which rotor is provided with permanent magnets, includes an inverter circuit, a position sensing circuit, a DC voltage sensor, and a conduction angle controller. The inverter circuit is connected to the brushless DC motor for driving this motor. The position sensing circuit senses a rotor position with respect to a stator from an induction voltage of the brushless DC motor. The DC voltage sensor senses a voltage value of a DC power voltage supplied to the inverter circuit. The conduction angle controller changes a conduction angle of the inverter circuit within a range less than 180 degrees in electric angles in response to a rate of change in the DC power voltage.
Abstract:
WHEN A LOCK DETECTING MEANS 17 DETECTS A LOCKED STATE OF A DC MOTOR 4 IN A STARTING STAGE, A TORQUE INCREASING MEANS 18, 27, 29 OR 31 IMMEDIATELY SELECTS A STARTING SEQUENCE PATTERN OF AN OUTPUT TORQUE THAT IS GREATER BY ONE STEP, AND OUTPUTS THE SAME TO A STARTING SEQUENCE CONTROL MEANS 13, SO THAT A COMPRESSOR 5 CAN BE RESTARTED SPEEDILY WITHOUT REPEATING STARTING FAILURES. A COMPRESSOR 41, DRIVEN BY A DC MOTOR 43, HAS A SHELL OF AN INTERNAL PRESSURE APPROXIMATELY EQUAL TO THE PRESSURE OF AN INHALATION GAS. AN INVERTER 53 IS PROVIDED TO MAKE THE SPEED OF THE DC MOTOR 43 VARIABLE. A ROTATIONAL FREQUENCY SETTING CURCUIT 56 SETS THE ROTATIONAL FREQUENCY OF THE DC MOTOR 43 TO A FREQUENCY THAT IS NOT GREATER THAN THE FREQUENCY OF A COMMERCIAL POWER SOURCE WHEN THE INTERNAL TEMPERATURE OF A REFRIGERATOR IS STABILIZED. BY THIS CONSTRUCTION, THE POWER CONSUMPTION CAN BE REMARKABLY REDUCED.
Abstract:
An inverter circuit includes a temperature measuring section for measuring a temperature of switching elements forming a powering section, a motor speed detector for detecting a speed of a motor, a carrier frequency determiner for determining a carrier frequency based on a temperature of the switching elements and a speed of the motor, and an output waveform determining circuit for determining a duty in response to a load applied to the motor and for switching a carrier frequency.
Abstract:
WHEN A LOCK DETECTING MEANS (17) DETECTS A LOCKED STATE OF A DC MOTOR (4) IN A STARTING STAGE, A TORQUE INCREASING MEANS (18, 27, 29 OR 31) IMMEDIATELY SELECTS A STARTING SEQUENCE PATTERN OF AN OUTPUT TORQUE THAT IS GREATER BY ONE STEP, AND OUTPUTS THE SAME TO A STARTING SEQUENCE CONTROL MEANS (13), SO THAT A COMPRESSOR (5) CAN BE RESTARTED SPEEDILY WITHOUT REPEATING STARTING FAILURES. A COMPRESSOR (41), DRIVEN BY A DC MOTOR (43), HAS A SHELL OF AN INTERNAL PRESSURE APPROXIMATELY EQUAL TO THE PRESSURE OF AN INHALATION GAS. AN INVERTER (53) IS PROVIDED TO MAKE THE SPEED OF THE DC MOTOR (43) VARIABLE. A ROTATIONAL FREQUENCY SETTING CIRCUIT (56) SETS THE ROTATIONAL FREQUENCY OF THE DC MOTOR (43) TO A FREQUENCY THAT IS NOT GREATER THAN THE FREQUENCY OF A COMMERCIAL POWER SOURCE WHEN THE INTERNAL TEMPERATURE OF A REFRIGERATOR IS STABILIZED. BY THIS CONSTRUCTION, THE POWER CONSUMPTION CAN BE REMARKABLY REDUCED.