799results about "Dc motor starters" patented technology

A load control system provides for automatically controlling a position of a motorized window treatment to control the amount of sunlight entering a space of a building through a window located in a façade of the building in order to control a sunlight penetration distance within the space and minimize occupant distractions. The load control system automatically generates a timeclock schedule having a number of timeclock events for controlling the position of the motorized window treatment during the present day. A user is able to select a desired maximum sunlight penetration distance for the space and a minimum time period that may occur between any two consecutive timeclock events. In addition, a maximum number of movements that may occur during the timeclock schedule may also be entered. The load control system uses these inputs to determine event times and corresponding positions of the motorized window treatment for each timeclock event of the timeclock schedule.

A driving apparatus for a DC brushless motor of a ceiling fan is provided. By setting at least one coder and one sensor outside the DC brushless motor, the driving apparatus can sense the position of magnetic poles of the motor for driving the motor. Meanwhile, a controller set with the motor stores the rotation speed of the motor before being turned off by detecting the turn-off time of a turn-on / off signal.

Disclosed herein is a method and system for initializing a rotating device such as an electronically commutated electric machine. The system comprises: an electric machine; a position sensor subsystem operatively connected to the electric machine configured to measure a position and transmit a position signal to a controller. The controller executes a method initializing position for the electric machine, the method comprising: establishing a sensor subsystem datum indicative of a measurement reference point for a sensor subsystem; obtaining a calibration value corresponding to a distance to a selected magnetic reference position for the electric machine, relative to the sensor subsystem datum; and measuring a position and calculating a position delta relative to an initial reference. The method also includes: estimating an offset from the sensor subsystem datum to an initial reference; determining an absolute position estimate of the electric machine relative to the magnetic reference position. The absolute position estimate is responsive to the calibration value, the position delta, and the offset from the sensor subsystem datum to the initial reference.

A method for reducing EMI emissions in the control of an electric motor supplied by a switching inverter fed by a DC bus comprising controlling a phase advance of a conduction angle period during which a phase of the motor is fed power by the inverter to control the conduction angle to control the speed of the motor, thereby to reduce the number of switching operations of the inverter and thereby reduce EMI.

A hybrid electric vehicle having an energy generation system, an energy storage system and at least one, and preferable two or more, traction drive units includes a controller for controlling operation of vehicle systems. The controller may adaptively control traction by one or more traction drive units to better propel the vehicle. The controller may, for example, prevent unnecessary wheel slip, allow a traction profile to match a desired profile, and may be used to assist in turning of the vehicle. A method of adaptive control is also provided.

A process to start a brushless direct current motor with a multiphase stator winding is disclosed, in which, during rotor standstill, a plurality of current impulses is intruded on the stator winding, the current rise time until a current threshold is reached is measured in the stator winding with every current impulse and the rotor position is derived from the measured current rise times. A more precise determination of rotor position is achieved with lower control-related effort for a regulated sensorless start-up in that a plurality of test current impulses is successively intruded on the stator winding in such a way that the test current impulses generate stator flow vectors offset by the same angular increments over 360° electrically in the stator. The current rise time for each stator flow vector is measured in the total current of the stator winding and the phase position of the stator flow vector with the smallest current rise time is determined as the rotor position.

A method of and apparatus for controlling an electric machine. The method can include using a controller to detect whether power is present at a first node of the controller, detect whether power is present at a second node of the controller, generate at least one signal based at least in part on the detection, and energize the electric machine using a detected power when the at least one signal indicates power is present at at least one of the first node, the second node, and a combination of the first node and the second node.

A startup control method of a BLDC motor is disclosed. The method can control the BLDC motor to prevent the generation of a transient current such that the vibration of the BLDC motor can be reduced at the startup stage and perform a stable conversion into a sensorless operation mode such that the startup failure rate of the BLDC motor can be reduced. The startup control method includes commutating a current applied to stator windings according to a rotor position. The method of operating the BLDC motor includes a rotor position that is forcibly aligned and so that phase commutation is performed, a back-electromotive force (back-emf) is detected from a lead voltage of a phase of a voltage which is not applied thereto after performing phase commutation and a determination is performed as to whether the detected back-emf is in a rising interval. The lead voltage of the phase of the voltage which is not applied thereto is integrated, such that if the back-emf is in a rising interval and if an instance that the integration result is greater than a predetermined value a phase commutation time point is set and conversion into a sensorless operation mode is performed if the back-emf detected from the lead voltage is in a stable interval, based on a frequency of the voltage applied to the stator winding.

A brushless DC (BLDC) motor system and a method of controlling the same are provided. The BLDC motor system comprises a BLDC motor including a rotator and a stator, a plurality of switches, a DC current sensor, a position detector and a controller. The stator has a plurality of coils to which currents having different phase are applied. The switches are driven with switching pulses for switching the currents applied to the coils. The position detector detects a position change of the rotator to thereby generate a counter-electromotive force and the DC current sensor senses currents when the currents are applied from the switches to the coils. Based on a magnitude of the counter electromotive force, the controller generates a compensation voltage in order to control the switches during the commutation interval. Further, a duty ratio of the switching pulse is controlled based on the differences between the currents applied to the coils and a reference current.

A power converter for a switched reluctance motor or a permanent magnet brushless direct current (dc) motor may include first and second partial circuits for forming multiple conduction circuits in cooperation with first and second phase windings of the motor. The controller also includes a switch operable to open and close a first conduction circuit, which includes the first phase winding, and to regulate energization of the first and second phase windings of the motor through opening and closing the first conduction circuit. Control of the switch provides four-quadrant operation of the motor through regulated energization of the first and second phase windings.