23949results about "AC motor control" patented technology

A motor driving method for driving a direct-current (DC) motor, designed for avoiding a reverse current induced by the Back Electromotive Force (BEMF), includes providing a driver circuit for driving the DC motor; comparing a signal level of a terminal of the DC motor and a predetermined voltage value to produce a comparing result; and controlling a specific lower gate switch to avoid the occurrence of a reverse current of the DC motor according to the comparing result.

The invention provides a forward and reverse motor for improving forward and reverse efficiency, and a control method thereof. By adopting the forward and reverse motor having a first winding and a second winding and a third winding both having the phase differences differing for 90 degrees of that of the first winding, and a switching circuit, the switching circuit connects the first winding as the main winding and the second winding as the secondary winding to the working circuit of the motor, or connects the third winding as the main winding and the first winding as the secondary winding tothe working circuit of the motor, thereby ensuring that the parameters of the number of turns, wire diameters and resistances of the main winding and the secondary winding in each case can be separately designed when the motor rotates forwards or reversely to ensure high efficiency of the motor in both forward and reverse rotations, which solves the problem that the forward and reverse motor cannot reach high efficiency in forward and reverse directions in the related art.

An inverter device includes a plurality of switching circuits in which first switching elements including Si semiconductors and second switching element including WBG semiconductors having ON resistance smaller than that of the first switching elements and having switching speed higher than that of the first switching elements are connected in parallel. The inverter device includes a converting circuit that converts a direct-current voltage into a desired alternating-current voltage and a driving unit that generates a plurality of driving signals for respectively turning on and off the switching circuits. The inverter device includes, for each of the switching circuits, a gate circuit that, based on the driving signals, turns on the second switching element later than the first switching element and turns off the first switching element later than the second switching element.

A driving controlling apparatus for a linear compressor, comprises: a storing unit for storing a reference phase difference to judge an overload state; and a controlling unit for judging an overload state based on a comparison result between the reference phase difference and a phase difference between a current and a stroke, and controlling a voltage or a current applied to a linear motor based on the judgement result.

A photovoltaic inverter control method includes steps of monitoring a variation in output voltage of a solar battery by a power and voltage monitoring circuit (51) and, when the variation occurs, accelerating or decelerating an electric motor (3) to maximize the output voltage of the solar battery (1), whereby the electric motor for driving, for example, a pump and a fan by the solar battery as a power source can be driven by a photovoltaic inverter always at the maximum power point of the solar battery.