Abstract: A semiconductor device includes a semiconductor part; first and second electrodes respectively on back and front surfaces of the semiconductor part; and a control electrode between the semiconductor part and the second electrode. The control electrode is provided inside a trench of the semiconductor part. The control electrode is electrically insulated from the semiconductor part by a first insulating film and electrically insulated from the second electrode by a second insulating film. The control electrode includes an insulator at a position apart from the first insulating film and the second insulating film. The semiconductor part includes a first layer of a first conductivity type provided between the first and second electrodes, the second layer of a second conductivity type provided between the first layer and the second electrode and the third layer of the first conductivity type selectively provided between the second layer and the second electrode.

Abstract: A control method, a controller, and a control system including a converter and the controller are provided to improve load responsiveness of control by the converter. The converter has a primary circuit that includes a voltage generation circuit for generating a square wave and a resonant circuit for converting a waveform of the generated square wave, and a secondary circuit that is electromagnetically coupled to the primary circuit and that generates an induced electromotive force. The controller controls the voltage generation circuit by a control target power factor. To implement power factor-based control, the controller controls the voltage generation circuit, based on a derived power factor derived from an active power and an apparent power relevant to the resonant circuit in the primary circuit or a derived power factor derived from a phase of the primary circuit.

Abstract: A control method, a controller, and a control system including a converter and the controller are provided to improve load responsiveness of control by the converter. The converter has a primary circuit that includes a voltage generation circuit for generating a square wave and a resonant circuit for converting a waveform of the generated square wave, and a secondary circuit that is electromagnetically coupled to the primary circuit and that generates an induced electromotive force. The controller controls the voltage generation circuit by a control target power factor. To implement power factor-based control, the controller controls the voltage generation circuit, based on a derived power factor derived from an active power and an apparent power relevant to the resonant circuit in the primary circuit or a derived power factor derived from a phase of the primary circuit.