A dielectric film includes a substrate being a film including a resin material, and a plurality of microscopic members on a first surface of the substrate. Each of the plurality of microscopic members includes a first portion spaced from the first surface, and a second portion extending from the first surface and supporting the first portion.

A power converter system is described. The power converter system includes a power converter comprising at least one converter unit, each converter unit comprising a plurality of semiconductor devices, each semiconductor device including at least a controllable semiconductor switch. A local controller is associated with at least one converter unit and adapted to receive CD and MD from a main controller. In response to a detected fault condition of the power converter system, the local controller is adapted to use at least one of the one or more locally-stored values to determine an operating state of the power converter system, and to use the determined operating state to select a fault operating procedure to control each associated converter unit according to the selected fault operating procedure without using any CD from the main controller.

A power supply used to convert an input voltage into an output voltage, and the power supply includes an input detection circuit, a conversion circuit, a detection circuit, and a controller. The input detection circuit provides a power good signal or a power fail signal according to the input voltage. The conversion circuit converts the input voltage into an output voltage, and the detection circuit detects the output voltage according to the power good signal to accordingly provide an output feedback signal with a first feedback value. The controller stabilizes a voltage level of the output voltage according to the first feedback value. The detection circuit self-adjusts a feedback condition according to the power fail signal, and correspondingly adjusts the output feedback signal to a second feedback value according to the feedback condition. The controller reduces the voltage level of the output voltage according to the second feedback value.

The disclosure relates to a modular arrangement of a converter for the electrical supply of a multi-phase electric motor. The modular arrangement includes multiple output stage modules, each module having a separate first housing. An output stage module is provided for each phase of the electric motor, wherein the output stage module has a phase intermediate circuit and an inverter circuit, together forming a commutation cell. The phase intermediate circuit supplies DC voltage and is electrically connected to the inverter circuit. The disclosure also relates to a motor arrangement and an aircraft having a motor arrangement of this type.

A voltage drop Vz.sub.s is calculated based on an output current detection value Iac and a virtual synchronous impedance Zs or a corrected virtual synchronous impedance Zs′, and a value obtained by subtracting the voltage drop Vz.sub.s from an internal induced voltage Ef is output as a grid voltage command value Vac*. Zs calculation unit 7 limits an output current phase θ so that the output current phase θ is within an effective range by a phase limiter 12a, and calculates the corrected virtual synchronous impedance Zs′ based on a limited output current phase θ, the internal induced voltage Ef, a grid voltage detection value Vac and a current limit value Ilim. Accordingly, in grid interconnection power conversion device that controls a virtual synchronous generator, it is possible to continue operation while suppressing an overcurrent and possess a synchronizing power generated by action or working of a virtual synchronous impedance.

An energy storage system comprises: an alternating-current/direct-current converter; a battery; a booster; a direct-current/alternating-current converter; a power control unit; an inductor having one terminal connected to a supply terminal to which normal alternating-current power is supplied; a switching unit having one terminal connected to the other terminal of the inductor and having the other terminal connected to an input/output terminal; a current determination unit which compares an inductor current flowing through the inductor with a power recovery limit current determined by a user; and a switching control unit.

An elevator monitoring device that can compensate for system voltage when an unbalanced short circuit occurs. A control device for a power conversion device includes: a current command value generator configured to generate a provisional normal phase d-axis current command value, a provisional normal phase q-axis current command value, a provisional reversed phase d-axis current command value, and a provisional reversed phase q-axis current command value to compensate for an alternating current (AC)-side voltage of a power converter; a limiter configured to respectively set limit values of a provisional normal phase d-axis current command value, a provisional normal phase q-axis current command value, a provisional reversed phase d-axis current command value, and a provisional reversed phase q-axis current command value so that the AC-side current value of the power converter does not exceed a preset value; and a controller configured to control the power converter within the limit values.

An apparatus according to an embodiment includes a control circuit to control operations of an inverter and a switch. The control circuit judges whether or not a power system has a power failure, based on values of the system voltage and a frequency of the power system; and calculates a phase difference between a phase of the output voltage of the inverter and a phase of the system voltage and generate, by means of the phase difference, an output frequency pattern for changing a frequency of the output voltage of the inverter. The control circuit, when it is judged that the power system has recovered from the power failure, controls the inverter to change the frequency of the output voltage of the inverter in line with the output frequency pattern, and closes the switch after the phase difference becomes smaller than or equal to a threshold.

A circuit (100) for use in voltage supply for an electrical device, having a first input (111) configured for connecting with a first voltage source, a second input (121) configured for connecting with a second voltage source, and a common output (133) configured for connecting with an input of the electrical device, comprising a first voltage converter (110) with an input connected to or being the first input (111), and configured to provide DC voltage at a first voltage level (V.sub.1) at an output (113), further comprising a second voltage converter (120) with an input connected to or being the second input (121), and configured to provide DC voltage at a second voltage level (V.sub.2) at an output (123), wherein the second voltage converter (120) is configured not to operate when a voltage level present at its output (123) is higher than a stop threshold, and to operate when a voltage level present at its output (123) is lower than a start threshold, the stop threshold is equal to or higher than the second voltage level (V.sub.2) and lower than the first voltage level (V.sub.1), and the start threshold is equal to or lower than the second voltage level (V.sub.2).

A control circuit for a power converter is applicable to a system that includes a power supply, a power converter, an interruption switch, a smoothing capacitor, and a series-connection body made of a discharge resistor and a discharge switch. In the control circuit, a discharge command unit outputs a discharge command for the smoothing capacitor. A discharge drive command unit outputs a drive command for the discharge switch based on the discharge command outputted from the discharge command unit. A drive circuit is connected to a gate of the discharge switch and performs drive control of the discharge switch based on the drive command outputted from the discharge drive command unit. An operation detecting unit detects a signal related to driving of the drive switch. A discharge determining unit determines whether the discharge drive command unit is normal based on a detected signal of the operation detecting unit.