A transmitting assembly (114, 214, 334) configured to transmit electric power in a universal wireless charging device (102, 200, 302) is presented. The transmitting assembly (114, 214, 334) includes a first coil (116, 216, 316) embedded in a printed circuit board (220) and configured to transmit a first AC voltage signal having a first frequency. Also, the transmitting assembly (114, 214, 334) includes a second coil (118, 218, 318) disposed on the printed circuit board (220) and configured to transmit a second AC voltage signal having a second frequency, wherein the second frequency is different from the first frequency, and wherein the first AC voltage signal having the first frequency and the second AC voltage signal having the second frequency are used to wirelessly charge a plurality of receiver devices (104, 106) having different frequency standards.

A fan and a motor thereof are provided. The motor includes a motor drive device. The motor drive device includes a printed circuit board. A control management unit and a voltage converter are arranged on the printed circuit board, the control management unit classifies target rotation speed signals provided by an ECU into multiple rotation speed intervals, with each rotation speed interval corresponding to a fixed duty ratio. The control management unit receives a target rotation speed signal transmitted from the ECU in a real-time manner, and outputs a pulse width modulation signal having a duty ratio corresponding to the rotation speed interval to which the target rotation speed signal transmitted from the ECU belongs. The voltage converter is connected between the power source and the winding, and is configured to regulate a voltage outputted to the winding in response to the pulse width modulation signal having the fixed duty ratio outputted from the control management unit, to control a rotation speed of the motor. The motor drive device performs segment control on the rotation speed of the motor, thereby reducing the cost.

A fan and a motor thereof are provided. The motor includes a motor drive device. The motor drive device includes a printed circuit board. A control management unit and a voltage converter are arranged on the printed circuit board, the control management unit classifies target rotation speed signals provided by an ECU into multiple rotation speed intervals, with each rotation speed interval corresponding to a fixed duty ratio. The control management unit receives a target rotation speed signal transmitted from the ECU in a real-time manner, and outputs a pulse width modulation signal having a duty ratio corresponding to the rotation speed interval to which the target rotation speed signal transmitted from the ECU belongs. The voltage converter is connected between the power source and the winding, and is configured to regulate a voltage outputted to the winding in response to the pulse width modulation signal having the fixed duty ratio outputted from the control management unit, to control a rotation speed of the motor. The motor drive device performs segment control on the rotation speed of the motor, thereby reducing the cost.

An electric power generation system and a method in an electric power generation system. The system comprising one or more generators for producing electrical energy, each generator being arranged to be driven with a corresponding prime mover, wherein the generators are multiphase AC generators adapted to generate a multiphase voltage having a frequency and an amplitude, the phase outputs of the generators are connectable to a common multiphase bus for distributing the electrical energy generated by the AC generators, the system comprises further means for providing independent reference values for a rotational speed of the prime movers and for amplitude of the multiphase voltage, the rotational speed of the prime movers defining the frequency of the multiphase voltage, and the system is adapted to operate in at least three operation points on the basis of the provided independent reference values, an operation point being defined by a ratio of the amplitude of the multiphase voltage to the frequency of the multiphase voltage, wherein the at least three operation points are different.

An electrical power supply system for an aircraft includes a plurality of generators, each being couplable to and rotatable by an aircraft engine. and a plurality of electrical conversion units, each having a plurality of inputs and at least one output. Each generator includes at least four AC phases. The inputs of each individual electrical conversion unit are connected to a plurality of phases of at least two of the plurality of generators. The electrical conversion units each includes a rectification and conversion device for providing an output voltage having a predeterminable frequency and voltage level at the output.

A power conversion system includes: a power converter connected between a DC power source and an AC power source; an AC switch connected between the power converter and the AC power source; an AC capacitor connected on the power converter side relative to the AC switch, on an output side of the power converter; and a control device configured to, in a state in which the AC switch is open, recognize a voltage of the AC capacitor and control the power converter to bring an output voltage of the power converter close to a voltage of the AC power source from the voltage of the AC capacitor gradually or in a step-by-step manner, and then close the AC switch. The power conversion system can suppress overcurrent at a time of start-up of a power converter and inrush current at a time of interconnection to an AC power source.

A power conversion system includes: a power converter connected between a DC power source and an AC power source; an AC switch connected between the power converter and the AC power source; an AC capacitor connected on the power converter side relative to the AC switch, on an output side of the power converter; and a control device configured to, in a state in which the AC switch is open, recognize a voltage of the AC capacitor and control the power converter to bring an output voltage of the power converter close to a voltage of the AC power source from the voltage of the AC capacitor gradually or in a step-by-step manner, and then close the AC switch. The power conversion system can suppress overcurrent at a time of start-up of a power converter and inrush current at a time of interconnection to an AC power source.

An electricity distribution system, arranged to provide low voltage to end users and located at end user locations, includes a first medium voltage line for providing medium voltage and several end user electricity providers associated with respective several end user locations. Each end user electricity provider is couplable to an end user located at the respective end user location, and is arranged to provide low voltage to the end user. The first medium voltage line is provided with a number of branches and the end user electricity providers are each couplable to a respective branch of the medium voltage line via a respective second medium voltage line to receive medium voltage, and are arranged to convert the medium voltage to the low voltage to be provided to an end user.

An electricity distribution system, arranged to provide low voltage to end users and located at end user locations, includes a first medium voltage line for providing medium voltage and several end user electricity providers associated with respective several end user locations. Each end user electricity provider is couplable to an end user located at the respective end user location, and is arranged to provide low voltage to the end user. The first medium voltage line is provided with a number of branches and the end user electricity providers are each couplable to a respective branch of the medium voltage line via a respective second medium voltage line to receive medium voltage, and are arranged to convert the medium voltage to the low voltage to be provided to an end user.

According to one aspect of the teachings herein, various feeder connection arrangements and architectures are disclosed, for collecting electricity from wind turbines in an offshore collection grid that operates at a fixed low frequency, e.g., at one third of the targeted utility grid frequency. Embodiments herein detail various feeder arrangements, such as the use of parallel feeder connections and cluster-based feeder arrangements where a centralized substation includes a common step-up transformer for outputting electricity at a stepped-up voltage, for low-frequency transmission to onshore equipment. Further aspects relate to advantageous generation arrangements, e.g., tower-based arrangements, for converting wind power into electrical power using, for example, medium-speed or high-speed gearboxes driving generators having a rated electrical frequency for full-power output in a range from about 50 Hz to about 150 Hz, with subsequent conversion to the fixed low frequency for off-shore collection.