An aircraft power generation unit to generate direct current (DC) power includes a flux regulated permanent magnet generator (PMG) that includes first through fourth sets of windings and a control coil and a rectifier section that include first through fourth six pulse rectifiers and a common local output bus. The unit also includes an output bus configured to be connected to the load and an H-bridge circuit connected across the output bus and outputs connected to the control coil. A controller receives an input signal from at least one of the windings and selectively couples either the common local output bus and fourth rectifier to the output bus negative rail and one or more of the first, second and third six-pulse rectifiers to the output bus to provide a constant voltage to the load.

The invention relates to a method for operating an electric machine which can be operated using PWM control (A1) and using block control (A3), wherein a transfer control (A2) is used for transfer between the PWM control (A1) and the block control (A3), in which method, within the scope of controlling a torque of the electric machine, a d value of a phase voltage is set as a manipulated variable and a q value of the phase voltage is changed continuously.

A vehicle includes an inverter having first and second half bridges configured to provide multiphase voltage to an electric machine. The vehicle further includes a controller configured to activate a switch of the first half bridge and pulse width modulate a switch of the second half bridge to conduct resonant output on a rail of the inverter to the electric machine such that the multiphase voltage is created for at least a sixth of a cycle of the electric machine. Thee activation is responsive to a torque command.

Embodiments of the present disclosure provide a method for controlling a fan, a system, and an air conditioner. The method includes: turning off a first bridge arm group in an inverter of the fan; applying a preset driving signal to a second bridge arm group in the inverter; detecting an electrical signal of a stator of the fan after the preset driving signal is applied; determining an initial state of the fan according to the electrical signal of the stator of the fan, wherein the initial state of the fan includes a downwind forward state, a static start state, or an unwind reverse state; and providing the fan with a control signal matching the initial state of the fan according to the initial state of the fan.

A system may include a power converter and a control system communicatively coupled to the power converter. The control system may determine a first DC voltage associated with the DC bus based on one or more DC external capacitance values that correspond to one or more loads coupled to the power converter. The control system may also determine a second DC voltage associated with the DC bus based on a capacitance of a system in which the power converter operates. The control system may also determine a third DC voltage associated with the DC bus based on the first DC voltage and the second DC voltage and adjust an operation of the power converter based on the third DC voltage.

A discharge control device performs discharging of a capacitor, in a state in which a battery is not connected to an inverter that drives a motor, by causing electric charges accumulated in the capacitor connected to the inverter to be consumed by windings of the motor. The discharge control device performs the discharging of the capacitor by sequentially generating command values for voltages applied to a axis and a axis while causing a voltage phase in an stationary coordinate system having a rotation axis of a rotor of the motor as an origin and defined by the axis and the axis orthogonal to each other to be inverted in a predefined period.

A main circuit power source and a control power source of a motor drive device are backed up. A first backup capacitor is inserted between a rectifier and a control power source output terminal that supplies power to a control circuit of a driver.

Provided is a power conversion unit, in which a power smoothing capacitor is configured such that a plurality of unit capacitors as conductive polymer hybrid aluminum electrolytic capacitors are arrayed in a grid pattern and connected in parallel on a circuit board, and also connected to a plurality of unit modules of different phases via positive and negative bus bars arranged on both sides of the circuit board so that each group of several unit capacitors and each unit module are arranged close to each other, to thereby reduce wiring impedance of a power supply circuit and suppress noise generation.

A motor drive device includes a power conversion unit configured to selectively execute a converter operation of converting AC power into DC power, and an inverter operation of converting DC power into AC power for motor driving, a power storage unit configured to store DC power output from the power conversion unit and also supply DC power to the power conversion unit, a switching unit configured to switch between an AC power supply and a motor a connection destination of the power conversion unit, and a control unit configured to control the switching unit to have the power conversion unit connected to the AC power supply and control the power conversion unit to have the converter operation executed, and configured to control the switching unit to have the power conversion unit connected to the motor and control the power conversion unit to have the inverter operation executed.

A fluid extraction system is presented. The fluid extraction system includes a direct current (DC) bus and a plurality of fluid extraction sub-systems configured to be electrically coupled to the DC-bus. At least one fluid extraction sub-system includes an electric machine configured to aid in the extraction of a fluid from a well. The electric machine includes a plurality of phase windings and a rotor. The at least one fluid extraction sub-system further includes a control sub-system to control a rotational speed of the rotor by selectively controlling a supply of a phase current to the plurality of phase windings such that the rotational speed of the rotor of the electric machine is different from rotational speed of a rotor of another electric machine in at least one of other fluid extraction sub-systems. Related method for controlling rotational speeds of electric machines is also presented.