A power conversion system 200 includes a power conversion device 2 configured to supply electric power to a motor 3 and a power supply device 1 configured to supply electric power to the power conversion device 2. The power conversion device 2 includes a reverse converter 7 configured to convert the electric power, a control circuit 8 configured to control the reverse converter 7, and a current detector configured to detect a current flowing through the reverse converter 7. The power supply device 1 includes a storage device 6 configured to store electric power in accordance with a voltage, a step-up/down power supply circuit 5 configured to change the voltage of the storage device 6 based on a voltage command, and a voltage command computing circuit 15 configured to compute the energy stored in the storage device 6 and output it as the voltage command to the step-up/down power supply circuit 5. The control circuit 8 calculates powered drive energy of the motor 3 by using information from the motor 3 and a current value detected by the current detector. The voltage command computing circuit 15 computes the energy stored in the storage device 6 based on the powered drive energy calculated by the control circuit 8. When it is determined that the characteristics of the motor 3 are restricted, the voltage command computing circuit 15 temporarily changes the voltage command to improve the motor characteristics.

A plurality of power supply circuits include a second power supply circuit for a CPU included in a control unit and a first power supply circuit for another circuit. An output voltage from the first power supply circuit is higher than an output voltage from the second power supply circuit. A range of input voltage is divided into three levels of voltage sub-ranges in accordance with a requirements specification. When the input voltage falls within a lower level voltage sub-range, both of an output function of the first power supply circuit and an output function of the second power supply circuit are stopped. When the input voltage falls within an intermediate level voltage sub-range, the output function of the first power supply circuit is stopped. When the input voltage falls within an upper level voltage sub-range, all circuits are controlled so as to operate.

A power converter for converting a voltage of direct-current power output from a direct-current power supply, the power converter including: a printed circuit board; a reactor being configured with a conductor pattern of the printed circuit board; a semiconductor element that is connected to another end of the reactor and performs switching for storing electrical energy in the reactor so as to boost the voltage of the direct-current power from a first voltage to a second voltage; a capacitor that smooths the direct-current power boosted to the second voltage; a diode that is connected to the another end of the reactor and supplies the direct-current power boosted to the second voltage to the capacitor; and a cooler, wherein the reactor, the semiconductor element, and the diode are included in a module in a single package, and the module is cooled by the cooler.

An example of a vehicle electrical system includes a rechargeable energy storage system (RESS) having a first voltage and a power inverter selectively connected to the RESS. The system further includes an electric motor having a plurality of machine windings with each of the machine windings including a polyphase terminal electrically connected to the power inverter. The machine windings further include a neutral terminal separate from the polyphase terminals and configured to electrically connect to an off-board power source having a second voltage that is below the first voltage of the RESS. The power inverter is configured to cycle between first and second operational states, such that the power inverter and the electric motor steps up the first voltage to the second voltage.

A motor control device includes: a power source device including a DC-output power conversion device having a first mode for outputting first voltage and a second mode for outputting second voltage higher than the first voltage; a power supply device; and a control device, and controls a motor. When a flying object takes off, the control device controls the power conversion device in the second mode. When the control device judges that flight information which is one or both of information of a motor parameter obtained along with control for the motor and information of an environmental factor relevant to the flight altitude satisfies a predetermined condition, or when the control device has received an operation mode signal for which the first mode is selected on the basis of the flight information during control for the motor, the control device controls the power conversion device in the first mode.

A battery boost converter system for a bicycle includes a bicycle frame and a motor mounted to the bicycle frame. The system also includes a battery mounted to the bicycle frame and configured to provide power to the motor. The system also includes a boost converter configured to receive a first output signal from the battery and to provide a second output signal to the motor. The boost converter is also configured to determine, based on an operating condition, whether to boost a voltage of the first output signal such that the second output signal has an increased voltage.

A voltage doubling circuit that increases input voltage to higher output voltage connected to a variable frequency drive. The voltage doubling circuit can include a power input that receives the input voltage from a power source and a first capacitor bank and a second capacitor bank connected with the power input. A current-limiting surge suppressor is positioned between the power input and the first capacitor bank and the second capacitor bank. The current-limiting surge suppressor includes a first current-limiting path and a second bypass path. A drain, when operable, dissipates the charge of the first capacitor bank and the second capacitor bank. A variable frequency drive (VFD) is operable in response to the higher voltage output from the first capacitor bank and the second capacitor bank.

An inverter type engine generator includes an alternator; and a converter composed of the a three-phase rectifying bridge circuit including an upper and lower three sets of elements, and converting three-phase alternating current output from the alternator into direct current. The upper and lower three sets of elements of the three-phase rectifying bridge circuit of the converter are configured such that upper elements are configured at least from duty-controllable diode elements, and lower elements are configured at least from duty-controllable switching elements having diodes.

The first square wave control mode using the square wave pulse pattern is used when the voltage acting on the inverter is equal to or higher than the threshold voltage. On the other hand, when the voltage acting on the inverter is lower than the threshold voltage, a square wave pulse pattern is used when the rotation speed of the motor is equal to or higher than the first predetermined rotation speed that is higher than the first resonance region, and the second square wave control mode using the first switching pattern for suppressing the LC resonance in the first resonance region is used when the rotation speed of the motor is lower than the first predetermined rotation speed.

An example power system for supplying AC output power to an AC load includes: a variable-speed generator configured to be driven by a prime mover, the generator comprising a first winding and a reference tap in the first winding; a rectifier configured to rectify an input voltage from the first winding to output a positive DC signal with respect to the reference tap and a negative DC signal with respect to the reference tap; a first boost converter configured to convert the positive DC signal to generate a positive DC bus voltage with respect to the reference tap; a second boost converter configured to convert the negative DC signal to generate a negative DC bus voltage with respect to the reference tap; and an inverter circuit configured to convert the positive DC bus voltage and the negative DC bus voltage to an AC output signal with respect to the reference tap.