A voltage conversion system including a source configured to supply a voltage and a switch capacitor circuit electrically coupled to the source. The switch capacitor circuit is configured to switch between a discharging state and a charging state. The switching between the discharging state and the charging state produces a boost to the supplied voltage. The voltage conversion system includes a capacitor in the switch capacitor circuit configured to store charge during the charging state and drain charge during the discharging state. The voltage conversion system includes a switching arrangement having a plurality of switch pairs configured to supply a converted voltage to a load. The switch capacitor circuit and the switching arrangement are interfaced to produce a unified circuit.

A novel power inverter system for transferring electric power between a DC power source and a multi-phase electric machine is described, and includes a power inverter, a Z-source inverter, a first switch, and a second switch. The first switch is arranged between positive and negative conductors of a high-voltage bus that is electrically coupled to the DC power source, and the second switch is arranged in-line on the positive conductor of the high-voltage bus.

A power device includes: a DC voltage output circuit that generates a DC internal power voltage from external supply power; a capacitor that is connected to the internal power voltage; and a voltage supply control circuit that monitors a voltage level of the internal power voltage and that, when detecting a drop in the internal power voltage, cuts off supply of the internal power voltage. The power device supplies internal power to a load. The power device supplies, to a first load that is a part of the load, the internal power voltage, and supplies, to a second load that is a load other than the first load, the internal power voltage via the voltage supply control circuit.

The invention relates to a charging device for charging a battery of a motor vehicle having an electric drive motor. The charging device has an inductor and a drive converter, which converts a direct voltage of the battery for the electric drive motor during drive operation of the motor vehicle and which has a DC link center point. The inductor, together with the drive converter, is used as a step-up converter for charging operation of the battery. The aim of the invention is to provide a compact and economical charging device This aim is achieved in that the charging device has a controllable switching device, which is designed to charge and/or discharge the DC link center point to a voltage.

A motor control device includes: a voltage boosting circuit that boosts a power source voltage supplied from an outside; a condenser that smooths a voltage output by the voltage boosting circuit; an inverter circuit that generates a drive voltage of a motor by switching a voltage output by the voltage boosting circuit and smoothed by the condenser; and a control part that causes the voltage boosting circuit to bypass and causes the power source voltage to be supplied to the inverter circuit, and a distance between the voltage boosting circuit and the inverter circuit is a distance with which a parasitic inductance is equal to or less than a predetermined value.

There is provided a driving system including a motor; an inverter configured to drive the motor; a power storage device connected with the inverter via a power line; a smoothing capacitor mounted to the power line; a voltage sensor configured to detect a voltage of the smoothing capacitor; a current sensor configured to detect an electric current of each phase of the motor; and a control device configured to control the inverter, based on a detected value of the current sensor. The control device performs Fourier series expansion of a detected value of the voltage sensor to calculate an electrical first variation component of the voltage of the smoothing capacitor. The control device controls the inverter, such that the electrical first variation component of the voltage of the smoothing capacitor becomes equal to a value 0.

A dual inverter is connected to a double-ended three-phase coil of a three-phase motor. The dual inverter is operated as a rectifier for rectifying a grid voltage. The dual inverter is connected to a DC power supply including a bi-directional DCDC converter for changing a power-supply voltage. Each of three H-bridges of the dual inverter consists of a PWM-leg and a fixed potential leg, which are regularly changed. An upper arm switch is continuously turned on. A cold battery supplies a single-phase AC current to the three-phase motor in order to produce an alternating magnetic field.

The present disclosure relates to a drain pump driving apparatus and a laundry treatment machine including the same. A drain pump driving apparatus according to an embodiment of the present disclosure includes: a converter; a voltage dropper to drop the DC voltage from the converter; an inverter module to operate based on a first voltage from the voltage dropper and to output AC voltage converted by a switching operation to a drain pump motor; a controller to operate based on a second voltage from the voltage dropper and to control the inverter module; and a voltage adjuster to adjust the level of voltage information of the motor outputted from the inverter module and to output the adjusted voltage information to the controller. Accordingly, it is possible to stably drive the drain motor.

A control method for a motor system, the motor system having a battery; a boost converter configured to increase DC voltage supplied by the battery; an inverter connected to the boost converter and configured to execute a conversion between DC power and AC power; and a motor generator connected to the inverter. The control method comprising: a limiting power determination step of determining a limiting power in response to an operating point of the motor generator such that an oscillation of a terminal voltage of the boost converter at a side of the inverter is suppressed; and a controlling step of controlling the operating point of the motor generator such that a passing power of the boost converter does not exceed the limiting power.

In a motor driving apparatus including a DC power supply circuit of variable output voltage value, an inverter of variable frequency, and a connection switching device for selecting connection, switching of the connection switching device is performed in a state where an output voltage of the DC power supply circuit is increased, a rotational speed of a motor is increased, and a current flowing through the motor is made not greater than a predetermined threshold. For example, the switching of the connection switching device is performed in a state where the current through the motor is made zero. For example, the switching is performed in a state where the output voltage of the DC power supply circuit is set at a value corresponding to the rotational speed of the motor during the switching. It is possible to prevent increase in apparatus size and switch the connection of windings while the motor is rotating.