Precharging systems and methods are presented for precharging a DC bus circuit in a power conversion system, in which precharging current is connected through a precharging resistance coupled between only a single AC input line and the DC bus circuit when the DC bus voltage is less than a non-zero threshold, and a controller individually activates controllable rectifier switching devices when the DC bus voltages greater than or equal to the threshold using DC gating or pulse width modulation to selectively provide a bypass path around the precharging resistance for normal load currents in the power conversion system.

An AC power converter converts power from an AC power source to an AC load. A DC power holding source is coupled to an input half-bridge switch, a common half-bridge switch and an output half-bridge switch. A controller is coupled to at least two of the input half-bridge switch, the common half-bridge switch, and an output half-bridge switch. The controller switches the input half bridge at the first switching frequency in boost mode and at the line frequency in buck mode. The controller also switches the output half bridge switch at the first switching frequency in buck mode and at the line frequency in boost mode. Input and output low pass filters can eliminate switching frequency energy from entering the AC source and load. The converter maintains a DC power holding source voltage slightly above peak AC input voltage and significantly less than twice the peak AC input voltage.

An AC power converter converts power from an AC power source to an AC load. A DC power holding source is coupled to an input half-bridge switch, a common half-bridge switch and an output half-bridge switch. A controller is coupled to at least two of the input half-bridge switch, the common half-bridge switch, and an output half-bridge switch. The controller switches the input half bridge at the first switching frequency in boost mode and at the line frequency in buck mode. The controller also switches the output half bridge switch at the first switching frequency in buck mode and at the line frequency in boost mode. Input and output low pass filters can eliminate switching frequency energy from entering the AC source and load. The converter maintains a DC power holding source voltage slightly above peak AC input voltage and significantly less than twice the peak AC input voltage.

Provided is a modular multi-level converter including a plurality of sub-modules including switching elements, a plurality of sub-control units respectively controlling the plurality of switching elements included in the plurality of sub-modules, and a central control unit which determines switching operation conditions of the plurality of sub-modules, and transmits control signals corresponding to the determined switching operation conditions to the plurality of sub-control units. Each of the plurality of sub-control units acquires state information on the sub-module controlled thereby and transmits the acquired state information to the central control unit.

Provided is a modular multi-level converter including a plurality of sub-modules including switching elements, a plurality of sub-control units respectively controlling the plurality of switching elements included in the plurality of sub-modules, and a central control unit which determines switching operation conditions of the plurality of sub-modules, and transmits control signals corresponding to the determined switching operation conditions to the plurality of sub-control units. Each of the plurality of sub-control units acquires state information on the sub-module controlled thereby and transmits the acquired state information to the central control unit.

A motor driving device includes a rectifier to rectify inputted alternating current (AC) power, a boost converter to boost and to output the power rectified by the rectifier, and an inverter including a plurality of switching devices to output converted AC power to a motor using a voltage from the boost converter. Accordingly, a voltage utilization ratio of a voltage input to an inverter in the motor driving device using a low-capacitance capacitor is enhanced.

A motor driving device includes a rectifier to rectify inputted alternating current (AC) power, a boost converter to boost and to output the power rectified by the rectifier, and an inverter including a plurality of switching devices to output converted AC power to a motor using a voltage from the boost converter. Accordingly, a voltage utilization ratio of a voltage input to an inverter in the motor driving device using a low-capacitance capacitor is enhanced.

A power generating system. The system generates enough energy to allow the processes needed to operate while also generating enough energy for an outside product to operate at capacity to the machine limits by the use of electric motor control(s) and mechanical advantage by utilizing proper gearing with the use of sprockets, pulleys, gears or any combination to create the necessary ratio. The invention utilizes increased electrical motor torque, horsepower and motor control to rotate a power generating unit, causing the power generating unit to produce electricity. A transmission device is coupled between the motor and the power generating unit to increase the torque and horsepower of the motor so as to power the generating unit by gearing, torque, force, and lever force by way of the use of simple machines such as levers and pulleys.

A converter arrangement comprises first and second modular multilevel converters, Each of the modular multilevel converters comprises two converter branches. Each converter branch comprises a plurality of series-connected converter cells. Each converter cell comprises a cell capacitor and semiconductor switches for connecting and disconnecting the cell capacitor to the converter branch. At least two converter branches of the first modular multilevel converter are connected via first branch connection point and at least two converter branches of the second modular multilevel converter are connected via second branch connection point. The multilevel converters are connected in parallel via a phase connection point for connecting the converter arrangement to a load or a power source, wherein the phase connection point is connected via a first inductance with the first branch connection point and/or via a second inductance with the second branch connection point. At least one of the modular multilevel converters comprises a protection system.

A converter arrangement comprises first and second modular multilevel converters, Each of the modular multilevel converters comprises two converter branches. Each converter branch comprises a plurality of series-connected converter cells. Each converter cell comprises a cell capacitor and semiconductor switches for connecting and disconnecting the cell capacitor to the converter branch. At least two converter branches of the first modular multilevel converter are connected via first branch connection point and at least two converter branches of the second modular multilevel converter are connected via second branch connection point. The multilevel converters are connected in parallel via a phase connection point for connecting the converter arrangement to a load or a power source, wherein the phase connection point is connected via a first inductance with the first branch connection point and/or via a second inductance with the second branch connection point. At least one of the modular multilevel converters comprises a protection system.