A power conversion system includes a transformer, a power conversion device for travel, a power conversion device for auxiliary power sources, an electrical storage device, and an auxiliary device. The power conversion device for travel converts AC power into power for travel and supplies it to a travel motor. The power conversion device for auxiliary power sources includes an AC to DC conversion unit which converts AC power into DC power, a power conversion unit for AC loads which converts the DC power into AC power and supplies it to an AC load, and a power conversion unit for DC loads which converts DC power to DC power and supplies it to a DC load. The electrical storage device is connected to power lines connecting DC power output terminals of the AC to DC conversion unit and DC power input terminals of both the power conversion units for AC and DC loads. The auxiliary device is connected to power lines connecting the power conversion device for auxiliary power sources and the electrical storage device and operates with power supplied from the electrical storage device.

A power conversion system includes a transformer, a power conversion device for travel, a power conversion device for auxiliary power sources, an electrical storage device, and an auxiliary device. The power conversion device for travel converts AC power into power for travel and supplies it to a travel motor. The power conversion device for auxiliary power sources includes an AC to DC conversion unit which converts AC power into DC power, a power conversion unit for AC loads which converts the DC power into AC power and supplies it to an AC load, and a power conversion unit for DC loads which converts DC power to DC power and supplies it to a DC load. The electrical storage device is connected to power lines connecting DC power output terminals of the AC to DC conversion unit and DC power input terminals of both the power conversion units for AC and DC loads. The auxiliary device is connected to power lines connecting the power conversion device for auxiliary power sources and the electrical storage device and operates with power supplied from the electrical storage device.

A system and method for high speed switching comprises receiving voltage inputs at a bridge rectifier, generating a control signal from a transistor, and driving a gate of a field effect transistor (FET) via the control signal of the transistor, wherein a source of the FET is connected to a negative output of the bridge rectifier and a drain of the FET is connected to a positive output of the bridge rectifier through a load. The system and method further comprises limiting current flowing to the gate of the FET through first and second resistors and first and second diodes connecting the voltage inputs to the gate of the FET and limiting voltage to the gate of the FET below a maximum voltage rating of the FET by a Zener diode connected to the gate of the FET.

A system and method for high speed switching comprises receiving voltage inputs at a bridge rectifier, generating a control signal from a transistor, and driving a gate of a field effect transistor (FET) via the control signal of the transistor, wherein a source of the FET is connected to a negative output of the bridge rectifier and a drain of the FET is connected to a positive output of the bridge rectifier through a load. The system and method further comprises limiting current flowing to the gate of the FET through first and second resistors and first and second diodes connecting the voltage inputs to the gate of the FET and limiting voltage to the gate of the FET below a maximum voltage rating of the FET by a Zener diode connected to the gate of the FET.

A voltage monitoring control system includes voltage control apparatuses controlling voltage on a power distribution line, a local voltage control device adjusting a voltage value controlled by the voltage control apparatuses such that it is maintained within a range between voltage upper-and-lower-limit values updated every first cycle, a voltage and power-flow measurement device calculating and transmitting fluctuation-band information indicating fluctuation band of the voltage every third cycle longer than a second cycle based on voltage on the power distribution line measured every second cycle shorter than the first cycle, and a centralized voltage control device. The centralized voltage control device includes a voltage-fluctuation-band calculation unit calculating fluctuation band within the first cycle, an optimal-voltage-distribution determination unit determining a threshold value for allowance for each of upper and lower limits of an appropriate voltage range and acquiring an optimal control amount, and a voltage upper-and-lower-limit-value determination unit.

A voltage monitoring control system includes voltage control apparatuses controlling voltage on a power distribution line, a local voltage control device adjusting a voltage value controlled by the voltage control apparatuses such that it is maintained within a range between voltage upper-and-lower-limit values updated every first cycle, a voltage and power-flow measurement device calculating and transmitting fluctuation-band information indicating fluctuation band of the voltage every third cycle longer than a second cycle based on voltage on the power distribution line measured every second cycle shorter than the first cycle, and a centralized voltage control device. The centralized voltage control device includes a voltage-fluctuation-band calculation unit calculating fluctuation band within the first cycle, an optimal-voltage-distribution determination unit determining a threshold value for allowance for each of upper and lower limits of an appropriate voltage range and acquiring an optimal control amount, and a voltage upper-and-lower-limit-value determination unit.

Systems and methods that can be retrofitted into an existing wired electrical system replacing existing switches whether as a standalone single switch or part of a multi-way switch configuration that can be controlled locally nominally by touch, controlled remotely by a remote, or controlled remotely by a computer. The systems and method provide that the switches establish a local network allowing for retrofit or construction of a structure or facility with electrical system automation without the need for additional wiring.

Systems and methods that can be retrofitted into an existing wired electrical system replacing existing switches whether as a standalone single switch or part of a multi-way switch configuration that can be controlled locally nominally by touch, controlled remotely by a remote, or controlled remotely by a computer. The systems and method provide that the switches establish a local network allowing for retrofit or construction of a structure or facility with electrical system automation without the need for additional wiring.

A method of controlling power transfer in a power system including a main bus, having a first and second bus sections, the first bus section connectable to the second bus section, first and second power generating units connectable to the first and second bus sections, a first and second drive systems connectable to the first and second bus sections, a central energy storage system, and a control system. The first and second drive systems include first and second bi-directional power converters connectable to the central energy storage system, and wherein the control system is arranged to control the first bi-directional power converter to transfer power from the first drive system to the central energy storage system, and to control the second bi-directional power converter to transfer power from the central energy storage system to the second drive system.

A method of controlling power transfer in a power system including a main bus, having a first and second bus sections, the first bus section connectable to the second bus section, first and second power generating units connectable to the first and second bus sections, a first and second drive systems connectable to the first and second bus sections, a central energy storage system, and a control system. The first and second drive systems include first and second bi-directional power converters connectable to the central energy storage system, and wherein the control system is arranged to control the first bi-directional power converter to transfer power from the first drive system to the central energy storage system, and to control the second bi-directional power converter to transfer power from the central energy storage system to the second drive system.