A bi-directional medium voltage converter topology includes an n-pulse line-interphase-transformer, LIT; a plurality of bi-directional medium voltage, MV converters connected to the LIT on an AC side thereof and connected in parallel on a DC side thereof; a bi-directional multi-stage DC/DC converter connected to the plurality of bi-directional MV converters; and a bi-directional low voltage, LV, DC/DC converter; wherein the multi-stage DC/DC converter and the LV DC/DC converter are connected to each other galvanically insulated.

An adapter device, including an AC connection including first AC contact and second AC contact; a DC connection including first DC contact and second DC contact; a first bridge branch including first switching device and second switching device, the first switching device and second switching device connected in series at a first bridge point, the first bridge point connected to first AC contact; a second bridge branch including third switching device and fourth switching device, third switching device and fourth switching device connected in series at a second bridge point, the second bridge point connected to second AC contact; and mode-setting device configured to predetermine a direction of power flow between AC connection and/or DC connection, first bridge branch and second bridge branch connected in parallel to the first DC contact and second DC contact, and different types of switching devices used as switching devices of a bridge branch.

A circuit for minimizing energy provided to a ground fault includes a source, a multiple switches, an output filter, and a controller. The switches include a first side pair of switches and a second side pair of switches configured to provide an output signal based on the source. The output filter includes one or more energy storage elements coupled to the first side pair of switches or the second side pair of switches. The controller is configured to receive a ground fault signal that indicates a fault has occurred and configured to generate a switch signal for the switches for a minimum energy state of the output filter and in response to the ground fault signal.

A circuit for minimizing energy provided to a ground fault includes a source, a multiple switches, an output filter, and a controller. The switches include a first side pair of switches and a second side pair of switches configured to provide an output signal based on the source. The output filter includes one or more energy storage elements coupled to the first side pair of switches or the second side pair of switches. The controller is configured to receive a ground fault signal that indicates a fault has occurred and configured to generate a switch signal for the switches for a minimum energy state of the output filter and in response to the ground fault signal.

A power converting system includes a power converting device, a protection device, and a charging device. The power converting device is coupled to a first and a second power source. The protection device is coupled to the power converting device, a load, and a grid, and switches electrical connections among the power converting device, the load, and the grid. The charging device is coupled to the power converting device and a third power source. The power converting device charges the third power source through the charging device, or receives electricity through the charging device. Select at least one power source of the first power source, the second power source, the third power source and the grid to provide electricity to the load according to multiple preset modes.

A power supply device is provided. The power supply device includes a rectifier circuit for rectifying an inputted alternating current power supply, a capacitor circuit comprising a first and second capacitor which are connected in series, and smoothing the alternating current power supply rectified in the rectifier circuit, an inverter for converting the output power of the capacitor circuit to a preset power and outputting same, a switch for selectively connecting a middle node of the first capacitor and the second capacitor and an end of the alternating current power, a sensor for detecting a size of the alternating current power, and a controller which confirms a power mode of the alternating current power on the basis of an output value of the sensor, and which controls the switch so that the capacitor circuit multiplies and amplifies the selectively rectified alternating current power based on the confirmed power mode.

A power supply device is provided. The power supply device includes a rectifier circuit for rectifying an inputted alternating current power supply, a capacitor circuit comprising a first and second capacitor which are connected in series, and smoothing the alternating current power supply rectified in the rectifier circuit, an inverter for converting the output power of the capacitor circuit to a preset power and outputting same, a switch for selectively connecting a middle node of the first capacitor and the second capacitor and an end of the alternating current power, a sensor for detecting a size of the alternating current power, and a controller which confirms a power mode of the alternating current power on the basis of an output value of the sensor, and which controls the switch so that the capacitor circuit multiplies and amplifies the selectively rectified alternating current power based on the confirmed power mode.

A circuit for minimizing energy provided to a ground fault includes a source, a multiple switches, an output filter, and a controller. The switches include a first side pair of switches and a second side pair of switches configured to provide an output signal based on the source. The output filter includes one or more energy storage elements coupled to the first side pair of switches or the second side pair of switches. The controller is configured to receive a ground fault signal that indicates a fault has occurred and configured to generate a switch signal for the switches for a minimum energy state of the output filter and in response to the ground fault signal.

A circuit for minimizing energy provided to a ground fault includes a source, a multiple switches, an output filter, and a controller. The switches include a first side pair of switches and a second side pair of switches configured to provide an output signal based on the source. The output filter includes one or more energy storage elements coupled to the first side pair of switches or the second side pair of switches. The controller is configured to receive a ground fault signal that indicates a fault has occurred and configured to generate a switch signal for the switches for a minimum energy state of the output filter and in response to the ground fault signal.

Provided is a new control method that causes no time lag or hunting when a power conversion direction is reversed. The power conversion apparatus includes switching elements (S1 and S2) that alternately perform switching and are capable of reversing the power conversion direction without suspension, and an up/down counter register (RT) that has two different thresholds and selects counting up at a smaller threshold, counting down at a larger threshold, and holding of the value between the two thresholds. According to the value of the up/down counter register (RT), a gate pulse is generated to control the switching of the switching elements (S1 and S2).