Abstract: A device for electrically connecting a direct current (DC) microgrid to a DC bus of an electrical power network, which is operating at a higher voltage than the microgrid, comprises a pair of electrical port each configured for connection with either the DC bus or the microgrid; a DC-DC power converter operatively interconnecting the electrical ports for power transmission therebetween from a first voltage at the port connected to the DC bus to a lower second voltage at the port connected to the DC microgrid; a DC circuit breaker connected between the DC-DC power converter and one of the electrical ports for selectively conducting current therebetween; and a controller which is configured to communicate with constituent devices in the DC microgrid as well as a control center representative of the electrical power network in order to exchange information about electrical energy consumption in the DC microgrid and the larger network.

Abstract: In some examples, a circuit includes a first power converter cell and a second power converter cell. The first power converter cell has a first bidirectional interface. The first power converter cell is configured to switch power from the first bidirectional interface to a second bidirectional interface in a first operation mode. The second power converter cell has a third bidirectional interface. The second power converter cell is configured to switch power from the third bidirectional interface to the second bidirectional interface in the first operation mode in parallel with the first power converter cell.

Abstract: A device for electrically connecting a direct current (DC) microgrid to a DC bus of an electrical power network, which is operating at a higher voltage than the microgrid, comprises a pair of electrical port each configured for connection with either the DC bus or the microgrid; a DC-DC power converter operatively interconnecting the electrical ports for power transmission therebetween from a first voltage at the port connected to the DC bus to a lower second voltage at the port connected to the DC microgrid; a DC circuit breaker connected between the DC-DC power converter and one of the electrical ports for selectively conducting current therebetween; and a controller which is configured to communicate with constituent devices in the DC microgrid as well as a control center representative of the electrical power network in order to exchange information about electrical energy consumption in the DC microgrid and the larger network.

Abstract: A direct current circuit breaker comprises a mechanical relay in a first supply line configured to conduct electrical current during steady-state operation and an auxiliary relay assembly in parallel with the mechanical relay to define an auxiliary breaker path for conducting electrical current during transient operation of the circuit breaker. The auxiliary relay assembly comprises a power-semiconductor circuit configured for selective current conduction and for bidirectional current blocking when in a non-conductive state.

Abstract: A bidirectional bridgeless buck-boost power converter circuit is provided that can function as both a voltage source inverter (VSI) circuit to transform direct current (DC) voltage to alternating current (AC) voltage and as a power factor corrector (PFC) circuit to transform AC voltage to DC voltage. The disclosed converter fully utilizes inductors to form a CL filter and buck-boost converter energy storage element. Thus, low inductance chokes are used in the converter, which leads to a higher power density and is more cost-effective. Further, the bridgeless configuration minimizes conduction losses of semiconductors, and coupled with the use of low inductance chokes this improves system efficiency.

Abstract: A bidirectional bridgeless buck-boost power converter circuit is provided that can function as both a voltage source inverter (VSI) circuit to transform direct current (DC) voltage to alternating current (AC) voltage and as a power factor corrector (PFC) circuit to transform AC voltage to DC voltage. The disclosed converter fully utilizes inductors to form a CL filter and buck-boost converter energy storage element. Thus, low inductance chokes are used in the converter, which leads to a higher power density and is more cost-effective. Further, the bridgeless configuration minimizes conduction losses of semiconductors, and coupled with the use of low inductance chokes this improves system efficiency.