Abstract: Arc flash mitigation devices are employed to protect personnel during maintenance of photovoltaic inverters. During normal operation, an alternating current (AC) output of a photovoltaic inverter is coupled to a low voltage winding of a step up transformer through a bus-bar (e.g., an electrically conductive interconnect), which has higher current rating than a fuse. During maintenance, the bus-bar is replaced with the fuse. The fuse may be employed in conjunction with a switch. The switch may be a disconnect switch that places the bus-bar in parallel with the fuse during normal operation, and decouples the bus-bar from the fuse during maintenance. The switch may also be a transfer switch that places either the bus-bar or the fuse in series with the AC output of the photovoltaic inverter and the low voltage winding of the step up transformer.

Abstract: A photovoltaic power plant includes solar cells and inverters that convert direct current generated by the solar cells to alternating current. The reactive powers generated by the inverters are based on a reactive power generated by a virtual inverter. The virtual inverter has an equivalent impedance representing the impedances of the inverters in the photovoltaic power plant. The reactive power setpoints of the inverters may be received from a local interpreter. The local interpreter may generate the reactive power setpoints from a global reactive power setpoint generated by a grid controller.

Abstract: A photovoltaic power plant includes solar cells and inverters that convert direct current generated by the solar cells to alternating current. The reactive powers generated by the inverters are based on a reactive power generated by a virtual inverter. The virtual inverter has an equivalent impedance representing the impedances of the inverters in the photovoltaic power plant. The reactive power setpoints of the inverters may be received from a local interpreter. The local interpreter may generate the reactive power setpoints from a global reactive power setpoint generated by a grid controller.

Abstract: A photovoltaic power plant includes solar cells and inverters that convert direct current generated by the solar cells to alternating current. The reactive powers generated by the inverters are based on a reactive power generated by a virtual inverter. The virtual inverter has an equivalent impedance representing the impedances of the inverters in the photovoltaic power plant. The reactive power setpoints of the inverters may be received from a local interpreter. The local interpreter may generate the reactive power setpoints from a global reactive power setpoint generated by a grid controller.

Abstract: Arc flash mitigation devices are employed to protect personnel during maintenance of photovoltaic inverters. During normal operation, an alternating current (AC) output of a photovoltaic inverter is coupled to a low voltage winding of a step up transformer through a bus-bar (e.g., an electrically conductive interconnect), which has higher current rating than a fuse. During maintenance, the bus-bar is replaced with the fuse. The fuse may be employed in conjunction with a switch. The switch may be a disconnect switch that places the bus-bar in parallel with the fuse during normal operation, and decouples the bus-bar from the fuse during maintenance. The switch may also be a transfer switch that places either the bus-bar or the fuse in series with the AC output of the photovoltaic inverter and the low voltage winding of the step up transformer.

Abstract: Arc flash mitigation devices are employed to protect personnel during maintenance of photovoltaic inverters. During normal operation, an alternating current (AC) output of a photovoltaic inverter is coupled to a low voltage winding of a step up transformer through a bus-bar (e.g., an electrically conductive interconnect), which has higher current rating than a fuse. During maintenance, the bus-bar is replaced with the fuse. The fuse may be employed in conjunction with a switch. The switch may be a disconnect switch that places the bus-bar in parallel with the fuse during normal operation, and decouples the bus-bar from the fuse during maintenance. The switch may also be a transfer switch that places either the bus-bar or the fuse in series with the AC output of the photovoltaic inverter and the low voltage winding of the step up transformer.

Abstract: Arc flash mitigation devices are employed to protect personnel during maintenance of photovoltaic inverters. During normal operation, an alternating current (AC) output of a photovoltaic inverter is coupled to a low voltage winding of a step up transformer through a bus-bar (e.g., an electrically conductive interconnect), which has higher current rating than a fuse. During maintenance, the bus-bar is replaced with the fuse. The fuse may be employed in conjunction with a switch. The switch may be a disconnect switch that places the bus-bar in parallel with the fuse during normal operation, and decouples the bus-bar from the fuse during maintenance. The switch may also be a transfer switch that places either the bus-bar or the fuse in series with the AC output of the photovoltaic inverter and the low voltage winding of the step up transformer.

Abstract: A photovoltaic power plant includes solar cells and inverters that convert direct current generated by the solar cells to alternating current. The reactive powers generated by the inverters are based on a reactive power generated by a virtual inverter. The virtual inverter has an equivalent impedance representing the impedances of the inverters in the photovoltaic power plant. The reactive power setpoints of the inverters may be received from a local interpreter. The local interpreter may generate the reactive power setpoints from a global reactive power setpoint generated by a grid controller.

Abstract: This invention provides a wind turbine-battery-dump load stand-alone renewable energy system and an optimal control of the same. The system may include both power conversion and control units. In one embodiment, the power conversion unit features a wind-turbine-driven three-phase induction generator, a diode rectifier, a battery charger, a boost dc/dc converter, a battery bank (48V), and a dc/ac inverter. A dump load is also used to dissipate excess power that is not required for either the battery charging or for the load. The integrated control unit may use the TMS320LF2407A DSP microcontroller from Texas Instruments, which allows operations of the wind power system and the battery storage system to be merged into a single package under a master controller. An embodiment of the control system features battery-charging control, battery voltage-boost control, dump load control, PWM inverter control, and system protection.