Abstract: A refrigerant system includes a first, substantially outdoor, two phase heat transfer fluid vapor compression circulation loop including a compressor, a heat exchanger condenser, an expansion device, and the heat absorption side of a heat exchanger evaporator condenser, connected by conduit in a closed loop and having disposed therein a first heat transfer fluid having a critical temperature of greater than or equal to 31.2° C. The system also includes a second, at least partially indoor, two phase heat transfer fluid circulation loop that transfers heat to the first loop through the heat exchanger evaporator condenser. The second loop includes the heat rejection side of the heat exchanger evaporator condenser, a liquid pump, and a heat exchanger evaporator, connected by conduit in a closed loop and having disposed therein a second heat transfer fluid that has an ASHRAE Class A toxicity rating and an ASHRAE Class 1 or 2L flammability rating.

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: A refrigerant system includes a first, substantially outdoor, two phase heat transfer fluid vapor compression circulation loop including a compressor, a heat exchanger condenser, an expansion device, and the heat absorption side of a heat exchanger evaporator condenser, connected by conduit in a closed loop and having disposed therein a first heat transfer fluid having a critical temperature of greater than or equal to 31.2° C. The system also includes a second, at least partially indoor, two phase heat transfer fluid circulation loop that transfers heat to the first loop through the heat exchanger evaporator condenser. The second loop includes the heat rejection side of the heat exchanger evaporator condenser, a liquid pump, and a heat exchanger evaporator, connected by conduit in a closed loop and having disposed therein a second heat transfer fluid that has an ASHRAE Class A toxicity rating and an ASHRAE Class 1 or 2L flammability rating.

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 radio frequency (RF) power generator includes a first switch-mode amplifier that generates a first RF signal in accordance with a first control signal and a second switch-mode amplifier that generates a second RF signal in accordance with a second control signal. The first and second control signals determine a phase difference between the first and second RF signals. An output signal envelope is based on the first and second RF signals and the phase difference. The first control and second control signals alternate phases of the first and second RF signals.

Abstract: A radio frequency (RF) power generator includes a first switch-mode amplifier that generates a first RF signal in accordance with a first control signal and a second switch-mode amplifier that generates a second RF signal in accordance with a second control signal. The first and second control signals determine a phase difference between the first and second RF signals. An output signal envelope is based on the first and second RF signals and the phase difference. The first control and second control signals alternate phases of the first and second RF signals.