摘要:
A power generation system configured to provide direct current (DC) power to a DC link is described. The system includes a first power generation unit configured to output DC power. The system also includes a first DC to DC converter comprising an input section and an output section. The output section of the first DC to DC converter is coupled in series with the first power generation unit. The first DC to DC converter is configured to process a first portion of the DC power output by the first power generation unit and to provide an unprocessed second portion of the DC power output of the first power generation unit to the output section.
摘要:
A power generation system configured to provide direct current (DC) power to a DC link is described. The system includes a first power generation unit configured to output DC power. The system also includes a first DC to DC converter comprising an input section and an output section. The output section of the first DC to DC converter is coupled in series with the first power generation unit. The first DC to DC converter is configured to process a first portion of the DC power output by the first power generation unit and to provide an unprocessed second portion of the DC power output of the first power generation unit to the output section.
摘要:
A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.
摘要:
A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.
摘要:
A partial power converter includes a converter leg including an upper portion comprising at least one diode connected to a positive output node of an output terminal of the partial power converter and a lower portion comprising at least two switches connected in series with each other and with the at least one diode and to a negative output node of the output terminal of the partial power The partial power converter also includes at least one flying capacitor connected between the at least two switches at a first end and to either of the upper portion of the converter leg or the positive output node of the partial power converter at a second end.
摘要:
A system and method are provided for enabling a PV inverter to be connected to a string of series connected PV modules without exposing the inverter to elevated voltage stresses. The input voltage to the inverter is gradually built up by sequentially switching in more series PV modules. This system and method are simple to implement in both centralized and distributed PV power plants and in either case, it significantly increases the utilization of the PV inverter. The input switching elements can be implemented using a wide variety of parts including electro-mechanical switches, semiconductor switches (IGBTs, MOSFETs . . . , etc.) as well as MEMS devices depending on the current level and target cost. A mix of switches can also be used to assist in minimizing impedance of the final switching stage that remains connected during normal operation.
摘要:
A system and method of using one or more DC-DC/DC-AC converters and/or alternative devices allows strings of multiple module technologies to coexist within the same PV power plant. A computing (optimization) framework estimates the percentage allocation of PV power plant capacity to selected PV module technologies. The framework and its supporting components considers irradiation, temperature, spectral profiles, cost and other practical constraints to achieve the lowest levelized cost of electricity, maximum output and minimum system cost. The system and method can function using any device enabling distributed maximum power point tracking at the module, string or combiner level.
摘要:
A system and method of using one or more DC-DC/DC-AC converters and/or alternative devices allows strings of multiple module technologies to coexist within the same PV power plant. A computing (optimization) framework estimates the percentage allocation of PV power plant capacity to selected PV module technologies. The framework and its supporting components considers irradiation, temperature, spectral profiles, cost and other practical constraints to achieve the lowest levelized cost of electricity, maximum output and minimum system cost. The system and method can function using any device enabling distributed maximum power point tracking at the module, string or combiner level.
摘要:
A refrigeration system is provided. The refrigeration system includes at least one thermal blocking thermotunneling device. The thermal blocking thermotunneling device comprises a first and a second surface separated by a nanoscale gap of less than about 20 nm, such that tunneling of electrons causes a unidirectional transfer of heat from the first surface to the second surface. Further, the at least one thermal blocking thermotunneling device has a thermal back path of less than about 70 percent.
摘要:
A method of manufacturing a heat transfer device including providing first and second thermally conductive substrates that are substantially atomically flat, providing a patterned electrical barrier on the first or second thermally conductive substrates and disposing a low work function material on the first or second thermally conductive substrates in an area oriented between the patterned electrical barrier in a configuration in which the first and second thermally conductive substrates are positioned opposite from one another. The method also includes bonding the first and second thermally conductive substrates in the configuration and extracting a plurality of units having opposite sections of the first and second thermally conductive substrates, each unit having a portion of the patterned electrical barrier disposed about the low work function material.