Apparatus comprising a photovoltaic system
The present disclosure relates to an apparatus configured to supply electrical power to a transport refrigeration unit, the apparatus comprising a power converter and a photovoltaic system including a photovoltaic cell. The power converter includes a rectifier, an inverter and a DC bus internal to the power converter. The DC bus is electrically connected to an output of the rectifier and an input of the inverter, an input of the rectifier is electrically couplable to a power source external to the apparatus at a connection port, and an output of the inverter is electrically couplable to the transport refrigeration unit.
1 . An apparatus configured to supply electrical power to a transport refrigeration unit, the apparatus comprising:
a power converter including:
a rectifier;
an inverter; and
a DC bus, wherein the DC bus is internal to the power converter and is electrically connected to an output of the rectifier and an input of the inverter,
wherein an input of the rectifier is electrically connectable to a power source external to the apparatus at a connection port of the apparatus and an output of the inverter is electrically couplable to the transport refrigeration unit;
a power distribution unit electrically coupled to the DC bus of the power converter; and
a photovoltaic system including a photovoltaic cell and provided with a voltage regulator arrangement configured to regulate an output voltage of the photovoltaic system at a target voltage magnitude, wherein an output of the photovoltaic system is electrically coupled to the power distribution unit,
wherein the power distribution unit is configured to act as an interface between the DC bus and the photovoltaic system such that power can be supplied to the transport refrigeration unit from the photovoltaic system to meet a power demand of the transport refrigeration unit in use of the transport refrigeration unit, and
wherein the apparatus further comprises a DC-DC converter connected between the DC bus of the power converter and the power distribution unit, wherein the DC-DC converter is configured to:
convert a voltage supplied to the DC-DC converter by the power distribution unit from a second voltage magnitude to a first voltage magnitude for supply to the DC bus, the first voltage magnitude corresponding to an operating voltage of the DC bus and the second voltage magnitude corresponding to an operating voltage of the power distribution unit; and
convert a voltage supplied to the DC-DC converter by the DC bus from the first voltage magnitude to the second voltage magnitude for supply to the power distribution unit.
2 . The apparatus according to claim 1 , further comprising a battery electrically connected to the power distribution unit, and wherein the target voltage magnitude is selected to correspond to a voltage of the battery.
3 . The apparatus according to claim 1 , wherein the output of the inverter is electrically couplable to the transport refrigeration unit via an output sine-wave filter, and/or wherein the input of the rectifier is electrically couplable to the external power source via an input filter.
4 . The apparatus according to claim 1 , wherein
the photovoltaic system comprises a plurality of photovoltaic strings arranged in parallel, each photovoltaic string comprising at least one photovoltaic cell; and
each photovoltaic string further comprises an isolation contactor configured to isolate the respective photovoltaic string.
5 . The apparatus according to claim 1 , wherein
the photovoltaic system comprises a plurality of photovoltaic strings arranged in series, each photovoltaic string comprising at least one photovoltaic cell; and
each photovoltaic string further comprises an isolation contactor configured to isolate and bypass the respective photovoltaic string.
6 . The apparatus according to claim 4 , wherein each of the plurality of photovoltaic strings comprises a plurality of photovoltaic cells connected in series.
7 . The apparatus according to claim 1 , further comprising an electrical generator, and wherein the input of the rectifier is also electrically coupled to the electrical generator, and optionally wherein the electrical generator comprises an internal combustion engine, a gas turbine engine and/or a kinetic energy recovery system.