A power system for powering a refrigeration unit of a hybrid vehicle, the power system comprising: a first connection configured to receive power from a first power source, the first power source being a first high-voltage alternating current power source between 150 and 600 VAC; a second connection configured to receive power from a second power source, the second power source being a high-voltage direct current power source between 263 to 408 VDC; a third connection configured to receive power from a third power source, the third power source being a second high-voltage AC power source between 150 and 600 VAC; and a power converter configured to supply power to the refrigeration unit; wherein the power system couples the first power source to the power converter when power is received at the first connection, couples the second power source to the power converter when power is received at the second connection but not the first connection, and couples the third power source to the power converter when power is not available from both the first and second connections; a switch configured to allow only one of the first power source, the second power source, and the third power source to be coupled to the power converter at any one time, the power system being characterized in that the power converter includes an accumulation choke that includes a plurality of inductors, a PWM rectifier configured to convert the received power to a second DC power, and a frequency inverter that are connected in series, wherein the switch connects one of the first power source and the second power source to the accumulator choke and connects the third power source to the PWM rectifier. a first connection configured to receive power from a first power source, the first power source being a first high-voltage alternating current power source between 150 and 600 VAC; a second connection configured to receive power from a second power source, the second power source being a high-voltage direct current power source between 263 to 408 VDC; a third connection configured to receive power from a third power source, the third power source being a second high-voltage AC power source between 150 and 600 VAC; and a power converter configured to supply power to the refrigeration unit; wherein the power system couples the first power source to the power converter when power is received at the first connection, couples the second power source to the power converter when power is received at the second connection but not the first connection, and couples the third power source to the power converter when power is not available from both the first and second connections; a switch configured to allow only one of the first power source, the second power source, and the third power source to be coupled to the power converter at any one time, the power system being characterized in that the power converter includes an accumulation choke that includes a plurality of inductors, a PWM rectifier configured to convert the received power to a second DC power, and a frequency inverter that are connected in series, wherein the switch connects one of the first power source and the second power source to the accumulator choke and connects the third power source to the PWM rectifier.