Systems and methods of powering a refrigeration unit of a hybrid vehicle

1. A power system for powering a refrigeration unit, 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 (AC) power source;

a second connection configured to receive power from a second power source, the second power source being a high-voltage direct current (DC) power source;

a third connection configured to receive power from a third power source, the third power source being a second high-voltage AC power source;

a power converter configured to supply power to the refrigeration unit, wherein the power converter includes an accumulation choke and a PWM rectifier configured to receive the first high-voltage AC power, the second high-voltage AC power, and the high-voltage DC power and convert the received power to a second DC power; and

a switch connecting one of the first connection, the second connection and the third connection to the power converter;

wherein the power system couples the first power source to the power converter based on a position of the switch when power is received at the first connection, couples the second power source to the power converter based on a position of the switch when power is received at the second connection but not the first connection, and couples the third power source to the power converter based on a position of the switch, and

wherein the PWM rectifier includes:

a plurality of diodes configured as a bridge rectifier,

a plurality of electronic switches, one of the plurality of electronic switches coupled across each of the plurality of diodes, and

a pre-charging circuit maintaining power to the power converter when switching between the first power source, the second power source, and the third power source.

2. The system of claim 1 , wherein the second DC power is between about 0 and 750 volts.

3. The system of claim 1 , wherein the first high-voltage AC power source includes a shore power.

4. The system of claim 1 , wherein the high-voltage DC power source includes a plurality of high-voltage batteries used to power a hybrid vehicle.

5. The system of claim 1 , wherein the second high-voltage AC power source includes a belt-driven alternator.

6. The system of claim 1 , wherein the first high-voltage AC power source includes a shore power, the high-voltage DC power source includes a plurality of high-voltage batteries used to power a hybrid vehicle, and the second high-voltage AC power source includes a belt-driven alternator.

7. A system for powering a refrigeration unit coupled with a vehicle having a plurality of high-voltage batteries, the system comprising:

a power system coupled to the plurality of high-voltage batteries, the power system configured to receive power from a shore power source, and the power system configured to receive power from an alternator, wherein the power system includes a power converter having an accumulation choke and a PWM rectifier, the power converter configured to receive one of a high-voltage DC power from the plurality of high-voltage batteries, a high-voltage AC power from the shore power source, and a high-voltage AC power from the alternator and to convert the received power into a second high-voltage DC power, the power system also including a switch connecting one of the shore power source, the alternator and the plurality of high-voltage batteries to the power converter based on a position of the switch;

a refrigeration control unit coupled to the power system, the refrigeration control unit receiving an indication from the power system of the availability of power from the high-voltage batteries, the shore power source, and the alternator; and

wherein the refrigeration control unit links power from the power system to the refrigeration unit when power is available from the power system,

wherein the PWM rectifier includes:

a plurality of diodes configured as a bridge rectifier,

a plurality of electronic switches, one of the plurality of electronic switches coupled across each of the plurality of diodes, and

a pre-charging circuit maintaining power to the power converter when switching between the shore power source, the alternator, and the plurality of high-voltage batteries.

8. The system of claim 7 , wherein the power system includes a frequency inverter configured to receive the second high-voltage DC power from the PWM rectifier and convert the second high-voltage DC power to an AC voltage and to provide the AC voltage to the refrigeration unit.

9. A method of powering a refrigeration unit, the method comprising:

receiving at a first input a high-voltage DC power from a plurality of batteries of a hybrid vehicle;

receiving at a second input a high-voltage AC power from an electric mains;

receiving at a third input a third high-voltage AC power from an alternator;

connecting one of the first input, the second input and the third input to a power converter based on a position of a switch, the connecting act coupling one of the high-voltage DC power, the high-voltage AC power, and the third high-voltage AC power to the power converter thereby resulting in a coupled power;

disconnecting the coupled power from the power converter when the position of the switch has changed;

converting the high-voltage DC power into a second high-voltage AC power by directing the high-voltage DC power through an accumulator choke and a PWM rectifier when the high-voltage DC power is coupled to the power converter and converting the high-voltage AC power into the second high-voltage AC power by directing the high-voltage AC power through the accumulator choke and the PWM rectifier when the high-voltage AC power is coupled to the power converter;

providing the second high-voltage AC power to the refrigeration unit; and

directing one of the high-voltage DC power and the high-voltage AC power through a pre-charging circuit at an output of the PWM rectifier, the pre-charging circuit maintaining power to the power converter when switching between the first input, the second input, and the third input.

10. The system of claim 7 , wherein the pre-charging circuit buffers a current surge when an input power is switched from a first power source to a second power source.

11. The system of claim 1 , wherein the PWM rectifier is configured to receive the second high-voltage AC power directly such that the second high-voltage AC power bypasses the accumulation choke.

12. The system of claim 7 , wherein the power system is coupled to an alternator, and the PWM rectifier is configured to:

receive one of the high-voltage DC power from the plurality of high-voltage batteries, the high-voltage AC power from the shore power source, and a third high-voltage AC power from the alternator, and

to convert the received power into the second high-voltage DC power.

13. The system of claim 12 , wherein the PWM rectifier is configured to receive the third high-voltage AC power directly such that the third high-voltage AC power bypasses the accumulation choke.

14. The method of claim 9 , further comprising:

receiving at a third input a third high-voltage AC power from an alternator;

connecting one of the first input, the second input and the third input to a power converter based on the position of the switch, the connecting act coupling one of the high-voltage DC power, the high-voltage AC power, and the third high-voltage AC power to the power converter thereby resulting in a coupled power;

converting the third high-voltage AC power into the second high-voltage AC power by directing the third high-voltage AC power through the PWM rectifier when the third high-voltage AC power is coupled to the power converter.

15. The system of claim 1 , wherein the switch is an automatic switch, wherein a controller automatically selects a position of the automatic switch to connect one of the first connection, the second connection and the third connection to the power converter.

16. The system of claim 7 , wherein the switch is an automatic switch, wherein a controller automatically selects a position of the automatic switch to connect one of the shore power source, the alternator and the high-voltage batteries to the power converter.

17. The method of claim 9 , wherein the switch is an automatic switch, wherein a controller automatically selects a position of the automatic switch to connect one of the first input, the second input and the third input to the power converter.

18. The system of claim 1 , wherein the switch is a manual switch, wherein a user selects a position of the manual switch to connect one of the first connection, the second connection and the third connection to the power converter.

19. The system of claim 7 , wherein the switch is a manual switch, wherein a user selects a position of the manual switch to connect one of the shore power source, the alternator and the high-voltage batteries to the power converter.

20. The method of claim 9 , wherein the switch is a manual switch, wherein a user selects a position of the manual switch to connect one of the first input, the second input and the third input to the power converter.