Power control systems and methods
A power supply configured to be operatively connected to at least one load, comprising an AC bus operatively connected to the load, a first AC power source operatively connected to the AC bus, a DC bus, a DC/AC converter operatively connected between the DC bus and the AC bus, a first DC power source, and a load balancer operatively connected between the first DC power source and the DC bus. The power supply operates in a first mode in which power is supplied to the load from the first AC power source through the AC bus and in a second mode in which power is supplied to the load from the first DC power source through the DC bus, the DC/AC converter, and the AC bus.
1. A power supply configured to be operatively connected to at least one load, comprising:
an AC bus operatively connected to the load;
a first AC power source operatively connected to the AC bus;
a DC bus;
a DC/AC converter operatively connected between the DC bus and the AC bus;
a first DC power source; and
a load balancer operatively connected between the first DC power source and the DC bus; wherein
the power supply operates in
a first mode in which power is supplied to the load from the first AC power source through the AC bus; and
a second mode in which power is supplied to the load from the first DC power source through the DC bus, the DC/AC converter, and the AC bus.
2. A power supply as recited in claim 1 , in which the load balancer substantially equalizes the charge on first and second split rail capacitors.
3. A power supply as recited in claim 1 , in which the load balancer comprises a resonant capacitor and a resonant inductor connected in series.
4. A power supply as recited in claim 2 , in which load balancer comprises a balance circuit that is alternately connected between the first and second split rail capacitors.
5. A power supply as recited in claim 4 , in which the balance circuit is included in a DC/DC converter, in which the balance circuit is alternately connected between the first and second split rail capacitors at a frequency and duty cycle that substantially matches a frequency and duty cycle of the DC/DC converter.
6. A power supply as recited in claim 4 , in which the balance circuit is alternately connected between the first and second split rail capacitors such that the load balancer operates with nearly zero voltage switching.
7. A power supply as recited in claim 4 , in which the balance circuit is passive.
8. A power supply as recited in claim 4 , in which the balance circuit comprises an inductor-capacitor resonant charge pump circuit.
9. A power supply as recited in claim 1 , in which the first DC power source is renewable.
10. A power supply as recited in claim 1 , in which the first DC power source is a photovoltaic system.
11. A power supply as recited in claim 1 , further comprising a second DC power source operatively connected to the DC bus.
12. A power supply as recited in claim 1 , in which the second DC power source is a battery.
13. A power supply as recited in claim 1 , further comprising a second AC power source operatively connected to the AC bus.
14. A power supply as recited in claim 13 , in which the second AC power source is an AC generator.
15. A power control system to operatively connect at least first and second AC power sources and at least first and second DC power sources to at least one load, comprising:
an AC bus operatively connected to the load;
a DC bus;
a DC/AC converter operatively connected between the DC bus and the AC bus;
a first DC/DC converter operatively connected between the first DC source and the DC bus;
a second DC/DC converter operatively connected between the second DC power source and the DC bus;
a load balancer operatively connected to at least one of the first and second DC/DC converters;
a first control switch operatively connected between the DC/AC converter and the AC bus;
a second control switch operatively connected between the first AC power source and the AC bus; and
a third control switch operatively connected between the second AC power source and the AC bus.
16. A power control system as recited in claim 15 , in which the load balancer substantially equalizes the charge on first and second split rail capacitors.
17. A power control system as recited in claim 16 , in which the load balancer substantially equalizes the charge on first and second split rail capacitors.
18. A power control system as recited in claim 16 , in which the load balancer comprises a resonant capacitor and a resonant inductor connected in series.
19. A power control system as recited in claim 17 , in which load balancer comprises a balance circuit that is alternately connected between the first and second split rail capacitors.
20. A method of supplying power to at least one load, comprising:
operatively connecting an AC bus to the load;
operatively connecting a first AC power source to the AC bus;
providing a DC/AC converter to convert voltages between the DC bus and the AC bus;
operatively connecting a load balancer between a first DC power source and the DC bus; and
operating the power supply in
a first mode in which power is supplied to the load from the first AC power source through the AC bus; and
a second mode in which power is supplied to the load from the first DC power source through the DC bus, the DC/AC converter, and the AC bus.