Microgrid power system
Embodiments are directed to a microgrid power system, and applications thereof. In an embodiment, the microgrid power system comprises a power station including an AC power source and a stabilizing battery system. The power station may be configured to generate an AC power and to provide the first AC power to a power distribution network. A plurality of load centers may be connected to the power distribution system. Each load center may include a local battery and a switch connecting the power station to a local load. A system controller may open the switch to provide power from the local battery to the local load, and close the switch to provide power from the power station to the local load. In an embodiment, a microgrid controller may determine an amount of AC power generated by the power station that may be consumed by each load center.
1. A method comprising:
monitoring a state of charge of a battery system of a power station of a microgrid power system;
monitoring a state of charge of an energy storage unit coupled to a different point of the microgrid power system than the power station, wherein the energy storage unit comprises a plurality of battery packs having cells and a battery pack controller that controls a state of charge of the cells; and
controlling charging of the energy storage unit from an AC power source of the power station based on the state of charge of the battery system and the state of charge of the cells of the energy storage unit.
2. The method of claim 1 , wherein controlling charging of the energy storage unit comprises determining an amount of AC power allowed to be consumed to charge the energy storage unit based on the state of charge of the battery system and the state of charge of the cells of the energy storage unit.
3. The method of claim 1 , further comprising monitoring a usage of the battery packs and determining a warranty value for the battery packs based on the usage.
4. The method of claim 1 , further comprising circulating cooling air around the battery packs to regulate a temperature of the battery packs.
5. The method of claim 1 , wherein controlling charging of the energy storage unit is performed by a microgrid controller communicatively coupled to the energy storage unit and the power station.
6. The method of claim 1 , wherein the energy storage unit is one of a plurality of energy storage units, each comprising a respective plurality of battery packs having cells and a respective battery pack controller that controls a state of charge of the cells, and wherein the method comprises controlling charging of each of the plurality of energy storage units from the AC power source based on the state of charge of the battery system and the state of charge of the cells of each energy storage unit.
7. The method of claim 6 , wherein controlling charging of each of the plurality of energy storage units comprises determining, for each energy storage unit, an amount of AC power allowed to be consumed to charge the energy storage unit based on the state of charge of the battery system and the state of charge of the cells of the energy storage unit.
8. The method of claim 1 , wherein controlling the charging of the energy storage unit comprises one or both of charging the plurality of battery packs or discharging the plurality of battery packs with a bi-directional power converter.
9. The method of claim 8 , wherein controlling the charging of the energy storage unit comprises issuing a command to the bi-directional power converter from an energy management system via a communication network.
10. The method of claim 1 , further comprising, for at least one battery pack of the plurality of battery packs, determining a warranty value of the battery pack with a warranty tracker based on the usage of the battery pack.
11. The method of claim 10 , wherein determining the warranty value of the battery pack comprises:
(i) determining a C-rate value indicating a charge or discharge rate of the battery pack; and
(ii) comparing the C-rate value to a maximum C-rate warranty threshold.
12. The method of claim 10 , wherein determining the warranty value of the battery pack comprises:
(i) measuring a temperature of the battery pack; and
(ii) comparing the temperature of the battery pack to one or both of a minimum temperature warranty threshold or a maximum temperature warranty threshold.
13. The method of claim 10 , wherein determining the warranty value of the battery pack comprises:
(i) measuring a voltage of one or more of the cells of the battery pack; and
(ii) comparing the voltage of the one or more cells to one or both of a minimum voltage warranty threshold or a maximum voltage warranty threshold.
14. A method comprising:
monitoring, with a microgrid controller of a microgrid power system, a state of charge of a battery system of a power station of the microgrid power system;
monitoring, with the microgrid controller, a state of charge of one or more cells of an energy storage unit that is coupled to a different point of the microgrid power system than the power station;
monitoring, with the microgrid controller, an amount of a first AC power that is outputted by an AC power source of the power station;
determining, with the microgrid controller, an amount of the first AC power that may be consumed to charge the energy storage unit, wherein determining the amount of the first AC power is based on the state of charge of the battery system and the state of charge of the cells of the energy storage unit; and
controlling, with the microgrid controller, charging of the energy storage unit based on the determined amount of the first AC power.
15. The method of claim 14 , further comprising:
controlling, with a battery pack controller of the energy storage unit, a state of charge of the cells, wherein controlling the state of charge of the cells comprises one or both of:
(i) operating a battery cell back balancer of the energy storage unit to adjust an amount of energy stored in the cells; or
(ii) operating a battery pack charger of the energy storage unit to charge the cells.
16. The method of claim 14 , further comprising:
converting, with a bi-directional power converter, the first AC power to DC power to charge the energy storage unit.
17. The method of claim 14 , further comprising:
supplying electrical power from the energy storage unit to a load center.
18. The method of claim 17 , wherein supplying electrical power from the energy storage unit to the load center comprises controlling, with the microgrid controller, discharging of the energy storage unit.
19. The method of claim 18 , wherein controlling discharging of the energy storage unit comprises converting, with a bi-directional power converter, DC power from the energy storage unit to a second AC power that is provided to the load center.
20. The method of claim 18 , wherein the load center is one of a plurality of load centers comprising one or more non-critical load centers, and wherein controlling discharging of the energy storage unit comprises disconnecting the one or more non-critical load centers from the energy storage unit.