Battery energy storage design with black starting capability
Systems and methods for black-starting a power system using a battery energy storage system can be provided. In one example implementation, a method includes obtaining, by the one or more controllers, a signal requesting a black-start of the power system using the battery energy storage system. The method further includes increasing, by one or more controllers, a system bus voltage to a nominal voltage level using the battery energy storage system for a start period according to a start ramp. The method further includes maintaining, by one or more controllers, the system bus voltage at about the nominal voltage level using the battery energy storage system during a normal period following the start period.
1. A method for black-starting a power system using a battery energy storage system, the power system comprising one or more loads coupled to a system bus, the method comprising:
obtaining, by the one or more controllers, a signal requesting a black-start of the power system using the battery energy storage system;
increasing, by one or more controllers, a system bus voltage to a nominal voltage level using the battery energy storage system for a start period according to a start ramp; and
maintaining, by one or more controllers, the system bus voltage at about the nominal voltage level using the battery energy storage system during a normal period following the start period, wherein the start period has a sync period and a nominal period, the system bus voltage is increased using the battery energy storage system to a sync threshold level during the sync period and the battery energy storage system comprises a plurality of battery energy storage units, each battery energy storage unit comprising one or more battery energy storage devices and an inverter, wherein during the sync period, a plurality of battery energy storage units are individually connected to the system bus per each battery storage unit's own criteria of bus voltage and phase.
2. The method of claim 1 , wherein the sync threshold level is less than the nominal voltage level.
3. The method of claim 2 , wherein the sync threshold level is determined as a function of a maximum in-rush current for the power system.
4. The method of claim 2 , wherein the method comprises maintaining the system bus voltage at about the sync threshold level until a threshold number of battery energy storage units have been connected to the system bus.
5. The method of claim 4 , wherein the system bus voltage is increased using the battery energy storage system from the sync threshold level to the nominal voltage level during the nominal period.
6. The method of claim 1 , wherein the method further comprises decreasing the system bus voltage during a stop period following the normal period.
7. The method of claim 6 , wherein the method comprises disconnecting the plurality of battery energy storage units from the system bus during the stop period.
8. A control system for black-starting a power system using a battery energy storage system, the power system comprising one or more loads coupled to a system bus, the control system configured to perform operations, the operations comprising:
obtaining a signal requesting a black-start of the power system using the battery energy storage system, wherein the power system comprises one or more loads coupled to a system bus:
increasing a system bus voltage to a nominal voltage level using the battery energy storage system for a start period according to a start ramp; and
maintaining the system bus voltage at about the nominal voltage level using the battery energy storage system during a normal period following the start period, wherein the start period has a sync period and a nominal period, the system bus voltage is increased using the battery energy storage system to a sync threshold level during the sync period and the battery energy storage system comprises a plurality of battery energy storage units, each battery energy storage unit comprising one or more battery energy storage devices and an inverter, wherein during the sync period, a plurality of battery energy storage units are individually connected to the system bus per each battery storage unit's own criteria of bus voltage and phase.
9. The control system of claim 8 , wherein the sync threshold level is less than the nominal voltage level.
10. The control system of claim 9 , wherein the sync threshold level is determined as a function of a maximum in-rush current for the power system.
11. The control system of claim 9 , wherein the operations further comprise maintaining the system bus voltage at about the sync threshold level until a threshold number of battery energy storage units have been connected to the system bus.
12. The control system of claim 11 , wherein the system bus voltage is increased using the battery energy storage system from the sync threshold level to the nominal voltage level during the nominal period.
13. The control system of claim 8 , wherein the operations further comprise decreasing the system bus voltage during a stop period following the normal period.
14. The control system of claim 13 , wherein the operations further comprise disconnecting the plurality of battery energy storage units from the system bus during the stop period.