Island grid power supply apparatus and methods using energy storage for transient stabilization

A system comprising:

• an island grid;
• at least one engine/generator set coupled to the island grid;
• and
• a transient frequency stabilization system comprising at least one energy storage unit and configured to detect a frequency deviation of the island grid and to responsively perform a momentary transfer of energy between the at least one energy storage unit and the island grid, wherein the transient frequency stabilization system comprises:
• at least one converter coupled to the at least one energy storage unit and configured to be coupled to the island grid;
• and
• a control circuit configured to detect a frequency variation of the island grid and to responsively cause the at least one converter to transfer power between the at least one energy storage unit and the island grid, wherein the control circuit comprises a frequency control loop configured to reduce a frequency error of the island grid and a power control loop configured to reduce a power transfer between the energy storage unit and the island grid and wherein the control circuit is configured to control a power transfer from the energy storage unit to the island grid based on a combination of outputs of the frequency control loop and the power control loop.

A system comprising:

• at least one generator coupled to an island grid;
• at least one energy storage unit;
• at least one converter coupled to the at least one energy storage unit and configured to be coupled to the island grid;
• and
• a control circuit configured to cause the at least one converter to transfer power between the at least one energy storage unit and the grid responsive to a change in a load on the island grid to maintain operation of the at least one generator at a predetermined operating point, wherein the at least one generator comprises a control system configured to match generator output to the load and wherein the control circuit is configured to maintain the control system of the at least one generator within a predetermined dynamic response capability limit responsive to the change in the load.