Patent ID: 9614400
Date: 2017-04-04
CPC Classifications: H02J,H02M

Claim:
1. A method of operating a dc energy store system comprising a dc energy store, an AC/DC power converter having ac terminals connected to an ac power supply and dc terminals connected to the dc energy store, and at least one auxiliary unit associated with the dc energy store, the method comprising the steps of: (i) in a first mode supplying power from the ac power supply to the dc energy store wherein the power is stored therein; (ii) in a second mode supplying power from the dc energy store to the ac power supply, wherein the DC energy store supplies bi-directional power flow between the AC power supply and the DC energy store depending on whether energy is being stored in the DC energy store or returned to the ac power supply; (iii) in a third mode supplying power from the ac power supply to the at least one auxiliary unit associated with the dc energy store; and (iv) in the event of a fault in the ac power supply receiving power from an external power source, supplying the power stored from the dc energy store to the at least one auxiliary unit associated with the dc energy store and from the dc energy store back to the ac power supply, until the power stored in the dc energy store is exhausted.