Fuel Cell Inverters

The Inverters include the ability to run islanded mode (voltage source) operation, also called UF mode. In islanded mode, the CPS accepts Voltage (U) and Frequency (F) setpoints. The CPS can handle full real power transitions with extremely tight voltage and frequency regulation forming a ‘stiff backbone’ to the microgrid

Dynapower’s proprietary Dynamic Transfer™ algorithm monitors grid stability and, upon detecting a grid disturbance, disconnects from the grid and transitions to stand-alone battery backup power mode on the load connection. The transition is seamless to the critical loads and supports 100% phase imbalance in UF mode.

In the event of a complete system power outage, our patented black start restores power to the facility without the need for external power. Dynapower’s black start technology can start distribution networks even with transformer magnetizing currents that exceed the power rating of the inverters. Multiple units can be restarted at once.

F-Comp monitors the grid frequency for deviations from nominal, and if a deviation exceeds a max allowed, the Inverters will automatically follow a user-defined frequency correction curve. F-Comp is ideally suited to very rapid Fast Frequency Regulation applications as well as power quality correction of critical facility loads.

E-Comp monitors the grid voltage for deviations from nominal and automatically attempts to correct three-phase voltage magnitude deviations (usually voltage sags) experienced by a critical load in an effort to avoid the need to transfer to backup power mode.

The Inverters have AC current limiting, so that the system will deliver up to (but not exceed) full rated AC current to avoid nuisance AC overcurrent faults due to excessive load inrush current demand. When current limiting in UF, the AC voltage and frequency may deviate from nominal and this is permissible within the Inverters’ abnormal voltage frequency limits and timers. It is expected that, if the system is properly sized to the microgrid, any voltage or frequency deviations due to large inrush loads will be very minor and short duration, and not affect the load.

In the event the grid experiences a voltage sag, the Inverters will enter into low voltage ride-through operations to maintain proper AC voltage connection. The Inverters will enter either Momentary Operation, where the converter supplies at least 80% active current command, or Momentary Cessation, where the converter ceases to export active current but does not fault. The trip levels and trip times for the LVRT settings are configurable by the end user and meet the requirements for IEEE 1547.