Ametek Ships 1 MVA AC+DC Grid Simulation System to NREL

Ametek Programmable Power recently shipped a regenerative 1 MVA AC + DC source system to the ESIF (Energy Systems Integration Facility) at the U.S. Department of Energy's NREL (National Renewable Energy Laboratory) in Golden, Colorado. The system, which is for grid simulation in the test and evaluation of advanced energy systems such as micro-grids and renewable energy inverters, is based on AMETEK's California Instruments RS Series High-Power AC source. Dubbed the RS1M, the twelve chassis configuration consists of four RS270 systems, each comprising three 90 kVA chassis. Each RS270 system is capable of generating 270 kVA of 3 ø power at up to 692 VAC (L-L). Four control chassis allow ESIF engineers to remotely configure the entire installation as a single 1 MVA, two 540 kVA, four separate 270 kVA, or one 810 kVA and one 270 kVA system. This capability will give ESIF the flexibility it needs to size the simulated power grid appropriately for the DUTs (devices under test), as well as understand how different renewable energy technologies interact with each other in a distributed generation micro-grid. A key feature of the simulation system is the ability to present the DUT with anomalous grid conditions. The RS Series source has a built-in capability to generate these grid anomalies, but, to support the ESIF's HIL (hardware in the loop) simulation requirements, Ametek customized the RS1M to allow ESIF engineers to control it in real time via external drive signals. These modifications bypass the system controller to permit the external signals to control directly the high-power source, eliminating any control signal delays. HIL simulation is not a new concept, but adding megawatt-scale power takes research to another level. ESIF's Smart Power Lab will use the HIL simulators for research and development of power electronics components, circuits, and controls for clean and sustainable energy integration. This allows researchers and manufacturers to conduct component and system tests at full power and real-world load levels in real time. RS Series' key features include:

• Power regeneration
• Simplified test configuration
• Sophisticated signal generation and measurement

The RS Series can re-capture and return to the facility's utility grid up to 85% of the inverter's output, or, in other words, up to 85% of the energy input to the inverter, which the facility grid sources during testing. This reduces costs in two ways:

• Energy costs directly related to driving the DUT
• Heat load on the facility HVAC system and therefore resultant secondary energy use and cost

This approach eliminates the need for traditional AC source and load combinations with complex controllers. The RS Series uses a DSP-based arbitrary-waveform generator and power analyzer for generating, measuring, and documenting anomalous grid conditions. This integrated, multi-instrument approach effectively eliminates the need for additional equipment to create a complete AC-power test system The ESIF will be the nation's first facility able to conduct integrated megawatt-scale research and development of the components and strategies needed to safely move clean energy technologies onto the electrical grid. Ametek Programmable Power