Equipment

InteGrid Equipment

Dynamic Wind Turbine Simulation

The Wind Turbine Simulator acts as wind resources on the network through physical and dynamic simulation. Currently, up to 8 individual induction generator based wind turbines, up to a combined total of 100kW of scaled wind power, can be simulated. Each turbine can be assigned its own performance profile allowing turbines of different types and manufacturers to be incorporated into the system being tested. The Wind Turbine Simulator is designed such that the system’s supervisory controller sees eight turbines with different production characteristics and individual controls to bring a turbine online or take it offline.

Transmission Connection and Substation Emulation

The InteGrid Lab is tied to a distribution system interconnection (750kVA tied to 13.2 kV utility feed). The lab switchgear comprises electrical disconnects and circuit breakers similar to those found in an electrical substation. The switchgear allows the InteGrid Lab to interconnect with the local utility, Fort Collins Utilities, and to grid parallel and import or export power to the grid as specific testing scenarios require. This flexible interconnect allows the InteGrid Lab to test strategies which include import/export control, intentional islanding, and resynchronization for hybrid power systems.

Conventional Natural Gas Reciprocating Generator Sets

The InteGrid Lab has two 100KW natural gas Onan generator sets. These generators can be used for scaled testing of distributed generation and will act as dispatchable generation resources capable of operating in multiple modes such as baseload, droop, isoch master, and isoch loadshare. Within the next few months, it is expected that a 1.6MW natural gas Caterpillar engine will also be added to the generation mix. These engines will be the primary power sources for large scale tests run at the InteGrid Lab.

Utility Style SCADA Control Room and Communications

To manage the various resources available in the InteGrid Lab, an easy to use SCADA HMI has been developed to interact with the equipment, integrate the various levels of controls, and collect data of interest. This front end communicates with the individual control programs of the lab resources and provides a remote interface for all system resources. This interface includes development and testing screens as well as system operator based screens used to manage the advanced capabilities of the InteGrid Lab. The monitoring, control, and data collection systems collectively constitute the InteGrid Lab Control Center.

Communications are primarily accomplished using TCP/IP links using field protocol is necessary to interface with individual assets. Since the lab is set up to emulate resources distributed across a distribution network, the individual equipment can only communicate with each other through the high level communications media without recourse to the more common hardwired links for load sharing or mode changing.

Utility Load Simulator

The load bank used by the InteGrid Lab is manufactured by LoadTec and is capable of providing 400KW of reactive load and 300KVAR of inductive load. The load on the system being tested can be managed through a manual control program or by the via the Utility Load Simulator (ULS) program. The ULS is a computer program that acts as the interface between the high level system controllers and the load bank. It uses profiles generated from field data to replicate load trends on 1-8 feeder lines allowing control systems and equipment to be tested in a wide range of load conditions. The ULS is controlled remotely from the InteGrid Control Room.

Microturbines

There are two microturbines employed in the InteGrid Lab, one manufactured by Bowman and the other by Ingersoll Rand. They are both approximately 80kW and are setup in a combined heat and power configuration in order to provide heat resources to the Engines and Energy Conversion Lab. These units represent inverter based generation and have much different operational characteristics than conventional generation, and compliment the wide variety of distributed generation in the lab.

Secondary Load Controller

The Secondary Load Controller (SLC) provides fast, high-resolution resistive load up to 170KW. On a small system, such as a cell in island mode, the SLC acts as a shock absorber. It can quickly react to spikes in power generation to keep the system within desired operating conditions and greatly enhances the frequency stability of the system. The SLC is capable of acting as frequency master enabling the slower gensets to “catch up” to transient events without causing undesirable frequency excursions.

Synchronous Condenser

This 125KVAR Kato synchronous condenser allows a high level of control over the reactive power on the network. It can generate or absorb reactive power to support the system’s voltage level or to maintain a specified power factor. The synchronous condenser is started using an induction motor using custom controls developed at the lab. The system is designed to bring the synchronous generator up to speed, parallel and synchronize with the grid and then close the breaker to the main bus. Excitation control enables the system to provide reactive power support, perform power factor correction, etc.