Provide efficient fluid flow control in new and retrofit applications.
Adjustable speed drives (ASDs) are in common use throughout the nation. Low- and medium-voltage, pulse-width, modulated ASDs are widely available from multiple manufacturers and in all size ranges. The 1998 "Industrial Electric Motor Systems Market Opportunities Assessment," indicated that about 8.8% of all motor systems in the manufacturing sector employed ASD speed control. This number has increased significantly in the last 14 years.
Vector control (positioning control) for drives is also available and has been employed in conveyor and elevator applications. ASDs are now built into air compressor cabinets and variable speed trim compressors and are available from many manufacturers. ASDs have also been optimized for constant torque applications such as elevators.
From 18% to 25% of motor energy use in manufacturing could cost-effectively be equipped with ASDs. Barriers to additional drive installations include the need for additional education for plant staff, metering to understand process requirements and the short 1- to 3-year simple paybacks required by industrial plant managers. ASDs are being employed to more closely follow variable system or process flow requirements, such as changing ventilation rates and filter baghouse flows to correspond to various requirements during an electric arc furnace’s melting, charging, and tipping processes.
ASDs work as advertised and early problems with premature motor failures (due to voltage overshoot and bearing failures due to shaft current formation) have been solved using load reactors, dV/dt filters, shaft grounding brushes and insulated motor bearings and couplings.
Energy savings of 20% to 50% are typical in good ASD applications.
Status:
Baseline Description: Constant Speed Motor-Driven Systems Baseline Energy Use: 2923 kWh per year per hp
The baseline is a 200 hp boiler forced draft fan motor operating at constant speed at a lumber drying kiln. It uses 584,752 kWh/year according to a study performed by the Washington State University Energy Program.
"Typical" Savings: 31% Energy Savings Reliability: 6 - Approved Measure
Energy Use of an Emerging Technology is based upon the following algorithm. Baseline Energy Use - (Baseline Energy Use * Best Estimate of Energy Savings (either Typical savings OR the high range of savings.))
Simple payback, new construction (years): N/A
Simple payback, retrofit (years): N/A
Cost Effectiveness is calculated using baseline energy use, best estimate of typical energy savings, and first cost. It does not account for factors such as impacts on O&M costs (which could be significant if product life is greatly extended) or savings of non-electric fuels such as natural gas. Actual overall cost effectiveness could be significantly different based on these other factors.