Progress Report on the Endurance Residential Wind Turbine System

摘要

The Endurance wind turbine was developed by Windward Engineering, and grew out of a threeyear, over-speed protection system design and demonstration project partially funded by the U.S. Department of Energy. It addresses important issues that exist in the small wind turbine market including high cost and reliability issues with inverters, noise and safety of machines, and turbine size and performance concerns. These are addressed through three basic aspects of the Endurance that are unique for a small turbine: 1. Use of an induction generator foregoes the need for an inverter 2. Redundant and failsafe brake calipers can stop the rotor in any wind condition 3. An anemometer senses cut-in and cut-out wind speeds for optimal performance. The Endurance is sized to closely match energy production to the average U.S. household demand (～11,000 kWh/yr) when installed in a Class-3 wind resource. By closely matching energy production to demand, return on investment for the system is maximized. It is rated at 4.25kW at 12 m/s (27 mph) hub-height wind speed. The design recognizes the need for safe, quiet and efficient operation in the residential market. This is achieved in part through the low speed shaft brake system and the non-furling, upwind design. Results from operating four Endurance units are presented here. Relatively few problems have been encountered over the course of operation of all units. The turbine has proven itself to be efficient and robust, both in normal as well as unexpected conditions. Evaluation of these units is ongoing while additional installations are planned for later this year.