Warwick Wind Turbine Build Report.pdf - Engineers Without Borders ...

Hazard D: In an event when the electricity grid requires maintenance, the turbinecontinues to feed electricity into the grid.3 People AffectedThe turbine is located adjacent to Cryfield Ground Maintenance Depot. People likely tobe in the vicinity of the turbine are sports playing students and ground maintenancestaff.4 Control Measures4.1 Tripping – Hazard AThe turbine will be located so that the path adjacent to the turbine is clear of guy ropesand there is a safe passage past the turbine.4.2 <strong>Turbine</strong> Falling Over – Hazard BThe turbine uses a set of 4 redundant guy ropes, so that there are 8 guy ropes in total.Due to the redundancy of the guy rope system a failed guy rope is likely to behighlighted and maintained in the maintenance programme before the hazard escalatesto the turbine falling over.4.3 Blade Balancing – Hazard CThe blades of the turbine must be statically and dynamically balanced to preventunsmooth rotation causing excess wear and in extreme circumstances detachment ofthe blades. Consequently, <strong>Engineers</strong> <strong>Without</strong> <strong>Borders</strong> and Estates Office commissionedspecific blade balancing carried out by V3 Power. V3 Power’s report is included inAppendix H.4.4 High Speed Testing – Hazard CTo verify the win d turbines high speed operation, testing was commissioned by<strong>Engineers</strong> <strong>Without</strong> <strong>Borders</strong> and Estates Office to be carried out by V3 Power. V3Power’s report is included in Appendix I.4.5 Load Diversion Regulator 96-15 – HazardA wind turbine will rotate faster if there is no electrical load on the turbine. The EWBwind turbine will operate normally around 300 rpm, but will rotate up to 600 rpm if theelectrical load is removed. The fully certified Load Diversion Regulator ensures there isalways an electrical load on the turbine, even in case of disconnection from the grid,either by a fault in the connection, or a fault with the inverter. In such a case, the LoadDiversion Controller feeds the electricity to a dump load power resistor in the turbineelectronics box. This ensures an electrical load is constantly connected to the turbineand the turbine is prevented from overspinning.4.6 Furling – Hazard CAll wind turbines have furling mechanisms to protect the turbine in high wind speeds.They may use pitch controlled blades, ‘shuttlecock’ style furling, or yawing the turbineout of the wind. The Hugh Piggott design uses a mechanical furling system not relianton electronics or control systems. The tail of the turbine is hinged off-centre from thealternator so there is a constant momen between tail and alternator. In low wind speeds4