Electrical Equipment for Small Hydropower Plants Generators with Permanent Magnet Excitation (PME) Lausan 30 th June20 Jochen Bard Head of Energy Conversion Institute for Solar Energy Supply Technologies (ISET) Kassel University, www.iset.de TNSHP: Small Hydropower Workshop
Institut für Solare Energieversorgungstechnik e.v. Systems Technology for the Use of Renewable Energies and Efficient Energy Conversion Applications-oriented Research and Development Wind Energy Photovoltaics Use of Biomass Hydropower, Ocean Energy Technologies Energy Conversion and Storage Hybrid Systems Energy Economy Information and Training Executive Board: Prof. Dr.-Ing. Jürgen Schmid Dr. rer. nat. Oliver Führer Personnel: 75 Employees Budget: approxim. 8 Mio. Euro Information: www.iset.uni-kassel.de
Electrical Equipment for Small Hydropower Plants turbine: electrical drives for guide vanes and runner control generators: high efficiency induction machines, direct drive concepts low loss & environmental friendly transformers improved control: improved gate control optimised trash rack cleaner operation higher turbine output (optimisation of runner guide vane setting) detailed monitoring and supervision remote control and SCADA-interface (web cam, automated reports) advanced analysis facilities optimisation of multiple turbine installations... examples of improvements in particular for modernisation
Medium to high head turbines small pelton Source: Hitzinger spiral case Francis Project/Country: EW Lüsen / I Type: SGT9D06T Nominal output 1400 KVA Speed: 1000 rpm Specification: IEC 34, VDE 0530
Typical low head site: SHP plant Lewitzschleuse head: 3.6 m power: 270 kw discharge: 9 m³/s Turbine: Kaplan n = 190 rpm = 1600 mm
disadvantages of gearboxes losses of 1-1.5% per stage (up to 5% overall) vibration and noise investment cost and lifetime maintenance requirements and cost environmental risk from oil efficienc 1 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0 0 5 10 15 2 power [kw]
Alternative to gearboxes: reinforced belt (up to 400 kw)
Example of submersible turbines with direct coupled induction generator ITT Flyght hydropower plant Reichenbach/Fils
Kaplan turbine: speed and torque vs discharge (simplified with constant design parameters) 800 700 600 turbine speed [rpm] torque [knm] equivalent number of poles 80 70 60 turbine speed [rpm] 500 400 300 200 100 50 40 30 20 10 number of poles, torque torque [knm] [knm] 0 0 0 5 10 15 20 25 discharge [m³/s] at 5 m 90 kw 700 kw
Performance improvement by replacing and old drive train 1 0,9 0,8 power train efficiency 0,7 0,6 0,5 0,4 0,3 0,2 PME generator ASG+belt old power train (ASG+ gear box) 0,1 0 0 10 20 30 40 50 60 70 80 90 100 Power [%]
Possible drive train arrangement for refurbishment using a direct coupled SE or PME synchronous generator source: OKD
Design and operational aspetcs of grid connected PME generators + no excitation losses very good part load efficiency + smaller pole pitches than separate excitation lighter design + no brushes or slip rings - damping of oscillations between grid and rotor required - no regulation of the power factor - voltage proportional to speed no regulation of the voltage run away speed + loss of load very high open circuit voltages - no isolated operation possible rotor stator only for integration into an existing strong and stable electrical network e.g. in Europe and North America
New compact turbine concepts using direct coupling Matrixturbine 200-700 kw per unit ECOBulb Kaplan turbine 500 kw-5 MW 2 to 15 m pictures: VATECH Hydro
ECOBulb: typical efficiencies achieved generator turbine total source: VATECH Hydro
ECOBulb generator first machine 330 kva 214 rpm max. eff 96% pole face with magnets damper cage 1250 kva, 150 rpm, max. eff 96,5% photos: VATECH Hydro 4000 kva 144 rpm max. eff 96,8%
Straflo Matrix by VATECH StrafloMatrix pilot project Agonitz pictures: VATECH Hydro 700 kw at 8.5 m head 430 rpm, 1.12 m runner diameter unregulated turbine ring generator with PME target size > 1.5 MW
realised slow speed generators in µ-hydro demonstration projects refurbishment of a low head Francis turbine head 1m, discharge: 2.9 m³/s rated power 22 kva rated speed 42 rpm rated torque 5000 Nm rated frequency 21 Hz power factor 1,0 weight 3,2 t PME generator for a water wheel power 16 kw speed 22 rpm 24 poles efficiency 88% stator diameter 1,2m Köhler, Karslruhe University, 1997 projects in Switzerland engineering school Biehl Swiss SHP programme 2003 source: Kassel University
EC-Project VASOCOMPACT: Development of a commercial concept for variable speed operation of unregulated submersible compact turbines new turbine design for runner and guide vane special PME-generator directly coupled special frequency converter scaling from 50 bis 500 kw per unit installation and test of a 50 kw pilot this summer (Tirva, Finnland) Stator windings direct flow cooling Rotor draft tube Permanentmagnets fix runner fix guide vanes
Generator with permanent magnet excitation (Elmotec, CH) rated speed 600 rpm, 40 poles rated frequency 200 Hz design torque 840 Nm voltage 313 V, current 92 A
Application example for the VASOCOMPACT turbines xample design,18 m head 1510 mm runner 2,4 m³/s discharge 265 rpm 24 kw power/unit PME-Generator
Future prospects of PME generators Innowind 1.2 MW PMG 21 rpm 96 t similar developments e.g. by Siemens: first PM motor in 1987 other applications: CHP units based on ICEs industrial drive applications ABB medium Speed Permanent Magnet Generator integrated into a one-stage gearbox 120-240 rpm some MW new high speed PMG 3.6 MW on a 500mm frame >98% efficiency