The need for an economic alternative to the traditional speed governor for micro hydro applications is discussed and the Electronic Load Governor (ELG) is identified as the solution. The international market for the ELG is seen to vary in accordance with the development and traditions of those countries with micro hydro resources. Technical and economic design parameters for a novel, prototype ELG are developed in relation to previous work in the field. The need for a reliable unit based on digital electronic circuits and capable to three phase balancing is identified. The significance of the 'droop' is introduced, along with the concepts of 'deadband', 'wait delay' and the 'coefficient of stability'. A technique for prediction of the droop, and hence the deadband, using the turbine runaway speed is presented. The predictions are confirmed as a result of empirical tests. The voltage-speed characteristics are also determined empirically. A mathematical expression is derived which represents the frequency variation with time of the system, when subjected to a load rejection, and controlled by the ELG. The transfer function of the control system is derived as far as is practicable given the non-linear nature of the ELG control action. A computer model is developed which predicts the frequency transient for any Pelton installation under the control of the ELG. The mode is modified to predict the performance of the ELG subject to proportional-derivative control actions.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:652345 |
| Date | January 1992 |
| Creators | Henderson, Douglas Stuart |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/14046 |
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