A novel electromechanical system for guide vane adjustment in a small turbine test rig

Abstract

A cost-effective and reliable electromechanical system for guide vane (GV) control is designed and developed, which is easy to install and operate for micro hydro and model turbine test rigs.The electromechanical system can hold the GVs against the forces of the flowing fluid. The GV control mechanism contains a two-phase permanent magnet synchronous motor (PMSM), field-oriented control, and a feedback mechanism to control current and speed. The transfer functions, algorithm, and working of PMSM by supervisory control and data acquisition are integrated with drivers written in C++. The validation of the model and prototype shows good agreement with a maximum deviation of 2.14% in unit discharge values. The GV operating mechanism is used to run the turbine at design and off-design operating conditions, and the corresponding flow field of the draft tube is analysed. The GVO of 34˚ is identified as a BEP condition that matches with the prototype's BEP condition. The maximum pressure pulsations are observed at 22.10˚ GVO, 63.70% of the BEP condition. The rotating vortex rope formed shows a normalised frequency of 0.284 with the normalised pressure fluctuations amplitude of 2 to 3 times.