A new approach to the development of a nonlinear model for micro-Pelton turbines

Abstract

Abstract:In this study, a new approach that is closer to the real turbine without abandoning the advantages of nonlinear modeling simplicity compromising the simplicity of the nonlinear model is proposed. The purpose of the study is to contribute to making theoretical studies of microhydroelectric power plants (MHPPs) more realistic. Studies on their control, especially frequency control, have increased with the expansion of grid-connected power plants. However, some problems have occurred when converting simulation studies of the frequency control to practical studies. The reasons for these problems are that the systems cannot be modeled completely. In this study, first, the nonlinear model equations of a Pelton turbine are primarily constituted. The efficiency curve of the turbine is then obtained experimentally and added to the nonlinear model. The simulation results are compared with the data obtained from the prototype MHPP with a Pelton turbine developed in the laboratory. Finally, it is seen that the proposed method is successful. Thus, with the help of the proposed method, theoretical studies that researchers do can be easily converted into practical applications.

Design of a Low-Cost Autonomous Controller, Management and Security System for Pico-Hydroelectric Power Plants

“…On the other hand, the obtained waveform of the different departures' currents could be used as a proof for different load variations occurred in the three departures. The obtained frequency curve, illustrated in Figure 10(a), when applying overloads and discharges, has a high accordance behavior with recent research publications [5,6,10,31].…”

“…Thus, a controller system is required. In the literature, there are several known PHPP frequency regulations which have been widely used [10,[24][25][26][27]. The first, the speed-flow controller (SFC) consists to adjust the water flow reaching the hydraulic turbine in order to keep constant turbine speed (frequency constant).…”

“…On the other hand, the presented system uses a PLC's proportional integral derivative (PID) bloc which maintains the frequency around its standard value. The system does not have the flexibility to improve the PHPP frequency response using advanced controllers [7][8][9], while the PHPP system is non-linear system [4,5,[10][11][12]. The proposed controller could not guarantee good performances for all operating points.…”

An Integrated Approach for Modeling Three-Phase Micro Hydropower Plants

“…For example, ∆P=5% gives a ∆f=0.91Hz while ∆P=45%=5%*9 gives ∆f=10.59Hz instead of ∆f=8.19Hz=0.91Hz*9. This behavior is completely normal by comparing this result with recent research publications [16,17,23,35]. The MHPP modeling with experimental validation, developed by the published article [16], has a strong nonlinearity system and the frequency varies significantly with load variations.…”