Automated small HPPS as the backbone of power grids for mountaineous regions of Tajikistan

The article briefly analyzes the existing small hydropower plants in the Republic of Tajikistan. Analysis reveals why such units are not suitable for stand-alone operation and what renders them less reliable. The paper proposes a simpler design for better reliability and stand-alone, low-maintenance operation. A design based on simpler and more reliable components requires less maintenance, which could be limited to regular inspections, hence no need for round-the-clock staff presence. A centrifugal pump is proposed as a turbine, as it does not require additional parameter controls, while a synchronous permanent magnet-excited unit is proposed as a generator, as it does not require a special channer to control the excitation flux. For better quality of generated electricity, the paper proposes using a semiconductor-based voltage converte that will stabilize the input voltage to a required accuracy of frequency and amplitude. Self-diagnosis instrumentation is part of the design, as it can monitor not only the input voltages, but also the condition of primary components: turbines, voltage converters, switches, and communications with the mission control center. The paper also analyzes the problems of implementing this design, which mainly pertain to balancing the input voltage given a significantly asymmetrical load; another challenge is to improve the accuracy and reliability of instrumentations implemented to monitor the health of specific small-HPP elements.