Abstract
The hydropower station with a super long headrace tunnel is a significant development type for hydropower energy. By constructing a super long headrace tunnel, the huge natural water fall head can be utilized to generate more electricity. With the development of hydropower energy, a hydropower station with a super long headrace tunnel becomes more and more competitive. Compared with a hydropower station with a short headrace tunnel, the transient process and control for a hydropower station with a super long headrace tunnel is much more complicated and becomes an intractable challenge. It is well known that the transient process and control is the basis of the design and operation of a hydropower station. To overcome the challenge of the transient process and control, much research has been carried out. This paper provides a systematic review on the latest research progress of the transient process and control for hydropower stations with a super long headrace tunnel. Firstly, two key issues for the transient process and control, i.e., hydraulic design optimization of the surge tank and operation control of unit, are illuminated. Secondly, for both single surge tanks and surge tanks with special types or combinations, the hydraulic design optimization methods are described. The most disadvantageous design and advantageous operation of surge tanks under combined operating conditions are discussed. Thirdly, the stability and regulation quality of the hydro-turbine governing system under isolated and grid-connected operation conditions are presented. Finally, some trends and recommendations for future research directions are made. A research thought for establishing the complete theory and application system of the transient process and control for hydropower stations with a super long headrace tunnel from the perspective of multi-slice and multi-scale is proposed.
Highlights
Renewable energy sources, which include biomass, hydropower, geothermal, solar, wind, and marine energies, are considered to be clean, low risk, and inexhaustible [1]
The results indicated that, with the increase of the throttled loss coefficient of tank, the controlling operating operating condition condition for the highest level in the surge tank changed the surge tank, the controlling for thewater highest water level in the surge tank from the load-acceptance--rejection condition to condition the successive loadsuccessive rejection condition, while changed from the load-acceptance--rejection to the load rejection the controlling condition for the condition lowest water in the water surge level tank changed fromtank the condition, whileoperating the controlling operating for level the lowest in the surge load-rejection--acceptance condition to the successive load acceptance condition.load acceptance changed from the load-rejection--acceptance condition to the successive
The studywith on the transient headrace tunnels, thecomplicated transient process and control for hydropower stations super long process and control is the key to overcoming the challenge of the design and operation of hydropower headrace tunnels is much more complicated and becomes an intractable challenge
Summary
Renewable energy sources, which include biomass, hydropower, geothermal, solar, wind, and marine energies, are considered to be clean, low risk, and inexhaustible [1]. The coupling effect among the superimposed hydraulic waves, machinery subsystem, and electrics subsystem appears and makes the transient process for the hydropower station with a super long headrace tunnel much more complicated. For the hydraulic design optimization of the surge tank and operation control of the unit for hydropower stations with a super long headrace tunnel, the complete theory and application system is deficient. Because of the unique transient process and essential nonlinear characteristics of hydropower stations with super long headrace tunnels, it is necessary to study and propose the complete theory and application system for the hydraulic design optimization of the surge tank and operation control of the unit. Some trends and recommendations for future research directions are made
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
