Optimization of a pump-turbine runner

Pumped hydro energy storage (PHES) is currently the only proven large-scale (>100 MW) energy storage technology. The benefits of PHES on electrical system operations are well documented in textbooks and journals.

The flexible generation of PHES can provide upregulation and downregulation in power systems. Furthermore, the quick start capabilities of PHES make it suitable for black starts and for the provision of spinning and standing reserves. PHES was previously developed in many countries, such as Europe, the United States, and Japan to facilitate the integration of large base load generation. Interest in this technology has recently been renewed because of the increase in variable renewable generation, such as wind power. Thus, many new PHES stations are currently being designed and built in China.

The pump-turbine installed in PHES stations usually takes only one runner functioning as pump and turbine and should be effectively operated during water pumping and electricity generation. Therefore, pump and turbine efficiencies should be guaranteed for the runner. Furthermore, the stability and cavitation performances for both operating conditions have to be improved. Given that the targets for the two operations affect each other and are sometimes
conflicting, designing a pump-turbine runner with high performance in both operation modes is difficult.

Frequent changes between the pump and turbine operations pose significant challenges in the design of pump-turbine runners with high efficiency and stability. Download our publication 'Optimization design of a reversible pump-turbine runner with high efficiency and stability'. The publication explores the challenges and how a multiobjective optimization design system, including a 3D inverse design, computational fluid dynamics, the design of the experiment, response surface methodology, and multiobjective genetic algorithm, is introduced and applied to the design of a middle-high-head pump-turbine runner.

Fig. 1. Optimized blade shapes. 

This publication covers:

• Multiobjective optimization design system
• 3D inverse design
• CFD analysis
• Optimization process
• Design, specification and parameters of a scaled pump-turbine runner
• Optimization results
• Model tests