Study on the influence of guide vane - blade number matching relationship (20-9) on the phase resonance risk coefficient of pumped storage units

In this paper, 19 pumped storage units put into operation or under construction in China (the matching relationship between the number of guide vanes and blades is 20-9, and the rated output of a single unit is not less than 200MW) were taken as the research object. Considering the risk of phase resonance caused by pressure wave propagation in the spiral casing of the unit, the phase resonance risk coefficients of units with different rotational speeds were analyzed. The concept of perimeter equivalent coefficient was proposed, and the design criteria for controlling the phase resonance risk coefficient within 25% was obtained, which provided references for optimal hydraulic design of pumped storage units.