Optimization of a variable frequency drive pump working on a water tower N.V. Hruntovich, A.A. Kapanski, D Baczynski, G.V. Vagapov and O.V. Fedorov E3S Web Conf., 124 (2019) 05060 Published online: 10 February 2020 DOI: 10.1051/e3sconf/201912405060