4Kamnev V I, Sakov I A. Using an adjustable low-voltage electric drive for pumps supplying makeup water to a cogeneration station's heating network [J]. Thermal Engineering, 2007, 54(6) : 468 - 473.
5Anishev E Yu, Lazarev G B. Specific features of the application of frequency converters in power electric drives of circulation pumps [ J]. Russian Electrical Engineering, 2008,78 (10) : 560 -564.