FREQUENCY REGULATION OF THE ELECTRIC DRIVE OF PUMP UNITS OF THE CENTRALIZED HEAT SUPPLY NETWORK BASED ON ASYNCHRONOUS MOTORS WITH A SHORT-CIRCUITED ROTOR

Abstract

The quantitative and qualitative parameters of the frequency regulation of the electric drive of the pumping units of the centralized heat supply network were determined. The necessity and possibility of using the frequency-regulated electric drive of pumping units in the networks of centralized heat supply, in the mode of their operation of quantitative and qualitative regulation of the coolant supply, is well-founded. The frequency control parameters were calculated on the basis of technical data related to the operating mode, where the flow rate of the coolant changes according to the hydraulic load typical for HVAC applications defined by the European Union Regulation, as well as the technical data of the pump, frequency converter and electric motors provided by the manufacturers. The definition of parameters concerns the operation of pumping units in a typical operating cycle characteristic of district heating networks, which involves operation with a reduced load for a long time. The results were obtained that correspond to the range of the speed of rotation of the electric drive, its power, torque, coolant supply and hydraulic pressure of the pump in a real typical network of centralized heat supply. The practical significance of the obtained results is that they can be used for the modernization of the electric drive of pumping units of the centralized heat supply network, which until now are operated with non-regulated electric drives based on an asynchronous motor with a short-circuited rotor and throttle regulation of the coolant supply.