Comparative Assessments of the Possibility of Starting a 1.3 MW Turboblower in the Original and Autonomous Scheme of Treatment Facilities

The introduction of own power sources at production facilities under the conditions of joint operation of autonomous and centralized power sources of power supply systems of production facilities requires the assessment of the existence of the main production modes. For this purpose a mathematical model of the power supply system with autonomous and centralized sources has been developed, which takes into account the closed electrical network of sewage treatment plants of a large city. Calculated studies of start-up schemes of a powerful blower drive in the autonomous and centralized system are performed. To increase the accuracy of calculations of residual voltages and motor starting parameters, the proposed mathematical model takes into account the control of EMF angles of generators, synchronous (SM) and asynchronous motors (AM) relative to the EMF of the balancing unit. The network parameters are taken into account by complex resistances, and the parameters of blower drives and other mechanisms are recalculated when the angular speed of rotation changes. Calculated studies have confirmed that in the scheme of autonomous power supply with four generators the direct start of SM with capacity 1.3 MW is possible, but at the same time the start-up time increases up to tp = 11.7 sec, and the voltage on sections of switchgear and transformer substations decreases to the value U = 0,67 o.u. It is recommended to use a soft-start scheme for SM of turbo blower with capacity of 1.3 MW, which will allow to avoid significant voltage drop during the start-up period even in the scheme of autonomous power supply from generators of mini-station, as well as to increase the number (capacity) of generators of mini-station.