Open AccessPROPERTIES OF THE REACTIVE POWER OF THE ASYNCHRONOUS MACHINE AS A LOAD OF THE ELECTRIC NETWORK
Author(s) -
O. Klyuyev,
E. Khmelnitsky
Publication year - 2021
Publication title -
zbìrnik naukovih pracʹ dnìprodzeržinsʹkogo deržavnogo tehnìčnogo unìversitetu. tehnìčnì nauki/zbìrnik naukovih pracʹ dnìprovsʹkogo deržavnogo tehnìčnogo unìversitetu. tehnìčnì nauki
Language(s) - English
Resource type - Journals
eISSN - 2617-8389
pISSN - 2519-2884
DOI - 10.31319/2519-2884.37.2020.6
Subject(s) - ac power , voltage optimisation , power factor , voltage , power (physics) , computer science , switched mode power supply , electric power , asynchronous communication , control theory (sociology) , electrical engineering , engineering , physics , telecommunications , control (management) , quantum mechanics , artificial intelligence
It is known that the voltage mode of the electrical network is associated with the balance of reactive power and directly affects the operation of production equipment. A typical static characteristic of a power supply unit in terms of reactive power, obtained for a load composition characteristic of electrical networks, is an extreme function with a minimum point. It is the presence of a minimum point in the dependence of reactive power on voltage that makes it possible to develop this type of instability as a voltage avalanche. This mode is especially dangerous for industrial units with abruptly variable loads, which can create significant fluctuations in the supply voltage, which significantly affects the operation of powerful asynchronous motors. Therefore, the issues of the relationship between the parameters mode of the electrical network and the properties of electrical loads are always important, especially asynchronous machines as the main consumer of electricity, which largely determines the properties of the generalized reactive power curve of the entire load unit. Literary sources do not explain in detail why the curve of the dependence of the reactive power of the power supply unit on voltage has a minimum. The article sets out this issue in sufficient detail for asynchronous machines as the main consumer of reactive power in electrical networks. The task is to obtain the dependence of the reactive power of an induction machine with a squirrel-cage rotor on the voltage of the supply network, as well as to determine the criteria for controlling reactive power flows in order to inadmissibly reduce the voltage in the load unit. As a result, based on the system of equations of an asynchronous machine, the dependence of its reactive power on the supply voltage of the network was derived. The mathematical properties of this function are investigated with a physical justification of its unimodality and the presence of a minimum point. The obtained expressions make it possible to determine the magnitude of the control action on the high-speed reactive power compensation devices to stabilize the voltage level in the power supply unit.