STABILIZATION OF A LIQUID LEVEL IN A FLOW RESERVOIR

Abstract

The article considers the problem of the operation of a pumping unit with a flow tank, in which a constant liquid level is maintained by changing the speed of the pump motor using a frequency converter. The control of the rotational speed of the pump motor is made from the measuring transducer of the liquid level in the tank, thus, feedback is formed. As you know, when using a frequency controller in a closed-loop feedback tracking system, there is a system stability problem caused by signal delays in integrating circuits, and the system may enter auto-generation mode. Therefore, the article explores the problem of the stability of the system against the occurrence of auto-generation. For this, a block diagram of the pumping unit is compiled, where all delay circuits are taken into account. According to the structural diagram, a mathematical model of the installation was compiled in the MATLAB Simulink program and a simulation of the transient process on the influence of an external disturbance was carried out. For the stability of the pump installation, a phase correction of the system is proposed by introducing a phase filter. A schematic diagram of a phase filter is given.