Development of a hardware-software system for the experimental study of the ferromagnetic groove carrying conductor surface
The paper presents the results of an experimental study of the ferromagnetic groove electromagnetic field based on a developed laboratory bench equipped with a hardware — software measuring system. A technique for determining the current density in the conductor cross-section by measuring the magnetic field induction when immersing two types of sensors (frameless fine measuring coil and Hall sensor of a digital millislotometer) has been implemented for various depths inside the groove. The use of a measuring coil as a sensor makes it possible to obtain the current density distribution over the conductor height through the procedure of integrating the voltage proportional to the EMF induced in the measuring coil using a LabVIEW environment-built in a digital integrator. Measurement of magnetic field induction by the Hall digital sensor at a laboratory bench provides the measuring coil verification and the reliability of the experimental study results determination. With the help of the hardware-software complex, a distribution of the current density and magnetic induction along the conductor height in the ferromagnetic groove is obtained at a laboratory bench. The results of an experimental investigation of the surface effect are compared with the results of calculating the alternating magnetic field of a conductor with a current in a ferromagnetic groove in the Elcut 5.6 program complex. The active and the inductive conductor resistance at the industrial frequency are determined.
Development of a Hardware-Software Complex for Determining the Technical Condition of Pumping Equipment
Diagnostic assistance is used for failure-free performance of machine units. Each machine is regarded as a single structure that consists of actuator, muffs and working mechanism. After that, the conclusion about efficiency of the whole machine unit is done on the basis of inference about technical state of elements and joints. Broad range of the various methods and diagnostic facilities has to be used for the technical state estimation of individual elements of the machine units, whereupon necessity appears in applying of the integral criterion that allows to estimate technical state of the whole machine unit. In this work, as integral criterion, it is encouraged to use aggregate of the parameters of higher harmonic components of the currents and voltages, generated by engine of the electric drive - Fourier transform of technical state of machine unit.
Pressure control system of the pumping units with frequency-controlled induction motor
The ever-increasing demands to the quality of production processes are associated with the pumping of non-viscous liquids, which indicate the need in improving operating conditions of liquid transfer systems with centrifugal pumps, including by means of mathematical modeling. The purpose of the paper is to develop a system for stabilizing the pressure in the calculated point by a scalar frequency-controlling of an induction motor speed, and to study its dynamic operation modes. The following methods are used in the research: theory of the variable frequency drive and electrical machines, methods of operational calculus, theory of centrifugal bladed machines. As a result, a scheme for controlling the pressure of the centrifugal pumping unit in the calculated point by controlling the rotational speed of the induction motor and determining calculated pressure indirectly using the respective models of the centrifugal pump was developed.