Oleksandr Bondarenko

Multicell-type transistor converter with combined control for micro resistance welding

Micro resistance welding is effective way to reliably join small-scale parts in electronics industry and instrument-making. High quality welded joints are obtained by accurate regulation of welding current with transistor converter module which is one of the most important sub-systems in micro resistance welding machine. Multicell-type transistor converter with combined control, represented in the paper, provides high accuracy of current regulation and high energy efficiency therefore is proposed for use in micro resistance welding.

The former of special form current pulses for micro resistance welding

Conditions of obtaining high quality welded joints by micro resistance welding are analyzed. Construction principle of the former of special form current pulses for micro resistance welding is offered. The former provides forming of weld current power pulse in accordance with electrophysic processes in welding contact. Offered pulse former included in experimental welding machine is used for welding details of important application. The results of experiments are given.

Current and force control in micro resistance welding machines Review and development

Micro resistance welding is effective way to reliably join small-scale parts in electronics industry and instrument-making. High quality welded joints are obtained by coordinating welding current and electrodes squeezing force profiles. The decisions for minimizing inertia of welding machine units proposed in the paper allow achieving accurate coordinated control of current and force profiles.

Control features of multicell-type current regulator for resistance welding

The features of resistance welding process are considered. A multiceli buck converter as a simplest, efficient and stable topology for resistance welding power supply is proposed. The efficiency of a buck converter cell is analyzed. The particularities of welding pulse generation are described. Relay control as an appropriate method for minimizing the welding pulse curve error is analyzed. The restrictions of relay method use for multiceli converter topology are shown. A modified strategy to reduce the error of welding pulse generation by multiceli converter is proposed. The theoretical aspects of the converter design are verified with MATLAB Simulink.

Features of compensation of a reactive power at the transient mode

The problem of reactive power compensation in power grids with variable load is analyzed. An inefficient implementation of existing methods of reactive power compensation for this case is shown. The method of analysis of the transmitting energy between the source and the load during the transition process based on the theory of instantaneous power is proposed. The efficiency of energy transfer from source to load based on the instantaneous value of power factor, which is calculated on the basis of the measured values of grid current and voltage is proposed. The proposed method realization on the example of the linear circuit of the first order is shown. The principles of reactive power compensation in transient mode is given.

Control of hydraulic system servo motor converter in mold oscillation waveform formation

The issues of synthesis of regulator for hydraulic system servo converter and generation of reference signal for forming a waveform of oscillation were investigated in the paper. The model of hydraulic drive, which took into account nonlinear character of the servo motor load, was developed. The method of reference signal formation, which eliminates impact loads, was proposed for similar systems.

Estimation of supercapacitor efficiency in use for resistance welding

The appearing of supercapacitor internal resistance influence on efficiency of energy delivery in resistance welding circuit was studied in the paper. The dependencies of supercapacitor energy storage efficiency on load resistance were obtained. The limits of supercapacitor use for resistance welding area were determined.

Data transmission with code division based on transform in rotating coordinates

The paper describes mathematical mean of spectral transforms as the instrument for constructing the data transmitting system based on matched filtration. New method of spectral transform at oriented basis and in a rotating coordinate system is considered and analyzed. The structure of multichannel transmission system is proposed and simulated.

Multicell-type current regulator based on Cuk converter for resistance welding

Resistance welding technology features are discussed. The ways of improving the efficiency of the system, which consists of energy storage unit, current regulator and welding load, are analyzed. A multiceli structure of the output current regulator with a cell topology based on Cuk converter is suggested. The maximal inductance values of input and output inductors are calculated. Cuk converter efficiency is estimated using its mathematical model. Theoretical considerations are proved with developed Simulink model of current regulator.

Electrical characteristics of the equipment for the hybrid plasma-MIG welding

In order to formulate requirements for electrical equipment for a prospective hybrid welding process Plasma-MIG, the following studies were carried out. The theoretical analysis of the influence of the plasma discharge temperature with non-consumable electrode on the melting of the electrode wire was carried out. The dynamics of the melting of the electrode wire and dynamics of circuit with consumable electrode arc were been investigation. The estimation of maximum values of the temperature of plasma have been made. Influence of the MIG process on the volt-ampere characteristics of the plasma discharge have been studied. These results were used for carrying out the technological experiments.