Applying Semiconductor Frequency Converters to Optimize Control Systems Operating at Nonferrous Metallurgy Production Facilities

Abstract

Optimization of control systems for semiconductor frequency converters is considered for applications in nonferrous metallurgical facilities. Namely, optimization of subsystems to measure input, internal, and output voltages in power converters is examined at the system level. This optimization allows reducing the cost of converters through simplifying control system and through improving the metrological parameters of measuring devices. Optimization is achieved through integrating voltage dividers, input filters, analog-to-digital converters, and the measurement data transmission system and using an optical communication line to make a single functional unit to be installed directly near the area where the voltage is measured. The comparison of the simulation data in a single-channel and multichannel optimized voltage measurement subsystems with experimental data confirmed the optimization results. It is shown that the cost of control system is reduced through decreasing the number of functional units, through decreasing inter-unit connections and through simplified assembly. The control system is simplified because of reducing the number of analog inputs which makes the requirements to the element base of the control system less stringent. It is established that the metrological parameters of the voltage measurement subsystem can be improved if the selection of the component base takes into account the criterion of adopted model to transform the variable measured.