Frequency Converter for Induction Heating Oil in Oil Pipelines

Abstract

Heating oil in oil pipelines to the required temperature, with the most efficient use of electrical energy,is possible with using of the induction heating method. The most important parameter of induction heating settings is frequency. For each process, there is an optimal frequency range that provides the best technological and economic results. Induction heating of the oil pipeline occurs as follows, if alternating high-frequency current is passed through the windings of the oil pipeline inductor (Fig. 1), an alternating magnetic field is formed, which intersects the metal walls of the oil pipeline and induces eddy currents in them. These currents heat the metal walls of the pipeline to the desired temperature and, accordingly, the oil. MITSUBISHI's VIPM Series Intelligent Power Transistor Modules (IPM), which is a functionally complete product, are currently developed and marketed. These transistor modules are designed for high voltages, currents and power. A frequency converter made on these transistor modules allows to heat large diameter oil pipelines. A prototype IGBT transformer was designed and manufactured. Figure 2 shows a prototype of a frequency converter with a power of 6 kW at frequencies from 2 to 20 kHz. Induction heating of metal was used as a load for the frequency converter