| This paper is concerned with the design of the power control system for a single-phase voltage source inverter feeding a parallel resonant induction heating load and the analyse of its energetic performances. The control of the inverter output current, meaning the active component of the current through the induction coil when the control frequency is equal or slightly exceeds the resonant frequency, is achieved by a Proportional-Integral-Derivative controller tuned in accordance with the Modulus Optimum criterion in Kessler variant. The control system response, in terms of the rms current at the inverter output when a prescribed step current is applied, shows that the dynamic and static performances are very good. In the second part, the paper presents the energetic performances of a proposed system for drying of current transformer from 110 kV Ciungetu power station. First, based on the actual technical solution and experimental recording of voltage and current, the equivalent parameters of the load circuit have been determined. In the proposed solution, the drying process is based on an induction heating system that contains a halfcontrolled rectifier and a voltage source inverter that operates with resonant load. The energetic performances have been determined in order to ensure zero-current switching of the inverter. |
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