Harmonious outcome for Thyristor controller

A new power controller, employing novel technology has been developed by REO. Called the ‘REOTRON MEW 700/50 2S’, the controller operates on the phase-angle principle but, unlike traditional systems, it reduces harmonics (power factor) and provides a smoother process. The unit can be used for voltage, current or power regulation.

The REOTRON controller produces two output voltages simultaneously; one is adjusted by firing the thyristors at a variable phase-angle, whilst the other is permanently on full conduction but at a lower voltage level. This avoids abrupt switch-on of current at the firing angle. The two outputs are combined by interposing a transformer, with two primary windings, between the controller and load.

Possible applications include water treatment, electroplating, lasers, smelting, heat treatment and metal coating.

The standard REOTRON controller is built as a module with a bus bar, snap-on connections and it has a digital control panel for setting up operating parameters. It can also be provided with a choice of field bus interfaces for applications where a number of control stations are run and monitored from a central, supervisory system, such as a PLC.

The concept provides a solution for situations where a cost-effective power regulation method is required but without undesirable harmonic voltage distortion on the mains supply and a power factor that is close to unity.