Indirect electroheat regulation

Electroheat regulation by means of on/off controllers is a commonly used regulation scheme. When the thermal process to be regulated has a large inherent time delay, or when it is not possible to have the temperature-sensing point at the output of the thermal process, another scheme, which consists of a feedback loop around a model, is suitable. This auxiliary process may be another thermal process or an electrical analogue of the main process. The main process is then controlled by open-loop control. It is shown that, by a suitable choice of the auxiliary-process parameters, better performance criteria can be obtained.