Measuring group geyser consumption patterns with a single waterheater and a PC-based measurement and control system

摘要

A PC-based measurement and control system, connected to a singlegeyser, is proposed as a hardware based calculation technique in orderto experimentally determine the relationship between water andelectrical consumption patterns for a large number of users. Under theassumption that the thermostatic controllers present on the geysersdeliver an average controlled temperature, the controller set-point(target) is set to that average value. Either the electrical usagepattern (controlled via a phase-controlled triac) or the water usagepattern (controlled via a PWM modulated water control valve) are fed asdisturbances to this control system. The controller then varies theopposite parameter (water or electrical energy) in order to keep thetemperature constant. This controlled input variable, in conjunctionwith the disturbance variable, deliver the required correlation betweenthe water and electrical usage patterns as functions of time