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

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