2.2.5.7 Maximum Demand

The Demo Meter application includes an example showing how to calculate and store the Maximum Demand data in non-volatile memory.

The Maximum Demand values are computed averaging the instantaneous active power readings during 15-minute time intervals for the present rate. If the average value is higher than the one stored in non-volatile memory, then the stored value is updated. The user can modify the provided source code, considering different intervals (for example, 5, 10, 15, 30, or 60 minutes), subintervals, calculation methods (for example, integrating demand method instead of averaging) or different measurement techniques (for example, a sliding window in such a way that the computation of the average value is done each minute).

The application saves the information from the last 12 months, and takes into account the TOU periods. Example:

; Read maximum demand and occurrence time
MDR[1]
Last 1 Month MaxDemand is:
TT=2.248kW 10-26 12:15 T1=1.125kW 10-19 10:15 T2=2.248kW 10-26 12:15 T3=1.798kW 10-26 13:15 T4=2.108kW 10-4 8:00

In this example, showing the data of the previous month, the application provides the following information:

The Maximum Demand, 2.248 kW, happened on 10/26 between 12:00 and 12:15, corresponding to rate T2.
The Maximum Demand for rates T1 (1.125kW), T3 (1.798kW) and T4 (2.108kW) are provided.

Warning: The maximum demand buffers are cleared each time the TOU period changes, even if the 15-minute period is not finished. Modify the application source code if another behaviour is desired.