A two-way approach to leakage determination: Sophisticated demand modelling and discriminative demand pattern analysis

This paper presents a combination of two new approaches to leakage determination. The first approach is based on the classic bottom-up leakage determination, but uses a sophisticated demand model, SIMDEUM, to estimate night demand. The second approach is a new analysis method for flow patterns, the Comparison of Flow Pattern Distributions (CFPD). This method allows distinguishing so called consistent from so called inconsistent changes in flow patterns. The latter includes leakage, the former does not. In an application of the first method, simulated demand is compared to measured demand for four different supply areas/DMAs. These examples illustrate cases with and without leakage, and difficulties related to the night demand of a large volume customer. CFPD analysis is applied to data from two areas. These applications illustrate, respectively, the identification and pinpointing (in time) of a small leak and the independent quantification of concurrent different types of changes with opposite signs in a supply pattern. In each case, the power of the CFPD block analysis is illustrated: discriminative quantification and visualization result in features and trends in complicated time series becoming apparent at a glance.