Aggregated power system load area models with three different approaches

Aggregated load area model (ALAM) is a method of modelling the power system load by aggregating loads within a load area to derive a simplified load model. The aggregated model will generalise a set of equivalent system parameters which are unknown and immeasurable. The paper presents three different ALAM approaches, in which different parameter identification methods are adopted, which are voltage-two-step (VTS), current-two-step (CTS) and direct-one-step (DOS) approaches. The VTS approach identifies the parameters of by adopting a voltage-matching scheme but the CTS approach using a current-matching scheme. The DOS approach identifies the parameters based on a bus-matching scheme. Theoretical explanation and analysis to the three approaches are given in the paper and simulation studies were carried out for IEEE-14, IEEE-57 and IEEE-118 power systems. The three approaches are compared and an initial test on topological organisation of load areas is carried out. All the test results indicate that ALAM has a great potential for practical applications in load analysis and prediction