Third-order load identification under nonsinusoidal conditions

This paper presents an extension of the well known load identification method, valid under non-sinusoidal conditions, which makes use of a 2nd-order passive circuit and an auxiliary voltage or current generator. The proposed solution is similar, but uses a 3rd-order passive circuit. This allows to identify the passive circuit components with positive or negative parameters, according to the aim of the identification (load modeling or compensation). Moreover, the proposed approach keeps the orthogonality between current/voltage components and removes the indetermination which occurs, with the 2nd-order approach, in the case of sinusoidal operation. As an application example, the proposed approach is applied to the design of a hybrid compensation system including active and passive filtering.