Three-Phase EPLL-I

There are multiple extensions of the enhanced phase-locked loop (EPLL) to three-phase, and they are grouped under the name three-phase EPLL (3EPLL). This chapter presents the first member of this group called the 3EPLL-I. This structure can address direct current (DC) component and harmonics within its loop structure; something that is not possible with the synchronous reference frame (SRF)-PLL. The chapter focuses on the detail derivation, analysis, design, and modifications of the 3EPLL-I. It begins with a discussion on the 3EPLL, and explains the relationship between 3EPLL-I and SRF-PLL. Next, the chapter talks about 3EPLL-I in stationary frame and the mathematical derivation of 3EPLL-I . Numerical simulations show that the responses of the 3EPLL-I and the SRF-PLL are identical.