Computer-aided Algorithm Research Articles

A new computer-aided method of distortion sensitivity-analysis and its elimination scheme for power electronic circuits

A new general computer-aided algorithm for computing parameter sensitivities of distortion in power electronic circuits and its elimination scheme are proposed. The adjoint network approach is employed for calculating parameter sensitivities of the distortion factor and the ripple factor of current and voltage waveforms. An optimal filter design-algorithm to reduce undesirable harmonics is also proposed. Their performance is shown to be superior through demonstrated numerical examples.

Optimizing the operation of a stand-alone photovoltaic power system with distinctive insolation profiles using an on-line computer

To optimize the operation of an array of solar cells, Z. Zinger and A. Braunstein (IEEE Trans. PAS-100 (1981) 1189 – 1192) approximated the insolation profile by three discrete levels only throughout the day. In our previous two papers, the problem was solved using a clear, but real, insolation profile. This paper presents an accurate and computer-aided algorithm to achieve this optimization continuously for any insolation profile. The computer is programmed so that it can deal with any dynamic changes in the insolation and load demand. Its commands to switch on or off the parallel strings of the array are decided so that the technical constraints imposed will be satisfied. In addition, the daily delivered, stored and total output energies are deduced for two different arrangements of the system. They differ mainly with regard to the battery location with respect to the other subsystems. The numerous results obtained are analysed fully and discussed.

A Suboptimal Observer-Based Controller for Linear Discrete-Time Systems with Unknown Initial States

This paper proposes a design technique of a subopti-mal observer-based controller for linear discrete-time systems with inaccessible states. Attention is focused on the case when the initial conditions are completely unknown. The performance criterion of interest is the standard quadratic one. An upper bound on the degradation in performance, due to absence of state, is developed and expressed as the Probenius norm of a symmetric positive definite matrix. Minimization of this bound produces the observer parameters. Computer-aided algorithms for arriving at the optimizing solution are given.

Two Design Techniques for Digital Phase Networks

Two computer-aided algorithms for the design of all-pass digital filters are presented. The first technique is based on a linear programming approach to solving the approximation problem posed by the minimax design of an all-pass digital filter. A new iterative algorithm with stability constraints is offered for direct form design. The second technique implements a gradient search for those quadratic factors of an all-pass transfer function that lead to a locally optimal approximation (in the least-squares sense) of a desired phase function. New initial guess procedures and the parameterization of linear-phase offset enhance the least-squares design procedure. Examples illustrating the result of both procedures are included.