[BURN77A] Burns III, W. W., and T. G.
Wilson, *Analytic Derivation and Evaluation of a
State-Trajectory Control Law for DC-to-DC Converters*, PESC'77 Record,
IEEE Power Electronics Specialists Conference - 1977 Record, pp. 70-85.

Mathematical representations of a state-plane switching boundary employed in a state-trajectory control law for dc-to-dc converters are derived. Several levels of approximation to the switching boundary equations are presented, together with an evaluation of the effects of nonideal operating characteristics of converter power stage components on the shape and location of the boundary and the behavior of a system controlled by it. Digital computer simulations of dc-to-dc converters operating in conjunction with each of these levels of control are presented and evaluated with respect to changes in transient and steady-state performance. (AUTHOR ABSTRACT) Department of Electrical Engineering, Duke University, Durham, NC 27706. 16 pages, 20 figures, 2 tables, 32 equations, 6 references.

[MIDD76B] Middlebrook, R. D., and S.
Cuk, *A General Unified Approach to Modeling
Switching-Converter Power Stages*, IEEE Power Electronics Specialists
Conference - 1976 Record, pp. 18-34. PESC Republished in *Advances in
Switch-Mode Power Conversion, Volumes I and II*, 2nd edition, TESLAco,
1983, paper 6, pp. 73-89. Republished in *Modern Power Electronics,
Evolution, Technology, and Application*, paper 5.2, pp. 297-313.

A method for modeling switching-converter power stages is developed, whose starting point is the unified state-space representation of the switched networks and whose end result is either a complete state-space description or its equivalent small-signal low-frequency linear circuit model. A new canonical circuit model is proposed, whose fixed topology contains all the essential input-output and control properties of any dc-to-dc switching converter, regardless of its detailed configuration, and by which different converters can be characterized in the form of a table conveniently stored in a computer data bank to provide a useful tool for computer aided design and optimization. The new canonical circuit model predicts that, in general, switching action introduces both zeros and poles into the duty ratio to output transfer function in addition to those from the effective filter network. (AUTHOR ABSTRACT) California Institute of Technology, Pasadena, CA. 17 pages, 19 figures, 1 table, 56 equations, 10 references.

[YU76A] Yu, Y., M. Bachmann, F. C. Y.
Lee, and J. E. Triner, *Formulation of a Methodology for Power
Circuit Design Optimization*, IEEE Power Electronics Specialists Conference
- 1976 Record, pp. 35-44.

A power processing optimization methodology is established to effectively conceive a design, to meet all requirement specifications and concurrently optimize a given design quantity deemed particular desirable. Such a quantity can be the weight, efficiency, regulator response, or any other physically-realizable entity. Four design examples are given to demonstrate the methodology. The method of Lagrange multipliers is applied to three examples to acquire optimum solutions are not [stet] closed form [should be closed form - JF]. When closed-form solutions are not amenable in the other example, a nonlinear programming algorithm is used to conceive the optimum design numerically. Areas of future investigations are outlined to foster the power processing optimization into its ultimate maturity. (AUTHOR ABSTRACT) TRW Defense & Space Systems, Redondo Beach, CA. NASA Lewis Research Center, Cleveland, OH. 10 pages, 2 figures, 81 equations, 16 references. [Check the equations before using, they contain errors. - JF]

[CUK77B] Cuk, S., and R. D.
Middlebrook, *A New Optimum Topology Switching DC-To-DC
Converter*, IEEE Power Electronics Specialists Conference - 1977 Record,
pp. 160-179. PESC Republished in *Advances in Switch-Mode Power Conversion,
Volumes I and II*, 2nd edition, TESLAco, 1983, paper 18, pp. 311-330.

A novel switching dc-to-dc converter is presented, which has the same general conversion property (increase or decrease of the input dc voltage) as does the conventional buck-boost converter, and which offers through its new optimum topology higher efficiency, lower output voltage ripple, reduced EMI, smaller size and weight, and excellent dynamic response. One of its most significant advantages is that both input and output current are not pulsating but are continuous (essentially dc with small superimposed switching current ripple), thus resulting in a close approximation to the ideal physically nonrealizable dc-to-dc transformer. The converter retains the simplest possible structure with the minimum number of components which, when interconnected in its optimum topology, yield the maximum performance. The new converter is extensively experimentally verified, and both the steady state (dc) and the dynamic (ac) theoretical model are correlated well with the experimental data. Both theoretical and experimental comparisons with the conventional buck-boost converter, to which an input filter has been added, demonstrate the significant advantages of the new optimum topology switching dc-to-dc converter. (AUTHOR ABSTRACT) California Institute of Technology, Pasadena, CA. 20 pages, 34 figures, 30 equations, 10 references.

[YU79A] Yu, Y., F. C. Lee, and J.
Kolecki, *Modeling and Analysis of Power Processing
Systems*, IEEE Power Electronics Specialists Conference - Record 1979, pp.
11-24.

Effort of a NASA-sponsored, computer-based program on "Modeling and Analysis of Power Processing System" is reported. The overall program objective is to provide an engineering tool to reduce the design, analysis, and development time, and thus the cost, in achieving the required performance for power processing equipment and systems. Program philosophy, structures, and design and analysis examples are given to illustrate the program's utility in power and control circuit design, analysis, and optimization. (AUTHOR ABSTRACT) TRW Defense and Space Systems, Redondo Beach, CA (Yu). VPI & SU, Blacksburg, VA (Lee). NASA-Lewis Research Center, Cleveland, OH (Kolecki). 14 pages, 7 figures, 2 tables, 19 equations, 20 references.