Three-step impedance criterion for small-signal stability analysis in two-stage DC distributed power systems

Small-signal stability analysis methods based on an impedance criterion originate from the minor loop gain method and are gradually utilized in two-stage DC distributed power systems. In this paper, we conclude that the impedance criterion directly dependent on output impedance Z/sub o/(s) of the source subsystem and input impedance Z/sub i/(s) of the load subsystem is possible but gives an incorrect stability analysis for systems with a regulated source subsystem. Through introducing a mapped pure impedance of the load subsystems and the preliminary system, we develop a general three-step impedance criterion, with which a correct small-signal stability analysis can be guaranteed, regardless of the type of source subsystem. Furthermore, we introduce the application of the three-step impedance criterion in two small-signal stability analysis cases and utilize it in an example system to predict the stability shift process arising from the variation on the load resistance and input voltage value.

[1]  George C. Verghese,et al.  Nonlinear Phenomena in Power Electronics , 2001 .

[2]  C. M. Wildrick.  Stability of distributed power supply systems , 1993 .

[3]  Dushan Boroyevich,et al.  Fault detection in DC distributed power systems based on impedance characteristics of modules , 2000, Conference Record of the 2000 IEEE Industry Applications Conference. Thirty-Fifth IAS Annual Meeting and World Conference on Industrial Applications of Electrical Energy (Cat. No.00CH37129).

[4]  Fred C. Lee,et al.  On-line measurement on stability margin of DC distributed power system , 2000, APEC 2000. Fifteenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.00CH37058).

[5]  Spiro P. Karatsinides.  Line-of-sight pointing accuracy improvements through analytic boresighting , 2000, IEEE Trans. Aerosp. Electron. Syst..

[6]  Fred C. Lee,et al.  Stability margin monitoring for DC distributed power systems via current/voltage perturbation , 2001, APEC 2001. Sixteenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.01CH37181).

[7]  Fred C. Lee,et al.  Individual load impedance specification for a stable DC distributed power system , 1999, APEC '99. Fourteenth Annual Applied Power Electronics Conference and Exposition. 1999 Conference Proceedings (Cat. No.99CH36285).

[8]  R. D. Middlebrook,et al.  Null double injection and the extra element theorem , 1989 .

[9]  Scott D. Sudhoff,et al.  Admittance space stability analysis of power electronic systems , 2000, IEEE Trans. Aerosp. Electron. Syst..

[10]  Dushan Boroyevich,et al.  Theoretical and experimental investigation of the fast- and slow-scale instabilities of a DC-DC converter , 2001 .

[11]  Sung-Soo Hong,et al.  Dynamics and control of DC-to-DC converters driving other converters downstream , 1999 .

[12]  R. D. Middlebrook,et al.  Input filter considerations in design and application of switching regulators. , 1976 .

[13]  Fred C. Lee,et al.  A method of defining the load impedance specification for a stable distributed power system , 1993 .

[14]  F. C. Lee,et al.  Modeling, analysis and design of distributed power systems , 1989, 20th Annual IEEE Power Electronics Specialists Conference.

[15]  Ali Emadi,et al.  Dynamics and control of multi-converter DC power electronic systems , 2001, 2001 IEEE 32nd Annual Power Electronics Specialists Conference (IEEE Cat. No.01CH37230).

[16]  Fred C. Lee,et al.  Impedance specifications for stable DC distributed power systems , 2002 .