Search results for "säätötekniikka"
showing 3 items of 3 documents
Stability of charge-pump phase-locked loops : the hold-in and pull-in ranges
2020
The problem of design and analysis of synchronization control circuits is a challenging task for many applications: satellite navigation, digital communication, wireless networks, and others. In this article the Charge-Pump Phase-Locked Loop (CP-PLL) electronic circuit, which is used for frequency synthesis and clock generation in computer architectures, is studied. Analysis of CP-PLL is not trivial: full mathematical model, rigorous definitions, and analysis still remain open issues in many respects. This article is devoted to development of a mathematical model, taking into account engineering aspects of the circuit, interpretation of core engineering problems, definition in relation to m…
Harmonic balance analysis of pull-in range and oscillatory behavior of third-order type 2 analog PLLs
2020
The most important design parameters of each phase-locked loop (PLL) are the local and global stability properties, and the pull-in range. To extend the pull-in range, engineers often use type 2 PLLs. However, the engineering design relies on approximations which prevent a full exploitation of the benefits of type 2 PLLs. Using an exact mathematical model and relying on a rigorous mathematical thinking this problem is revisited here and the stability and pull-in properties of the third-order type 2 analog PLLs are determined. Both the local and global stability conditions are derived. As a new idea, the harmonic balance method is used to derive the global stability conditions. That approach…
Analytical-numerical analysis of closed-form dynamic model of Sayano-Shushenskaya hydropower plant : stability, oscillations, and accident
2021
This work is devoted to the analysis of a mathematical model of hydropower unit, consisting of synchronous generator, hydraulic turbine, and speed governor. It is motivated by the accident happened on the Sayano-Shushenskaya hydropower plant in 2009 year. In the analysis we follow the line of classical control theory approach developed in the works of famous scientists J.C. Maxwell, I.A. Vishnegradsky, A.A. Andronov, and F. Tricomi for the study of centrifugal turbine governor and electrical machines limit-load problem. It is shown that the occurrence of vibrations in the Sayano-Shushenskaya hydropower plant can be caused by nonlinear dynamics of the closed-form model. peerReviewed