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Improved sinusoid-locked loop equipped with a virtual stator impedance to estimate the grid voltage parameters
- Source :
- Electric Power Systems Research. 173:86-99
- Publication Year :
- 2019
- Publisher :
- Elsevier BV, 2019.
-
Abstract
- Grid voltage parameters, including the amplitude, frequency and phase angle, are the essential information for the control and protection of power systems. The sinusoid-locked loop (SLL) is a novel approach to estimate the grid voltage parameters, which achieves accurate estimation and strong robustness in the presence of harmonic disturbances. However, the conventional SLL is sensitive to large voltage variations or computation errors, which may fail to achieve accurate estimation when the controller is trapped in the undesired equilibrium. In this paper, a modified sinusoid-locked loop (MSLL) is designed to improve the estimation performance with respect to large voltage variations. A virtual stator impedance is introduced to eliminate the undesired equilibrium, which mimics the armature reaction of a virtual synchronous machine (VSM). In addition, the closed-loop stability is investigated based on the small-signal model of the proposed MSLL. Following the idea of the VSM, the output voltage of the VSM is locked with the input grid voltage when the real power and reactive power are both driven to zero. Simulation and experimental results are presented to illustrate the effectiveness of the proposed MSLL, which achieves excellent estimation performance in the presence of large voltage variations and harmonic disturbances.
- Subjects :
- Computer science
Stator
020209 energy
020208 electrical & electronic engineering
Energy Engineering and Power Technology
02 engineering and technology
AC power
law.invention
Electric power system
Amplitude
Robustness (computer science)
Control theory
law
0202 electrical engineering, electronic engineering, information engineering
Electrical and Electronic Engineering
Synchronous motor
Electrical impedance
Voltage
Subjects
Details
- ISSN :
- 03787796
- Volume :
- 173
- Database :
- OpenAIRE
- Journal :
- Electric Power Systems Research
- Accession number :
- edsair.doi...........07a8c4170c447f46138c72a9a297ab6f