scholarly journals Lyapunov-Based Large Signal Stability Assessment for VSG Controlled Inverter-Interfaced Distributed Generators

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2273 ◽  
Author(s):  
Meiyi Li ◽  
Wentao Huang ◽  
Nengling Tai ◽  
Moduo Yu
Keyword(s):  
Transient Stability ◽  
Stability Domain ◽  
Assessment Method ◽  
Stability Assessment ◽  
Large Signal ◽  
Machine Model ◽  
Signal Stability ◽  
Distributed Generators ◽  
Linearized Stability ◽  
The Stability

Inverter-interfaced distributed generators (IIDGs) have been widely applied due to their control flexibility. The stability problems of IIDGs under large signal disturbances, such as large load variations and feeder faults, will cause serious impacts on the system. The virtual synchronous generator (VSG) control is an effective scheme for IIDGs to increase transient stability. However, the existing linearized stability models of IIDGs are limited to small disturbances. Hence, this paper proposes a Lyapunov approach based on non-linearized models to assess the large signal stability of VSG-IIDG. The electrostatic machine model is introduced to establish the equivalent nonlinear model. On the basis of Popov’s theory, a Lyapunov function is derived to calculate the transient stability domain. The stability mechanism is revealed by depicting the stability domain using the locus of the angle and the angular frequency. Large signal stability of the VSG-IIDG is quantified according to the boundary of the stability domain. Effects and sensitivity analysis of the key parameters including the cable impedance, the load power, and the virtual inertia on the stability of the VSG-IIDG are also presented. The simulations are performed in PSCAD/EMTDC and the results demonstrate the proposed large signal stability assessment method.

Mid-Term Stability Assessment of Jiangxi Power Grid

2013 ◽  
Vol 732-733 ◽  
pp. 882-887
Author(s):  
Yong Chun Su ◽  
Hao Wei Jia
Keyword(s):  
Power System ◽  
Power Grid ◽  
Assessment Method ◽  
Control Measures ◽  
Assessment Process ◽  
Jiangxi Province ◽  
Stable Operation ◽  
Stability Assessment ◽  
Term Stability ◽  
The Stability

Mid-term stability assessment is an important work to support power system operation in a province power grid of China every year. The stability assessment method and process was introduced in this paper. As an example, the stability of Jiangxi province power system was evaluated in the following two years. Weak area and weak transmission line were found out in each power supply area. Prevention and control measures were proposed. According to problems among the assessment process and using the state monitoring data, an approach was discussed to increase the assessment result accuracy. The analysis conclusion provides the reference to the safe and stable operation of Jiangxi power system.

Analysis and Stability Enhancement of DG Sourced Power System with Modified AVR and PSS

2013 ◽  
Vol 768 ◽  
pp. 313-316
Author(s):  
P. Sivakumar ◽  
C. Birindha
Keyword(s):  
Power System ◽  
Distribution System ◽  
Transient Stability ◽  
Probabilistic Approach ◽  
Small Signal Stability ◽  
Signal Stability ◽  
The Stability ◽  
System Stabilizer ◽  
Stability Issues ◽  
Stability Enhancement

Distribution system is facing stability issues with integration of distributed generators and controllers. This proposed method presents the stability of renewable energy based distribution system with varying energy source considering intermittent nature of wind and solar energy using probabilistic approach. The system is supplied by conventional and distributed generating sources like PV and wind. Monte Carlo approach is used for predicting the wind and solar power uncertainties. Proposed work explains both small signal stability and transient stability enhancement of DG sourced power system with power system stabilizer and automatic voltage regulator .It is carried out in is 4 machine 10 bus system. The initial simulation has been carried out using MATLAB/SIMULINK.

scholarly journals Qualitative and Quantitative Transient Stability Assessment of Stand-Alone Hybrid Microgrids in a Cluster Environment

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1286
Author(s):  
Kishan Veerashekar ◽  
Halil Askan ◽  
Matthias Luther
Keyword(s):  
Transient Stability ◽  
System Stability ◽  
Stability Assessment ◽  
Large Signal ◽  
Operating Modes ◽  
Stability Point ◽  
Cluster Environment ◽  
Angle Stability ◽  
Rotor Angle ◽  
Rotor Angle Stability

Neighboring stand-alone hybrid microgrids with diesel generators (DGs) as well as grid-feeding photovoltaics (PV) and grid-forming battery storage systems (BSS) can be coupled to reduce fuel costs and emissions as well as to enhance the security of supply. In contrast to the research in control and small-signal rotor angle stability of microgrids, there is a significant lack of knowledge regarding the transient stability of off-grid hybrid microgrids in a cluster environment. Therefore, the large-signal rotor angle stability of pooled microgrids was assessed qualitatively and also quantitatively in this research work. Quantitative transient stability assessment (TSA) was carried out with the help of the—recently developed and validated—micro-hybrid method by combining time-domain simulations and transient energy function analyses. For this purpose, three realistic dynamic microgrids were modelled regarding three operating modes (island, interconnection, and cluster) as well as the conventional scenario “classical” and four hybrid scenarios (“storage”, “sun”, “sun & storage”, and “night”) regarding different instants of time on a tropical partly sunny day. It can be inferred that, coupling hybrid microgrids is feasible from the voltage, frequency, and also transient stability point of view. However, the risk of large-signal rotor angle instability in pooled microgrids is relatively higher than in islanded microgrids. Along with critical clearing times, new stability-related indicators such as system stability degree and corrected critical clearing times should be taken into account in the planning phase and in the operation of microgrids. In principle, a general conclusion concerning the best operating mode and scenario of the investigated microgrids cannot be drawn. TSA of pooled hybrid microgrids should be performed—on a regular basis especially in the grid operation—for different loading conditions, tie-line power flows, topologies, operating modes, and scenarios.

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