scholarly journals Inter-Area Oscillation Damping in Large-Scale Power Systems Using Decentralized Control

2018 ◽  
Author(s):  
Roghieh A. Biroon ◽  
Pierluigi Pisu ◽  
David Schoenwald
Keyword(s):  
Power Systems ◽  
Power System ◽  
Large Scale ◽  
Order System ◽  
Small Signal Stability ◽  
Large Scale System ◽  
Signal Stability ◽  
Oscillation Damping ◽  
System Frequency ◽  
Lower Order System

Inter-area oscillation is one of the main concerns in power system small signal stability. It involves wide area in power system, therefore identifying the causes and damping these oscillations are challenging. Undamped inter-area oscillations may cause severe problems in power systems including large-scale blackouts. Designing a proper controller for power systems also is a challenging problem due to the complexity of the system. Moreover, for a large-scale system it is impractical to collect all system information in one location to design a centralized controller. Decentralized controller will be more desirable for large scale systems to minimize the inter area oscillations by using local information. In this paper, we consider a large-scale power system consisting of three areas. After decomposing the system into three subsystems, each subsystem is modeled with a lower order system. Finally, a decentralized controller is designed for each subsystem to maintain the large-scale system frequency at the desired level even in the presence of disturbances.

scholarly journals Small-Signal Stability of Multi-Converter Infeed Power Grids with Symmetry

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 157
Author(s):  
Jiawei Yu ◽  
Ziqian Yang ◽  
Jurgen Kurths ◽  
Meng Zhan
Keyword(s):  
Power Systems ◽  
Power System ◽  
Large Scale ◽  
System Stability ◽  
Characteristic Matrix ◽  
Small Signal ◽  
Power Electronic ◽  
Energy Integration ◽  
Small Signal Stability ◽  
Signal Stability

Traditional power systems have been gradually shifting to power-electronic-based ones, with more power electronic devices (including converters) incorporated recently. Faced with much more complicated dynamics, it is a great challenge to uncover its physical mechanisms for system stability and/or instability (oscillation). In this paper, we first establish a nonlinear model of a multi-converter power system within the DC-link voltage timescale, from the first principle. Then, we obtain a linearized model with the associated characteristic matrix, whose eigenvalues determine the system stability, and finally get independent subsystems by using symmetry approximation conditions under the assumptions that all converters’ parameters and their susceptance to the infinite bus (Bg) are identical. Based on these mathematical analyses, we find that the whole system can be decomposed into several equivalent single-converter systems and its small-signal stability is solely determined by a simple converter system connected to an infinite bus under the same susceptance Bg. These results of large-scale multi-converter analysis help to understand the power-electronic-based power system dynamics, such as renewable energy integration. As well, they are expected to stimulate broad interests among researchers in the fields of network dynamics theory and applications.

scholarly journals Assessing the Impact of DFIG Synthetic Inertia Provision on Power System Small-Signal Stability

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3440 ◽  
Author(s):  
Edgar Lucas ◽  
David Campos-Gaona ◽  
Olimpo Anaya-Lara
Keyword(s):  
Power System ◽  
Large Scale ◽  
Damping Ratio ◽  
System Stability ◽  
Electrical Network ◽  
Small Signal ◽  
Small Signal Stability ◽  
Signal Stability ◽  
Electromechanical Modes ◽  
The Impact

Synthetic inertia provision through the control of doubly-fed induction generator (DFIG) wind turbines is an effective means of providing frequency support to the wider electrical network. There are numerous control topologies to achieve this, many of which work by making modifications to the DFIG power controller and introducing additional loops to relate active power to electrical frequency. How these many controller designs compare to one-another in terms of their contribution to frequency response is a much studied topic, but perhaps less studied is their effect on the small-signal stability of the system. The concept of small-signal stability in the context of a power system is the ability to maintain synchronism when subjected to small disturbances, such as those associated with a change in load or a loss of generation. Amendments made to the control system of a large-scale wind farm will inevitably have an effect on the system as a whole, and by making a DFIG wind turbine behave more like a synchronous generator, which synthetic inertia provision does, may incur consequences relating to electromechanical oscillations between generating units. This work compares the implications of two prominent synthetic inertia controllers of varying complexity and their effect on small-signal stability. Eigenvalue analysis is conducted to highlight the key information relating to electromechanical modes between generators for the two control strategies, with a focus on how these affect the damping ratios. It is shown that as the synthetic inertia controller becomes both more complex and more effective, the damping ratio of the electromechanical modes is reduced, signifying a decreased system stability.

Impact of Large-Scale Integrated Wind Farms on the Small Signal Stability of Power System

2013 ◽  
Vol 805-806 ◽  
pp. 393-396
Author(s):  
Zhen Yu Xu ◽  
Zhen Qiao ◽  
Qian He ◽  
Xu Zhang ◽  
Jing Qi Su
Keyword(s):  
Power System ◽  
Large Scale ◽  
Power Grid ◽  
Wind Farms ◽  
Small Signal ◽  
Small Signal Stability ◽  
Direct Drive ◽  
Signal Model ◽  
Signal Stability ◽  
The Impact

With the penetration of wind energy is becoming higher and higher in power grid, it is very important to investigate the impact of wind generations on small signal stability. In this paper, a complete small signal model of wind turbine with direct-drive permanent magnet generator is built to study the impact of large-scale wind farms on the small signal stability of power system. By means of simulation and eigenvalue analysis, an actual power system is investigated, and the damping characteristic of power grid under different wind power penetration is discussed.

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