Huy Nguyen-Duc

A Power Oscillation Damping Control Scheme Based on Bang-Bang Modulation of FACTS Signals

In this paper, we develop a new damping control scheme for FACTS devices, using bang-bang modulation of FACTS signals. The scheme is used to attenuate quickly the systems most dominant mode which is identified using online Prony analysis. An analysis framework to evaluate the robustness of the control schemes to changes in operating conditions and to time-delay is also proposed. Simulation results on various test systems show that following large disturbances, the proposed control scheme is very effective to mitigate the power system critical modes of oscillation. Furthermore, the problem of control interactions is completely avoided with the proposed control scheme.

Selection of input/output signals for wide area control loops

This paper studies the various aspects of input/output selection for wide-area damping controllers, targeted at the power system inter-area oscillation modes. The objectives is to choose a control loop which has large impact to a few selected modes, while does not affect the other system modes, hence the interactions problem can be greatly reduced. For this purpose, a new modal interaction index is proposed. Non linear simulations are also carried out to validate the modal analysis results.

Power system robust stability analysis using structured singular value theory and model reduction method

Robust stability analysis of power systems using structured singular value theory is studied in this paper. A method to reduce the order of the open loop uncertain model for power systems is also proposed. Two cases studies are performed and they show that the reduced order uncertain model keeps the most important modes of the system. The system behaviour with respect to parameter variations is also preserved.

Simulation of a power grid blackout event in Vietnam

This paper presents some results of our ongoing research on the dynamic performance of the Vietnam power system. The study involves simulations of N-1 events in the 500-220kV transmission system, especially the loss of an 500kV circuit, which in reality has caused a large scale blackout in the Southern grid of Vietnam, in May 2013. The simulations reveal some interesting results, regarding the operation of transmission line and generators protection systems. The sequence of relay operation can change the course of a large scale event drastically. The results provide us with new insight to revise relay settings that helps reduce the risk of cascade tripping.

An Approach to Solve Transient Stability-Constrained Optimal Power Flow Problem Using Support Vector Machines

Abstract The Transient Stability-Constrained Optimal Power Flow (TSC-OPF) is a challenging optimization problem, and is the subject of several recent researches. This paper proposes a novel approach to solve TSC-OPF. In the proposed framework, Support Vector Machines (SVMs) are used to classify whether an operating condition satisfies predefined transient contingencies. A novel classification strategy is proposed to ensure the optimal solution satisfies all considered contingencies with certain security margin. Besides, the weight coefficients of the SVM are used as sensitivity measures in order to help optimization solver find solutions more effectively. The proposed approach is demonstrated for the New England system and the IEEE 300 bus system.

Analysis and Design of a Robust Power System Damping Controller Considering Time Delay

Abstract This article presents a detailed analysis and design of a static var compensator damping controller for a power system. The drawbacks of the conventional approach to the design of damping controllers are demonstrated. It is found that the interaction between the static var compensator and other system control modes can be worsened by time delay. The relation between time delay uncertainty and control interaction is revealed, using the proposed analysis framework, and is also demonstrated using non-linear simulations. A robust controller based on the μ-synthesis method is designed to overcome the design challenges.

Optimal sizing of energy storage devices in wind-diesel systems considering load growth uncertainty

Nowadays, wind energy has become a very viable alternative solution to provide electrical energy. The development of wind energy is especially relevant for the case of isolated island in the south central provinces of Vietnam, where there is great potential for wind energy. For these isolated systems, the co-generation of diesel generators and wind turbines is a common configuration, but also poses several technical challenges. Auxiliary equipments such as battery storage, flywheel and dump loads are often needed to ensure a more stable operation, higher penetration level of wind energy. However, the cost for these auxiliary equipments can be substantial. This paper proposes an optimization framework to determine the optimal size of energy storage devices in a hybrid wind-diesel system. The optimization problem considers two main uncertain factors, which are the wind speed and the load growth rate.

Power system losses minimization with transient stability constraints

This paper presents a study of Optimal Power Flow calculation, coupled with additional transient stability constraints (TSC-OPF). Besides, with some modifications to the formulation of the transient stability constraint, a better convergence property can be achieved. The framework is applied to the cases of two standard test power systems, with the objective of minimizing total active power loss. It is shown that the current TSC-OPF framework can be used for loss minimization TSC-OPF.