Controlled Islanding for a Hybrid AC/DC Grid With VSC-HVDC Using Semi-Supervised Spectral Clustering

Abstract

As the last resort of emergency control, controlled islanding is an effective means of preventing fault-propagation and a system-wide blackout. However, conventional AC transmission lines are unavailable to be employed for power exchange between these islands. To make full use of the DC power modulation capability of VSC-HVDC links, a new controlled islanding model is put forward for an AC/VSC-HVDC hybrid grid to minimize the composite power-flow disruption, in which the DC-terminals belonging to a VSC-HVDC link are placed in different islands. To solve this model, a semi-supervised spectral clustering-based approach is proposed by transforming the problem into a weighted undirected graph segmentation problem. The novelty of our work is to find an optimal islanding solution in real time such that the power exchanges between islands are implemented via a VSC-HVDC link to reduce the generation-load imbalance. The simulation results on the IEEE 39-bus system and a real-world system verify the effectiveness and superiority of the proposed approach.

Security-Constrained Multi-Objective Optimal Power Flow for a Hybrid AC/VSC-MTDC System With Lasso-Based Contingency Filtering

“…For implementing this transition, as an emerging and powerful transmission technology, the voltage source converter (VSC) based high voltage direct current (HVDC) (VSC-HVDC for short) has attracted ever-growing attention since the 1990s and the amount of VSC-HVDC projects dramatically increases in recent years [2]. Compared with conventional current source converter based HVDC, the VSC-HVDC has some significant advantages, such as independent control of active and reactive powers, and controlled islanding [3]. Most importantly, VSC-HVDC offers good prospects for construction of multi-terminal HVDC (MTDC), which makes it suitable for the integration of high-penetration renewable energy sources into smart grids.…”

Overview of the Optimal Smart Energy Coordination for Microgrid Applications

“…The smart grid refers to a novel electrical network that acts intelligently to accommodate clean energy, electric power management, grid modernization and consumer participation in an energy-efficient manner [15]- [18]. The intelligent electrical grid also assists the improvement of power operation that minimises power disruptions, which can guarantee a proper network control scheme [19], [20] and a good protection philosophy [18], [21]. Through a communication network, the combination of these four goals of a smart grid, namely RERs, electrical power management or energy management, grid modernization and consumer participation [15] reduce the harmful greenhouse gas emissions of the electrical power industry [15]- [17].…”

“…The hybrid AC/DC microgrid offers several benefits to the entire electrical system from power generation to consumption [257]. Due to system improvement, the hybrid structure can be flexible and provide more efficiency on the system but can have a complex architecture which is caused by different voltage system and power configuration [20], [258]. Besides, a microgrid clustering architecture is considered as an advanced hybrid microgrid which contains multiple microgrids within a specific range of distance with one or different power configuration [259], [260].…”

State Estimation for Hybrid VSC Based HVDC/AC Transmission Networks

“…The same architecture is used with the HVDC stations and transmission grids, they are operated by separate SCADA systems as shown in Figure 1 [1][2][3][13][14][15]. As a result, the research on SCADA for hybrid HVDC/AC transmission (mainly VSC based) is divided into two main approaches, a distributed or decentralized approach such as in [16][17][18][19], and centralized or hierarchical structure such as in [1,2,[20][21][22]. In the centralized approach, both AC and DC sides are controlled by one unified SCADA, leading to several challenges and modifications have to be addressed such as:…”