Loi Lei Lai

• BSc (1st); PhD; DSc; FIEEE; CEng; FIET
• Professor (Full) at Guangdong University of Technology

The contactor is a key component in the pre-charging circuit. Once it malfunctions, it will interrupt the power flow in electrical traction drive system (ETDS), resulting in parking. There are various reasons that can cause abnormalities in contactors, and not all fault causes require parking for maintenance. However, there is currently no effectiv...

The scientific and reasonable island partition of microgrids containing DG is of great practical significance for ensuring the safe switching of microgrid island operation and improving the reliability of microgrid power supply. The existing island partitioning strategies focus on power balance and basic load distribution but often neglect multiple...

With the rapid development of smart home technology, residential microgrid (RM) clusters have become an important way to utilize the demand-side resources of large-scale housing. However, there are some key problems in existing RM cluster optimization methods, such as difficult in adapting to the local observable environment and with poor privacy a...

The inverter output overcurrent (IOO) is a common abnormal state in an electric traction system (ETS), which can be caused by several sources within the ETS and results in an immediate inverter shutdown and requires maintenance at the station. In order to improve the efficiency and intelligence level of maintenance, this article proposes an event s...

The traditional energy hub based model has difficulties in clearly describing the state transition and transition conditions of the energy unit in the integrated energy system (IES). Therefore, this study proposes a state transition modeling method for an IES based on a cyber-physical system (CPS) to optimize the state transition of energy unit in...

Identifying circular RNA (circRNA)-drug sensitivity association (CDsA) is crucial for advancing drug development. As conducting traditional wet experiments for determining CDsA is costly and inefficient, calculation methods have already proven to be a valid approach to cope with this problem. However, there exists limited research addressing the pr...

Underfrequency load shedding is the third level protection measure to ensure the safe and stable operation of power systems, which can effectively prevent the rapid decrease in system frequency caused by power system failure. To compensate for the power deficit resulting from faults during the island operation of a microgrid, a two-stage underfrequ...

Online energy management utilizing the real-time information of a residential microgrid (RM) can make full use of renewable energy and demand-side resources at the residential level. However, existing online energy management methods for RMs have poor robustness against environmental changes, which limits their applicability in highly uncertain sce...

Unsupervised feature selection has emerged as a significant and challenging issue in multi-view learning due to the need to process a large amount of unlabeled and high-dimensional multi-view data. Although numerous methods have been developed to this point, the majority of them are offline and have substantial computational and memory costs. Unlik...

With the high penetration of renewable generation systems in the power grid, the accurate simulation of the uncertainty in renewable energy generation is vital to the safe operation of the power system This paper proposes a novel controllable method for renewable scenario generation based on the improved VAEGAN model. The standard VAEGAN model is f...

Driven by carbon neutrality and sustainable development policies, the adoption of photovoltaic (PV) sources has grown significantly in recent years. The integration of distributed PV generation into DC microgrids has proven to be an effective solution. However, as the penetration of the PV sources increases, there is a growing need for these source...

With the increasing number of electric vehicles (EVs), their uncoordinated charging poses a great challenge to the safe operation of the power grid. In addition, traditional individual-EV scheduling models may be difficult to solve due to the increasing number of constraints. Therefore, this paper proposes a cluster-based EV scheduling model. First...

The astounding rate of advance in consumer electronics industry has made a huge impact on smart home energy management. Besides the popular and dominating benefit in energy usage, it can improve comfort, safety and security. Key advantage is interoperability with replacement of devices easily if open standards are adopted.

Isolated grids, with large-scale intermittent renewable energy sources (RESs), face more severe frequency stability issues. Fortunately, grid-connected electric vehicles (EVs) present an opportunity to provide frequency services. In this paper, a two-stage frequency regulation strategy, in which EVs participate in the form of a virtual synchronous...

The transition from traditional power systems to smart grids has led to the widespread utilization of multimicrogrids (MMGs) as a medium for integrating renewable energy sources (RES). However, due to the weak damping and low inertia characteristics of interconnected systems, multi-scale oscillation problems inevitably arise during autonomous opera...

Improved interval-valued prediction models for solar power and irradiance forecasting allow enhanced planning and operation of solar power systems. Highly uncertain atmospheric and environmental factors are major challenges of solar irradiance forecasting. Existing upper and lower bound estimation methods mainly focus on narrowing the prediction in...

Ground faults can be caused by abnormal grounding of several different modules in the electrical traction drive system, leading to vulnerable train operation. Therefore, rapid and accurate diagnosis of ground faults is of great significance to improve safety and reliability of electric locomotives and electric multiple units (EMU). This paper propo...

The operational cost of a microgrid is significantly influenced by the response of storage systems and the complexities of the power market’s tariff structures. This paper addresses the challenges arising from the coexistence of new market entries and traditional tariffs, which contribute to a complex market environment. To tackle this issue, the p...

With the rapid promotion of photovoltaic (PV) power generation, the local consumption of distributed PV power generation at medium and low voltage levels widely forms PV-based microgrids. The continuous increase in the penetration rate of uncertain PV power generation requires it to actively participate in the frequency and voltage regulation of we...

Photovoltaic (PV) power generation is booming in rural areas, not only to meet the energy needs of local farmers but also to provide additional power to urban areas. Existing methods for estimating the spatial distribution of PV power generation potential either have low accuracy and rely on manual experience or are too costly to be applied in rura...

Due to the high-order model of photovoltaic and wind power generation systems, it is complicated to accurately establish the detailed state-space model of the multi-source renewable energy microgrid (MG) system. In addition, when the MGs are interconnected into microgrid clusters (MGCs), the difficulties of the control and stability analysis are gr...

With the aggravation of global environmental pollution problems and the need for energy restructuring, hydrogen energy, as a highly clean resource, has gradually become a hot spot for research in countries around the world. Facing the requirement of distributed hydrogen in refueling the original station for hydrogen transportation and other usage,...

This paper studies the risk management of a battery bidding in both day-ahead and intraday markets arising from the uncertain nature of electricity prices. To this end, a coherent risk measure, Second-order Stochastic Dominance (SSD), which is capable of expressing battery preferences in the form of a preset fixed benchmark (profit), is incorporate...

Most traditional artificial intelligence-based fault location methods are very dependent on fault signal selection and feature extraction, which is often based on prior knowledge. Further, these methods are usually very sensitive to line parameters and selected fault characteristics, so the generalization performance is poor and cannot be applied t...

In the electricity market environment, the regional integrated energy system (RIES) can reduce the total operation cost by participating in electricity market transactions. However, the RIES will face the risk of load and electricity price uncertainties, which may make its operation cost higher than expected. This paper proposes a method to optimiz...

The continuous growth of wind power requires greater power system operational flexibility owing to the variability and uncertainty of wind power generation. Retrofitting existing coal-fired units is a demonstrated cost-effective method for improving system flexibility. This study proposes a decision support tool that provides optimal investment dec...

The integration of a large number of renewable energy sources (RES) into the micro-energy grid (MEG) brings certain challenges to its optimal dispatching, especially the impact of RES and load prediction error on optimal dispatching. Therefore, this paper proposes a multi-timescale coordinated optimization framework for economic dispatch of MEG con...

Grid-side overcurrent (GSOC) is a common anomaly state in traction drive system (TDS). Once GSOC occurs, to protect the train, traction control units (TCU) will trip the main circuit breaker and stop the train in a short time. Since TCU cannot locate the source of the GSOC fault, troubleshooting can only be done by inspecting the components one by...

Multi-microgrids (MMGs) provide an effective modality to integrate high-penetration renewable energy as well as other distributed sources. However, the inherent uncertainties from nature and load demand significantly impact the secure operation of the MMGs system. Considering these challenges, this paper proposes a novel intraday robust energy mana...

Multi-microgrids (MMGs) provide an effective solution for further improving the overall economy and ensuring resilience under major disasters, while high penetration level of renewable energy generations inevitably brings adverse oscillation problems to the system. So far, no comprehensive study has been carried out to assess the interaction and os...

Main circuit ground fault (MCGF) is an electrical fault that occurs in electrical traction drive systems (ETDS). Timely detection and processing are effective ways to avoid further deterioration and safety accidents. Aiming at improve maintenance efficiency and train operation safety, this paper proposes a feature vector learning-based method for r...

With the large-scale integration of wind power, the frequency stability of the power system is facing a significant challenge due to the wind power generation system typically operating in maximum power point tracking (MPPT) mode. Traditional frequency support control methods for wind turbines (WTs) do not consider the state of WTs and the frequenc...

The Special Issue on “Smart Buildings for Smart Cities” presents work on multidisciplinary research for novel, scientific, technological insights, principles, algorithms, and experiences on technologies, case studies, novel approaches, and visionary ideas related to data-driven innovative solutions and big data-powered applications to cope with the...

Unsupervised multi-view feature selection has become an important research direction in the field of pattern recognition and machine learning. However, most of existing methods fail to consider the redundancy information within and between views or the noise information in each view. In this paper, we propose a multi-level regularization-based unsu...

Large-scale integration of battery energy storage systems (BESS) in distribution networks has the potential to enhance the utilization of photovoltaic (PV) power generation and mitigate the negative effects caused by electric vehicles (EV) fast charging behavior. This paper presents a novel deep reinforcement learning-based power scheduling strateg...

The emerging wireless technologies facilitate the network expansion by connecting different kinds of devices and sensors together. The integration of the wearable sensors is usually defined as wireless body network which facilitates real‐time monitoring status of human in numerous applications such as worker safety and patient tracking. It is found...

The wide adoption of electric vehicle (EV) has been identified as a major challenge for future development of smart grids. The ever‐increasing EV charging further increases the energy demand. This chapter reports the development of an Advanced Metering Infrastructure (AMI) as an effective tool to reshape the load profile of EV charging by adopting...

Apart from smart energy, transportation, and health as described in the previous seventeen chapters, within a smart city, there are many more elements such as water and waste; bio, food and agriculture; education and safety and well‐being; government and social and civic engagement; social entrepreneurship, digital finance and law and economic deve...

Internet of Things (IoT)‐based infrastructures and applications are essential for smart cities deployment. The low‐power wide‐area network (LPWAN) plays a key role in IoT techniques due to the characteristics of wide coverage and low power consumption. However, it is hard to decide which one of the LPWAN techniques to be implemented in a specific a...

With increasing penetration of solar photovoltaic (PV) resources in distribution networks, voltage regulation becomes an important issue. In addition, due to the growth in air conditioning load in summer days, overloading management draws researchers’ attentions as well. This chapter proposes a two‐level consensus‐driven distributed control strateg...

The use of distributed computation and control is pervasive for a wide range of smart grid research topics. However, recent developments of smart grid co‐simulation platforms have not been able to provide effective support for the modeling and simulation of distributed software systems. In particular, co‐simulation literatures only focused on the i...

In this chapter, bioinformatics and telemedicine for healthcare will be discussed. Some models, designs, and frameworks for potential applications will be illustrated. Opportunities and challenges will be detailed and scientifically investigated. The importance of the development of decision support systems and the advancement of artificial intelli...

This chapter proposes a novel two‐stage game‐theoretic residential photovoltaic (PV) panels planning framework for distribution grids with potential PV prosumers. One innovative contribution is that a residential PV panels location‐allocation model is integrated with the energy sharing mechanism to increase economic benefits to PV prosumers and mea...

Nonintrusive load monitoring (NILM) and semi‐intrusive load monitoring (SILM) are fast developing techniques for devices operation recognition in system monitoring. Many traditional researches focus on feature space improvements for better recognition accuracy and classifier/meter quantity reduction. But practically, cost of each classifier/meter w...

As plug‐in hybrid electric vehicles (PHEVs) are expected to be widely used in the near future, a mathematical model is developed based on the traditional security constrained unit commitment (SCUC) formulation to address the power system dispatching problem with PHEVs taken into account. With the premise of power system secure operation, both the e...

It is foreseen that the trends for the next decade in healthcare will include more patients requiring care, increased use of technology, need for greater information storage capacity, development of new healthcare delivery models, error reduction, more emphasis on preventative healthcare, faster disease diagnosis, and innovation driven by competiti...

As more and more electric buses (EBs) in use, the reasonable location of charging station plays an important role in the process of bus electrification. This chapter proposes a location planning model for electric bus fast‐charging stations that takes the bus operation network and the distribution network into account. The model simulates the opera...

This chapter proposes a novel framework for home energy management (HEM) based on reinforcement learning in achieving efficient home‐based demand response (DR). The concerned hour‐ahead energy consumption scheduling problem is duly formulated as a finite Markov decision process (FMDP) with discrete time steps. To tackle this problem, a data‐driven...

The information technology in a cyber‐physical power system plays a significant role in quickly regulating the energy flow that can cope with the complexity of power system operation and control. The energy processing capability of power systems depends heavily on the reliability of information systems. The reliability model of cyber space includes...

Demand response (DR) is one of the typical methods to optimize load characteristics in power system. Utilities offer DR scheme to generate incentive toward consumers’ behavior for load optimization. In tariff planning, power usage transformation is an important issue which is difficult to be analyzed quantifiably. This chapter introduces a boundary...

In this chapter, the definition of smart city will be discussed, and its functions, characteristics, and domains will be explained. To demonstrate the smart city deployment and benefits derived from it, different elements of a smart city, such as smart energy, smart transportation, and smart health, based on the advancement of information and commu...

Electrical energy storage (EES) such as lithium‐ion (Li‐ion) batteries can reduce curtailment of renewables, maximizing renewable utilization by storing surplus electricity. Several techno‐economic analyses have been performed on EES, but few have investigated the financial performance. This chapter presents a state‐of‐the‐art financial model obtai...

Off‐grid renewable energy system is a critical infrastructure in providing electrical power for small communities, especially in remote and rural areas where grid connection points are not available. Due to the diurnal and intermittent nature of solar irradiance, the photovoltaic (PV) power plant can introduce generation and load power imbalance pr...

Several electricity tariffs have emerged for demand side management (DSM), and residential customers are faced with challenges to choose the plan satisfying their personal needs. Electricity plan recommender system (EPRS) can alleviate the problem. This chapter proposes a novel EPRS model named EPRS with electrical instruction‐based recovery (EPRS‐...

Networking of microgrids (MGs) has received increasing attentions in recent years, which requires the uncertainty management associated with variations in the system. In this chapter, a two‐stage energy management strategy is developed for networked MGs under the presence of high renewable resources. It decomposes the MGs energy management into two...

As wind power generation transitions from centralized development mode to decentralized on-site consumption mode, microgrid (MG) can provide an efficient solution for wind power integration into the distribution network. However, the high-penetration wind power MG is the typical weak power grid system. The traditional wind turbine generator (WTG) p...

A hybrid short-term wind power prediction model based on data decomposition and combined deep neural network is proposed with the inclusion of the characteristics of fluctuation and randomness of nonlinear signals, such as wind speed and wind power. Firstly, the variational mode decomposition (VMD) is used to decompose the wind speed and wind power...

Photovoltaic (PV) generation is increasing in distribution systems following policies and incentives to promote zero-carbon emission societies. Most residential PV systems are installed behind-the-meter (BTM). Due to single meter deployment that measures the net load only, this PV generation is invisible to distribution system operators causing a n...

Driven by rising energy demand and the goal of carbon neutrality, renewable energy generations (REGs), especially photovoltaic (PV) generations, are widely used in the urban power energy systems. While the intelligent control of microgrids (MG) brings economic and efficient operation, its potential stability problem cannot be ignored. To date, most...

To fully reveal the interplay of the cyber system and physical system in the microgrid, this paper proposes a generic hierarchical modeling framework for cyber-physical integration modeling of microgrid, including two layers: physical device layer and controller layer. Each layer includes two parts: the continuous part (characterizing the physical...

High precision short-term photovoltaic (PV) power prediction can reduce the damage associated with large-scale photovoltaic grid-connection to the power system. In this paper, a combination deep learning forecasting method based on variational mode decomposition (VMD), a fast correlation-based filter (FCBF) and bidirectional long short-term memory...

With the flexible integration of local renewable energy with the smart distribution network system, the problems of high operating costs and power shortage can be effectively solved. However, taking the industrial park microgrid with high penetration photovoltaic as an example, due to the uncertainties and fluctuations arising from the meteorologic...

Distribution utilities can flexibly control distribution networks by allocating the automatic and remotely controlled sectionalizing switches (SSs), which work with tie lines (TLs) to speed up fault management and are alternative devices for distribution operation mode adjustment. Hence, the SSs and the TLs play an important role in distribution ne...

As smart cities strive towards using green and renewable energy, sustainable energy plays a critical role. A smart city requires its energy generation, supply, transmission, distribution, and management components to be modular, automated, reliable, safe, and controllable. A smart city energy system must be reliable, efficient, and robust against a...

Research on preventive generation dispatch schemes for resilient power system operation is often based on the DC power flow model, ignoring the influence of reactive power and voltage magnitude. This paper presents an in-depth study of a linearized AC power flow (LAC) model with reactive power and voltage magnitude to derive sensitivity factors, in...

To achieve the national carbon-peak and carbon-neutral strategic development goals, it is necessary to build power systems dominated by renewable and sustainable energy. The future power system with a high proportion of renewable and sustainable energy is required to have large-scale, low-cost, flexible, and adjustable resources. To this end, this...

Multi-view subspace clustering has drawn significant attention in the pattern recognition and machine learning research community. However, most of the existing multi-view subspace clustering methods are still limited in two aspects. (1) The subspace representation yielded by the self-expression reconstruction model ignores the local structure info...

As extreme weather events have become more frequent in recent years, improving the resilience and reliability of power systems has become an important problem. In this paper, a robust preventive-corrective security-constrained optimal power flow (RO-PCSCOPF) model is proposed to improve power system reliability under N-k outages. Both the short-ter...

The multi-terminal HVDC system based on the modular multilevel converter (MMC-MTDC) is a promising technique for flexible power transmissions to multiple regions. As such a system is quite sensitive to DC faults, there is an acute need to propose a protection element that can trip the local DC circuit breaker (CB) within several milliseconds once t...

Three-phase power imbalances may occur in the distribution network due to high electric vehicle (EV) charging demand. The imbalances become severe with the increasing number of EVs in the future and may be addressed with coordinated charging strategies. In this paper, we propose a phase-balancing and peak-shaving scheme for a community in the three...

The fast determination of internal or external fault for the VSC-MTDC is essential for its safety and continuous operation. As very limited time is permitted in an internal fault, transient-based protection elements are widely applied to locate the fault in a very small-time window. However, with such a short time window, location methods based on...

The multi-terminal HVDC system based on the modular multilevel converter (MMC-MTDC) has very high technical merits for long-distance, flexible power transmission. In recent years, there has been a significant improvement in developing its fast-speed primary protection, especially for local-measurement-based ones immune to communication anomalies. H...

We present a circuit design of the hierarchical attention network for multimodal affective computing, which can be used in mental health monitoring. Specifically, a kind of cost-effective memristor is fabricated using the albumen protein, and the corresponding testing performance is conducted to ensure its efficiency and stability. Then, considerin...

An increasing number of behind-the-meter (BtM) rooftop photovoltaic (PV) panels is being installed and maintained by site owners. However, invisible PV power generation (PVPG) will lead to the difficulty for system operators in power dispatch and affect the safety and stability of the power system. To better quantify BtM PVPG, a novel unsupervised...

Memristive technologies are attractive due to their non-volatility, high-density, low-power and compatibility with CMOS. For memristive devices, a model corresponding to practical behavioral characteristics is highly favorable for the realization of its neuromorphic system and applications. This paper presents a novel flexible memristor model with...

A microgrid is considered to be a smart power system that can integrate local renewable energy effectively. However, the intermittent nature of renewable energy causes operating pressure and additional expense in maintaining the stable operation by the energy management system in a microgrid. The structure of multimicrogrids provides the possibilit...

A distributed data center cluster (DDCC) consists of data centers that are geographically dispersed while managed by the same company. A DDCC is composed of several data centers in different regions, so it purchases electricity from several electricity retailers in different regions. Commonly, there is a lack of cooperation between the several elec...

Various disturbances can lead to frequency deviations and multiple operating states of the islanded micro-energy grid (MEG) system. However, the existing research on optimal scheduling of MEG does not perform optimal scheduling based on the frequency deviation division, which is difficult to adapt to the variable operating states of MEG. Therefore,...

This paper proposes a novel maximum power point tracking (MPPT) method based on the variant of the pigeon-inspired optimization (PIO) algorithm for photovoltaic (PV) systems under partial shading conditions (PSCs). The proposed method integrates the hierarchical network behavior of pigeon flock and revises the map and compass operator of the origin...

The role of biomass resources to diminish the dependency on fossil fuels is steadily increasing worldwide. More importantly, governments set goals to boost the share of renewable energy resources in the power sector to face up to global warming issues. In this paper, a coalitional game model for the trading of a Biomass Power Plant (BPP) paired wit...

Due to policy support, low cost and easy applicability, distribution photovoltaic systems (DPVSs) are increasingly popular among residential community. However, small-scale DPVSs of less than 10 kWp are always installed behind the meter (BTM), which results in the invisible of the photovoltaic (PV) power generation. Only access of composite power d...

To achieve net-zero emissions economy, the transition to online entertainment and retail, aging populations, urban population growth, and pressures on public finance have created huge interests for human to run cities differently and smartly. A term titled smart city is created which is considered as an idealistic city, where the quality of life fo...

In this paper, two short-term power prediction method based on singular spectrum analysis (SSA) and Stacking ensemble learning framework have been proposed. A household load forecasting method based on multiple cycles self-boosted neural network named as MultiCycleNet was also proposed. Simulation results have been used to demonstrate the benefits...

The electricity market reform in China stimulates the capacity of demand-side resources regulation and provides a new approach to promote large-scale renewable energy access to power grid. However, there is no effective modeling method to describe the participation of demand-side resources in power grid regulation, which seriously affects the resea...

Abstract The reform of power spot market in China provides a new profit mode, determining energy trading strategy based on the power spot prices for distributed energy storages. However, individually accessing every distributed energy storage to the dispatch centre results in a high cost and low efficiency, which needs to be improved by connecting...