Current Research
Hybrid renewable energy systems for remote communities
Despite high cost and environmental impacts, diesel generation is still the standard source of electricity supply in most remote communities of northern Canada. Many of these remote communities do not have overland roads and therefore rely on winter roads for diesel transportation. Changing climate is adversely affecting the dependability of winter roads. It is possible to integrate solar Photovoltaics (PV), wind power and energy storage into existing diesel-based grids obtain reliable, cost-effective and efficient energy supply for these communities. Such hybrid renewable energy systems operating as well managed microgrids can significantly reduce the diesel use without scarifying the reliability. The main goals of this research are to develop improved methods for (i) optimization of the configuration of HRES consisting of PV, wind and energy storage, (ii) day ahead energy management based on load, wind, solar radiation and demand response forecasts, (iii) modeling and control of HRES for interconnections studies, and (iv) protection of microgrids during faults and abnormal operating conditions.
Protection of multi-terminal HVDC grids
Power industry is actively investigating HVDC grids for transporting remote and offshore renewable energy, flexible power flow control to meet market requirements, and overcoming technical constraints in HVAC transmission systems. There are a few multi-terminal HVDC (MT-HVDC) systems based on multi-level modular converter (MMC) technology operating in a trial basis, and the industry trend clearly indicates a growth of MT-HVDC grids. However, detection and clearing of DC side faults in MT-HVDC grids with minimum disruption of power flow in the healthy parts of the system is a major challenge, particularly due to technical limitations and high costs of DC circuit breaker technology. This research investigates improved methods for detection, discrimination, classification and clearing of DC side faults. In addition to purely MMC based MT-HVDC grids, DC fault protection in hybrid HVDC transmission systems involving both MMC and the traditional line commutated converter (LCC) technologies are investigated.
Protection of microgrids and active distribution systems
Existence of distributed energy resources (DER) causes many problems for traditional protection used in radially operated distribution networks. The issues include false operation of protection, lack of sufficiently large sustained fault current to detect faults, unintentional islanding, and unsynchronized reclosing. In this research, application of various transient based protection strategies that do not rely on the traditionally assumed radial network structure or sustained fault currents from DER for the fault discrimination. The investigations include development of sensors specifically suitable for transient measurements, signal processing methods, hybrid protection approaches that combine reliability of traditional protection with selectivity and sensitivity of transient based protection. Recent research include exploration of centralized protection for active distribution systems capitalizing on routable sample values (R-SV) and routable GOOSE (R-GOOSE) communication proposed in latest edition of IEC 61850 standard.
Planning of distribution grids to accommodate electric vehicles and renewable energy
After introducing deregulated power markets
and small scale distributed generation (DG) in power distribution systems, the
probabilistic evaluation gained much attention to quantify the uncertainties
due to parameters such as wind speed, solar irradiation, power market price
etc. Due to increasing penetration of electric vehicles (EVs), the load demand
due to EV charging has become very relevant information needed for power system
planning studies. Thus this project aims to quantify those uncertainties
associated with active elements such as DGs, EVs, and storage devices for
developing the most economic expansion and operational plans for a power
distribution system. For that purpose, some new stochastic models will be
developed for each of the aforementioned active elements for evaluating the
power system reliability.
Wide Area Protection and Control Using Synchronized Measurements
Synchrophasor measurement technology is now well established and many utilities have at least pilot synchrophasor measurement systems. Time stamped synchronized phasor measurements reported at sub-cycle intervals allow capturing fast dynamics of system-wide phenomena. While offline applications such as model validation, post-event analysis, etc. as well as wide-area monitoring applications such as oscillation monitoring, grid code compliance monitoring, etc., are common, use of synchrophasor measurements for protection and control is still limited. This stream of research investigates novel ways for using these measurements for early detection of system instabilities, determination of emergency remedial control actions such as controlled islanding, backup protection, fault location, and other novel applications. Many of these complex applications require exploitation of the strengths of machine learning and data mining technologies.