Program: 2nd Session on Wednesday (11:00-12:20)

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W2-1 – Protection and Communication

11:00 A High-Speed Digital Current Differential Protection Algorithm for Power Transmission Lines in Smart Grids

Adel Aktaibi (Memorial University of Newfoundland, Canada); Glyn George (Memorial University of Newfoundland, Canada); Aziz Rahman (IEMD – Chair, Canada)

The objective of this paper is to propose and investigate a novel hybrid technique consisting of wavelet packet transform (WPT) and direct and quadrature (dq) axis components for current differential protection of transmission lines. The idea in this paper is to develop and implement this hybrid technique by localizing the frequency sub-bands of dq axis components of the differential currents using the WPT in order to find out and evaluate the best signature of the internal faults. The results show that the high-frequency sub-band provides the best signature and enough information to detect any fault in the transmission lines. This hybrid technique provides good accuracy and fast fault clearance speed with minimum level of WPT of the dq components of the differential current. Off-line results of the collected data from a laboratory experimental setup are provided in this paper for different faults at different locations on the transmission line.

11:20 A Control Technique for Operation of Single-Phase Converters in Stand-alone Operating Mode

Seyedkazem Hosseini (Université du Québec, Canada); Shamsodin Taheri (Université du Québec en Outaouais, Canada); Edris Pouresmaeil (Polytechnic University of Catalonia, Spain); Joao Catalão (University of Beira Interior, Portugal)

A droop-Lyapunov based control technique using direct-quadrature (d-q) rotating frame dynamic model is presented in this paper for the frequency and voltage magnitude regulation of a stand-alone single-phase voltage-source inverter (SPVSI). Steady-state and dynamic performance of the controller are analyzed based on the d-q frame model and direct Lyapunov method respectively to satisfy control aims and system stability as operation criteria. To further clarify the operation area of the inverter, positive and negative maximum values for d-q components of inverter current are acquired by introducing a capability curve (CC) for entire operating condition. The performance of the proposed control technique is evaluated numerically in the MATLAB/Simulink environment. The simulation results validate the capability of the proposed control method in both steady-state and transient responses.

11:40 Impact of IEC 61850 GOOSE Communication Quality on Decentralized Reactive Power Control in Smart Distribution Grids – a Co-simulation Study

Thijs Peirelinck (Grenoble Alpes University, France); Antoneta Iuliana Bratcu (CNRS / GIPSA-lab & Grenoble Institute of Technology, France); Yvon Bésanger (Grenoble Alpes University / G2Elab, France)

Smart grids are expected to increase efficiency, reliability and sustainability of future energy usage. Employing state-of-the-art information and communication technologies, within power grids, is defining for smart grids; therefore interaction between energy grids and communication networks requires thorough study. Combined simulation of the behaviour of the electrical and communication network would allow to analyse their influences on one each other.

In this paper, the results of a MATLAB®/Simulink® co-simulation of an electrical distribution grid containing two renewable sources in interaction with its communication network are presented. Communication between different nodes is based on the IEC 61850 GOOSE protocol, whose simulation model incorporates its different efficiency and reliability features. Communication network and electrical grid are modelled using SimEvents® blocks and SimPowerSystems® blocks, respectively. The effect of perturbations on the reliability of the data transfer links, while information to perform decentralised reactive power control is flowing on them, is examined.

12:00 Optimal Coordination of Directional Overcurrent Relays Using Hybrid BBO/DE Algorithm and Considering Double Primary Relays Strategy

Ali Al-Roomi (Dalhousie University, Canada); Mohamed El-Hawary (Dalhousie University, Canada)

Finding optimal settings of directional overcurrent relays (DOCRs) has been extensively solved by many scenarios with adopting different traditional and modern optimization algorithms. For sake of simplicity, all conducted studies in the literature are restricted on a condition that all DOCRs are numerical, static, or electromechanical. There is a fact that when jumping from electromechanical or static relays to numerical relays the former devices could be used as a second wall of protection instead of just throwing them. With a very extreme condition, which may not happen in the real-world applications, all buses will have double primary DOCRs, which where act as backup DOCRs for other buses. That is, the dimension of any given problem is duplicated and becomes very hard to be feasibly and optimally solved. This paper covers this uncommon scenario, and a new hybrid algorithm with some additional sub-algorithms is developed to solve the IEEE 6-bus test system. Moreover, both numerical with electromechanical DOCRs or numerical with static DOCRs are considered in this study.

W2-2 – Micro-Grid – Stability & Optimization

11:00 An Application of a Centralized Model Predictive Control on Microgrids

Khaled Hajar (Gipsa-lab, France); Ahmad Hably (Université Grenoble Alpes, GIPSA-Lab, France)

In this paper, a centralized model predictive control (MPC) is applied on a group of interconnected microgrids (MGs) with the main grid. The objective is to maximize the benefits from one hand for all the elements constituting the MGs and for the main grid on the other hand. The MPC application in our case needs a forecasting information about energy prices, production power, and loads. The algorithm is tested on five interconnected MGs with main grid. Results have shown the performance of the proposed algorithm, especially for the benefits of MG owners, the coordination between MGs while respecting of the constraints related to each on of them.

11:20 Improved Reactive Power Sharing with Adaptive Droop Control in Islanded Microgrids

Javad Fattahi (University of Ottawa, Canada); Joan Haysom (Leidos Canada & University of Ottawa, Canada); John Cook (University of Ottawa, Canada); Karin Hinzer (University of Ottawa, Canada); Henry Schriemer (University of Ottawa, Canada)

Appropriate control strategies for power sharing between multiple generation units operating in parallel are required to create a stable AC microgrid bus. In this paper, we explore the droop control strategy, implemented by power electronics units, to maintain a stable AC bus voltage without the need for a separate (central) communication layer. In particular, our suggested control method is based on adaptive control. Fundamentally in microgrids, due to the effects of feeder and line impedance, the droop control method is subject to real and reactive power coupling and steady-state reactive power sharing errors, and in particular for complex microgrid configurations, the reactive power sharing poses certain challenges. To improve the reactive power sharing equalization, an enhanced adaptive strategy has been utilized to calculate a droop coefficient for reactive power control, where the reactive power error has been compensated through the injection of small real power disturbances. Root locus analysis of a representative microgrid with three inverters has been undertaken to confirm that stable solutions are feasible.

11:40 Power Flow Analysis of AC/DC Hybrid Microgrids

Abdelsalam Eajal (University of Waterloo, Canada); Mohamed Abdelwahed (University of Waterloo, Canada); Ehab El-Saadany (Waterloo University, Canada); Kumaraswamy Ponnambalam (University of Waterloo, Canada)

The future smart grid can have an AC/DC hybrid structure that enables the integration of AC/DC energy supply and demand, thus permitting the formation of AC/DC hybrid microgrids (HMGs). The AC/DC HMG is a promising concept that provides the envisioned smart grid with the plug-and-play feature. Nevertheless, understanding such hybrid systems, especially during islanding, require an accurate and robust load flow program. To this end, this paper proposes a novel robust power flow algorithm for isolated AC/DC HMGs. The power flow problem is formulated as a least-squares minimization problem, and solved using the Levenberg-Marquardt algorithm. The accuracy of the proposed load flow algorithm is validated against time domain simulation results, while its robustness is demonstrated on a highly-resistive network. The proposed load flow algorithm is expected to reveal the light for further studies on AC/DC HMGs.

12:00 Educational Microgrid- A Microgrid Training Platform and Emulator

Clinton Murtagh (British Columbia Institute of Technology, Canada); Omar Mihirig (British Columbia Institute of Technology, Canada); Ygor Gonzalez (British Columbia Institute of Technology, Canada); Ali Palizban (British Columbia Institute of Technology, Canada); Katherine Manson (British Columbia Institute of Technology, Canada)

With the ever growing demand for power and development of renewable energy technologies, the concepts of distributed generation and microgrids are quickly coming to the forefront. A microgrid is an electrical power grid where the load and power generation are within close proximity. Increasingly educational institutions are trying to capitalize on the need to educate future and current professional engineers in the design, maintenance, and operation of a microgrid. The main concept behind our project is to create a live, scaled down microgrid system which incorporates renewable energy sources and interconnection to utility power, all using industry standard equipment. Our educational microgrid platform will allow for comprehensive education with practical hands-on experience which will be useful for practicing engineers, undergrad students, as well as technologists and technicians. We have designed and tested a prototype that can be used as a basis for future instruction for the subject, which will in turn benefit students, education, and the industry as a whole.