Program: 3rd Session on Thursday (13:20-15:00)

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T3-1Energy Storage – Management

13:20 Tracking Techniques for the PEMFC in Portable Applications

Venkataraghavan Karunamurthy Kumaraswamy (Memorial University of Newfoundland, Canada); John Quaicoe (Memorial University of Newfoundland, Canada)

Proton exchange membrane fuel cell (PEMFC) exhibits nonlinear output characteristics which may result in low efficiency and low power operation of the PEMFC. Different tracking techniques are used to track the maximum power point (MPP) to extract maximum power and maximum efficiency point (MEP) to operate at maximum efficiency. However, the output power and efficiency of the PEMFC should be high for portable applications but they are low at MEP and MPP respectively. In this paper, an alternative tracking technique referred to as the midpoint tracking (MPT) technique is proposed to overcome the limitations of the MEP and MPP tracking techniques for portable applications. A detailed analysis of the model-independent tracking techniques based on simulation results is presented. It is found that the proposed MPT technique is the most suitable technique with high output power and high efficiency compared with the MEP and MPP respectively.

13:40 Use of Active Power Filters to Reduce the Effects of Harmonics in Solid Oxide Fuel Cells

Aparna Biswas (Memorial University of Newfoundland, Canada); John Quaicoe (Memorial University of Newfoundland, Canada)

The propagation of ripple currents in fuel cells, due to nonlinear loads, is a challenging problem, as it interferes with the electrical performance of the fuel cell. In this paper an electrical system, powered by a modeled Solid Oxide Fuel Cell is used to study the behavior of ripple propagation. In order to remove the harmonics superimposed on the fuel cell current by the propagating ripples, an Active Power Filter, suitable for removing harmonics from DC systems, is proposed. The performance of the Active Power Filter is analyzed using harmonic analysis and power calculations.

14:00 Power Flow Management Strategy for Renewable Hybrid Energy System

Hatem Hosni (Université du Québec à Rimouski, Canada); Sihem Benhamed (Université du Québec à Rimouski, Canada); Hussein Ibrahim (Wind Energy TechnoCentre, Canada); Mazen Ghandour (Univeriste Saint Joseph- ESIB, Lebanon); Adrian Ilinca (Université du Quebec à Rimouski, Canada); Karim Belmokhtar (Wind Energy TechnoCentre, Canada)

In remote sites (north Canada, islands …); diesel generators are used to produce electricity. This method is relatively inefficient, very expensive and responsible for the emission of large amounts of greenhouse gases. The development and use of a wind-solar-diesel-battery hybrid system will eliminate the main barriers to the deployment of renewable energy in remote locations and decrease production costs. The originality of this system consist in optimizing its overall performance by designing an intelligent algorithm and optimized strategy for power flow management which meet the operational constraints and the user’s requirement . The main objective of this study is to determine the most efficient operation strategy for the power supply of isolated sites. This strategy should be characterized by an ability to reduce the use of diesel generator and integrate optimally the renewable resources while providing a significant reduction in fuel consumption and the emission of greenhouse gases .In order to validate the proposed strategies under real conditions, measurements of real weather conditions and power consumption for the months of February and may 2013 are considered. Once the assessment and analysis of results are complete, optimization will be done on the best strategy found with varying the number and size of the diesel generators. Simulations results are highlighted showing the impact of this approach.

14:20 Safety Study of Three Types of Lithium Ion Batteries

Rui Zhao (Carleton University, Canada); Sijie Zhang (Carleton University, Canada); Junjie Gu (Carleton University, Canada); Jie Liu (Carleton University, Canada)

Safety is the first priority of any energy storage system. In this paper, safety studies are performed on three types of 2.6 Ah lithium ion batteries: high-drain thin-electrode battery (Cell 1), cellphone battery (Cell 2) and 18650 type battery (Cell 3), which are different in geometry and internal parameters. The batteries’ discharge behaviors are tested on a battery analyzer, and their performances in nail penetration are simulated with an electrochemical-thermal coupling model. It is found that both the battery geometry and internal parameters have significant effects on the performance and safety of battery. Cell 1, with the lowest internal resistance among all, has the minimal temperature variations during discharges, but its simulated temperature rise in penetration is dramatic, especially at the nail point. As the internal resistance of battery increases, Cell 2 and Cell 3 experience severer temperature elevations and significant losses of available power and capacity at high-rate discharges, but meanwhile, they show better thermal behaviors in penetration simulation, with the maximum temperatures of both keeping below 200oC.

14:40 Modeling the Impact of Electrical Energy Storage Systems on Future Power Systems

Marco Pruckner (University of Erlangen-Nuremberg, Germany)

All over the world power systems are faced with great challenges because of the rapidly increasing integration of renewable energy sources. Electrical energy storage systems (EESS) can help to stabilize the output from volatile and intermittent renewable energy sources such as wind and solar energy. Basically they can be installed close to large wind farms or photovoltaic parks and provide many advantages for future integrated power systems. In this paper we study the impact of EESS on power systems on a larger scale. Therefore we describe the implementation of two different charging strategies for EESS for an already developed simulation model for the German power system and investigate different scenarios with respect to the installed capacities of renewable energy sources and the aggregated capacity of EESS. As a result different output parameters such as the electricity generation mix and CO$_2$ emissions can be investigated. The simulation results show how EESS contribute to a) the integration of electrical energy generated by renewable energy sources and b) the reduction of electricity imports and exports.

T3-2Energy Efficiency, Demand Response, & Energy Markets

13:20 Fuzzy Predictive Filtering in Nonlinear Economic Model Predictive Control for Demand Response

Rui Santos (Instituto Superior Técnico, Portugal); Yi Zong (Technical University of Denmark, Denmark); João Sousa (IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Portugal); Luís Mendonça (Escola Superior Náutica Infante D. Henrique, Portugal); You Shi (Technical University of Denmark, Denmark); Lucian Mihet-Popa (Oestfold University College & Politehnica University of Timisoara, Norway)

The performance of a model predictive controller (MPC) is highly correlated with the model’s accuracy. This paper introduces an economic model predictive control (EMPC) scheme based on a nonlinear model, which uses a branch-and-bound tree search for solving the inherent non-convex optimization problem. Moreover, to reduce the computation time and improve the controller’s performance, a fuzzy predictive filter is introduced. With the purpose of testing the developed EMPC, a simulation controlling the temperature levels of an intelligent office building (PowerFlexHouse), with and without fuzzy filtering, is performed. The results show that the controller achieves a good performance while keeping the temperature inside the predefined comfort limits. Fuzzy predictive filtering has shown to be an effective tool which is capable of reducing the computational burden and increasing the performance level of the control algorithm.

13:40 Transmission Expansion for Profit Maximization of Generators in a Decentralised Market Structure

Harivina Gunnaasankaraan (University of Newcastle, Singapore); Aparna Viswanath (University of Newcastle, Singapore); Kaushik Mahata (University of New Castle, Australia)

This paper presents a transmission expansion formulation that maximizes the profits of the generators in a decentralized market structure. Transmission expansion of congested lines increases the dispatch by the generators and hence the generator surplus. The generators profit is the difference in surplus and the transmission congestion charges. Previous work on profit maximization was a simple quadratic formulation as the transmission charges were taken as fixed investment costs. In this paper, transmission congestion charges are based on the difference in spot market locational marginal prices. To ensure that transmission merchants always profits from expansion, the transmission congestion charges are modeled as several blocks of congestion prices and transmission capacities. The profitable transmission expansion for generators is thus formulated as a mixed integer (0-1) quadratic programming problem. Examples are provided to explain the method.

14:00 A Review of the Mexican Power System Market Policies for Competiveness and a More Diverse Generation Portfolio

Pedro Hernandez (WSU & WSU, Sweden)

After more than five decades of state monopoly, Mexican Power Market has been restructured and wholesale transactions started in January 1st, 2016. This paper discusses the market design features, its goals and challenges. Since deregulated market transactions and clean energy oriented policies are new to Mexican grid operations, a transition ensuring a successful establishment of the market design should be assessed in order to verify that ongoing transformation can lead to the accomplishment of its economic and environmental targets. The expected outcomes are underlined based on the impact that applied policies have had in the North American context.

14:20 The Smart Grid Impact on the Danish DSOs’ Business Model

Zheng Ma (Center for Energy Informatics & University of Southern Denmark, Denmark); Simon Sommer (Center for Energy Informatics, Denmark); Bo Jorgensen (University of Southern Denmark, Denmark)

The transformation progress of the smart grid challenges the market players’ business models. One of those market players is the Distribution System Operators (DSOs). This paper aims to elaborate how smart grid influences the DSOs’ business models with case studies of two Danish DSOs – EnergiFyn and TREFOR. The main findings indicate that the Danish smart grid transformation process influences the Danish DSOs’ business models via four smart grid related factors: (1) smart meters, (2) Distributed Energy Resources (DERs), (3) Bidirectional electricity flow, and (4) R&D. Therefore, The results show that the smart grid incrementally not revolutionary influences the Danish DSOs’ business models, and the transformation progress of the Danish smart grid is slower than the agenda of the official Danish smart grid development strategy.

14:40 Intelligent Management of Baseboard Heaters to Level Peak Demand

Ajit Pardasani (National Research Council Canada, Canada); Marianne Armstrong (National Research Council Canada, Canada); Guy Newsham (National Research Council Canada, Canada); Brody Hanson (Siemens Canada Ltd, Canada)

This paper presents results from an evaluation of a demand response (DR) strategy applied to residential electric baseboard heating loads. The underlying principle is based on storing electricity as thermal energy in the building envelope and household contents before the peak period and then discharging that stored energy to maintain conditions for thermal comfort during the peak period. Five different variations of the strategy were tested at the twin houses of Canadian Centre for Housing Technology (CCHT) for a four weeks period in the winter of 2015 using a side-by-side comparative assessment. The tests showed that a load shift up to 4 kW for the first 30 minutes and a total shift up to 5.7 kWh during the 2-hour period was possible, depending on the outdoor temperature. The approach holds significant potential for shifting peaks loads in locations where electricity is a major source of energy for space heating.

T3-3Power Electronics

13:20 Improving Dynamic Performance of Five Types of dqCDSC-PLL Using Digital Phase-Lead Compensator

Xie Menxi (Soochow University, P.R. China); Canyan Zhu (Soochow University, P.R. China); Yang Yong (School of Urban Railway Transportation, Soochow University, P.R. China)

Synchronization control is of great importance for grid-connected power converter so that precise phase angle information of the grid voltage is required. As three-phase grid voltages are imbalanced or distorted, Synchronous Reference Frame Phase-Locked Loop (SRF-PLL) aims to track fundamental frequency positive sequence with zero steady state error. The in-loop Cascaded Delayed Signal Cancellation (CDSC)in dq rotate frame used to eliminate the disturbances of phase error. Due to additional time constant induced by CDSC, the transient response of the dqCDSC-PLL is slow. As a consequence, that deteriorates the entire dynamic performance of converter. In this paper, five types of CDSC with corresponding Phase-Lead Compensators (PLC) set in loop was proposed to improve the PLL dynamic response. The simulation carried out by Matlab/Simulink verified the correctness and effectiveness. The transient track process of phase jump and harmonics are dramatically faster than before.

13:40 A Novel Axial Flux Switched Reluctance Motor with Multi-level Air Gap Geometry

Jianing Lin (McMaster University, Canada); Tim Lambert (Accelerated Systems Inc., Canada); Yinye Yang (McMaster University, Canada); Berker Bilgin (McMaster University, Canada); Rob Lankin (Accelerated Systems Inc., Canada); Ali Emadi (McMaster University, Canada)

The switched reluctance motor (SRM) is a promising drive solution for electric vehicle propulsion thanks to its simple, rugged structure, satisfying performance and low price. Among other SRMs, the axial flux SRM (AFSRM) is a strong candidate for in-wheel drive applications because of its high torque/power density and compact disc shape. In this paper, a four-phase 8-stator-pole 6-rotor-pole double-rotor AFSRM is investigated for an e-bike application. A series of analyses are conducted to reduce the torque ripple by shaping the rotor poles, and a multi-level air gap geometry is designed with specific air gap dimensions at different positions. Both static and dynamic analyses show significant torque ripple reduction while maintaining the average electromagnetic output torque at the demanded level.

14:00 Improving Electromagnetic Compatibility of Integrated Switching Converters for Hybrid/electric Vehicles

Sergio Saponara (University of Pisa, Italy); Gabriele Ciarpi (University of Pisa, Italy); Carlo Mattaliano (University of Pisa, Italy); Luca Fanucci (University of Pisa, Italy); Voicu Groza (University of Ottawa, Canada)

Practical techniques to reduce electromagnetic interference (EMI) for integrated DC/DC converters are discussed in the paper. As application case study a 48 V DC/DC converter for electric/hybrid cars is considered. Firstly, an EMI filter with very low values of inductor is designed to facilitate its integration and to reduce the overvoltage issues. Experimental results prove that the proposed EMI filter design procedure, taking into account the source and terminal impedance, avoids the state-of-art tendency of over-designing EMI filter components. Then, EMI is reduced further by integrating in the DC/DC converter a soft-start technique, which mitigates EMI issues reducing by 3 times the currents spikes at the car’s power on.

14:20 Switching Frequency Selection for Aerospace Power Converter System Considering the Design of Output LC Filter Inductor Optimizing Weight and Power Loss

Tharmini Thavaratnam (Ryerson University, Canada); Chushan Li (Ryerson University, Canada); Dewei Xu (Ryerson University, Canada)

Switching frequency is one of the main deciding factors in development of high power converter systems used in industrial applications. This paper aims at verifying the switching frequencies range between 9kHz and 20kHz by selecting and designing the inductor of the output LC filter for each switching frequency within that range while optimizing the weight and power loss of the overall power converter system used in aerospace industry. In this paper, the power loss of the inverter semiconductors is also studied for each switching frequency by considering the weight of the heat sink needed to cool the system using air as the coolant. An example design of 50kW, 540VDC, 0.8pf Motor Drive, 3 phase 2 level 400Hz system is used to analyze the results obtained using the proposed methods. The optimization of the overall power converter system weight is finalized by a trade-off between the heat sinking and filtering requirements.

14:40 D-Q Frame Optimal Control of Single Phase Grid Connected Inverter with LCL Filter

Naima Arab (ETS, Canada); Bachir Kedjar (Ecole de Technologie Supérieure, Canada); Kamal Al-Haddad (Ecole de Technologie Supérieure, Canada)

The aim of this paper is to present the design of a linear quadratic regulator (LQR) based on optimal control of single phase grid connected inverter with an LCL output filter used in solar applications. The converter model is set in the D-Q rotating reference frame. Integral action is added to the grid current in order to cancel steady state errors. The controller is tested in steady state, dynamic regime and for parameters variation. The simulation results carried out showed good performance and robustness of the adopted controller.