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

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W3-1Renewables Integration & Optimization – Solar

13:20 The Transient Behavior of the Volt/Var Control of Photovoltaic Systems for Solar Irradiation Variations

Insu Kim (Alabama A&M University, USA); Ronald Harley (Georgia Institute of Technology, USA)

Nowadays, photovoltaic (PV) systems supply reactive power in limited situations with mutual agreements so that they can minimize an increase in over- and under-voltages. However, since PV systems depend on weather conditions, including solar irradiation, they have, in nature, intermittency in their output. Therefore, the objective of this study is to analyze the effect of ramp events of solar irradiation on the generation output of PV systems in the transient state. For this purpose, this study models a distribution system that includes a PV system (e.g., a PV array, a DC bus and capacitor model, a controller, and a static generator) in DIgSILENT of Power Factory, generates a ramp event of solar irradiation as input data to the PV system, and examines the transient behavior of the PV system in the electromagnetic transient mode of DIgSILENT. Finally, the effect of reactive power control for the ramp event on over- and under-voltages will be addressed.

13:40 An Adaptive Neuro-Fuzzy Inference System-based MPPT Controller for Photovoltaic Arrays

Farhad Khosrojerdi (Université du Québec en Outaouais (UQO) & Université du Québec en Outaouais (UQO), Canada); Shamsodin Taheri (Université du Québec en Outaouais, Canada); Ana-Maria Cretu (Université du Québec en Outaouais, Canada)

This paper presents a Maximum Power Point Tracking (MPPT) method applying an Adaptive Neuro-Fuzzy Inference System (ANFIS) for a stand-alone photovoltaic (PV) system. The proposed ANFIS-based MPPT technique determines the optimal operating point of a PV system which is designed in conjunction with a Z-source DC-DC converter as an interface between the PV array and the load. In the ANFIS-based MPPT controller, real meteorological data are used to define the two input membership function plots assuming that the PV array is located in Ottawa, Canada. The performance of the proposed MPPT technique in tracking the maximum power point (MPP) is assessed numerically in the MATLAB/Simulink environment. The simulation results highlight the benefits of determining reference voltage and duty cycle as output membership functions of the control system without using the current and voltage sensors. Moreover, in comparison with conventional control systems, the proposed solution can reduce the complexity and cost of the control system by eliminating the PID controller.

14:00 Tilt Angle Optimization for Maximum Solar Power Generation of a Solar Power Plant with Mirrors

Isuru Vidanalage (Ryerson University, Canada); Kaamran Raahemifar (Ryerson University, Canada)

Solar power generation is mainly based on direct, diffused and reflected solar radiation. This paper will give an insight of the strategy of the implementation of optimization of the tilt angle of the solar panel to maximize the electricity generation, at presence of mirrors. Mirrors will improve the reflected solar radiation, leading to increase the radiation on solar panel. For the purpose of analysis, as the site Toronto in Canada was selected. Renewable energy data was gathered through National Renewable Energy Laboratory (NREL). Energy increment due to the addition of mirrors are discussed and it will be a really useful input for designing solar equipment.

14:20 Sensitivity Analysis of a Current-Source Inverter-Based Three-phase Grid-connected Photovoltaic System

Prajna Dash (Energent, Canada); Mehrdad Kazerani (University of Waterloo, Canada)

In this paper, first, an accurate small-signal model of a three-phase current source inverter (CSI)-based grid-connected photovoltaic (PV) system is derived. The model takes into account the nonlinear characteristics of PV arrays, as well as the controller and grid-side dynamics. Then, the developed small-signal model is employed to investigate the impact of different parameters on the stability of the CSI-based PV system, through sensitivity analysis. The sensitivity to variations of different parameters is assessed by tracking the positions of real parts of the eigenvalues corresponding to the dominant state variables in the s-plane. Insolation level, controller gains, and grid inductance are the parameters considered to study the sensitivity of state variables.

14:40 Impact of Systems Cost Incentives on the Economics of Distributed Solar Power in Canada

Hillary MacDougall (University of Ottawa, Canada); Steve Tomosk (DAI Inc, Canada); David Wright (University of Ottawa, Canada)

Systems cost incentives have been used in USA and Canada to stimulate the deployment of solar power. This paper analyzes the impact of such incentives on the internal rate of return (IRR) from residential, offsetting projects in Canada, focusing on Regina, a high irradiance city. For a given percentage systems cost reduction, the IRR increases by a higher percentage. The impact on the IRR for photovoltaic (PV) projects is higher than for concentrating PV (CPV) projects. During the period 2016 to 2020 systems prices decline and electricity costs increase resulting in an increase in IRR from deferring the project start date. That increase is higher for CPV than for PV. Orienting the PV modules so as to maximize revenues has a minimal impact on IRR.

W3-2Micro-Grid – Stability & Optimization

13:20 Design of Renewable Energy System for a Remote Mobile Office in Newfoundland

Emadeddin Hussein (Memorial University of Newfoundland, Canada); Tariq Iqbal (Memorial University of Newfoundland, Canada)

Renewable Energy Systems are becoming a common choice for small communities in Canada where the cost of diesel fuel are high. In this paper, a PV/Wind hybrid system is been considered for supplying an electrical load of a Mobile office which is proposed and presented along with relevant statistics. An optimal configuration of different renewable energy system is been obtained. The optimal configuration has been determined by taking the total cost as the objective function. The system optimization done through optimization features from NREL, HOMER. The results show the hybrid renewable energy system is a cost effective solution. Furthermore, it is expected that the proposed system will help companies to provide uninterrupted power for their sites in remote areas.

13:40 Optimal Sizing of a Stand-Alone Hybrid Energy System for Water Pumping in Sirte, Libya

Faisal Alkarrami (Memorial University, Canada); Mohammad Tariq Iqbal (Memorial University of Newfoundland, Canada); Kevin Pope (Memorial University of Newfoundland, Canada)

In this paper, the size optimization of standalone Photovoltaic (PV)/Wind turbine hybrids system for water pumping in Sirte City, Libya are compared using HOMER Pro, HOMER Beta, and iHOGA softwares, specifically the cost of energy (COE), total net present cost (NPC), and size of the system. Various loads of water pumping for farm land are used. The optimal system suggested by iHOGA had the lowest NPC but highest COE, whereas HOMER Pro had the highest NPC but lowest COE. The results are supportive of using the renewable hybrid system for water pumping in Sirte, Libya.

14:00 Comparison of Microgrid Solutions for Remote Areas

Mark Markovic (BHP Billiton, Australia); Zorica Nedic (University of South Australia, Australia); Andrew Nafalski (Uni. Of South, Australia)

Often, remote locations are not within close proximity to a mains power grid. A common solution to providing electricity in remote areas is diesel generation. Historically, it is a type of power generation that is proven reliable, but not without adverse environmental impacts. Diesel generation is not capital intensive. However, it can have long term negative financial impacts as well as producing less than desirable amounts of greenhouse gases due to excessive consumptions of diesel fuel. Alternative is the use of renewable sources especially that e.g. solar energy is vastly available in the Australian outback. However, solar generation, unlike diesel requires large initial capital investment, which companies are hesitant to allocate without a proper economic analysis of alternative solutions. To alleviate these concerns, this article investigates the economy of the use of renewable sources complemented by diesel generation for a remote area pump station. It is shown that diesel powered system not only has inevitable adverse environmental impact but also contributes to the company’s financial inefficiency.

14:20 Renewable Energy Assisted Base Station Collaboration as Micro Grid

Faran Ahmed (National University of Science and Technology & Pakistan air force, Pakistan); Muhammad Naeem (Ryerson University, Canada); Muhammad Iqbal (COMSATS INSTITUTE OF IT, Pakistan); Alagan Anpalagan (Ryerson University, Canada)

In this paper, we present the case for cellular base stations enabled with renewable energy sources (RES) to be interconnected in a mini-smart grid (SG). Such an arrangement is envisaged to power the base stations (BSs) with clean sustainable energy as well as provide power to the local community. The technologies associated with RES as well as SGs have matured enough to be integrated with cellular NWs, for the benefit of both the network operator and the community. We also explore an energy cost minimization framework for a cellular network, by formulating a novel energy cooperation scheme that ensures optimal energy cooperation between green BSs. In our proposed economical and environment friendly frame work, the grid energy is minimized by optimal sharing of surplus green energy among the base stations. The intended scenario requires causal knowledge of harvested energy as well as traffic awareness by the network to workout energy demand of a BS and local grid. A realistic objective is developed, which entails energy borrowing from neighboring base stations offering their cheaper surplus energy, thereby reducing the overall energy cost of the network.

14:40 Equal Power Sharing in Islanded AC/DC Hybrid Microgrids

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

AC/DC hybrid microgrid is a promising architecture that allows for hosting energy resources and modern loads from AC and DC types; and in turn, it reduces the number of conversion stages among other technical and economical benefits. Consequently, power distribution planners started to investigate the possibility of hybridizing the existing AC grids and designing new AC/DC hybrid clusters referred to as microgrids as a step towards the envisioned smart grid with AC/DC technologies and “plug-and-play” feature. Nevertheless, while being islanded, AC/DC hybrid microgrids bring operational challenges to the system operation such as coordination among the distributed resources in both AC/DC subgrids, control and management of the power transfer through the interlinking converters, droop control of inverter-based distributed energy resources, and accurate power sharing. This paper looks closely at the problem of active and reactive power sharing in islanded droop-based AC/DC hybrid microgrids and proposes a unified power sharing scheme that is able to simultaneously ensure precise power sharing in both AC and DC subgrids. Test results demonstrate the capability of the proposed scheme in achieving exact power sharing not only among the energy resources in proportion to their ratings but also among the interlinking converters.