The purpose of this study is to determine a model for analysis of integrating solar generation to the electric grid .The model is then used in determining Harmonics of Integrating solar panels to the electric grid that are based on parallel or series combination of solar cells. To study integration of solar generation to the grid, we have used solar series and solar parallel models in EMTP (Electro Magnetic Transient Program) real time simulation software. When integrating solar generation models to the grid, due to DC to AC conversion and due to variation of solar energy intensity, the electric utility shall experience undesired harmonics that may impact quality of service to other customers in the grid. This study identifies one method of analysis for determining harmonic content of solar panels before solar generation can be integrated in to the electric grid.

abstract: An important operating aspect of all transmission systems is power system stability and satisfactory dynamic performance. The integration of renewable resources in general, and photovoltaic resources in particular into the grid has created new engineering issues. A particularly problematic operating scenario occurs when conventional generation is operated at a low level but photovoltaic solar generation is at a high level. Significant solar photovoltaic penetration as a renewable resource is becoming a reality in some electric power systems. In this thesis, special attention is given to photovoltaic generation in an actual electric power system: increased solar penetration has resulted in significant strides towards meeting renewable portfolio standards. The impact of solar generation integration on power system dynamics is studied and evaluated. This thesis presents the impact of high solar penetration resulting in potentially problematic low system damping operating conditions. This is the case because the power system damping provided by conventional generation may be insufficient due to reduced system inertia and change in power flow patterns affecting synchronizing and damping capability in the AC system. This typically occurs because conventional generators are rescheduled or shut down to allow for the increased solar production. This problematic case may occur at any time of the year but during the springtime months of March-May, when the system load is low and the ambient temperature is relatively low, there is the potential that over voltages may occur in the high voltage transmission system. Also, reduced damping in system response to disturbances may occur. An actual case study is considered in which real operating system data are used. Solutions to low damping cases are discussed and a solution based on the retuning of a conventional power system stabilizer is given in the thesis. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2015

No / The current global challenge of climate change has made renewable energy usage very important. There is an ongoing drive for the deployment of renewable energy resource at the domestic level through feed-in tariff, etc. However the intermittent nature of renewable energy has made storage a key priority. In this work, a community having a solar farm with energy storage embedded in the house of the energy consumers is considered. Consumers within the community are aggregated in to a local virtual power plant. Genetic algorithm was used to develop an optimized energy transaction for the virtual power plant. The results shows that it is feasible to have a virtual power plant setup in a local community that involve the use of renewable generation and embedded storage. The result also show that when maximization of battery state of charge is considered as part of an optimization problem in a day ahead market, certain trade-off would have to be made on the profit of the virtual power plant, the incentive of the prosumer, as well as the provision of peak service to the grid.

Due to the rapid growth of grid-tied solar photovoltaic (PV) systems in the generation mix, the distribution grid will face complex operational challenges. High PV penetration can create overvoltages and voltage fluctuations in the network, which are major concerns for the grid operator. Traditional voltage control devices like switched capacitor banks or line voltage regulators can alleviate slow-moving fluctuations, but these devices need to operate more frequently than usual when PV generation fluctuates due to fast cloud movements. Such frequent operations will impact the life expectancy of these voltage control devices. Advanced PV inverter functionalities enable solar PV systems to provide reliable grid support through controlled real injection and/or reactive power compensation. This dissertation proposes a voltage regulation technique to mitigate probable impacts of high PV penetrations on the distribution voltage profile using smart inverter functionalities. A droop-based reactive power compensation method with active power curtailment is proposed, which uses the local voltage regulation at the inverter end. This technique is further augmented with very short-term PV generation forecasts. A hybrid forecasting algorithm is proposed here which is based on measurement-dependent dynamic modeling of PV systems using the Kalman Filter theory. Physical modeling of the PV system is utilized by this forecasting algorithm. Because of the rise in distributed PV systems, modeling of geographic dispersion is also addressed under PV system modeling. The proposed voltage regulation method is coordinated with existing voltage regulator operations to reduce required number of tap-change operations. Control settings of the voltage regulators are adjusted to achieve minimal number of tap-change operations within a predefined time window. Finally, integration of energy storage is studied to highlight the value of the proposed voltage regulation technique vis-à-vis increased solar energy use. / Ph. D. / Rapid growth of grid-tied solar photovoltaic (PV) systems poses both opportunities and technical challenges for the electric distribution grid. Significant among them are overvoltage and voltage fluctuations in the network, which may lead to overheating of electrical devices and equipment malfunction. Due to the variable nature of solar irradiance, existing voltage control devices often need to operate more frequently than usual which can cause recurring maintenance needs for these devices. To make solar PV more grid-friendly, changes are taking place in grid codes which encourage developing advanced PV inverter functions. With these functions, a smart inverter, which possesses bidirectional communication capability, can be integrated into a smart grid environment. This work discusses how these inverters can provide active power curtailment and reactive power compensation to maintain voltages at their points of interconnection. The inherent variability and uncertainty in solar energy production can be addressed with solar forecasting. Application of PV generation forecasting as a tool to aid distribution voltage control is proposed in this dissertation. Using solar forecasting, smart inverters can contribute in relieving the stress on other voltage control devices due to PV-induced fluctuations. Integrating storage elements can also aid this voltage regulation method, as they can consume surplus PV generation when needed. This dissertation is designed to provide a systematic approach to manage the overvoltage and voltage fluctuations on a real-time basis for a high PV penetration scenario. Proposed methodology combines smart inverter functionalities with solar forecasting and develops an application which can be realized to ensure seamless PV integration in a growing landscape of renewables.

Medidas atualmente em curso no país, encaminhadas por agentes do setor elétrico, reforçam a expectativa do desenvolvimento de um mercado fotovoltaico sólido em alguns anos. A flexibilidade dos sistemas fotovoltaicos permite a construção de usinas de diferentes capacidades, estas podem estar concentradas, cobrindo vastas áreas de solo, ou distribuídas em pequenas unidades integradas na arquitetura em meio urbano. Entretanto, pesquisas demonstraram que em países com grande capacidade instalada de sistemas fotovoltaicos, o sombreamento parcial de módulos fotovoltaicos é responsável por perdas médias de 10%. Visando agregar conhecimento ao setor energético e contribuir com o desenvolvimento do mercado fotovoltaico nacional, esse texto tem o objetivo de apresentar os resultados de uma pesquisa, em que foi estabelecido um modelo utilizado para construir um plug-in, que transforma o Google SketchUp em uma ferramenta gratuita para estimar o fator de sombreamento e a irradiação em superfícies selecionadas em um modelo tridimensional de uma edificação. Assim, foi conduzida uma pesquisa bibliográfica responsável por identificar e selecionar modelos utilizados nas diversas etapas envolvidas com a estimativa do fator de sombreamento e irradiação. Realizadas algumas alterações, esses modelos convergiram para um modelo único que foi aplicado ao desenvolvimento de um plug-in, denominado Solar3DBR. O desempenho do Solar3DBR foi avaliado através de comparações com os softwares PVsyst e Ecotect, e também por meio de medições reais realizadas em um experimento onde foi monitorada a irradiância em uma célula fotovoltaica parcialmente sombreada e a irradiação horária em plano inclinado. Os resultados das medições permitiram determinar o fator de sombreamento da célula e estes foram comparados aos resultados da simulação de um modelo tridimensional do sistema através do Solar3DBR. Essas confrontações demonstraram que as simulações realizadas com o Solar3DBR apresentam grande proximidade com os resultados apresentados por PVsyst, Ecotect e medições reais. / Measures that are currently underway in the country, forwarded by agents of the electricity sector, reinforce the expectation of developing a solid photovoltaic market in a few years. The photovoltaic systems flexibility, allows plant\'s construction of different capacities, these may be concentrated, covering vast areas of land, as divided into small units, integrated into urban architecture. However, researches have shown that in countries with a large capacity of photovoltaic systems installed, the partial shading of photovoltaic modules is responsible for average losses of 10%. Aiming to add knowledge to the energy sector and contribute to the development of the domestic photovoltaic market, this text aims to present the results of a research, in which was established a model used to build a plug-in that turns Google SketchUp into a free tool, with the ability to estimate the shading factor and irradiation in selected surfaces in a three-dimensional model of a building. Thus, was realized a literature research, responsible for identifying and selecting models used in the various steps, involved in estimating the shading factor and irradiation. After some changes have been implemented, these models converged to a single model that was applied to the development of a plug-in called Solar3DBR. The performance of the Solar3DBR was evaluated through comparisons with the softwares PVsyst and Ecotect, and in actual measurements performed in an experiment. In this experiment irradiance in a partially shaded PV cell and hourly irradiation on inclined plane were monitored. Measurement results allowed to determine the shading factor of the cell, and were compared to simulation results of a three-dimensional model of the system through Solar3DBR. The result of these confrontations demonstrated that the results obtained from the Solar3DBR are similar to the ones presented by PVsyst, Ecotect and actual measurements.

Medidas atualmente em curso no país, encaminhadas por agentes do setor elétrico, reforçam a expectativa do desenvolvimento de um mercado fotovoltaico sólido em alguns anos. A flexibilidade dos sistemas fotovoltaicos permite a construção de usinas de diferentes capacidades, estas podem estar concentradas, cobrindo vastas áreas de solo, ou distribuídas em pequenas unidades integradas na arquitetura em meio urbano. Entretanto, pesquisas demonstraram que em países com grande capacidade instalada de sistemas fotovoltaicos, o sombreamento parcial de módulos fotovoltaicos é responsável por perdas médias de 10%. Visando agregar conhecimento ao setor energético e contribuir com o desenvolvimento do mercado fotovoltaico nacional, esse texto tem o objetivo de apresentar os resultados de uma pesquisa, em que foi estabelecido um modelo utilizado para construir um plug-in, que transforma o Google SketchUp em uma ferramenta gratuita para estimar o fator de sombreamento e a irradiação em superfícies selecionadas em um modelo tridimensional de uma edificação. Assim, foi conduzida uma pesquisa bibliográfica responsável por identificar e selecionar modelos utilizados nas diversas etapas envolvidas com a estimativa do fator de sombreamento e irradiação. Realizadas algumas alterações, esses modelos convergiram para um modelo único que foi aplicado ao desenvolvimento de um plug-in, denominado Solar3DBR. O desempenho do Solar3DBR foi avaliado através de comparações com os softwares PVsyst e Ecotect, e também por meio de medições reais realizadas em um experimento onde foi monitorada a irradiância em uma célula fotovoltaica parcialmente sombreada e a irradiação horária em plano inclinado. Os resultados das medições permitiram determinar o fator de sombreamento da célula e estes foram comparados aos resultados da simulação de um modelo tridimensional do sistema através do Solar3DBR. Essas confrontações demonstraram que as simulações realizadas com o Solar3DBR apresentam grande proximidade com os resultados apresentados por PVsyst, Ecotect e medições reais. / Measures that are currently underway in the country, forwarded by agents of the electricity sector, reinforce the expectation of developing a solid photovoltaic market in a few years. The photovoltaic systems flexibility, allows plant\'s construction of different capacities, these may be concentrated, covering vast areas of land, as divided into small units, integrated into urban architecture. However, researches have shown that in countries with a large capacity of photovoltaic systems installed, the partial shading of photovoltaic modules is responsible for average losses of 10%. Aiming to add knowledge to the energy sector and contribute to the development of the domestic photovoltaic market, this text aims to present the results of a research, in which was established a model used to build a plug-in that turns Google SketchUp into a free tool, with the ability to estimate the shading factor and irradiation in selected surfaces in a three-dimensional model of a building. Thus, was realized a literature research, responsible for identifying and selecting models used in the various steps, involved in estimating the shading factor and irradiation. After some changes have been implemented, these models converged to a single model that was applied to the development of a plug-in called Solar3DBR. The performance of the Solar3DBR was evaluated through comparisons with the softwares PVsyst and Ecotect, and in actual measurements performed in an experiment. In this experiment irradiance in a partially shaded PV cell and hourly irradiation on inclined plane were monitored. Measurement results allowed to determine the shading factor of the cell, and were compared to simulation results of a three-dimensional model of the system through Solar3DBR. The result of these confrontations demonstrated that the results obtained from the Solar3DBR are similar to the ones presented by PVsyst, Ecotect and actual measurements.

This work explores the development of a home energy management system (HEMS) that uses weather and market forecasts to optimize the usage of home appliances and to manage battery usage and solar power production. A Moving Horizon Estimation (MHE) application is used to find the unknown home model parameters. These parameters are then updated in a Model Predictive Controller (MPC) which optimizes and balances competing comfort and economic objectives. Combining MHE and MPC applications alleviates model complexity commonly seen in HEMS by using a lumped parameter model that is adapted to fit a high-fidelity model. HVAC on/off behaviors are simulated by using Mathematical Program with Complementary Constraints (MPCCs) and solved in near real-time with a nonlinear solver. Removing HVAC on/off as a discrete variable decreases potential solutions and consequently reduces solve time and increases the probability of reaching a more optimal solution. The results of this work indicate that energy management optimization significantly decreases energy costs and balances energy usage more effectively throughout the day compared to a home with regular temperature control. A case study for Phoenix, Arizona shows an energy reduction of 21% and a cost reduction of 40%. Homes using this home energy optimization will contribute less to the grid peak load and therefore, improve grid stability and reduce the amplitude of load following cycles for utilities. This case study combines renewable energy, energy storage, forecasts, cooling system, variable rate electricity plan and a multi-objective function allowing for a complete home energy optimization assessment. There remain several challenges, including improved forecast models, improved computational performance to allow the algorithms to run in real-time, and mixed empirical / first principles machine learning methods to guide the model structure.