Aggregated effect of demand response on performance of future grid scenarios

Session 32 - Future power system infrastructure: no. 459750Conference Theme: Towards Future Power Systems and Emerging TechnologiesThe existing future grid (FG) feasibility studies have mostly considered simple balancing, but largely neglected network related issues and the effect of demand response (DR) for modelling nett future demand. This paper studies the effect of DR on performance of the Australian National Electricity Market in 2020 with the increased penetration of renewable energy sources (RESs). The demand model integrates the aggregated effect of DR in a simplified representation of the effect of market/dispatch processes aiming at minimising the overall cost of supplying electrical energy. The conventional demand model in the optimisation formulation is augmented by including the aggregated effect of numerous price anticipating users equipped with rooftop photovoltaic (PV)-storage systems. Simulation results show that increasing penetration of DR improves loadability and damping of the system with the increased penetration of RESs.postprin

Avaliação antropométrica e a concentração plasmática de dapsona em pacientes com hanseníase na cidade de Belém-Pará

Hanseniasis is a serious problem of public health in the state of Pará, with high incidence and prevalence rates. This paper aimed to evaluate the nutritional status of patients bearing multibacillary hanseniasis relating them to their plasma concentration of dapsone. It is a transversal epidemiological study performed with 29 individuals of both sexes with multibacillary hanseniasis referred to the Ambulatório do Núcleo de Medicina Tropical da Universidade Federal do Pará. Social-demographic, anthropometric, plasma concentration of dapsone and use of prednisone indicators were evaluated. It was evaluated the nutritional status through the body mass índex and percentage of body fat. Plasma determination of dapsone was performed through high efficiency liquid chromatography. Other data were obtained through a semi-structured interview form which was answered by the patients. The results have pointed out that most patients were male, average age of 41.73 (±13.14) and living in the municipality of Belém (58.6%).They have lived into an unfavorable social situation, minimum wage family income (65.6%) and low schooling to the elementary level (51.7%). The nutritional status, according to the body mass index has indicated that 48.3% of the patients were eutrophic. However, 51.6% presented overweight and 13.8% out of them were obese. As for the percentage of body fat, 48.3% were obese. It was observed that 37.9% of the patients have already presented a hansenic reaction, with predominance of type 1 reaction (RR) and 34.5% used prednisone. From the patients using prednisone, 60.0% were overweight and 50.0% were obese, according to the body mass index and percentage of body fat, respectively, though without any statistical significance (p>0.05), when compared to the ones who did not. The plasma average concentration of dapsone in the patient was 0.56 μg/mL. As for the body mass index, it was verified that as the weight of the patient raised, the plasma concentration of dapsone reduced. Eutrophic, pre-obese and obese patients presented plasma concentrations of 0.56 μg/mL, 0.54 μg/mL and 0.44 μg/mL, respectively. Considering the percentage of body fat, it was observed that the average plasma concentration of dapsone was 0.54 μg/mL in eutrophic and obese patients. It was not evidenced any statistical significance between the plasma concentration of dapsone and the nutritional status (p>0.05). Conclusion: The nutritional status did not interfere in the plasma concentration of dapsone, independently from the nutritional parameter, body mass index or percentage of body fat used as well as the use of prednisone was not related to the gain of weight.A hanseníase é um grave problema de saúde publica no Estado do Pará, com altas taxas de incidência e prevalência. O presente estudo objetivou avaliar o estado nutricional de pacientes portadores de hanseníase multibacilar relacionando-os as concentrações plasmáticas de dapsona. Trata-se de um estudo epidemiológico transversal realizado com 29 indivíduos de ambos os sexos com hanseníase do tipo multibacilar atendidos no Ambulatório do Núcleo de Medicina Tropical da Universidade Federal do Pará. Foram avaliados indicadores sociodemográficos, antropométricos, concentração plasmática da dapsona e uso de prednisona. Avaliou-se o estado nutricional pelo índice de massa corporal e percentual de gordura corpórea. A determinação plasmática da dapsona foi realizada através da cromatografia liquida de alta eficiência. Os demais dados foram obtidos por meio de um formulário de entrevista, semi-estruturado respondidos pelos pacientes. Os resultados apontaram que a maioria dos pacientes era do sexo masculino, com idade média de 41,73 (±13,14) anos e residência no município de Belém (58,6%). Viviam em situação social desfavorável, com renda familiar de até um salário mínimo (65,6%) e baixa escolaridade, até o ensino fundamental (51,7%). O estado nutricional, segundo o índice de massa corporal, indicou que 48,3% dos pacientes eram eutróficos, entretanto 51,6% apresentavam excesso de peso, destes 13,8% eram obesos. Em relação ao percentual de gordura corporal, 48,3% eram obesos. Observou-se que 37,9% dos pacientes já apresentaram reação hansênica, com predominância da reação tipo 1 (RR) e 34,5% utilizavam prednisona. Dos pacientes em uso de prednisona, 60,0% estavam com excesso de peso e 50,0% com obesidade, segundo o índice de massa corporal e percentual de gordura corporal, respectivamente, entretanto sem significância estatística (p>0,05), quando comparado com os que não usavam. A concentração plasmática média de dapsona nos pacientes foi de 0,56 μg/mL. Em relação ao índice de massa corporal, verificou-se que a medida que aumentava o peso do paciente reduzia a concentração plasmática de dapsona, pacientes eutróficos, pré-obesos e obesos apresentaram concentrações plasmáticas de 0,56 μg/mL, 0,54 μg/mL e 0,44 μg/mL, respectivamente. Considerado o percentual de gordura corporal, observou-se que a concentração plasmática média de dapsona foi de 0,54 μg/mL em eutróficos e obesos. Não foi observada diferença estatística significativa entre concentração plasmática de dapsona e estado nutricional (p>0,05). Conclusão: O estado nutricional não interferiu na concentração plasmática da dapsona, independente do parâmetro nutricional utilizado, índice de massa corporal ou percentual de gordura corpórea. Assim como o uso de prednisona não foi relacionado ao ganho de peso

Aggregated effect of price-taking users equipped with emerging demand-side technologies on performance of future grids

The increased penetration of intermittent renewable energy sources (RESs) requires flexible resources such as demand response (DR) and energy storage to achieve balance between demand and supply in future grids (FGs). Hence, it is necessary to consider the impact of emerging demand-side technologies for modelling net demand in FG Scenarios. This paper studies the aggregated effect of PRICE-TAKING USERS equipped with such technologies on the performance of FGs. For such a study, a GENERIC demand model is developed, which captures the essential behaviour of those users at higher voltage levels. The demand model, inspired by the smart home concept, is formulated as an optimisation problem aiming to minimise the electricity cost. To showcase the performance of the model, we study the effect of price-taking users equipped with rooftop photovoltaic (PV)-battery systems on the load profile, balancing and loadability of the Australian National Electricity Market with an increased penetration of RESs

A Novel Adaptive Supervisory Controller for Optimized Voltage Controlled Demand Response

Marzooghi, H ORCiD: 0000-0001-8488-8817IEEE Recently, it has been shown that voltage-controlled demand response (VCDR), which is based on the principle of the dependence of the active power of demand on the system voltage, can provide ancillary services in future power systems. Voltage control devices used for VCDR can improve system frequency stability to various extents, depending on their locations, load size and load-voltage dependency in the grid. Thus, designing a supervisory controller to guarantee that such devices are optimally utilized for VCDR is necessary, as this can contribute in enhancing system frequency stability. In this paper, a novel adaptive supervisory controller (ASC) is proposed to optimally use VCDR resources in large power systems for such purposes. To ensure the effective operation of the ASC, an assessment of the impacts of on-load tap changer (OLTC) transformers on the system frequency is essential. In this regard, clustering techniques and principal component regression are used as offline tools to evaluate the influences of OLTCs transformers on VCDR in large-scale power systems using the IEEE 39-bus test system. Also, to estimate the effects of the OLTC transformer clusters on VCDR, a comprehensive sensitivity analysis with respect to the gain of the modified OLTC controllers’ frequency input is conducted

Impact of prosumers on frequency stability of the Australian Future Grid

This paper investigates the impact of high penetration of non-synchronous generation (NSG) and different penetration levels of price-responsive users equipped with rooftop photovoltaics-battery storage (PBS) (sometimes times referred to as prosumers) on the frequency stability of the Australian future grid. To do this, we employed a generic demand model proposed by the authors that captures the interaction between prosumers and an independent system operator (ISO) to provide the initial conditions for frequency stability assessment. In this approach, the ISO aims at minimising the total electricity costs, while prosumers' aggregation aims at maximising their self-consumption. To capture the inter-seasonal variation of renewable resources, we perform time-series simulation for a whole year. The results show the connection between NSG and frequency response of the system and how the system frequency response is affected with high penetration of NSG. Further, low PBS capacity of prosumers can worsen the frequency response of the system, whereas a higher PBS capacity of prosumers can improve the frequency response of the system due to a flatter net demand profile compared to the low PBS capacity

Impact study of prosumers on loadability and voltage stability of future grids

Feed-in-tariffs (FiTs) have been reduced due to combinations of economic and technical reasons. So, existing and new rooftop-photovoltaic (PV) owners are left with the option to either concede the low value arrangement or to use battery storage to maximise their self-consumption, and so minimise their electricity cost. This paper explores the effect of increasing penetration of residential battery systems on balancing and voltage stability of future grid (FG) scenarios. For this purpose, a generic demand model based on a Stackelberg game is employed to capture the interaction between an independent system operator (ISO) and prosumers. In this arrangement, the ISO attempts to minimise the total generation cost, whereas the prosumers aim to maximise their self-consumption by reducing their feed-in power. As a case study, we use the Australian National Electricity Market (NEM) to explore the impact of increased penetration of residential battery system on performance of the grid in 2020

Hybrid fast damping control strategy for doubly fed induction generators against power system inter-area oscillations

Marzooghi, H ORCiD: 0000-0001-8488-8817Here, a hybrid fast damping control strategy based on bang-bang modulation is proposed for doubly fed induction generators (DFIGs) against inter-area oscillations. Since the changes in active power modulation of DFIG may result in its interactive effect with torsional oscillations, this study relies on the modulation of DFIG reactive power to rapidly attenuate the system's critical oscillation mode. In order to overcome the buffeting of the bang-bang modulation, the proposed control strategy is designed as a hybrid scheme consisting of three operating modes which are switched based on the amplitude of the detected critical oscillation mode. The required lead phase for the proposed control strategy is determined using frequency domain analysis using detailed dynamic model of the DFIG. A comprehensive test is carried out by conducting simulation studies on a modified two-area system including an aggregated wind farm. It has been shown that the proposed strategy damps inter-area oscillations much quicker than the conventional continuous damping controller. Simulation results also showed that the control scheme is robust to the operation point variation and identification errors for practical application

Hybrid fast damping control strategy for doubly fed induction generators against power system inter-area oscillations

Marzooghi, H ORCiD: 0000-0001-8488-8817Here, a hybrid fast damping control strategy based on bang-bang modulation is proposed for doubly fed induction generators (DFIGs) against inter-area oscillations. Since the changes in active power modulation of DFIG may result in its interactive effect with torsional oscillations, this study relies on the modulation of DFIG reactive power to rapidly attenuate the system's critical oscillation mode. In order to overcome the buffeting of the bang-bang modulation, the proposed control strategy is designed as a hybrid scheme consisting of three operating modes which are switched based on the amplitude of the detected critical oscillation mode. The required lead phase for the proposed control strategy is determined using frequency domain analysis using detailed dynamic model of the DFIG. A comprehensive test is carried out by conducting simulation studies on a modified two-area system including an aggregated wind farm. It has been shown that the proposed strategy damps inter-area oscillations much quicker than the conventional continuous damping controller. Simulation results also showed that the control scheme is robust to the operation point variation and identification errors for practical application