Energy homeostasis management strategy for building rooftop nanogrids, considering the thermal model and a HVAC unit installed

This paper presents a case study on power control and energy management for a 60 apartments’ residential building with solar generation and energy storage tied to the grid in Santiago, Chile. A new energy management algorithm based on energy homeostasis is designed for a small electro thermal generation system (nanogrid), with smart metering. The test bed employs supervisory control with energy management that regulates the temperature inside a large room by the action of an HVAC (Heating/Ventilating/Air Conditioning) unit. The main objective of supervisory control is to allow temperature comfort for residents while evaluating the decrease in energy cost. The study considers a room with rooftop grid-tie nanogrid with a photovoltaic and wind turbine generation plant, working in parallel. It also has an external weather station that allows predictive analysis and control of the temperature inside the abode. The electrical system can be disconnected from the local network, working independently (islanding) and with voltage regulation executed by the photovoltaic generation system. Additionally, the system has a battery bank that allows the energy management by means of the supervisory control system. Under this scenario, a set of coordination and supervisory control strategies, adapted for the needs defined in the energy management program and considering the infrastructure conditions of the network and the abode, are applied with the aim of efficiently managing the supply and consumption of energy, considering Electricity Distribution Net Billing Laws 20.571 and 21.118 in Chile (https://www.bcn.cl/historiadelaley/historia-de-la-ley/vista-expandida/7596/), the electricity tariffs established by the distribution company and the option of incorporating an energy storage system and temperature control inside the room. The results show the advantage of the proposed tariffs and the overall energy homeostasis management strategy for the integration of distributed power generation and distribution within the smart grid transformation agenda in Chile

Design and simulation of an energy homeostaticity system for electric and thermal power management in a building with smart microgrid

Nowadays, microgrids are gaining importance in electric power generation and distribution environments due to their flexibility, versatility, scalability and the possibility of supplying ancillary services when connected to the grid. They allow for the customization of electric supply for very different types of consumers. Therefore, a new control model for power and energy management based on homeostaticity of electric power systems (EPS) is presented, which has been already analyzed and approved by ENEL Chile in its developmental stage. ENEL, the largest electric utility in the country, is interested in incorporating smart microgrids in the electricity distribution market, as part of a worldwide policy. Such microgrids are to be installed in buildings serviced by ENEL. To demonstrate the model’s utility, a Simulink model of a real microgrid is used, which is comprised of PV generation, energy storage, an air conditioning (AC) equipment and thermal storage of the building upon which the microgrid is installed. The behavior of every element is simulated, including the dynamic thermal model of the building in order to optimize energy management and power supply versus consumption. The behavior of the whole system is analyzed under different environmental profiles and energy consumption patterns using the proposed homeostaticity system.Ministry of Education RTI2018-094917-B-I00Fondo Nacional de Desarrollo Científico, Tecnológico y de Innovación Tecnológica FPU16-03522,3170399,FP

A dynamic router for microgrid applications: Theory and experimental results

International audienceEfficient regulation of the energy transfer between generating, storage and load subsystems is a topic of current practical interest. A new strategy to achieve this objective, together with its corresponding power electronics implementation, was recently proposed by the authors. The device is called dynamic energy router (DER) because, in contrast with current practice, the regulation of the direction and rate of change of the power flow is done without relying on steady-state considerations. In this paper it is shown that, unfortunately, the DER becomes non-operational in the (unavoidable) presence of losses in the system. Hence, we propose a new DER that overcomes this problem. Experimental evidence of the performance of the original and new DER is presented

Grid-Tied Distributed Generation Systems to Sustain the Smart Grid Transformation: Tariff Analysis and Generation Sharing

In this paper a novel model is being proposed and considered by ENEL—the largest electric utility in Chile—and analyzed thoroughly, whereby electric power control and energy management for a 60-apartments’ residential building is presented as an example of the utility’s green energy program, part of its Smart Grid Transformation plan to install grid-tied distributed generation (DG) systems, namely microgrids, with solar generation and energy storage in Santiago, Chile. The particular tariffs scheme analysis shown is part of the overall projected tentative benefits of adopting the new scheme, which will require the utility’s customers to adapt their consumption behavior to the limited supply of renewable energy by changing energy consumption habits and schedules in a way that maximizes the capacity and efficiency of the grid-tied microgrid with energy storage. The change in behavior entails rescheduling power consumption to hours where the energy supply capacity in the DG system is higher and price is lower as well as curtailing their power needs in certain hourly blocks so as to maximize DG system’s efficiency and supply capacity. Nevertheless, the latter presents a problem under the perspective of ENEL’s renewable energy sources (RES) integration plan with the electric utility’s grid supply, which, up until now and due to current electric tariffs law, has not had a clear solution. Under said scenario, a set of strategies based on energy homeostasis principles for the coordination and control of the electricity supply versus customers’ demand has been devised and tested. These strategies which consider various scenarios to conform to grid flexibility requirements by ENEL, have been adapted for the specific needs of these types of customers while considering the particular infrastructure of the network. Thus, the microgrid adjusts itself to the grid in order to complement the grid supply while seeking to maximize green supply capacity and operational efficiency, wherein the different energy users and their energy consumption profiles play a crucial role as “active loads”, being able to respond and adapt to the needs of the grid-connected microgrid while enjoying economic benefits. Simulation results are presented under different tariff options, system’s capacity and energy storage alternatives, in order to compare the proposed strategies with the actual case of traditional grid’s electricity distribution service, where no green energy is present. The results show the advantage of the proposed tariffs scheme, along with power control and energy management strategies for the integration of distributed power generation within ENEL’s Smart Grid Transformation in Chile

Nouveau routeur dynamique prenant en compte les pertes : Théorie et résultats expérimentaux

Dans de nombreux r eseaux, la r egulation e cace du transfert d' energie entre les sous-syst emes de production, de stockage et d'utilisation demeure un sujet di cile a traiter. Les auteurs proposent ici une nouvelle strat egie pour atteindre cet objectif, ainsi que sa mise en oeuvre. Le dispositif est appel e routeur d' energie dynamique (RED), parce que, contrairement a la pratique actuelle, l'asservissement de l' ecoulement de puissance se fait sans s'appuyer sur des hypoth eses stationnaire. Une hypoth ese cl e pour le bon fonctionnement du RED est que la dissipation du syst eme est n egligeable. Toutefois, en pr esence de pertes en ligne le RED inital n'est plus op erationnel, car il est bas e sur l'hypoth ese cl e de non dissipation des interconnections. Dans ce papier, un nouveau RED prenant en compte la pr esence de pertes est propos e. Des preuves de l'am elioration des performances sont pr esent ees en simulation comme en exp erimentation

Nouveau routeur dynamique prenant en compte les pertes : Théorie et résultats expérimentaux

Dans de nombreux r eseaux, la r egulation e cace du transfert d' energie entre les sous-syst emes de production, de stockage et d'utilisation demeure un sujet di cile a traiter. Les auteurs proposent ici une nouvelle strat egie pour atteindre cet objectif, ainsi que sa mise en oeuvre. Le dispositif est appel e routeur d' energie dynamique (RED), parce que, contrairement a la pratique actuelle, l'asservissement de l' ecoulement de puissance se fait sans s'appuyer sur des hypoth eses stationnaire. Une hypoth ese cl e pour le bon fonctionnement du RED est que la dissipation du syst eme est n egligeable. Toutefois, en pr esence de pertes en ligne le RED inital n'est plus op erationnel, car il est bas e sur l'hypoth ese cl e de non dissipation des interconnections. Dans ce papier, un nouveau RED prenant en compte la pr esence de pertes est propos e. Des preuves de l'am elioration des performances sont pr esent ees en simulation comme en exp erimentation.Postprint (published version

Theory and experimental results of two dynamic energy routers

Efficient regulation of the energy transfer between generating, storage and load subsystems is a topic of current practical interest. A new strategy to achieve this objective, together with its corresponding power electronics implementation, was recently proposed by the authors. The device is called dynamic energy router (DER) because, in contrast with current practice, the regulation of the direction and rate of change of the power flow is done without relying on steady–state considerations. A key assumption for the correct operation of the DER is that dissipation in the system is negligible. Unfortunately, in the presence of dissipation the original DER ceases to be operational. In this paper a new DER that takes into account the presence of losses is proposed. Simulation and experimental evidence of the performance improvement with the new DER are presented.Postprint (published version

Impact of Residential Photovoltaic Generation in Smart Grid Operation: Real Example

AbstractThis paper assesses the impact of residential photo-voltaic (PV) generation on the operation of a distribution smart grid in Chile. In particular, we focus on distribution losses and bus voltage regulation. This smart grid is composed of three hundred residential customers and belongs to the Central Inter-connected System (CIS) of Chile. A set of scenarios with different daily load profiles and generating levels are considered. The demand of each client is obtained by measuring the total demand at the distribution transformer and is disaggregating it using consumption profiles. The possibility of reactive power injection through the PV power converters is also considered. To estimate its maximum impact, the reactive power injection is calculated by minimizing network losses through optimal power flow. The location of the PV generation is a random variable with uniform distribution, and the expected losses and voltage profiles are determined using the Monte Carlo method. Three levels of PV generation are considered, 5%, 10% and 15% of the total distribution load. As was expected, the voltage in all the buses of the system increases when reactive power is injected by the power converters of the PV generation. In addition, losses compared to the case without PV generation, decrease by 44% in the most favorable scenario and 1% in the worst case. An estimation for the 40% of residential customers in Chile, considering only 5% penetration of PV generation, give as more than 170.000 MWh of savings in generation per year

Nouveau routeur dynamique prenant en compte les pertes : Théorie et résultats expérimentaux

Dans de nombreux r eseaux, la r egulation e cace du transfert d' energie entre les sous-syst emes de production, de stockage et d'utilisation demeure un sujet di cile a traiter. Les auteurs proposent ici une nouvelle strat egie pour atteindre cet objectif, ainsi que sa mise en oeuvre. Le dispositif est appel e routeur d' energie dynamique (RED), parce que, contrairement a la pratique actuelle, l'asservissement de l' ecoulement de puissance se fait sans s'appuyer sur des hypoth eses stationnaire. Une hypoth ese cl e pour le bon fonctionnement du RED est que la dissipation du syst eme est n egligeable. Toutefois, en pr esence de pertes en ligne le RED inital n'est plus op erationnel, car il est bas e sur l'hypoth ese cl e de non dissipation des interconnections. Dans ce papier, un nouveau RED prenant en compte la pr esence de pertes est propos e. Des preuves de l'am elioration des performances sont pr esent ees en simulation comme en exp erimentation

A PI + Sliding-Mode Controller Based on the Discontinuous Conduction Mode for an Unidirectional Buck–Boost Converter with Electric Vehicle Applications

This paper solves the buck–boost converter operation problem in the discontinuous conduction mode and the feeding a DC bus of a combined battery/solar-powered electric vehicle grid. Since the sun’s radiation has a very important effect on the performance of photovoltaic solar modules due to its continuous variation, the main task of the system under study is the regulation of the output voltage from an MPPT system located at the output of the panels in order to obtain a DC bus voltage that is fixed to 24 V. This is ensured via a double-loop scheme, where the current inner loop relies on sliding-mode control; meanwhile, the outer voltage loop considers a proportional–integral action. Additionally, the current loop implements an adaptive hysteresis logic in order to operate at a fixed frequency. The closed-loop system’s performance is checked via numerical results with respect to step changes in the load, input voltage, and output voltage reference variations