An Embedded Platform for Testbed Implementation of Multi-Agent System in Building Energy Management System

This paper presents a hardware testbed for testing the building energy management system (BEMS) based-on the multi agent system (MAS). The objective of BEMS is to maximize user comfort while minimizing the energy extracted from the grid. The proposed system implements a multi-objective optimization technique using a genetic algorithm (GA) and the fuzzy logic controller (FLC) to control the room temperature and illumination setpoints. The agents are implemented on the low cost embedded systems equipped with the WiFi communication for communicating between the agents. The photovoltaic (PV)-battery system, the air conditioning system, the lighting system, and the electrical loads are modeled and simulated on the embedded hardware. The popular communication protocols such as Message Queuing Telemetry Transport (MQTT) and Modbus TCP/IP are adopted for integrating the proposed MAS with the existing infrastructures and devices. The experimental results show that the sampling time of the proposed system is 16.50 s. Therefore it is suitable for implementing the BEMS in a real-time where the data are updated in an hourly or minutely basis. Further, the proposed optimization technique shows better results in optimizing the comfort index and the energy extracted from the grid compared to the existing methods. Keywords: BEMS; MAS; embedded system; multi-objective optimization; genetic algorith

Design and Implementation of Fuzzy Controller for Non-Linear Thermally Insulated MIMO Greenhouse Building Utilizing Weather Conditions and Ground Temperature

The increased demand of electricity and water consumption for cooling and heating processes together with the continuous increase in earth temperature due to greenhouse gases emission urged the utilization of sustainable, affordable and clean energy resources. Globally, the biggest amount of water is consumed for agricultural purposes. Domestically, in Abu Dhabi Emirate, the agriculture sector consumes over 50% of the supplied water. Part of this consumption is due to the evaporative cooling approach that is typically used in cooling greenhouses. This approach utilizes a large amount of water and energy to maintain the greenhouse temperature within the desired range. Ground Heat-Exchanger is an environmentally-friendly solution used for heating or cooling applications. It is based on seasonal temperature difference between the ground and the ambient which varies with depth. As depth of ground increases, the temperature fluctuation decreases because of the soil high thermal inertia and the time lag in temperature fluctuation between the surface and the ground. The aim of this thesis is to design a control system using fuzzy logic controller to study the feasibility of utilizing weather conditions and soil temperature in cooling or heating processes of a special type of greenhouses. The proposed control system takes a decision of either utilizing the outside weather conditions or using the soil temperature. The study is conducted on a thermally insulated greenhouse system equipped with ground-to-air heat exchanger, actuated windows, fans, and sensors and the proposed controller performance is compared to a logical and conventional ON/OFF controllers. Results show the proposed control system is capable of maintaining the greenhouse temperature within the desired range for most of the day hours in winter utilizing only the weather and soil temperatures. However, when the temperature is extremely hot, especially in summer, the ground heat exchanger can be only used for pre-cooling with a capability of reducing the ambient temperature of about 6ºC on average. In such extremely hot periods, an auxiliary cooling unit has to be deployed for further cooling. In addition, results reveal that fuzzy controller consumes less power than the logical and the ON/OFF controller when operating the system actuators

Control of frequency in future power systems

Future power systems will face a significant challenge due to the reduced stability of frequency. The reduction of inertia drives this challenge due to the increasing level of power electronics connected to renewable energy sources. In this thesis, new control techniques,such as a new secondary frequency control, a control of a population of water heaters(WHs), and a control of a population of battery energy storage systems (BESSs), are studied. A fuzzy logic-based secondary frequency controller was developed to supplement the conventional frequency control in large synchronous generators. This controller is suitable for the provision of mandatory frequency response in the Great Britain (GB) power system, where an additional 10% power output for primary response and 10% for secondary response are required within ten seconds and thirty seconds respectively. The controller was demonstrated using a simplified GB power system and a multi-machine benchmark power system. The results showed that, following a disturbance, the controller improved frequency deviation and error compared to the conventional PI controller. Thus, the controller provides a stable frequency control in future power systems. A hierarchical control of a population of WHs and BESSs was used to provide frequency response services. This was based on two decision layers. The aggregator layer receives the states of WHs/BESSs and sends a command signal to each WH/BESS control layer. The hierarchical control enables the aggregator to choose the number of controllable WHs/BESSs and set the desired amount of responses to offer different frequency response services. As a result, it reduces the uncertainty associated with the response of the population during a frequency event. The WH/BESS controller provides a response based on the last command signal from the aggregator, the value of frequency deviation (ΔF) and the level of the water temperature or BESS state of charge (SoC). The WH/BESS controller provides a response even when a failure occurs in the communication with the aggregator control layer. The WH/BESS controller handles both negative and positive ΔF. Hence, the aggregated loads participate in both low and high frequency responses. The response of the population of BESSs goes from the highest to lowest SoC when the frequency falls and from the lowest to highest SoC when it rises. The response from WHs is from highest to lowest water temperature when the frequency drops. Thus, this reduces the risk of a simultaneous power change in a large number of controllable loads at the same time, which, in turn, reduces the impact. The dynamic behaviour of a population of WHs/BESSs was modelled based on the Markov chain to allow the aggregator to offer different frequency response services. A Markov-based model was also used to evaluate the effective capacity of aggregated WHs/BESSs during the frequency event. The Markov-based model was demonstrated on a simplified GB power system and the South-East Australian power system, considering different aggregation case studies

A study of energy-related occupancy activities in a sample of monitored domestic buildings in the UK

Domestic energy use is determined by multiple non-technological factors, such as the occupants’ lifestyle and activities, which can even offset the effect from energy-efficiency technologies. Acquiring the actual occupancy data relating to energy use in a uniform format to generate comparable and representative information is challenging. Projects that seek to address this issue, such as the Retrofit for the Future and Building Performance Evaluation programmes of the Technology Strategy Board in the UK, usually require major investment. Long-term monitoring and longitudinal observation are two major features in these major investment projects. The former approach refers to the frequent measurement of indoor / outdoor environments and energy use conducted over at least two heating seasons, in line with the whole-house carbon and energy monitoring protocol of the Energy Saving Trust (2011). The latter approach, longitudinal observation, refers to observations conducted on the same group of individuals over an extended study period of years or decades to examine changes over time (Bryman, 2012). The majority of existing households and associated stakeholders that could potentially benefit from the investigation of energy-related occupancy activities cannot feasibly be involved in projects requiring major investment

Sistem Smart Grid Untuk Optimalisasi Pemakaian Daya Listrik Pada Perumahan Dan Gedung Dengan Pemanfaatan Energi Surya

Sistem Smart Grid merupakan teknologi kelistrikan terkini yang mampu mengalirkan arus listrik dan informasi secara dua arah, dari pembangkit ke konsumen dan sebaliknya. Kemajuan teknologi ini mulai banyak diimplementasikan dalam pengelolaan energi listrik, salah satunya integrasi dengan sumber energi terbarukan. Salah satu permasalahan yang banyak ditemui dalam bidang kelistrikan adalah manajemen energi listrik. Pada penelitian ini, peneliti merancang model kelistrikan modern (Smart Grid) untuk manajemen energi di perumahan dan gedung-gedung dalam rangka pengembangan sistem Smart Home dan Smart Building. Penelitian yang dikembangkan akan mengoptimalkan pemakaian energi listrik secara real-time tergantung kondisi beban dan pembangkit energi yang ada saat itu. Pada tahun pertama dirancang model sistem Smart Grid untuk optimalisasi pemakaian daya listrik rumah (TKT-3). Sedangkan pada tahun kedua dirancang model sistem Smart Grid untuk optimalisasi pemakaian daya listrik gedung (TKT-3). Dengan sistem yang dikembangkan ini, diharapkan pemanfaatan, pengelolaan energi listrik utamanya yang bersumber dari energi surya dapat dimaksimalkan, dan sekaligus merupakan upaya pencapaian sasaran Renstra penelitian perguruan tinggi terutama pada bidang unggulan energi baru dan terbarukan