Smoothing Control of Wind Farm Output Fluctuations by Fuzzy Logic Controlled SMES

Due to random variations of wind speed, the output power and terminal voltage of a fixed speed wind generator fluctuate continuously. These irregularities in power output are affecting both the power quality and reliability. It is reported that STATCOM/SMES (Superconducting Magnetic Energy Storage) system can significantly decrease voltage and output power fluctuations of grid connected fixed speed wind generator. But the main problem in wind generator output power smoothing is the choice of the reference output power, because it corresponds to energy storage capacity. The storage capacity of SMES that is sufficient for the smoothing control but as small as possible is very important, considering cost effectiveness. In this paper, a fuzzy logic controlled STATCOM/SMES system is proposed, in which both SMA (Simple Moving Average) and EMA (Exponential Moving Average) are used to generate output power reference. Real wind speed data are used in the simulation analyses, whichvalidate the effectiveness of the proposed control strategy. Simulation results clearly show that the proposed STATCOM/SMES system can smooth well the wind generator output power and also maintain the terminal voltage at rated level in both cases when SMA or EMA is used to generate output reference power. Finally, it is shown that reference output power generated by EMA provides better performance with reduced SMES storage capacity than that of output power generated by SMA.Keywords: Minimization of fluctuations, fixed speed wind generator, STATCOM/SMES, simple moving average (SMA) and exponential moving average (EMA), and wind farm (WF).DOI:http://dx.doi.org/10.11591/ijece.v1i2.18

Performance of Governor System on Minimizing Frequency Fluctuations with Wind Power Generation

As wind turbine output is proportional to the cube of wind speed, the wind turbine generator output fluctuates due to wind speed variations. Hence, if the power capacity of wind power generators becomes large, wind power generator output can have an influence on the power system frequency. Therefore, this study investigates the influence of governor control systems of synchronous generators (SGs) for minimizing frequency fluctuations with high wind power penetration level, when a total capacity of SGs is considered as 100 MVA. It is seen that when both SGs operate as governor free (GF) operation, system perform better frequency control. But it can not be maintained to the acceptable level when SGs operate at GF-LFC or LFC-GF operation with wind power capacity about 5% of total capacity. Finally, it is seen that when several interconnected SGs are operated with different control modes, system frequency become more severe for 10% capacity of wind power.DOI:http://dx.doi.org/10.11591/ijece.v2i1.18

Machine Learning (ML) assisted Edge security framework on FPGAs

Edge computing (EC) is an act of bringing computational and storage capability near data sources. It helps to reduce response times and bandwidth requirements. However, the rapid proliferation of edge devices has expanded the attack surface and opportunity for adversaries to penetrate corporate networks. The limited computational abilities of edge devices and the heterogeneous nature of communication protocols further increase the security challenges of EC. Also, the trustworthiness of hardware devices is challenged due to security and privacy threats like trojan insertion, IP cloning, and hardware counterfeits. The application of Machine Language (ML) models in the edge computing paradigm creates a distributed intelligence architecture. Also, Field Programmable Gate Arrays (FPGAs) can exploit Physical Unclonable Functions (PUFs) characteristics to generate and store authentication keys. The PUF structure deployed with ML models in the edge layer can learn its complex input-output mapping from the Challenge and Response pairs (CRPs) to identify the suspicious and unknown responses. This article discusses the security and privacy issues in various layers of the EC architecture and proposes intrusion detection systems through the integration of FPGA-based edge sever and ML models. A PUF-assisted ML framework of the intrusion detection system is proposed to authenticate and detect potential attacks on the network

Analysis of the Oceanic Wave Dynamics for Generation of Electrical Energy Using a Linear Generator

Electricity generation from oceanic wave depends on the wave dynamics and the behavior of the ocean. In this paper, a permanent magnet linear generator (PMLG) has been designed and analyzed for oceanic wave energy conversion. The proposed PMLG design is suitable for the point absorber type wave energy device. A mathematical model of ocean wave is presented to observe the output characteristics and performance of the PMLG with the variation of ocean waves. The generated voltage, current, power, applied force, magnetic flux linkage, and force components of the proposed PMLG have been presented for different sea wave conditions. The commercially available software package ANSYS/ANSOFT has been used to simulate the proposed PMLG by the finite element method. The magnetic flux lines, flux density, and field intensity of the proposed PMLG that greatly varies with time are presented for transient analysis. The simulation result shows the excellent features of the PMLG for constant and variable speeds related to wave conditions. These analyses help to select proper PMLG parameters for better utilization of sea wave to maximize output power

Landlessness as the key challenge to climate change adaptation of the rural poor in Bangladesh : an empirical study

Bangladesh is ranked top among the locations most affected locations by extreme weather events over the last two decades and one of the potential victims of the consequences of climate change. Around 3.26 million rural Bangladeshi households are landless. These landless households usually constitute the poorest and most vulnerable groups in Bangladesh and are the first victims of climatic hazards. Despite the adaptation measures taken by the government and non-governmental organizations, landlessness generates constraints to adapt to the changing environment. Taking the above premises, this paper principally aims to unveil how landlessness poses challenges for the rural poor of Bangladesh in their endeavor to adapt to already emerging conditions of climate change. Based on qualitative interviews of relevant stakeholders, this paper finds that landlessness is a key challenge to the climate change adaptation process as it hinders livelihoods and income-generating activities of the people living in rural and coastal regions. Moreover, this study finds that landless people living near urban spaces are better placed to migrate to the cities for livelihoods and shelter. This study also adds insightful evidence suggesting that lack of access to land or land entitlement is a major setback to the existing climate change adaptation policy in Bangladesh

Microcontroller Based Single Phase Digital Prepaid Energy Meter for Improved Metering and Billing System

This paper presents a single phase digital prepaid energy meter based on two microcontrollers and a single phase energy meter IC. This digital prepaid energy meter does not have any rotating parts. The energy consumption is calculated using the output pulses of the energy meter chip and the internal counter of microcontroller (ATmega32). A microcontroller (ATtiny13) is used as a smart card and the numbers of units recharged by the consumers are written in it. A relay system has been used which either isolates or establishes the connection between the electrical load and energy meter through the supply mains depending upon the units present in the smart card.Energy consumption (kWh), maximum demand (kW), total unit recharged (kWh) and rest of the units (kWh) are stored in the ATmega32 to ensure the accurate measurement even in the event of an electrical power outage that can be easily read from a 20×4 LCD. As soon as the supply is restored, energy meter restarts with the stored values. A single phase prepaid energy meter prototype has been implemented to provide measurement up to 40A load current and 230V line to neutral voltage.Necessary program for microcontrollers are written in c-language and compiled by Win-AVR libc compiler.DOI: http://dx.doi.org/10.11591/ijpeds.v1i2.138

Capacitor voltage balancing with Reduction of Arm current and THD control of MMC: A modified triangular injection approach.

For high power applications, in recent time, multilevel converter has become popular because of the composition of a number of DC sources. In both variable and controllable frequency system, stair voltage output waveform of this type of converter is controllable. Different types of DC sources like as batteries, fuel cells, solar cell, wind and micro turbines are used in Modular Multilevel Converter (MMC) topology has been popular in the distributed energy resources area. Harmonic profile of a converter with a modulation scheme much depends on the carrier frequency used in it. On the other hand, with the control of Total Harmonic Distortion (THD), the arm current control is also the necessity to drive an MMC in smooth operation. Imbalance of the SM capacitor voltage affect the arm current as well as the life time of the capacitor. In this way the overall performance of the converter could be affected. As a result, several efforts of research in this area focuses on to minimize THD, to balance the capacitor voltage of Sub-module (SM) and to control the arm current of the converter. This paper proposed a modified triangular injection modulation structure for MMC converters to maintains minimum harmonic profile as well as to achieve lower arm current and capacitor voltage balancing of SM within a single algorithm structure. Some well-known modulation methods are compared with proposed method so that percentage of THD and arm current can be identified as minimum and quality of the output voltage is better