P. Meena

A modified simple algorithm for detection of voltage sags and swells in practical loads

This paper presents the implementation of a modified sliding window algorithm for the detection of sag and swell, by measuring RMS voltage updated every sample. The trigger obtained can be used in conjunction with the main control system of a Dynamic Voltage Restorer (DVR), or as a triggering function to a digital recorder or to a power line conditioner to detect the occurrence of sag and swell. The modeling of the algorithm and test of its functioning to variations in some of the parameters were carried out in a Matlab - Simulink environment. Reliability of the algorithm under conditions of noise and distortion in the input and to three different types of sags was tested on real data captured during events such as starting of induction motor, intermittent loading of welding transformer, and dynamic loading of a captive diesel generator.

A novel strategy for controlling the movement of a smart wheelchair using internet of things

Quadriplegia is a medical condition characterized by partial or complete paralysis of the four limbs and torso. Paraplegia is a variant of quadriplegia and is an impairment in motor or sensory function of the lower extremities. An automated wheelchair is a step taken with an intention to make a difference especially to the lives of these sections of people with restricted mobility. The different modes of control for the movement of the chair are made available in a modular form and can be incorporated by the user based on specific needs. Apart from the controls like joystick, chin control, voice activation, control through head movement, through calls made using a mobile, this chair can also be remotely controlled through the internet. Raspberry Pi is used as a master controller for both joystick as well as internet control. This paper specifically presents the details of control of the smart wheel chair through the internet using the technology of internet of things.

Real-time detection and analysis of PQ disturbances with DSP using matlab embedded link to code composer studio

This paper presents, the hardware test set-up using a DSP for generation of a trigger signal for real - time detection and analysis of PQ waveforms. The trigger obtained can be used to initiate control of a Dynamic Voltage Restorer (DVR), power line conditioner, or recording of the disturbance by a recorder. The test bed has been successfully tested real time for signals such as starting current in a single phase induction motor, voltage of a welding transformer during intermittent load conditions, voltage of a captive diesel generator under dynamic variations in load. TMS320F6713 Digital Signal Processor has been used and the effectiveness of the algorithm used tested in comparison with the simulation results obtained from Matlab/Simulink.

Efficient MPPT for a stand-alone photovoltaic system

This paper presents an efficient MPPT controller. Incremental conductance algorithm is chosen for MPPT to improve the efficiency. The advantage of this algorithm is that the operating point does not oscillate around the Maximum Power Point. The algorithm also detects the atmospheric conditions. The operating point gets shifted according to the irradiance. The DC-DC converter chosen is a MOSFET based Boost converter as the Maximum Power Point is efficient in boost converter. The digital controller used is a DSP controller. The design and Simulations of MPPT are done using the MATLAB IDE link to DSP TMS320F2812. A comparison of MPPT control is done with the power control method known as limit cycle power control or sequential switching regulator. The simulation models are built using MATLAB for both the control methods and the results are compared.

E-Learning in signals, systems and signal processing through Matlab/Simulink

This paper presents a perspective of delivering some of the basic abstract concepts in Signals and Signal processing through e-learning material developed using the simulation tool Matlab/ Simulink. An attempt has been made to create a visual presentation of the results and the implications of which, is envisaged to lead to a clear understanding, as well as provide a strong foundation for creating an exciting world through signal processing.

A simple algorithm for fast detection and quantification of voltage deviations using space vectors

This paper presents the use of the concept of space vector representation of three phase quantities, effectively in the detection and quantification of voltage disturbances such as sags, swells, and interruptions in three phase supply systems. The algorithm involves the transformation of the space vector along the stationary reference frame α-β, as two alternating components orthogonal to each other. The resultant of these orthogonal components the resultant space vector, is sensed at every sampling instant. The magnitude of the resultant space vector has a fixed value under normal conditions. Deviations from this value during disturbances are measured. This is further processed, to generate a trigger signal. The trigger thus generated, can facilitate classification of the type of disturbance, quantification of its magnitude, instant of occurrence, as well as duration needed for a parameters recorder. This can also be used in conjunction with the main control system of a DVR (Dynamic voltage restorer), or a power line conditioner for mitigation purposes. The test of the algorithm was successfully done in Matlab / Simulink.

Power quality conditioner and load management system for an integrated residential grid

This paper presents the process of design, development and testing of a power quality conditioner and a load management system to be integrated as a part of a small grid (Nano 3kW) system suitable for residential power needs. This set-up is being developed at the college laboratory so as to facilitate execution of various studies in the domain of integration of renewables in small distribution systems. The grid is powered by solar and wind energy sources which are synchronized. The power quality conditioner is designed to take care of power quality issues that arise due to the integration of renewable energy sources and operation of power electronic loads. A load management system capable of identifying, monitoring and controlling the loads connected to the system is also put in place using Near Field Communication(NFC) and IPv6 over Low Power Wireless Personal Area Network(6LoWPAN) technologies. The working of the power quality conditioner as well as the load management system are implemented and tested in hardware as individual stages before they become part of the grid and agreement is observed between the simulation and experimental results.

A transformative approach to capstone projects in engineering

Engineering Institutions provide a rich human capital that can source research and innovation. Organizations build further on this, to ultimately realize game changing products that makes a lot of difference in the lives of people. As a part of the engineering curriculum, many exciting capstone projects are currently being executed that contribute to the ecosystem of technological advancement. An explicit direction or vision in these pursuits with tangible benefits to all the stake holders can be brought forth through a transformative alternate approach at the institutional level. This paper presents a new paradigm that can bring about a sea change in the way projects are selected, executed and handed over to the industry /research for consummation on a larger scale. This can also lead to profound and lasting impacts in the learning experience.

A cost effective automotive control for people with restricted mobility

Restricted mobility in individuals can be due to various medical conditions. Quadriplegia is a medical condition characterized by partial or complete paralysis of the four limbs and torso. Paraplegia is a variant of quadriplegia where only waist downwards is non-functional. An assistive solution for mobility of people under these situations is discussed in this work. The aim of which is at achieving a cost effective control unit. The module proposed for the purpose can be incorporated as a separate unit into a wheel chair thus, customized. The paper discusses the methodology used and the hardware components of the prototype which was arrived at. The unit was programmed using an Arduino platform.

A Simple Method for Detection of Voltage Sags and their Mitigation using a Dynamic Voltage Restorer

Power quality is the major focus of progressive nations.In the era of smart grid,power quality receives a lot of thrust at all voltage levels namely,medium ,high and low.The objective of this paper is to present a simple and cost effective method of sag detection and mitigation in three phase systems at the consumers end. The use of the concept of space vector representation of three phase quantities, effectively in the detection ,quantification and mitigation of short duration voltage disturbances such as sags in three phase supply systems under both balanced and unbalanced conditions of operation is presented.Three phase balanced quantities can be represented by a synchronously rotating space vector of constant magnitude .The two phase equivalent of which on a stationary reference frame are orthogonal to each other.When balanced sags occur,the magnitude of the rotating space vector obtained as a resultant of its orthogonal components is sensed for magnitude deviations from its constant nominal value.A trigger signal of varying amplitude is generated in proportional response to the detection of the deviation in its magnitude . In case of sags occurring on one or two phases of the supply, (unblanced),the positive sequence components of the unbalanced three phase quanities are determined using mathematical transformations and the magnitude of the resultant is found out. This resultant is sensed and its deviations from nominal value are measured and used to generate the trigger after processing.The trigger thus generated, initiates the control system of a Dynamic Voltage Restorer(DVR).When a sag is detected,the trigger signal generated, switches on the control circuit of the inverter which uses the space vector pwm control using sampled phase amplitudes of the control signal to generate the modulating wave in proportion to the deviation of the sag voltage from the reference value.The fundamental component of the output voltage which in proportion to the deviation from the nominal value is injected in series with the three phase disturbed signal through a transformer of suitable gain .The results show the successful operation of the DVR in maintaining nominal value of the voltage across the load through out the duration of the disturbance for all cases of balanced and unbalanced operation. The paper presents the detection algorithm as well as the control algorithm for restoration of voltage which are simple and easy to implement .