i-manager's Journal on Electrical Engineering (JEE)


Volume 4 Issue 3 January - March 2011

Article

A Survey on Hardware and Software Optimization of Microprocessors for Low Power Consumption

Ananthi Kaliyamoorthy* , S. Manoharan**
* Assistant Professor, Department of Electronics and Instrumentation Engineering, Karpagam College of Engineering, Coimbatore.
**Professor, Department of Electronics and Instrumentation Engineering, Karpagam College of Engineering, Coimbatore.
Ananthi Kaliyamoorthy, and S. Manoharan (2011). A Survey On Hardware And Software Optimization Of Microprocessors For Low Power Consumption. i-manager’s Journal on Electrical Engineering, 4(3), 1-9. https://doi.org/10.26634/jee.4.3.1393

Abstract

Today there is a growing need for reducing the power consumption of microprocessors, because they form a major share of the power budget of equipment. Power consumption in microprocessors can be reduced either by hardware, software or both. The power consumption of the processors increases along with increase in transistor count and clock frequencies. Thus there is a need to design a processor which consumes less power without affecting its performance and efficiency. Likewise, each instruction involves specific part of the microprocessor. Therefore, by selecting the correct instruction it is possible to reduce the power consumed by the processor. This paper presents a survey on hardware and software power reduction techniques used for several microprocessors.

Research Paper

A Low Cost Microcontroller Based Triggering Circuit for Multilevel Inverter

Adil Sarwar* , M.S. Jamil Asghar**
* Research Scholar, Department of Electrical Engineering, Aligarh Muslim University, Aligarh, India.
** Professor, Department of Electrical Engineering, Aligarh Muslim University, Aligarh, India.
Adil Sarwar, and M.S. Jamil Asghar (2011). A Low Cost Microcontroller Based Triggering Circuit For Multilevel Inverter. i-manager’s Journal on Electrical Engineering, 4(3), 10-16. https://doi.org/10.26634/jee.4.3.1394

Abstract

Multilevel inverters have drawn increasing attention in recent years, especially in the distributed energy resources area. Several renewable energy sources (batteries, fuel cells, solar cells, wind turbines or micro turbines) can be easily connected through a multilevel inverter to feed a load (off-grid) or interconnect to the ac grid (grid-tie) without voltage balancing problems. Moreover, multilevel inverters have a lower switching frequency than standard PWM inverters and thus have reduced switching losses. The output waveforms of multilevel inverters are in a stepped form, resulting in reduced harmonics compared to a square-wave inverter. In the present work, PIC 16F877A microcontroller based triggering circuit has been designed to be used with various levels of multilevel inverter. Multiple pulses with relative delay and requirement of a single variable dc supply (0-5V) for the control of all delay angles, makes it cost effective and simple. In addition, PIC 16F877A are cheaper with respect to other 8 bits microcontrollers available in market. It is a RISC controller with only 25 instruction sets. The Harvard architecture makes it more attractive. The simulation is done using MPLAB IDE and PROTEUS 7. Practical circuit has been designed and successfully implemented.

Research Paper

A 10-bit Ultra-Low-Power SAR ADC with a Novel DAC Switching Method

Weibo Hu * , Donald Lie**
* Research Scholar, ECE Department of Texas Tech. University, Lubbock.
** Associate Professor, ECE Department of Texas Tech. University, Lubbock.
Weibo Hu and Donald Y.C. Lie (2011). A 10-Bit Ultra-Low-Power SAR ADC with a Novel DAC Switching Method. i-manager’s Journal on Electrical Engineering, 4(3), 17-22. https://doi.org/10.26634/jee.4.3.1395

Abstract

A 10-bit single-ended ultra-low-power Successive Approximation Register ADC with a novel DAC switching technique is designed in the TSMC 0.18µm mixed-signal CMOS technology. This method uses a reference voltage of VR/2, rather than VR, as the only reference voltage to digitize the input signals with the amplitude range of [0, VR]. Compared with the conventional switching method, this work reduces the size of binary-weighted capacitor array by 50%, lowering the average power consumption in the DAC during digitizing by 87.5%, and it also reduces the power consumption during sampling by 63.5%. With the sampling frequency of 77 kHz, ADC’s post-layout simulation resolution is 8.84 bits and ERBW (Effective Resolution Bandwidth) is 60 kHz, and the post-layout simulation FOM of our 10-bit SAR ADC can reach 18.9 fJ/(conversion-step), which is among the best ADCs FOM reported in a CMOS 0.18 µm technology.

Research Paper

A 3P-3W UPQC integrated with Star-Hexagon Transformer for 3P-4W Distribution System

Yash Pal* , A. Swarup**, Bhim Singh***
* Assistant Professor,Department of Electrical Engineering, National Institute of Technology, Kuruksetra, Haryana
** Professor, Department of Electrical Engineering, National Institute of Technology, Kuruksetra, Haryana.
*** Professor, Department of Electrical Engineering, Indian Institute of Technology, New Delhi, India.
Yash Pal, A. Swarup and Bhim Singh (2011). A 3p-3w Upqc Integrated With Star-Hexagon Transformer For 3p-4w Distribution System. i-manager’s Journal on Electrical Engineering, 4(3), 23-31. https://doi.org/10.26634/jee.4.3.1396

Abstract

In this paper, a new topology is proposed for a three-phase four-wire (3P4W) distribution system utilizing a star-hexagon transformer along with three-phase three-wire (3P3W) Unified Power Quality Conditioner (UPQC).In this proposed topology the neutral point of the star connected transformer, used for the connection of series active power filter (APF) of 3P3W UPQC, is utilized as a fourth wire for 3P4W distribution system. The star-hexagon transformer is connected near the load to compensate the neutral current that may flow toward the neutral point of the series transformer of series APF. The series and shunt APF of 3P-3W UPQC are realized by readily available three-leg voltage source inverters (VSIs). For the mitigation of different power quality problems a control technique based on synchronous reference frame (SRF) theory is used for the control of UPQC. In this control scheme of UPQC, the current/voltage control is applied over the fundamental supply currents/voltages instead of fast changing APFs currents/voltages, there by reducing the computational delay. With the connection of star-hexagon transformer, no extra control is required for the neutral current; hence required numbers of current sensors are reduced. The performance of the proposed topology of UPQC is analyzed through simulations results using MATLAB software with its Simulink and Power System Block set toolboxes.

Research Paper

Distribution Network Planning with Advanced Centralized Voltage Regulation System

Sankar S*
Senior Lecturer, Panimalar Institute of Technology, Chennai.
S. Sankar (2011). Distribution Network Planning With Advanced Centralized Voltage Regulation System. i-manager’s Journal on Electrical Engineering, 4(3), 32-37. https://doi.org/10.26634/jee.4.3.1397

Abstract

Traditional voltage regulation systems for distribution networks fail to achieve their objective in presence of local generation resources as they are designed for passive distribution systems and based on assumptions that may not hold if distributed generation (DG) is connected to the network. An advanced centralised voltage regulation system has been studied by the Authors to allow a greater DG penetration and a high quality service to customers. However, depending on the characteristics of the specific network, it could be sometimes impossible to solve some operating conflicts between voltage regulation and correct DG operation. In practice, in order to connect a greater amount of DG, it might be necessary, not only to revise the employed regulation criteria, but also to act at the planning stage to make specific changes in the structure of a distribution system. In this view the paper presents a planning procedure that, besides existing distribution system data bases, load variation forecast,  environmental/climatic  conditions, and planners experience, takes into account information directly provided  by  the  operation  of  the  aforementioned  advanced voltage regulation system.

Research Paper

Mobile Voting System using Iris Recognition and Cryptography Techniques

K. Gopal* , S. Praveen**, N. Suthanthira Vanitha***
*,** BE. II-EEE, Knowledge Institute of Technology, Salem, India.
*** Professor, Department of EEE, Knowledge Institute of Technology, Salem, India.
K. Gopal, S. Praveen and N. Suthanthira Vanitha (2011). Mobile Voting System Using IRIS Recognition And Cryptography Techniques. i-manager’s Journal on Electrical Engineering, 4(3), 38-42. https://doi.org/10.26634/jee.4.3.1398

Abstract

With the advancement of electronics and computer science, mobile communication technology leads us to a fast moving entirely different world. In this scenario, we have lot of responsibilities, one of it is voting for our country, but even we don’t have time for it, and also our votes may not useful to our nation, because of fake votes and cheating process happened during the election. This problem is rectified by the latest voting system as “Mobile Voting System” which is discussed in this paper. The mobile voting system uses the efficient techniques, iris recognition and cryptography for the secured voting process. The iris recognition and cryptography avoids the fake votes and cheating process. The election commission spends lot of money, for each election unnecessarily, which will be minimized by this system. This system enables the voter to vote to the Nation from his place itself.

Research Paper

Adaptive Neuro-Fuzzy Dividing Frequency Controlfor the Development of Hybrid Active Power Filter

M. S. Sujatha* , T. Susritha**, Vijay Kumar***
*,** Research Scholar, Department of EEE,SVEC, A.Rangampeta, Tirupati.
*** Professor, Department of EEE, JNTUCEA, Ananthpur.
M.S. Sujatha, T. Susritha and M. Vijay Kumar (2011). Adaptive Neuro-Fuzzy Dividing Frequency Control For The Development Of Hybrid Active Power Filter. i-manager’s Journal on Electrical Engineering, 4(3), 43-53. https://doi.org/10.26634/jee.4.3.1399

Abstract

This paper deals with a hybrid active power filter with injection circuit (IHAPF). It shows great promise in reducing harmonics and improving the power factor with a relatively low capacity active power filter. To minimize the capacity of IHAPF, an adaptive fuzzy dividing frequency-control method is proposed which consists of two control units: a generalized integrator control unit and fuzzy adjustor unit. The generalized integrator is used for dividing frequency integral control, while fuzzy arithmetic is used for adjusting proportional-integral coefficients timely. And the control method is generally useful and applicable to any other active filters. Compared to other IHAPF control methods, the adaptive fuzzy dividing frequency control shows the advantages of shorter response time and higher control precision. The simulation and experimental results shows that the new control method is not only easy to be calculated and implemented, but also very effective in reducing harmonics. In this paper Adaptive Neuro-Fuzzy controller is also used to develop the Hybrid Active Power Filter which has the advantages of reduced rule-base and fast response compared to Adaptive Fuzzy dividing frequency control method [1].

Research Paper

Fuzzy-Differential Evolution Method for Optimal Capacitor Placement in Distribution Systems

Dinakara prasad Reddy* , V. Usha Reddy**
* Student, Electrical and Electronics Engineering, S.V.U College of Engineering, Tirupati, Andhra Pradesh, India.
** Assistant Professor, Electrical and Electronics Engineering, S.V.U College of Engineering, Tirupati, Andhra Pradesh.
P. Dinakara Prasad Reddy and V. Usha Reddy (2011). Fuzzy-Differential Evolution Method For Optimal Capacitor Placement In Distribution Systems. i-manager’s Journal on Electrical Engineering, 4(3), 54-58. https://doi.org/10.26634/jee.4.3.1400

Abstract

This paper presents a fuzzy and Differential Evolution (DE) method for the placement of capacitors on the primary feeders of the radial distribution systems to reduce the power losses and to improve the voltage profile. Fuzzy approach is used to find the optimal capacitor locations. Differential Evolution method is used to find the sizes of the capacitors. The proposed method is tested on 10-Bus,15-Bus and 34-Bus test systems and the results are presented.