Indexing

Abstract: Many electronic appliances powered up from the utility, utilize the classical method of AC-DC rectification which involves a diode bridge rectifier (DBR) followed by a large electrolytic capacitor. The uncontrolled charging and discharging of this capacitor instigates harmonic rich current being drawn from the utility which goes against the international power quality standard limits. Personal computer (PC) is one of the electronic equipment which is severely affected by power quality problems. Switched Mode Power Supply (SMPS) is an integral part of the computer that converts AC to multiple numbers of suitable DC voltages to impart power to different parts of the PC. It contains a diode bridge rectifier (DBR) with a capacitor filter followed by an isolated DC-DC converter to achieve multiple dc output voltages of different ratings. That result in a highly distorted, high crest factor, periodically dense input current at the single phase ac mains; this violates the limits of international power quality (PQ) standards such as IEC 61000 -3-2 . Employing various power factor corrected (PFC) single-stage and two stage converters effect a perceivable PQ improvement in these SMPSs. Hence from the analysis of different power factor converters a bridgeless buck boost converter is designed and implemented here for near unity power factor.

Abstract: AC-DC soft-switching resonant converter with interleaved boost power factor corrector (PFC) is presented. In this converter, an interleaved boost PFC circuit is integrated with a soft-switching resonant converter. High power factor is achieved by the interleaved boost PFC circuit. The input current can be shared among the inductors so that high reliability, power factor and efficiency in power system can be obtained and ripples are also reduced. Another advantage of interleaved technique is reduction of THD. Thus the converter performance can be improved. The voltage across the main switches is confined to the dc-link voltage. Soft-switching operation of main switches and output diodes is achieved. Hence the switching losses are reduced significantly. Therefore, the overall efficiency is improved. Circuit is simulated with 110V AC input voltage and 45V DC output voltage is verified. Performance parameters such as voltage stress and output ripple are also analyzed. The simulation is done in PSIM. Power factor of 0.96 is achieved with this converter. For the hardware, dsPIC30F2010 is used for generating PWM pulse with switching frequency 90 kHz.

Abstract: In an inversion system, high reliability is one of the main targets pursuing. Some problems will threaten the reliability of the system, such as, the shoot through issue and the failure of reverse recovery. The dual buck inverters can solve the above problems without adding dead time. A new topology of dual buck inverter with series connected diodes and a single inductor is presented here. The system retains the advantage of no reverse recovery of body diode. The inverter has just one filter inductor, which can make the volume and weight of the system decreased observably and improve the integration. By providing soft switching techniques the power loss can be well reduced. A resonant circuit contributes to reduced switching loss by providing ZVS property. The whole system is simulated in PSIM environment. This inverter retains the advantage of high reliability. A PIC microcontroller is used to generate control pulses since it is fast and easy to implement program when we compare with other microcontrollers. The ease of programming and interfacing with other peripherals make PIC a successful microcontroller. A two level inverter output can be well verified at the output of the dual buck inverter without any reverse recovery loss.

Abstract: Power system are designed to operate at a frequency of 50 or 60 Hz. However, certain types of non linear loads produce current and voltages with frequencies that are integer multiple of the fundamental frequency. These frequency components known as harmonic pollution and is having adverse effect on the power system network.
Inverter is the part of day to day life for every individual. Energy adversity is of special attention in recent days. Because of the sine wave output of the inverter, the electronic devices are efficiently operated. Most of the inverters provide square wave output. Electronic devices run by this inverter may be damaged due to harmonic contents. Available sine wave inverters are expensive and their output is not so good. Hence the improvement in the square wave output of the inverter is most essential. .For getting pure sine wave output SPWM technique is used in inverter. The PWM inverter has been the main choice in power electronics because of its simplicity. SPWM is the mostly used method in motor control and inverter applications. Most of the harmonics can be removed by the SPWM technique and hence improves the quality of power converter. By using active or passive filters or both, we can improve the power quality .

Abstract: Power system is designed to operate at a frequency of 50 or 60 Hz. However, certain types of non-linear loads produce current and voltages with frequency that are integer multiple of fundamental frequency. These frequency components known as harmonic pollution and is having adverse effect on the power system network. Harmonics generates serious problem to the quality of power supply of transmission and distribution network.. In today’s scenario, power system has not only to become reliable one, but also has to ensure about the quality of power. Due to few of the load side equipment only, the quality of power supply worsens. It affects not only the whole power system as well as many consumer side appliances and some sensitive equipment which cannot be afforded to be malfunctioned leading to even loss of life.
The output voltage waveform of ideal inverter should be sinusoidal. However, the waveforms of practical inverters are non sinusoidal and contain certain harmonics. For low and medium power applications, square-wave or quasi-square wave voltages may be acceptable; and for high-power applications, low distorted sinusoidal waveforms are required. With the availability of high-speed power semiconductor devices, the harmonic content of output voltage can be minimised or reduced significantly by switching techniques.

Abstract: As the LED's lumen efficiency increases rapidly in recent years, many new LED illumination applications are emerging. LEDs have features such as long-life, small and low power consumption. Therefore, they are used in various occasion such as full color large sized LED displays, traffic lights, and etc. In this paper, an energy efficient street lighting system is proposed. The presented system consists of a LED lamp module, which can be controlled from remote location. The proposed remote-control system can optimize intensity and efficiency of street lighting systems. It uses GSM based wireless devices which enable more efficient street lamp-system management, thanks to an advanced interface and control architecture. It uses a sensor combination to control and guarantee the desired system parameters; the information is transferred point by point using GSM Module and is sent to a control terminal used to check the status of the street lamps and to take appropriate measures in case of failure.A developed prototype system will be presented in this paper and experiments will be performed to verify the correctness of the proposed system. According to the experimental results, the lighting efficiency is 85 % and the conversion efficiency is 90 %.

Abstract: A new non isolated multi input multi output dc–dc boost converter is pesented in this paper. This converter is applicable in hybridizing alternative energy sources in electric vehicles. By hybridization of energy sources, advantages of different sources can be achieved. In this converter, the loads power can be flexibly distributed between input sources. Also, charging or discharging of energy storages by other input sources can be controlled properly. The proposed converter has several outputs with different voltage levels which makes it suitable for interfacing to multilevel inverters. Use of a multilevel inverter leads to reduction of voltage harmonics which, consequently, reduces torque ripple of electric motor in electric vehicles. Also, electric vehicles which uses dc motor have at least two different dc voltage levels, one for ventilation system and cabin lightening and other for supplying electric motor. The converter presented here has just one inductor. Depending on charging and discharging states of the energy storage system (ESS), two different power operation modes are defined for the converter. The validity of the converter and its control performance are verified by MATLAB/SIMULINK.

Abstract: Dependence of the extracted power of the photovoltaic (PV) and wind energies on environmental specifications and low dynamic response of  Fuel cells cause a battery to be required in these systems. In order to charge and discharge the battery, a bidirectional converter is needed. In this  paper, a non-isolated bidirectional DC-DC converter is presented. The converter consists of two boost converters to enhance the voltage gain. Four power switches are employed in the converter with their body diodes. Two inductors and a capacitor are also employed as passive components. The input current is divided to the inductor which causes the efficiency to be high and the size of them to become smaller. The voltage gain of the converter is higher than the Conventional Cascaded Bidirectional buck/boost Converter (CCBC) in step-up mode. Besides, the voltage gain in step-down mode is lower than CCBC.  Circuit is simulated with 25/250V input voltage and 250/25V DC output voltage is verified. Performance parameters such as voltage stress and output ripples are also analyzed. The efficiency of the converter is more than CCBC while the total stress on active switches are same. The simulation is done in MATLAB R2014a.

Abstract: An Interleaved Buck Converter (IBC) with continuous input current, extremely low output current ripple, low switching losses and improved step-down conversion ratio is presented in this work. The new interleaved buck converter has lower voltage stress in comparison to the conventional IBC and also can provide a high step-down ratio which makes it a proper choice for high power applications. Also new interleaved buck converter can provide current-sharing between two interleaved modules without using additional current-sharing control method. The new interleaved buck converter is simulated by using MATLAB/Simulink and the experimental results can be obtained.

Abstract: Multilevel converters are increasingly being considered for high power applications because of their ability to operate at higher output voltages while producing lower levels of harmonic components in the switched output voltages. This paper proposed a simulation model of four different typologies of single phase five-level inverter. The study investigated four topologies of multilevel inverter namely Flying Capacitor Multilevel Inverter (FCMLI), Diode Clamped Multilevel Inverter (DCMLI), Cascaded H-bridge Multilevel inverter (CHMLI) and POD inverter. These topologies were compared in terms of Total Harmonic Distortion (THD and the number of power electronic components being utilized. The simulation result was conducted using MATLAB/SIMULINK. The findings showed that the POD PWM H-Bridge topology has the lowest total harmonic distortion (THD).

Abstract: A boost converter is a DC to DC converter with an output voltage greater than the source voltage. But it produces large input current ripple. In order to improve the efficiency of the boost converter and reduce the ripple current, an interleaved boost converter is used. An interleaved boost converter consists of several boost converters connected in parallel with switching frequency and a phase shift of 180˚. A new interleaved high step-up DC-DC converter with the circuit of cumulative voltage unit (CVU) is presented in this work. This converter is suitable for the high gain applications. Only two switches are required to form the boosting path and the interleaved topology. Each CVU module can share common diodes to reduce the number of the components and step up the voltage gain. The interleaved structure in the input end can reduce the power loss in each current-owing component and the input current ripple. The interleaved boost converter with voltage summation unit can be verified by using MATLAB/SIMULINK.

Abstract: The main objective of this project is to design an embedded based control warning system. In this project Wireless Sensor Nodes(WSN)technology is used with the help of microcontroller The Zigbee module is used to transmit the data With the help of GSM technology the data is collected in the mobile phone Here we have three sections. In the Sensor section it has  humidity and temperature   to monitor the Lab parameters. It has Zigbee module which will transmit the data to the intermediate section. In the intermediate section we have a Zigbee module and a GSM modem. The Zigbee module will receive the data from the Sensor section and analyses it. If the value gets abnormal it will send the message to the supervisor’s mobile.

Abstract: This article deals with a transformerless buck-boost converter with simple structure. By inserting an additional switched network into the traditional buck-boost converter new converter is obtained. Compared with the traditional buck-boost converter, its voltage gain is quadratic of the traditional buck-boost converter. It can operate in a wide range of output voltage, that is, the proposed buck-boost converter can achieve high or low voltage gain without extreme duty cycle. Moreover, the output voltage of this  transformerless buck-boost converter is common-ground with the input voltage, and its polarity is positive. The two power switches of the proposed buck-boost converter operate synchronously. The operating principles and the steady-state analyses for the buck-boost converter operating in CCM are presented. The PSIM simulations are provided to compare and validate the effectiveness of the buck-boost converter.

Abstract: A proposed development of the Internet in which everyday objects have network connectivity, allowing them to send and receive data.(or) The concept of  internetworking of physical devices, vehicles, buildings and other items embedded with electronics, software, sensors, actuators, and network connectivity that enable these objects to collect and exchange data is defined as “Internet of things”.It is the basic necessity for developing a smart environment in which all the physical appliances communicate with each other to deliver ease of living reducing the manual work up to a great extent. This inter-connected smart environment is the future of electronic universe enabling sophistication to all the time consuming manual data transfers and instructions carried out by the mankind. The infrastructure of information society depends up on IOT, enhancing the opportunities for more direct integration between physical and cyber world. Therefore, ultimately providing improved efficiency, accuracy and economic benefits.

Abstract: AC/DC power converters are required to operate with high power factor (PF) and low total harmonic distortion (THD) for improved grid quality and full capacity utilization of the transmission lines. Passive PF correction (PFC) circuits consist of inductive and capacitive filters followed by a diode bridge. They provide the simplest way of achieving high PF with high efficiency; however, they require low line frequency filters which are bulky and heavy. This work presents a new single stage three level isolated AC/DC PFC converter for high DC link voltage low-power applications achieved through an effective integration of AC/DC and DC/DC stages where all of the switches are shared between two operations. With the converter and switching scheme, input current shaping and output voltage regulation can be achieved simultaneously without introducing additional switches or switching actions. Due to the flexible DC link voltage structure, high power factor can be achieved at high line voltage. The performance of the single stage PFC converter is simulated in MATLAB/SIMULINK environment.

Abstract: Energy from the sun and the wind can alleviate the pressure on traditional sources that has been considerably depleted. Many stages of renewable energy conversion require DC-DC converters with high voltage gain and high power. The applications where electrical isolation is not necessary, transformer less high gain converters can be used in order to avoid the difficulty of using large capacity transformers. This is a step up resonant converter which can achieve high voltage-gain using LC parallel resonant tank. Zero-voltage-switching (ZVS) of semiconductor devices in a resonant converter can be achieved by resonant devices. It is characterized by ZVS turn-on and nearly ZVS turn-off of main switches. Moreover, the equivalent voltage stress of the semiconductor devices is lower than other resonant step up converters. A resonant converter is simulated using MATLAB/SIMULINK and experimental results are also verified.

Abstract: Flexible Alternating Current Transmission Systems (FACTS) devices represents a technological development in electrical power systems to have a tendency to generate the power with minimum price and less time that fulfill our requirement according to our need. Now a days Flexible AC Transmission System (FACTS) devices play a vital role in boost the power of system performance and power transfer capability. TCSC is an important member of family. In practical TCSC implementation, several such basic compensators may be connected in series to obtain the desired voltage rating and operating characteristics, so its placement is very important. This paper represent a meta heuristic hybrid Algorithm of Artificial Bee Colony (ABC) and Differential Evolution (DE) for  finding the best placement and parameter setting of  Thyristor  Controlled Series capacitor to attain optimum power flow (OPF) of grid network. The proposed technique is tested at IEEE-30 bus test System. Result shows that the selected technique is one of the best for placement of TCSC for Secured optimum Power Flow (OPF).