Zeeshan Shahid

DC-AC inverter with perspective of common mode and wave-shaping

The use of photovoltaic panels for is becoming popular all over the world for producing electricity for grid connection via using transformer. Grid-connection of solar panel without using a transformer is being reported nowadays. Photovoltaic (PV) grid connected converter without transformer is associated with the problem of non-existent galvanic isolation as a result of transformer absence. The most prominent one issue is the development of common mode voltage leading to common-voltage leakage current. Hence the grid connected PV module of transformer-less panel, though improve power efficiency, suffers from the loss of power due to leakage current. The leakage current in between grid connection and PV panel develops through paths made up by the parasitic capacitances. Moreover, some topologies propose for omitting this abysmal common mode leakage current. This paper shows how low-pass filters of different order affect the wave-shape of the resulting output voltage in the presence of common mode leakage current in transformer-less topologies.

Wave shaping with reduced leakage current in transformer-less inverter

Converting DC into a good sinusoidal has been done in order for getting a solar panel (DC source) tied up to an AC (grid) for onward supply to load centers. Basically such conversion is a wave-shaping technique needing the use of low-pass filters. In contrast, it is quite difficult to get sinusoidal by using other filters such as high pass filters (HPF), band pass filters (BPF) and band stop filters (BPF). On the other hand, passive filters are shown to produce better harmonic-less results compared to using active filters. The issue of leakage current quite common in transformer less configuration is actually reason of escalating the cost and effect to get pure sine wave as well. In this paper, different filter configurations are tried to show how characteristic wave shapes are obtained from a square wave form. The shapes are characterized in terms of zero crossing, amplitude measurement and other criteria including the sine wave form that might be followed by low pass filters (LPF). The results are aimed at minimizing common mode leakage by getting ideally sinusoidal wave shape from Photovoltaic (PV) panel.

Application of UWB wireless MIMO connectivity inside modern aircraft

Monitoring a large number of interacting sensors, actuators and controllers in sensitive locations simultaneously, requires efficient and fast network. Sophisticated computer controlled systems in modern aircrafts have become a necessity. Wired connectivity can be both awkward and hazardous. In this paper we propose wireless connectivity based on Impulse-Radio Ultra Wideband (IR-UWB) system. It is a promising technology for the exchange of high data rates in a limited space. It acts like a Personal Local Area Network (PLAN) suitable for limited space within an aircraft. The proposed scheme utilizes the novel pulse generator developed in these laboratories. The pulse shapes comply with the FCC regulations regarding power levels and spectral mask limitations. It mitigates interference effects with narrowband systems. The proposed scheme has been analyzed theoretically and implemented practically giving sound results. It has so far proved to be an excellent short-range communication technology in terms of cost, speed, power consumption and capacity. A practical system is designed and built, which is capable of operating in the Gbps range. The proposal is anticipated to open possibilities for further applications such as ships, control towers operating theaters, and any other application where a large number of peripherals are in interaction simultaneously. The UWB pulse generator produces pulses, which are portions of simple monocycle sine wave shapes in the GHz range. Results obtained through simulation and theoretical analysis show excellent and constant agreement with results obtained by experimental measurements.

Randomness Analysis of Pseudo Random Noise Generator Using 24-Bits LFSR

We have described in previous work the generation of PN-sequence by employing a 4-bit shifted Linear Feedback Shift Register (LFSR) for application into Direct Sequence Spread Spectrum (DSSS) system by simulation. In this paper, is proposed a pseudo random number generator (PRNG) circuit consisting of 24-bit shift registers (LFSR) which has much longer period to improve statistical properties. We simulated the LFSR circuit by using Multisim 11.0 and the pseudo random sequence generated is tested with statistical test of NIST Test suite. The sequence is passed the entire selected test and we concluded that our pseudo random sequence has long enough period to be considered as random.

Pulse generation using avalanche transistor for ultra wide band communication: Analysis and simulation results

In this paper a simple pico-second pulse generator, its working principle and design. The design is supported by relevant theory, explaining the function of the circuit, and to ultimately show how the resulting pulses are related in their widths to respective parameter values of the circuit elements. The circuit is based on using four timers ICs with transistor and other external logic component. The resulting pulse is studied for its pulse width, amplitude and with a power spectral density lying well within the FCC defined range. The preliminary simulation results of this work shows a generated pulse with a width of around of 180 picoseconds, even shorter than reported in recently reported works.

Implementation and Statistics of Photovoltaic (Pv) Diesel Hybrid Solar System In Commercial Buildings of Pakistan

Pakistan is well known developing country in the world with a population of around 200 Million [1] with annual growth of 2.61 % [1] in 2017 and the energy demand gap of electrical power generation is 4500 to 5500 MWH [2] due to which a lot of load shedding occurs to cover the shortfall of energy crisis. This trend of energy crisis should be overcome and reduce by promoting solar system which can be drive independently with the help of generator sets by PV diesel hybrid solution. Environmental protection concerns are gradually increasing due to non-conventional generation of power in the whole world. Renewable energy sources (RES) with advanced technology plays a vital role in that sustainable increasing energy demand and burning of natural resources such as fossils fuels, coal etc. in the context of such environmental issue [3]. The renewable energy sources such as solar PV system is eco-friendly and less maintenance electrical power generation technique which can be synchronize with generator set to minimize the consumption of gas or diesel in the generator or shutdown the one generator in peak hours of solar system to reduce the cost of fuels of generator such as gas, diesel and other resources and decrease the foot prints of carbon dioxide from the environment. In this research paper the 200 kWp PV diesel hybrid solar system in Dream world resort Karachi Pakistan has been analyzed. This paper provides the working principal of PV diesel hybrid system and the energy generation from simulation report and the online portal that is realistic energy generation at site and the reduction of carbon dioxide foot prints from the environment in comparison of different energy generation resources.

Recognition of Metal Objects inside Wall using Antipodal Vivaldi Antenna

Received Dec 04, 2017 Revised Jan 11, 2018 Accepted Apr 15, 2018 Wireless Body Area Networks (WBANs) are fundamental technology in health care that permits the information of a patient’s essential body parameters to be gathered by the sensors. However, the safety and concealment defense of the gathered information is a key uncertain problem. A Hybrid Key Management (HKM) scheme [13] is worked based on Public Key Cryptography (PKC)-authentication scheme. This scheme uses a oneway hash function to construct a Merkle Tree. The PKC method increase the computational complexity and lacking scalability. Additionally, it increases expensive computation, communication costs and delay. To overcome this problem, Robust Security for Protected Health Information by ECC with signature Hash Function in WBAN (RSP) is proposed. The system employs hash-chain based key signature technique to achieve efficient, secure transmission from sensor to user in WBAN. Moreover, Elliptical Curve Cryptography algorithm is used to verifies the authenticate sensor. In addition, it describes the experimental results of the proposed system demonstrate the efficient data communication in a network.A Weblogs contains the history of User Navigation Pattern while user accessing the websites. The user navigation pattern can be analyzed based on the previous user navigation that is stored in weblog. The weblog comprises of various entries like IP address, status code and number of bytes transferred, categories and time stamp. The user interest can be classified based on categories and attributes and it is helpful in identifying user behavior. The aim of the research is to identifying the interested user behavior and not interested user behavior based on classification. The process of identifying user interest, it consists of Modified Span Algorithm and Personalization Algorithm based on the classification algorithm user prediction can be analyzed. The research work explores to analyze user prediction behavior based on user personalization that is captured from weblogs.Wireless Body Area Networks (WBANs) are fundamental technology in health care that permits the information of a patient’s essential body parameters to be gathered by the sensors. However, the safety and concealment defense of the gathered information is a key uncertain problem. A Hybrid Key Management (HKM) scheme [13] is worked based on Public Key Cryptography (PKC)-authentication scheme. This scheme uses a oneway hash function to construct a Merkle Tree. The PKC method increase the computational complexity and lacking scalability. Additionally, it increases expensive computation, communication costs and delay. To overcome this problem, Robust Security for Protected Health Information by ECC with signature Hash Function in WBAN (RSP) is proposed. The system employs hash-chain based key signature technique to achieve efficient, secure transmission from sensor to user in WBAN. Moreover, Elliptical Curve Cryptography algorithm is used to verifies the authenticate sensor. In addition, it describes the experimental results of the proposed system demonstrate the efficient data communication in a network.

Recognizing Foreign Object Debris (FOD): False Alarm Reduction Implementation

Received Dec 04, 2017 Revised Jan 11, 2018 Accepted Apr 15, 2018 Wireless Body Area Networks (WBANs) are fundamental technology in health care that permits the information of a patient’s essential body parameters to be gathered by the sensors. However, the safety and concealment defense of the gathered information is a key uncertain problem. A Hybrid Key Management (HKM) scheme [13] is worked based on Public Key Cryptography (PKC)-authentication scheme. This scheme uses a oneway hash function to construct a Merkle Tree. The PKC method increase the computational complexity and lacking scalability. Additionally, it increases expensive computation, communication costs and delay. To overcome this problem, Robust Security for Protected Health Information by ECC with signature Hash Function in WBAN (RSP) is proposed. The system employs hash-chain based key signature technique to achieve efficient, secure transmission from sensor to user in WBAN. Moreover, Elliptical Curve Cryptography algorithm is used to verifies the authenticate sensor. In addition, it describes the experimental results of the proposed system demonstrate the efficient data communication in a network.A Weblogs contains the history of User Navigation Pattern while user accessing the websites. The user navigation pattern can be analyzed based on the previous user navigation that is stored in weblog. The weblog comprises of various entries like IP address, status code and number of bytes transferred, categories and time stamp. The user interest can be classified based on categories and attributes and it is helpful in identifying user behavior. The aim of the research is to identifying the interested user behavior and not interested user behavior based on classification. The process of identifying user interest, it consists of Modified Span Algorithm and Personalization Algorithm based on the classification algorithm user prediction can be analyzed. The research work explores to analyze user prediction behavior based on user personalization that is captured from weblogs.Wireless Body Area Networks (WBANs) are fundamental technology in health care that permits the information of a patient’s essential body parameters to be gathered by the sensors. However, the safety and concealment defense of the gathered information is a key uncertain problem. A Hybrid Key Management (HKM) scheme [13] is worked based on Public Key Cryptography (PKC)-authentication scheme. This scheme uses a oneway hash function to construct a Merkle Tree. The PKC method increase the computational complexity and lacking scalability. Additionally, it increases expensive computation, communication costs and delay. To overcome this problem, Robust Security for Protected Health Information by ECC with signature Hash Function in WBAN (RSP) is proposed. The system employs hash-chain based key signature technique to achieve efficient, secure transmission from sensor to user in WBAN. Moreover, Elliptical Curve Cryptography algorithm is used to verifies the authenticate sensor. In addition, it describes the experimental results of the proposed system demonstrate the efficient data communication in a network.

Techno-commercial feasibility of grid-tied solar system in philips morris pvt ltd (commercial building) of Pakistan

Pakistan is a developing country. The population of Pakistan is increasing day by day and due to increase in population the demand of electrical energy is also rising. Currently, Pakistan has a power generation gap of average 4500 to 5500 megawatt hour (MWh) [1]. The Renewable energy plays a vital role in such energy crisis by generating alternative power which is environmental friendly and reduces the carbon foot prints from the environment. The renewable energy sector that is solar, wind and hydro power is a very active area of research and there is a huge space available for modern industrial units and commercial buildings to fill the gap of energy generation and demand energy of Pakistan. In order to void that gap Philips Morris Pvt. ltd initiate with an on-grid solar system with Orient Energy Systems Pvt. ltd with a solar photovoltaic(PV) potential 151.2 kWp for first phase and it will extend up to 458.6 kWp in three phases. By installing solar system the firm saves to millions of rupees in bills of grid and also contributes towards green environment by reducing foot print of carbon dioxide emission from other power generation techniques. This paper provides a techno commercial feasibility of the implementation of the project and environmental friendly impact of such projects on global warming and ozone layer as well as the also shows that in future to reduce the dependency over energy sector and move towards self-reliance in generating greener and cleaner energy.

Investigation on Grid Synchronization for Grid-Tied DC-AC Single Phase Inverters

This paper presents a single-phase Grid-tied inverter for renewable energy systems, which can be used for obtaining small-voltage AC supply for powering small electronic devices or can be used in a distributed grid system for utility supply. The issue of synchronization of these DC-AC inverters with the grid/utility systems is explained and investigated thoroughly in this research. The waveforms generated by each stage of inverter is shown and the issue of power loss caused by variation in phase and frequency due to in-accurate zero crossings is also shown and discussed.