A New Converter for Non-Isolated PV Systems

A new converter for the non-isolated PV (photovoltaic) system is presented in this paper. It has the advantage that the input terminal of the proposed converter is connected to the output negative terminal. In this way, the parasitic capacitance is bypassed to eliminate the undesirable leakage current. The proposed converter can achieve the step-up voltage with four switches only. Aside from that, the carried-based modulation is used, and the control structure is simple. The article analyzes the working modes and control strategy of the proposed converter. In addition, a comparative analysis is provided. The feasibility of the proposed converter under different working modes is verified by simulation. Finally, the digital control prototype with DSP plus FPGA is established and the experimental tests are carried out. The experimental results verify the effectiveness of the proposed converter.

Rancang bangun driver inverter 1000 Watt dengan kendali EGS - 002

Abstrak Penelitian ini dimulai dengan penentuan spesifikasi sistem yang akan dibuat, yaitu sebuah inverter sinusoida pada tegangan output 220Vac pada frekuensi 50 Hz dengan daya sekitar 1000 Watt. Kontrol utama menggunakan EGS-002 sebagai pembangkit sinyal SPWM dan sekaligus driver transistor switching. Sebagai peranti switching adalah 8 buah transistor MOSFET IRF 3205 dengan konfigurasi full-bridge. Sebagai pengubah sinyal SPWM menjadi sinyal sinusoida sekaligus penaik tegangan output digunakan trafo step-up 24V/220V 10A. Hasilnya berupa inverter dengan luaran berupa gelombang sinusoida dengan spesifikasi sebagai berikut: Tegangan masukan 24 VDC. Tegangan luaran 221 VAC dengan bentuk gelombang sinusoida murni pada frekuensi 50 Hz. Daya luaran sampai dengan 905 Watt. Dimensi alat adalah: Panjang 30,5 cm x Lebar 18,5 cm x tinggi 12 cm, dengan berat kurang lebih 3 kg, yang dilengkapi dengan terminal masukan 24Vdc dan 2 buah terminal output 220 Vac (stop kontak). Abstract This research begins with determining the specifications of the system to be made, namely a sinusoidal inverter at an output voltage of 220Vac at a frequency of 50 Hz with a power of about 1000 Watts. The main control uses the EGS-002 as the SPWM signal generator as well as the switching transistor driver. As a switching device are 8 MOSFET transistors IRF 3205 with a full-bridge configuration. To convert the SPWM signal into a sinusoidal signal as well as to increase the output voltage, a 24V / 220V 10A step-up transformer is used. The result is an inverter with a sine wave output with the following specifications: 24 VDC input voltage. Output voltage 221 VAC with pure sinusoidal waveform at a frequency of 50 Hz. Output power up to 905 Watts. The dimensions of the tool are: Length 30.5 cm x Width 18.5 cm x height 12 cm, weighing approximately 3 kg, equipped with a 24Vdc input terminal and 2 220 Vac output terminals (electric socket).

Energy Optimization of Electric Vehicles by Distributing Driving Power Considering System State Changes

In a battery-electric vehicle, a representative electric vehicle, there is a growing demand for performance and one-charge mileage improvement. As an alternative to such improvements, the capacity of the battery has been increased; however, due to the corresponding increase in the weight of the battery and the limited space in the vehicle, increasing the capacity of the battery also has limitations. Therefore, researches are being actively conducted to improve system operation efficiency to overcome such limitations. This paper proposes a distributing method of the driving forces to a battery-powered electric shuttle bus for last-mile mobility equipped with the decentralized driving system while taking into account voltage changes of the input terminals due to changes in the battery charge. The system operation efficiency changes were compared and evaluated by performing energy consumption analysis using ‘Manhattan Bus Driving Cycle’ at low voltage condition (SOC 20%). Various analyzes were performed and compared, such as the uniform distribution method of driving forces of the front and rear wheels (Uniform), the optimization method without considering the input terminal voltage change (Vnorm = 90 V), and the optimization method considering the input terminal voltage change (Vdclink). As a result, it shows that the proposed algorithm can improve 6.0% compared to the conventional uniform driving force distribution method (Uniform). Moreover, it shows that the real-time optimization method without considering the input voltage change (Vnorm = 90 V) can improve 5.3% compared to the uniform distribution method. The proposed method can obtain an additional 0.7% increase in total cost compared to the existing optimization method, which shows that the vehicle system has cost-effectiveness by reducing the battery capacity required to achieve the same mileage.

Finite Ground CB-CPW Bandpass Filter using Vertically Installed Coupled Open-ended Stubs

In this paper, a conductor backed coplanar waveguide (CB-CPW) 3rd order bandpass filter is designed using coupled open-ended stub resonator placed vertically to the signal line. Vertically loaded open ended stubs are designed at quarter wavelength so as to behave like a short circuit at the input terminal thus giving a band-accepted response with lesser metallic area or minimum size. Four such coupled open ended resonators are placed in series and also in closely manner to provide greater field confinement of the proposed bandpass filter. The bandpass filter is designed for a center frequency of 2.5 GHz with FBW of 97.89%, insertion loss of <0.5dB, rising and falling edge selectivity of 30.75 dB/GHz and 27.01dB/GHz respectively with a wide stopband of around 4GHz after the desired passband. Further to validate the design technique six such resonators are placed to obtain 5th order bandpass filter.

Optically and electrically modulated printed carbon nanotube synaptic transistors with a single input terminal and multi-functional output characteristics

A synaptic transistor with a single input terminal can mimick important high neural activities by modulating optical and electrical stimulations.

Performance Analysis of a Universal Circuit for Reversible ALU using QCA & CMOS Technology

The reversible logic and gates are one of the promising and upcoming technologies which are capable of overcoming the limitations of the design and applications based on the CMOS technology. In this technology, the schematic arrangement of the device is implemented in such a way that every input terminal has been provided with individual output terminals. The author has used the technology which is based on quantum computations with a basic feature of loss of energy in small amount. It has many advantages like very high operating speed, low energy dissipation, and high device density. An adder/subtractor is heart of arithmetic units of processors i.e. acts as universal circuit for carrying out the mathematical computations in the quantum processors. The author has put forward a novel reversible adder/subtractor circuit using reversible logic & QCA. The QCA based circuit reported by the author has been compared and analyzed for the performance on the basis of number of gates, size, delay, power dissipation etc. The experimental work has been completed with the use of the most suitable and reliable software i.e. QCA and the performance of the proposed circuit has proven to be quite useful for this circuit to be used in some promising applications. These results are also compared with those obtained with the use of CMOS Technologies.