This paper presents the development of single phase sinusoidal pulse width modulation (SPWM) microcontroller-based inverter. The attractiveness of this configuration is the used of a microcontroller to generate sinusoidal pulse width modulation (SPWM) pulses. Microcontroller is able to store the required commands to generate the necessary waveforms to control the frequency of the inverter through proper design of switching pulses. The SPWM technique was used to produce pure sinusoidal wave of voltage and current output. This inverter is designed to be either for stand-alone or for grid connected from a direct supply of photovoltaic (PV) cells. In this paper SPWM switching technique is first reviewed. Subsequently control circuit and power circuit for inverter are discussed. Finally the experimental results are discussed. The 200 W designed prototype of the inverter was tested with the resistive load and found that total harmonic distortion (THD) is less than 4% for voltage and 8% for current.

In this paper, a series of investigations on sensitivity and bandwidth for four types of Rogowski coil (RC) sensors was demonstrated. The proposed RC sensor design using acrylonitrile butadiene styrene material carries the advantages, such as lighter weight, robust, and higher temperature resistance. The prototype development first was carried out with the assistance of Solidwork 3D computer aided design software and MakerBot 2X 3D printer. Subsequently, the sensors were modeled and simulated using electromagnetic transient program-alternative transient program software environment based on the lumped parameter identification. A single-end measuring technique was used to locate the PD signal on the three-phase medium voltage underground cross-link polyethylene insulated power cable with a 240-mm ² nominal area copper conductor. In order to verify the results achieved from the simulation, an experiment was carried out. This experiment was repeated concurrently for each design of the RC sensors. In order to achieve the best PD detection, the precise selection for the best sensor is paramount. In this case, the results indicated that certain geometrical shape performed better with regard to the detection of the PD signal.

This paper presents a novel modified Levy flight optimization for a photovoltaic PV solar energy system. Conventionally, the Perturb and Observe (P&O) algorithm has been widely deployed in most applications due to its simplicity and ease of implementation. However, P&O suffers from steady-state oscillation and stability, besides its failure in tracking the optimum power under partial shading conditions and fast irradiance changes. Therefore, a modified Levy flight optimization is proposed by incorporating a global search of beta parameters, which can significantly improve the tracking capability in local and global searches compared to the conventional methods. The proposed modified Levy flight optimization is verified with simulations and experiments under uniform, non-uniform, and dynamic conditions. All results prove the advantages of the proposed modified Levy flight optimization in extracting the optimal power with a fast response and high efficiency from the PV arrays.

Partial discharge (PD) diagnostic on high voltage (HV) power cables is a modern technology in order to investigate the insulation health. The trending technology such as wireless sensor network (WSN) and internet of thing (IoT) are mostly process in digital signal by microprocessor where looking toward on automatic system. The high performance of analog to digital converter (ADC) in term of sampling rate which is much expensive in order to convert the high frequency of analog PD signal that captured by Rogowski coil (RC) sensor. Thus, this paper propose the implementation of the Sigma-Delta (∑Δ) ADC topology in Altera DE0-Nano development board as an effective method in this work to replace the conventional ADC chip and the cost is minimal. Then, peak PD detection technique is applied after the conversion of the digital PD signal. The Verilog hardware description language (VHDL) is used in Quartus II software which corporate with Altera DE0-nano development board for the prototype development. In order to achieve the accurate digital sampling of high frequency PD signal, the N-bit of voltage resolution is paramount.

A MEMS-based piezoelectric energy harvester is capable in producing the electrical output at certain level. The investigation on ability to successfully generating the electrical output power is highly recommended. Accordingly, an optimization on electrical output power based on micro-cantilever beam geometry is presented in this paper via simulation work using COMSOL Multiphysics software. Thus, four different geometries named as PPG 1, PPG 2, PPG 3 and PPG 4 are individually characterized. The simulation result shows the superior performances from PPG 2 which generating 393 mV of output voltage with 39 nA output current, while the output power is 15 nW at 10 MΩ optimal load and 1g vibration amplitude. The excitation frequency for PPG 2 is as low as 60 Hz. Therefore, the modification of micro-cantilever geometry is able to increase the production of electrical output power.