Driving ultrasonic piezoelectric transducer (UPZT) at maximum performance in real-time operations is a very challenging task due to the deterioration problem of ultrasound output causing by human-skin impedance fluctuations. This paper proposed ideas and solutions on how to maximize the UPZT driving circuit performance in or deter to solve the deterioration problem. A newly-designed feedback control block with a phase-locked-loop (PLL) technique controlled by microcontroller has been added to the conventional UPZT driving circuit to ensure the automatic resonance frequency tuning and tracking capabilities. After intensive experiments, it is clear that the proposed technique works flawlessly and much more efficient compared to the conventional one. The experimental results also confirm that the percentage of error in tuning to the desired frequency is less than ±0.2% and the speed of tuning convergence time is between 9-12 milliseconds on average.

This paper focuses on designing and implementing a prototype of smart monitoring system capable of doing multi functions i.e. monitoring, analysing and communicating with devices in a small micro-grid system. This research proposes the use of a combination between a low-cost data acquisition (NI compact DAQ) device and a commercially-used LabVIEW™ program in being a smart renewable monitoring and analysing system. The proposed set of equipment is capable of doing all the functions needed by utilities and users in the aforementioned micro-grid system. The proposed prototype is capable of measuring, monitoring and recording in both normal system operating conditions and when faults occurred. A number of power quality parameters that can be monitored and analysed are as follows: voltage (V), current (I), real power (P), reactive power (Q), apparent power (S), energy consumption (kWhr), power factor (PF), harmonics distortion (THDi and THDv), over/under voltage, sag as well as swell. Extensively in this paper, the principle design concepts, hardware implementations, the LabVIEW TM algorithm, how the overall system works, experimental results, the accuracy verification process and the conclusions will be thoroughly elaborated.