Antonino Madonia

Contributed Review: Review of thermal methods for space charge measurement

The space charge accumulation phenomenon has garnered great interest over the last two decades because of the increased use of direct current in high voltage electrical systems. In this context, a significant relevance has been achieved by the thermal methods, used for solid dielectrics. This paper presents a review of this non-destructive measurement system used for the measurement of space charge. The thermal pulse method, the thermal step method, and the laser intensity modulation method are described. For each configuration, the principle of operation, the thicknesses analyzed, and the spatial resolution are described, reporting also the main related applications.

Optimal power flow based on glow worm-swarm optimization for three-phase islanded microgrids

This paper presents an application of the Glowworm Swarm Optimization method (GSO) to solve the optimal power flow problem in three-phase islanded microgrids equipped with power electronics dc-ac inverter interfaced distributed generation units. In this system, the power injected by the distributed generation units and the droop control parameters are considered as variables to be adjusted by a superior level control. Two case studies with different optimized parameters have been carried out on a 6-bus test system. The obtained results showed the effectiveness of the proposed approach and overcomes the problem of OPF in islanded microgrids showing loads unbalance.

PV systems in the vertical walls: A comparison of innovative structures

This paper presents the performance comparison of PV windows with the purpose of tracing the behavior of next-generation systems, which could favor architectonical integration. More in detail, a dye sensitized solar cell (DSSC) and blue and grey thin film silicon panels have been analyzed. The systems can be placed behind a window or behind a wall of glass blocks. The three generation systems are then compared in terms of both efficiency and Fill Factor.

Partial Discharge of Gel Insulated High Voltage Power Modules subjected to Unconventional Voltage Waveforms

Performances and duration of the new generation of high voltage power electronic components are dependent on dielectric materials aim to insulating their internal terminals. The presence of defects, some due to faults generated during the manufacturing process, but also due to the internal design of layers and connections, can cause local enhancements of electric field and consequently possible activity of partial discharges phenomena or other effects (aging, tracking) that may result in reduction of device reliability. Furthermore, the usage of unconventional voltage waveforms, like square waves or pulse width modulated waves, additionally increases the electrical aging of the insulation system as compared to conventional sinusoidal waves.

Space Charges and Partial Discharges Simultaneous Measurements under DC Stress

In the field of HVDC, the main causes of insulation aging are due to the space charge and PD phenomena. In particular, the purpose of the present work is to verify a possibility to measure simultaneously the space charge and the PDs under DC stress in order to evaluate the correlation between both phenomena. The space charge was measured by using a modified PEA cell and PDs were measured by using a novel wireless sensor system. The space charge profile and the PD pulses carried out simultaneously have been reported and discussed.

Overcoming synchronization issues in wireless technology Partial Discharge measurement

In this paper, several aspects of the fundamentals of wireless Partial Discharge (PD) measurements are first discussed. Then, the relevance of the problem of voltage synchronization in PD wireless diagnosis is outlined. When portable instruments are used for PD detection, the main issue is the voltage measurement at the site where the PD detection is carried out. When such analysis is carried out over shielded cables, the AC (50/60 Hz) voltage reference signal is not easily detectable, while one of the basic parameters for PD diagnosis, the displacement of the inception voltage of the PD as compared to the reference voltage, is not available. Even if high-performance sensors are readily available on the market, the authors are investigating the possibility to use remotely measured reference voltage at the closest accessible substation to create a reliable reference, thus reducing the time and associated costs required for performing field wireless measurements.

Analysis of the new submarine interconnection system between Italy and Malta: Simulation of transmission network operation

In this paper, some simulations of the interconnected Sicilian and Maltese transmission systems are performed, in order to assess this new system configuration. The HVAC submarine interconnection between Italy and Malta came into operation in 2015 and is part of a European programme for transmission grid interconnection improvement. This new line has been built in order to allow a better management of the power system of both the islands. Firstly, a brief description of the interconnection system is given. Moreover, the transmission systems of Sicily and Malta are depicted and their structures are shown. The simulations are carried out by means of a model of the interconnected system created on purpose on NEPLAN® environment. Some working scenarios are assumed in order to perform load flow calculation and to highlight the effects of power export towards Malta. In order to find the contribution to the power exported through the interconnection line, a power flows tracing method is implemented. The results show that the Sicily-Malta interconnection makes possible a significant improvement of RES exploitation in Sicily, a better management of Sicilian traditional plants and a reduction of the polluting emissions from the two obsolete Maltese fuel oil thermal plants.

Wireless Power Transmission for house appliances: A small-scale resonant coupling prototype

This paper presents a low cost prototype of wireless power transfer system based on resonant coupling. The system here proposed can be useful for house appliances battery charging systems: as a matter of fact, it consists mainly of two copper wire coils or windings, placed one in front of the other on the same axis. By exploiting the coils resonance coupling effect, electric energy can be transferred from the inductor coil to the receiver in order to charge the batteries. Low cost experimental tests demonstrated the effectiveness of the proposed wireless power transfer prototype, being it capable to reach an efficiency of about 80% and more along a distance of 30 cm.