M. Chiandone

Industrial motion control applications using linux RTAI

RTAI extension to Linux operating system makes it possible to perform Hard Real-Time (HRT) controls using a commercial PC and utilizing open-source code. This paper details a software installation process, along with the suitable hardware chosen for realizing motion controls using Linux-RTAI. Advantages offered by the possibility of designing and developing motion controls using the powerful tools of high level object-languages (i.e. Simulink) are described. It is proven that the combination of Simulink as a development environment and Linux-RTAI PC as a controller platform brings advantages that can be greatly appreciated in industrial motion control applications, such as: very reduced time for development, diagnostics, design of controls; adequate control performance; cost reductions offered by the open-source status of the operating system.

New rules to employ distributed generators in voltage control: Assessment and numerical validation using DOME

In recent years, several countries have published new technical rules for the connection of distributed generators to medium and low voltage networks. A common requisite is that distributed generators should be able to module both active and reactive power. The paper duly reviews these rules and presents a variety of simulations referred to actual distribution networks using a new software tool: DOME.

Application of new voltage control rules in distribution networks

Several countries are undergoing a considerable development of distributed generation (DG). Hence, Distribution System Operators (DSO) are coping with unprecedented technical issues which force introducing new connection rules for customers that produce energy. This work focuses on voltage control issues of distribution systems with inclusion of distributed generation. A review of the standards that have been recently introduced is accompanied by a discussion on simulation results based on a real-world distribution grid. All simulations are solved with DOME, a novel Python-based software tool.

Evolution of the main economic parameters for photovoltaic plants installed in Italy

The Italian photovoltaic market is today the third worlds largest and represents a success story having attained the grid parity for certain type of residential and Commercial/Industrial (C&I) customers. In this paper, the main economic parameters involved in the installation of a photovoltaic plant (i.e. the Payback Time, the Internal Rate of Return and the Levelized Cost Of Energy) are calculated for three representative locations in Northern, Central, and Southern Italy. The parameters are calculated at different times between 2003 and 2014 considering different regime of governmental incentives and the grid parity scenario. The result of such analysis shows how the dramatic reduction of installation in the Italian market after 2011 cannot be directly related to a reduction of the economic convenience for the enduser. Moreover, the opportunities given by the attainment of the grid parity seem to have the potential to pave the way to a new impulse in the market of this solar technology.

Monitoring applications of electrical and climate data for PV systems using Linux RTAI

This work presents the design and development of an innovative system aimed at detecting, recording and transmitting electrical and climate data from a PV field. Data are to be taken both from the PV modules and from the power conditioning system of a given PV field, through appropriate sensors, to monitor: climate data (irradiance, temperature), electrical quantities (voltage, current, power), performance of the PV generator as a function of climate parameters, performance of the power conditioning system over different working conditions. The system will exchange data through a communication network (i.e. Ethernet/TCP-IP) to download data, visualize quantities and operative states. The proposed system is designed to be integrated into any PV field, independently from the plant layout, the inverter type, the presence of preexisting data loggers, sensors, etc. Such a result is achieved using an open architecture, which assures an extremely high flexibility of utilization.

Automatic voltage and reactive power control in distribution systems: Dynamic coupling analysis

The paper focuses on the dynamic response of a secondary voltage control scheme for distribution networks. The proposed control is based on a hierarchical architecture and is similar to the hierarchical voltage control implemented in some countries in high voltage transmission systems. The objective of the paper is to show a possible undesired dynamic coupling of different reactive power control loops of network generators. The effect of an algebraic decoupling matrix of the secondary voltage control as well as its effects simulated on a real-world case study are also duly discussed.

Automatic voltage control of a cluster of hydro power plants to operate as a virtual power plant

The paper proposes an application of a hierarchical automatic voltage regulation scheme for a cluster of hydro power plants connected to HV networks. The topology considered in the paper is a radial network in which the hydro power plants are connected to each other and have a single point of connection at the HV level. The technique proposed in the paper is based on well-assessed control strategies that are used in HV transmission systems, but has not been applied so far to medium voltage networks. A case study based on a cluster of hydro power plants composed of 11 generators and a distribution grid is presented and discussed in detail.

Automatic voltage and reactive power regulator for wind farms participating to TSO voltage regulation

This paper proposes an application of a hierarchical automatic voltage regulation scheme for wind power plants connected to HV networks. The proposed control schemes is based on a given topology of wind power plants. In particular, we assume that wind generators are connected to each other and have a unique point of contact at the HV level. The secondary voltage control scheme proposed in the paper is based on well-assessed control strategies that are used in HV transmission systems, but has not been applied so far to medium voltage networks. A case study based on a wind power plant composed of 14 wind turbines and a distribution grid is presented and discussed in details.

Motion control of marine electrical drives: Technical assessment and perspectives

Several different models for the propulsive shaft system have been proposed in literature. In this paper, the so called thruster level model is considered. Basically the system is composed of a propulsion motor, a transmission device (a shaft) and a propeller. In all-electric ships, propulsion is realized utilizing electrical drives. Time varying propeller loading induced by waves, hydrodynamics effects like cavitation, ventilation, variations in submerged level of the propeller interacts with the multi-mass system composed by the electrical motor, the shaft and the propeller. It is therefore important to investigate the resonance frequency of such system.

Dependable oriented design of complex integrated power systems on ships

The increasing complexity of ships Integrated Power Systems (IPSs) led to the need of a review of conventional design process. Moreover, several stakeholders influence ship design, each of them aiming to protect its own interests, in particular when responsibility of accidents has to be defined. Dependability could be the tool to modify conventional design, transforming it into a dependability oriented design, as to properly manage the inherent systems complexity avoiding future liabilities. In addition to that, dependability could become a new index recognized by all the involved subjects, capable of establishing design quality. This paper addresses motivations to include dependability into internal processes for all the stakeholders involved in ship design process, as well as the motivations to demonstrate internal dependability levels to others subjects. Subsequently, a notional dependability oriented design process, tailored on IPS design, is presented, together with a discussion on the influence of every stakeholder on design steps. This with the aim of explaining dependability impact on design and to demonstrate how modifying conventional process important advantages could be achieved.