Assumption-based offline analysis tools may not be able to provide sufficient and accurate information for the corrective decision making to mitigate solar photovoltaic (PV) impacts in the future distribution grids. This is mainly due to the increasing penetration level of intermittent power generation resources and also the fluctuating behavior of consumer demand. Online assessment tools can assist to manage PV impacts and aid to mitigate those on a real-time basis. This paper proposes an approach for online assessment of rooftop PV impacts on low-voltage (LV) networks using real-time network data. A variable-width sliding window will be used to provide the analysis an outcome-based online data. The width of the sliding window can be varied according to user input so that the changes in network behavior caused by PV integration can be investigated conveniently. Several numerical indices are proposed in this paper to assess solar PV impacts on the LV networks. This approach also uses the online data to develop real-time distribution network models for a dynamic “what-if” analysis. The usefulness of the proposed online assessment approach is verified using an Australian LV distribution feeder.

/pdf/an-approach-for-online-assessment-of-rooftop-solar-pv-4volak25z4.pdf

An Approach for Online Assessment of Rooftop Solar PV Impacts on Low-Voltage Distribution Networks

Switched power converters are used to interface the dc output in modern distributed power generation systems, which are usually aggregated to the main grid to yield the necessary power using interconnected modules. Synthesis, modeling, and stability analysis of interconnected systems using cascaded converters working under sliding-mode control are considered in this paper. A systematic procedure to synthesize cascaded connection of dc-dc boost converters is introduced. The approach is based on making each module to behave as a suitable canonical element for power processing. Three different elements are considered, which are the dc power gyrator, the dc transformer, and the dc loss-free resistor. These canonical elements are designed by means of a sliding-mode control theory and then their dynamic behavior is studied in detail. The sliding-mode conditions for each case are derived in closed form to obtain design-oriented criteria for selecting the parameters of the system. The aforementioned canonical elements are compared to select the most suitable one for a distributed power system. Simulation results ensure the correctness of the proposed approach. Experimental measurements corroborate the theoretical predictions and the numerical simulations.

Synthesis of Canonical Elements for Power Processing in DC Distribution Systems Using Cascaded Converters and Sliding-Mode Control

Multimodal interaction: A suitable strategy for including older users?

What works in auditory working memory? A neural oscillations perspective

Piezoelectric thick films have increasing interest due to the potential high sensitivity and actuation force for MEMS sensors and actuators. The screen printing technique is a promising deposition technique for realizing piezoelectric thick films in the thickness range from 10–100 μm. In this work integration of a screen printed piezoelectric PZT thick film with silicon MEMS technology is shown. A high bandwidth triaxial accelerometer has been designed, fabricated and characterized. The voltage sensitivity is 0.31 mV/g in the vertical direction, 0.062 mV/g in the horizontal direction and the first mode resonance frequency is 11 kHz. A Finite Element Method (FEM) model is used to validate the measured sensitivity and resonance frequency. Good agreement between the model and the measurements is seen.

Triaxial MEMS accelerometer with screen printed PZT thick film

The electrical distribution system will be undergoing a major evolution over the next decade. The increasing use of renew able generation, the implementation of electric vehicle charging, the installation of energy storage devices, and changes in the character of customer loads will alter the way the distribution system is designed and controlled. Increased attention needs to be paid to securing the communication systems that monitor and control the smart distribution system as well. Interoperability and the use of standards are fundamental principles that will give the utility industry the flexibility to adapt to changing grid requirements while stimulating vendor competition, fostering innovation, and realizing lower costs. The workforce needs to be trained so that all of these new technologies can be implemented smoothly. New technologies are being developed at a rapid pace. Projects such as the Circuit of the Future and the Irvine Smart Grid Demonstration are important test beds that allow rigorous technology evaluation in a real-world environment. These new technologies promise to make the electric distribution system more efficient and reliable. Planning for these advanced smart grid systems needs to be done now, before all of the new generation and load devices are connected to the grid. Because utility planning is typically based on rate case cycles spanning several years (three years in California), steps need to be taken now to ensure funds are available for smart grid system improvements when they are needed.

http://ieeexplore.ieee.org/iel5/8014/5989937/05989974.pdf

A. E. Kamiab

Papers

Good Vibrations