Appropriate methods to analyse power conversion harmonics

Nowadays, non-linear loads represent the majority of the residential electrical consumers. The limits on emission and immunity are imposed by IEC- standards, however there is a lack in the domain 2 – 150 kHz. Where power quality standards focus on the current, EMC standards use voltage limits. An appropriate method for measuring high frequency grid disturbances is explored. Measurement techniques described by the existing standards for power quality and EMC are investigated. The aim of this work is to find a robust measurement method for the considered frequency range 2 - 150 kHz. Experimental results are presented in order to validate the analyzed methods

Emulating bearing faults : a novel approach

The relation between evolving mechanical faults in rotating electrical machines and their reflection in the machines’ electrical parameters still requires a lot of research. This implies serious obstructions in the evolution of e.g. Motor Current Signature Analysis as a complete and reliable condition monitoring technology. This paper presents the translation of common bearing faults into specific rotor-stator movements using finite element modeling. Subsequently, a novel method to elucidate the complex relation between rotor movements and the electrical parameters of an induction machine using an experimental test setup is described, dimensioned and simulated. Replacing one of the induction machine’s bearings with an Active Magnetic Bearing will give the opportunity to create specific rotor movements and consequently evaluate different programmable mechanical faults and their reflection in the stator current and/or voltage with high relevance and reproducibility

Peak shaving through battery storage for low-voltage enterprises with peak demand pricing

The renewable energy transition has introduced new electricity tariff structures. With the increased penetration of photovoltaic and wind power systems, users are being charged more for their peak demand. Consequently, peak shaving has gained attention in recent years. In this paper, we investigated the potential of peak shaving through battery storage. The analyzed system comprises a battery, a load and the grid but no renewable energy sources. The study is based on 40 load profiles of low-voltage users, located in Belgium, for the period 1 January 2014, 00:00-31 December 2016, 23:45, at 15 min resolution, with peak demand pricing. For each user, we studied the peak load reduction achievable by batteries of varying energy capacities (kWh), ranging from 0.1 to 10 times the mean power (kW). The results show that for 75% of the users, the peak reduction stays below 44% when the battery capacity is 10 times the mean power. Furthermore, for 75% of the users the battery remains idle for at least 80% of the time; consequently, the battery could possibly provide other services as well if the peak occurrence is sufficiently predictable. From an economic perspective, peak shaving looks interesting for capacity invoiced end users in Belgium, under the current battery capex and electricity prices (without Time-of-Use (ToU) dependency)

Measuring line parameters of multiconductor cables using a vector impedance meter

In the present paper, a method to measure the parameters of a multiconductor transmission line is given. The method is accurate, straightforward and only needs a single vector impedance meter or equivalent. The method has been applied for frequencies in a range from 20 kHz up to 30 MHz

Industry and engineering education interacting in an interregional project: a Flanders' perspective

The Interreg-IVa 2-Seas project i-MOCCA (“interregional MObility and Competence Centers in Automation”) concentrates on two fast evolving topics in industrial automation: industrial data communication and embedded control [1]. Both require high-end training of practicing engineers in industry and demonstrators illustrating proof-of-principle of emerging technologies. The i-MOCCA project aims to develop competence centers in different universities in the coastal regions of the UK, France and Flanders, Belgium. The project started in July 2011 and ends in September 2014

Synchronous wearable wireless body sensor network composed of autonomous textile nodes

A novel, fully-autonomous, wearable, wireless sensor network is presented, where each flexible textile node performs cooperative synchronous acquisition and distributed event detection. Computationally efficient situational-awareness algorithms are implemented on the low-power microcontroller present on each flexible node. The detected events are wirelessly transmitted to a base station, directly, as well as forwarded by other on-body nodes. For each node, a dual-polarized textile patch antenna serves as a platform for the flexible electronic circuitry. Therefore, the system is particularly suitable for comfortable and unobtrusive integration into garments. In the meantime, polarization diversity can be exploited to improve the reliability and energy-efficiency of the wireless transmission. Extensive experiments in realistic conditions have demonstrated that this new autonomous, body-centric, textile-antenna, wireless sensor network is able to correctly detect different operating conditions of a firefighter during an intervention. By relying on four network nodes integrated into the protective garment, this functionality is implemented locally, on the body, and in real time. In addition, the received sensor data are reliably transferred to a central access point at the command post, for more detailed and more comprehensive real-time visualization. This information provides coordinators and commanders with situational awareness of the entire rescue operation. A statistical analysis of measured on-body node-to-node, as well as off-body person-to-person channels is included, confirming the reliability of the communication system

Flexible dual-diversity wearable wireless node integrated on a dual-polarised textile patch antenna

A new textile wearable wireless node, for operation in the 2.45 GHz industrial, scientific and medical (ISM) band, is proposed. It consists of a dual-polarised textile patch antenna with integrated microcontroller, sensor, memory and transceiver with receive diversity. Integrated into a garment, the flexible unit may serve for fall detection, as well as for patient or rescue-worker monitoring. Fragile and lossy interconnections are eliminated. They are replaced by very short radiofrequency signal paths in the antenna feed plane, reducing electromagnetic compatibility and signal integrity problems. The compact and flexible module combines sensing and wireless channel monitoring functionality with reliable and energy-efficient off-body wireless communication capability, by fully exploiting dual polarisation diversity. By integrating a battery, a fully autonomous and flexible system is obtained. This novel textile wireless node was validated, both in flat and bent state, in the anechoic chamber, assessing the characteristics of the integrated system in free-space conditions. Moreover, its performance was verified in various real-world conditions, integrated into a firefighter garment, and used as an autonomous body-centric measurement device

Comparing accuracy and runtime of simulation to the measurements in a real grid for the control of a grid-connected PV inverter

The proposition for this study is to assess how much simulation results can differ from real measurements on the implementation of a control strategy for a grid-connected PV inverter. The system is simulated in Matlab/Simulink and experimentally evaluated on a real low-voltage distribution grid. The PV inverter is implemented using a power-hardware-in-the-loop platform running the control algorithm. The influence of linear and nonlinear loads and the interaction with another distributed energy resource operating on the same grid is quantified both in simulation and in the measurements. Finally, the control strategy is applied and the results for simulation and experimental setup are shown