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Gallium Nitride (GaN) high electron mobility transistor (HEMT) is one of the promising candidates to replace existing switches in high-frequency high power converter applications. Reliability of GaN HEMT is an important issue for its commercial deployment. Online prognosis of this transistor ensures robust reliability for mission critical applications. Online prognosis requires identification of fault...
Lifetime of aluminum electrolytic capacitors is of paramount importance, since in many power electronic voltage source converter systems this capacitor type is used in the DC-link. Thermal stress is one of the most critical stressors for electrolytic capacitors leading to wear-out and failures. Therefore, methods to perform online monitoring of the hotspot temperature of capacitors would lead to beneficial...
Torque production capability of permanent magnet synchronous machines (PMSMs) depends on the permanent magnets (PM) magnetization state (MS). MS is a function of PM initial magnetization level, decreasing as temperature increases. Furthermore, excessive PM temperature can produce irreversible PM demagnetization. PM MS and temperature measurement/estimation is therefore important both for torque control...
The ability to estimate attitude (pitch, roll) and heading (yaw) in reference to the North-East-Down frame is of great importance for localization applications. Determining true north proves to be especially challenging. This paper presents a fast and simple north-seeking method by utilizing earth's rotation measured by a three-axis Inertial Measurement Unit (IMU) based on Fiber Optic Gyroscopes (FOG)...
Electric water heaters have been regarded as a load to be exploited in residential energy management applications due to their potential energy storage capacity. Nevertheless, the implementation of control strategies for water heater systems requires high-performance models which must be capable of reproducing a water heater's internal operation dynamics, especially their inner water temperature variations...
The objective of this paper is to estimate the compressor discharge temperature measurements on an industrial gas turbine that is undergoing commissioning at site, using a data-driven model which is built using the test bed measurements of the engine. This paper proposes a Bayesian neuro-fuzzy modelling (BNFM) approach, which combines the adaptive neuro-fuzzy inference system (ANFIS) and variational...
A CMOS digital temperature measurement technique is reported, which doesn't require an explicit reference voltage during temperature to digital conversion. Instead, one of the inputs from the sensor core serves as the reference. After eliminating the need to use an external reference, we observe at least twofold increase in temperature estimation accuracy compared to the reference based traditional...
This paper proposes a method to estimate the stator winding temperature of permanent magnet synchronous motor (PMSM) driven by direct torque control (DTC) strategy, where the stator resistance is used as a direct indicator of the temperature. In this method, the quantitative relationship between the dc current offset and the corresponding changes in torque is derived. The dc current offset is generated...
Reliability of energy storage systems, for stationary as well as mobile applications, is crucial for their stable long term operation. Among all the components that are susceptible to failure, modules made up of individual batteries determine the useful life of such a system. Hence, estimating health quotients of battery packs in typical energy storage systems takes on a high priority. The computational...
This paper considers a robust control strategy for main steam temperature system of thermal power plant that is affected by immeasurable bounded disturbances. An output-feedback min-max optimization approach is proposed to obtain a controller which could effectively reject disturbances and stabilize the system. This approach combines moving horizon estimation with model predictive control and is formulated...
In this paper an Extended Kalman Filter (EKF) is used as an observer for temperature monitoring, like a virtual sensor, of a metal-polymer fibre based heater structure. Metal-coated polymers are relevant for the realisation of smart systems (capable of both sensing and actuating). A real-time implementation of the temperature estimator is important to guarantee a gentle, fault-free operation of the...
This article presents dynamic thermal rating system named SUMO which has been developed in Slovenia in order to improve system security and enable optimal utilization of the existing power system infrastructure. It is a modern information system that produces real time and close future estimations of actual thermal capacities. Currently, power systems mostly operate using static thermal capacity limits...
This paper presents an on-line method for determining the hottest spot temperature of the copper windings of a Permanent Magnet Synchronous Machine (PMSM). The purpose is to protect the Electrical Machine (EM) from high temperatures which reduces the lifetime of the machine and can eventually lead to insulation faults of the motor. The method relies on experimental data acquired from a network of...
In this paper, a method to implement a platform of failure diagnosis and prognosis, and health monitoring based on data using Input Output Hidden Markov Models (IOHMM) is proposed. Several sensors on a diesel generator system give information such as on-line operating conditions. The goal of this work is to use on-line collected data in order to determine degradation state of the diesel generator...
The paper presents an approach to calibration of inertial measurement units (IMU) for space application based on hemispherical resonator gyroscopes without accelerometers on a two-axis calibration turntable. The conventional sensor instrumental errors include bias and scale factor, temperature variations of the factors above and misalignment of sensitive axes. Also, additional quantities associated...
This paper deals with an evaluation of a hydrometeorology data from sites of a different land use and mainly from the places with a different leaf area index. A few methods of an estimation of the Fractal Dimension of a hydrometeorology time series, which is based on the original principle of coastline length measuring, were developed. The first results indicate that developed methods are usable for...
In the last few years, Unmanned Aerial Systems (UAS) have been attracting enormous research interest, being employed in military and civilian missions (e.g. search and rescue, disaster assessment, urban traffic monitoring, 3D mapping, etc.) that would be risky or impossible for a human to perform. For autonomous or aided operations (e.g. automatic or aided landing), it is crucial to have on board...
In this paper, a missing temperature data estimation method using graph Fourier transform (GFT) is presented. First, the GFT based on graph Laplacian matrix is briefly reviewed. Then, the spectral analysis of the temperature data is provided by using GFT to show that its bandwidth is approximately limited. Based on this band-limited property, a missing temperature data estimation approach is proposed...
With the introduction of the photovoltaic systems (PVSs) in the low-voltage (LV) grids, the domestic consumers can become producers (prosumers). At high penetration levels their contribution to the feeders' energy losses are increasing significantly. Currently, due to the absence of Smart Grid infrastructure, the DSOs aggregate these losses to the total LV grid losses without being able to allocate...
In this paper, we propose a model-based filtering strategy to reconstruct the maximum power production of a PV power plant thanks to integrating measurements of the PV cell temperature, system DC voltage and DC current. The filter relies on a reversed physical model of the targeted PV system and enables to, first, determine analytically the irradiance incident to the panels, and, second, estimate...
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