The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This work deals with a parametric identification using the least square method based on the output error. An appropriate particle swarm optimization algorithm is applied as a technique to minimize the objective function in order to obtain simultaneously the electrical and the mechanical parameters. The validation and comparison of the two algorithms used are obtained from experiments carried out on...
With its new SineFormertrade EPCOS is introducing a fully new output filter technology for frequency converters. In contrast to conventional filter topologies the new SineFormertrade simultaneously converts the phase-to-phase voltage into a sinusoidal signal, damps the common mode currents and also forms the conductor-to-ground voltage to sine shaped voltage. This offers users a number of key benefits...
Actually, AC 16.7-Hz railway grids are fed via back-to-back converters from the public grid. A flux-based multivariable control for the three-phase-side converter is presented, which takes the resonant circuit of the single-phase-side converter into account, leading to excellent stationary and dynamic behaviour.
A coupled system simulator, based on analytical circuit equations and a finite element method (FEM) model of the motor, is used to analyze a direct-torque-controlled (DTC) frequency-converter-fed industrial 200 kW squirrel-cage induction motor. The measured stator voltage waveforms are used as inputs to the FEM motor model, and the results are compared with the measured ones. Comparison is also made...
It has been reported that the fundamental space vector PWM (SVPWM) waveforms of both a DC link voltage source inverter (VSI) and a matrix converter (MC) can be used as excitation signals for position estimation of a permanent magnet synchronous motor (PMSM). This paper evaluates the quality of the position estimates as well as the influence when the sensorless algorithm is implemented on a VSI and...
Linear quadratic Gaussian (LQG) based phase voltage control is implemented. The regulation performance, estimation accuracy and interference sensitivity of different LQG control schemes is evaluated and compared. Paper reveals that it is possible to make the control system more insensitive to EMI when compared to dual-loop PI control and that the synchronous co-ordinate control scheme's all-around...
This paper proposes a versatile system to test and measure systematically the real evolution for the I-V characteristic curves of photovoltaic (PV) modules or arrays. The system employs a novel circuit solution based on DC-DC converters that shows several advantages with regard to classical methods: simple structure, scalability, fast response and low cost. The measure of the desired characteristics...
We present the design of a cycle test system for automated stress testing of smart power switches under automotive load short circuit conditions up to 250A / 50V. A fast overcurrent detection and shutdown strategy protects the test equipment from damage. Device degradation and failure data are recorded individually for statistical analysis of time-to-failure distributions. Representative measurements...
Accurate measurement of distorted, noisy and pulsed currents is still a challenge. Current transformers introduce unacceptable errors in magnitude and/or phase shift. Rogowski coils are useful for clamp-on field measurements, but can be cumbersome to use. This paper presents a transducer consisting of coreless transformer and a non-integrating electronic amplifier. Calibration of two prototype transducers,...
According to earlier work and papers by other authors, the main flux path of an induction machine is not only saturated due to the magnetizing current, or in other words ldquothe magnetizing inductance can be modeled as a function of torquerdquo. In addition, at a given magnetizing current, the flux linkage decreases with rising supply frequency. These effects should be considered when using control...
Incipient fault detection and isolation (FDI) in the current sensors of a controlled induction motor is addressed by an original diagnosis system based exclusively on the three-phase signals model. In this way we avoid a reduction in the performance of the FDI system due to the uncertainty in the machine model. Assuming that the three current signals are measured, the proposed FDI system is made of...
The power transistor (IGBT) is one of the most important components of the inverter of domestic induction cookers. For this application the maximum junction temperature (Tjmax) of the IGBT is one of the most critical design parameters because the cooker has to decrease the output power when the junction temperature is near to Tjmax of the device. The junction temperature (Tj) of the IGBT principally...
Fast switching of PWM-inverters cause a lot of electromagnetic interference (EMI). To lower the dv/dt, output filters are available. In this paper, the influence of the cable and the output filters on conducted emission is investigated. By combining impedance measurements and EMI-measurements particular dips in the spectrum can be explained.
This work is intended to describe the origin of EMI from a state of the art flyback power supply and to explain some experimental techniques with current and near field probes useful to pass EMC regulations, to optimize a design or, simply, to better understand the culprits of the problem. The dialogue (poster) session in EPE09 is appropiated to show the technique in a practical way to delegates interested...
Silicon Carbide (SiC) power semiconductors being actually in development are promising devices for the future. To outline their characteristics the switching and conducting performance of a SiC-JFET and a SiC-BJT are investigated and compared to a state of the art Si-IGBT. The power losses, the switching times and the efforts for the driving circuits are investigated. The focus is put on the influence...
Two encoderless control methods for permanent magnet machines are compared for automotive applications. At low and zero speeds, model based methods cannot be utilised, and therefore a saliency tracking method is needed. A ldquod-axis injectionrdquo method and a ldquocurrent derivativerdquo method are evaluated in terms of quality of position signal and additional current distortion introduced. The...
The paper deals with a sensorless control of a permanent magnet synchronous motor drive for a hybrid electric catamaran. A surface-mounted permanent magnet motor has been chosen and a distinctive sensorless control of this machine is deeply described. Control performance is validated by simulation and experimental results. Start-up mode, reversal of speed and synchronization lost occurrence will be...
Nowadays the possibility to increase switching frequency in power converters has allowed minimizing their size and weight, and has permitted the improvement of their power density. This has been achieved by using soft-switching techniques that reduce the switching losses and the stress the switches suffer, quite of this techniques rely on resonance concept. However this increase of frequency is not...
Certain CCFL driver topologies produce an asymmetrical output voltage which causes migration of the mercury to one side of the CCFL tube. It is known that a DC voltage component across the CCFL leads to this effect. However, even when no DC component is present across the lamp, migration takes place if the voltage is asymmetrical. Eventually, in the absence of a series ballast capacitor, a DC current...
For the calculation of the common mode (CM) ground current in voltage source - inverter fed induction machines a simplified (SHF) and a distributed (DHF) high-frequency equivalent circuit are compared. The SHF circuit needs measured parameters of the electric machines, but gives good results in comparison to the measured CM ground current. The DHF circuit predicts the CM currents purely from calculated...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.