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This paper describes novel adaptive multiplicative general parameter finite impulse response filter with real coefficients (MGP-FIR). The MGP-FIR is adaptive, predictive digital FIR filter for fundamental harmonic estimation of distorted signal with small frequency fluctuations without phase shift (time delay). This property is necessary for high quality control of power converters connected to the...
Direct current measurement is one of the most important control characteristics for DC-DC converters. This sensitive method is used for current control of converters, which is much faster and more accurate than voltage control. Unfortunately, the sensitivity of the current measurement is also its major drawback. Especially in automotive applications, electromagnetic interference of the increasing...
In this work a method to detect insulation degradation of an adjustable speed drive (ASD) based on analyses of the transient current reaction caused by inverter switching is proposed. The drive system consists of an inverter fed three phase induction machine with 1.4MW. The standard current sensors are used to analyze the transient signal ringing to extract an insulation state indicator of the winding...
Their combination of large continuous energy ratings and very large time constants allows supercapacitors to be used in surge protection circuits. This fact, supported by recent research publications and laboratory tests, has assisted the authors to propose a new surge protection circuit topology known as the supercapacitor-assisted surge absorber (SCASA). This technique utilizes a multi-winding transformer,...
DC power has recently become a potential option and made a vital contribution to the growth of future power systems. On the other hand, DC power is more advantageous than AC power in terms of integrating of renewable energy sources into distribution power networks. Transients in a DC network are different from AC networks' due to a greater consumption sides as well as a greater participation of electronics...
Traditional microgrids have sources whose transient response is limited by process or mechanical time constants depending on the technology used. Inverter based sources provide the flexibility in designing and tuning the controller parameters so as to operate microgrid within specified constraint in voltage and frequency. For this it is imperative to investigate the effect of controller parameters...
This paper presents a new method for balancing currents of two or more parallel-connected IGBTs during an on-state of the switches, wherein each semiconductor is controlled by its own gate unit. Moreover, the imbalance of the collector currents are estimated by measuring the voltage across the inductance between the power-emitter and the auxiliary-emitter of the semiconductor. The imbalance control...
Understanding of faults and their impacts on the performance of Switched Reluctance Motor (SRM) is essential for fault detection and post fault control strategy development. In this paper, an 8/6 SRM is modeled and analyzed under various short circuit faults and operational conditions. Simulation and experimental investigation of the effects of fault in both transient and steady state is presented...
Permanent Magnet Heaters, PMH, have been recently proposed as a possible high efficiency solution for the heating of high conductive metals. The optimal design of a Permanent Magnet Heater is presented with reference to a real industrial case. The design has been carried out by means of transient magnetic and thermal 2D and 3D Finite Element Models coupled with multiobjective optimization algorithms.
Five-phase PM BLDC drives are a viable solution for safety-critical applications in road traction and aeronautics sectors. A common supply technique for these drives consists in the injection of square-wave currents into the motor phases, synchronized with the flat-top portion of the back-emf to produce both constant torque and maximum torque per ampere. In practice, the currents deviate from the...
This paper presents a phase-locked loop (PLL) method aimed to provide an estimation of the phase angle and the amplitude of the fundamental positive sequence component of a three-phase reference signal subject to severe unbalance and high harmonic distortion. In addition the proposed scheme provides the estimation of the angular frequency, and both the positive and negative sequences of the fundamental...
This paper presents a discrete phase-locked loop (PLL) method aimed to provide an estimation of the angular frequency, and both the positive and negative sequences of the fundamental component of an unbalanced and distorted three-phase reference signal. The design of the proposed scheme is based on a discrete model of the generator of a three-phase signal. This model involves both positive and negative...
This paper studies the operation of a microgrid under various scenarios with a focus on the effect of communication delays. The test microgrid is the CIGRE-IEEE low-voltage system, and a variety of loads are modeled in the system, including a nonlinear load, an impulse load, a battery, a highly capacitive load, and a highly inductive load. The simulation studies cover three scenarios: 1) a system...
Sensorless field oriented control (FOC) strategies have found their place in industry applications during the last few years. Stimulated by this development scientific research continues to improve their performance, which is directly linked to the estimation accuracy of flux and rotor position without a mechanical sensor by means of high frequency or transient excitation. The influence of induction...
This paper presents the results of the experimental and simulation investigation concerning the influence of remanence in the core of a single-phase transformer at the no-load transient state. Experimental studies consisted of the discharge of the capacitor through the primary winding at several different values of the residual magnetic flux. The paper presents a model of the transformer test system,...
Advanced analysis of motor currents during transient operation has proven to be a valuable source of information to reach a reliable assessment of the rotor condition. This novel approach may help to overcome some of the drawbacks of the classical Motor Current Signature Analysis (MCSA). One of the advantages of the approach is the robustness obtained due to its twofold perspective: 1) Qualitative...
This paper presents a single-phase voltage distribution static synchronous compensator which integrates a single-phase to three-phase four-wired transformer-less conversion. Beyond that, this structure are capable to interface a distributed alternative energy generation to the mains. The major advantage of this circuit is the combined operation capability, which is realized with a few switching components...
The use of real time digital simulation of large power systems is widely spreading due to its high precision result and increasing computing capability. However, in many cases, especially when large power system networks are to be modeled, the interconnection data and parameter data are available in flies which are used as input to simulation programs. Most transmission utilities use dynamic studies...
Up to now, detection of rotor faults in inverter-fed induction motors has received very little attention. This fault is difficult to be detected, since the fault-related components are too close to the fundamental (the inverter usually operates at low slip). Moreover, classic techniques cannot be applied since steady states are not common. The causes of this type of fault are analyzed in the paper,...
Squirrel-cage induction motors (IM) are the most popular motors used in industry, consuming around 85% of the power in industrial plants. IM are critical components for most industries, and an early detection of induction motor faults has been a main subject of investigation during last years. Broken rotor bars in induction motors are among the major failures that are desirable to detect at early...
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