EVALUATION OF IMPEDANCE OF CABLES IN GONIOPHOTOMETRY

In a goniophotometer system, it is often unavoidable to use long cables to connect power supply, electrical measuring instrument, and the device under test (DUT). The measurement errors caused by cable impedance should not be ignored. An equivalent electrical circuit model considering the cable impedance of a typical goniophotometer is established in this paper. The measurement errors caused by the cable impedance are analysed by simulation. In DC and low frequency circuits, the cable impedance is almost resistive, while the inductive impedance of cables is significant and may lead to considerable errors when frequency is above 1 kHz in the circuits. Cable solutions in goniophotometry are introduced and recommended.

Electrical Circuit Model of Lithium-ion Batteries and Revisiting of its Parametrization Procedures

Nowadays, Lithium-ion batteries are as the most preferable technology for consumer electronics. They found their way also to electric vehicles or even satellites, mainly due to their high energy density and long life. In the applications, the batteries require a battery management system for safe and optimal operation. Often, state estimation functionalities (as state-of-charge or state-of-health) require a running battery model. Therefore, an electrical circuit model (ECM) that accurately captures a battery behavior in suitable complexity is needed. This paper presents a three steps parametrization technique of ECM for Lithium-ion batteries based on laboratory experiments. Furthermore, an analysis of SOC and temperature dependence of battery parameters has been conducted. The developed ECM is validated, and its accuracy is evaluated by Root Mean Square Error (RMSE) and Maximal Absolute Error (MaE).

Extension of Winding Function Theory for Modeling and Diagnosis of Partial Demagnetization Fault in PMSM Drive

This paper proposes the development of a new mathematical model dedicated to the diagnostic of the partial Demagnetization Fault (DF) in Permanent Magnet Synchronous Motor (PMSM). To do this, an extension of the Modified Winding Function Approach (MWFA) is proposed to accurately take into account the air gap asymmetry caused by the Demagnetization Fault (DF) in the PMSM inductances calculation. The calculated inductances are then used in the magnetically coupled electrical circuit model to simulate the PMSM behavior in the different operating modes. Finally, a diagnostic method based on the stator current spectral analysis is used to highlight the PMSM stator current spectral content in the various operating modes (with and without Demagnetization Fault).

Modelling of Supercapacitors Based on Simplified Equivalent Circuit

The need for energy storage devices especially in renewable energy applications has increased the use of supercapacitors. Accordingly, several supercapacitor models have been proposed in previous researches. Nevertheless, most of them require an intensive test to obtain the model parameters. These may not be suitable for an initial simulation study, where a simple model based on the datasheet is required to evaluate the system performance before building the hardware prototype. A simplified electrical circuit model for a supercapacitor (SC) based on the voltage-current equation is proposed in this paper to address this issue. This model doesn’t need an intensive test for accuracy. The structural simplicity and decent modelling accuracy make the equivalent electrical circuit model very suitable for power electronic applications and real-time energy management simulations. The parameters of the proposed model can be obtained from the datasheets value with a minimum test requirement. The experimental method to provide the parameters of the supercapacitor equivalent circuit is described. Based on the proposed method, the supercapacitor model is built in Matlab/Simulink, and the characteristics of equivalent series resistance (ESR) measurement and cycle life are compared with datasheets. The simulation results have verified that the proposed model can be applied to simulate the behaviour of the supercapacitor in most energy and power applications for a short time of energy storage. A supercapacitor test circuit is given to test the charge and discharge of supercapacitor modules. The experimental results are suitable for simulation results.

Diode Parameters and Equivalent Electrical Circuit Model of n-Type Silicon/B-Doped p-Type Ultrananocrystalline Diamond Heterojunctions Manufactured Through Coaxial Arc Plasma Deposition

Coaxial arc plasma deposition (CAPD) was employed to manufacture n-type silicon/boron-doped p-type ultrananocrystalline diamond heterojunctions. Measurement and analysis of their dark current density-voltage curve were carried out at room temperature in order to calculate the requisite junction parameters using the Cheung and Norde approaches. For the calculation based on the Cheung approach, the series resistance (Rs), ideality factor (n) and barrier height (Φb) were 4.58 kΩ, 2.82 and 0.75 eV, respectively. The values of Rs and Φb were in agreement with those calculated using the Norde approach. Their characteristics for alternative current impedance at different frequency values were measured and analyzed as a function of the voltage (V) values ranging from 0 V to 0.5 V. Appearance of the real (Z′) and imaginary (Z″) characteristics for all V values presented single semicircles. The centers of the semicircular curves were below the Z′ axis and the diameter of the semicircles decreased with increments of the V value. The proper equivalent electrical circuit model for the manufactured heterojunction behavior was comprised of Rs combined with the parallel circuit of resistance and constant phase element.