Switched reluctance motors (SRMs) inherently exhibit issues such as torque ripples, noise, and vibrations, which are exacerbated by eccentricities. Eccentricity, one of the most common mechanical faults in SRMs, worsens with continued operation due to unbalanced magnetic pull. In extreme cases, this can lead to physical contact between the stator and rotor poles, causing irreversible damage to the motor. This article presents a scheme for the online diagnosis of static eccentricity (SE) and dynamic eccentricity (DE) in SRMs by switching the phases at a higher frequency in their respective negative torque regions. This technique leverages variations in inductance profiles caused by eccentricities to identify and distinguish between SE and DE, and to detect the phase along with which the rotor pole has shifted in case of SE. The proposed scheme has been validated through finite element method-based simulations in an ANSYS Maxwell environment for a 4-phase 8/6 SRM.

Power converter faults can result in malfunction or damage to motor windings and insulation due to unintended current flow within the motor. To avoid such damages the diagnosis of a power converter fault is very crucial. This article presents a simple, fast, and online fault diagnosis scheme using reference current signals. The proposed method utilizes the reference current signal adjusting unaffected phases through the controller to restore to its operation with reduced performance when fault occurs. This paper analyzes the characteristics of the reference current signals upon open- and short-circuits of the switched. By the observations made on the switch and its corresponding phases and accordingly, diagnosis performance is undertaken. The changes observed in the reference current signals were observed and expressed in the fault characterization. The proposed method better recognizes diagnosis under varying load torque and speed conditions. The above scheme verification was conducted with the simulations on a 4-phase 8/6 SRM drive system in MATLAB/Simulink environment.

Battery Monitoring System is a crucial part of a Battery Management System (BMS). In commercial Electrical Vehicles (EV) battery packs and battery-powered devices, the two most important parameters are the State of Charge (SOC) and State of Health (SOH) of the battery. The EV has multiple cells connected in Series and parallel and makes the Battery Packs to drive the motor. So, the battery real-time Status monitoring is a preliminary part of the SOC estimation and Cell Balancing algorithm. Battery monitoring System helps to detect the current status of the battery’s cell pack and makes alert of any unpredicted situation and avoid damages. This paper proposed series-connected Lithium-ion battery real-time monitoring with the help of the Internet of Things (IoT) with state-of-charge estimation methods for Battery cells pack. Also, the individual cell status will be updated in the internet cloud and onboard the HMI (Human to Machine interface) LCD Display. With the help of the Battery Open circuit voltage (OCV), the initial SOC is predicted and finally implemented with the Coulomb counting method using the current integral. The total pack voltage of the Battery and the charging-discharging currents were measured by the LEM LA-55p current sensor and LV-25p Voltage sensor respectively. The ESP8266 system on-chip wi-fi microcontroller is used for cloud computing and the data is displayed using Blynk IoT cloud.

Cell balancing in Li-ion batteries is a very crucial task considering the effective loss of unusable charge that remains in the cells when one or more cells of the pack loses charge. The main idea of the cell balancing is to achieve a state of charge among cells where minimum or no charge of the battery remains unused while discharging and none of the cells overcharge in a response to charge the weaker cell to the full capacity. Several active cell balancing methods are available that mainly focus on same limb or string cells balancing. In this article focus is made on charge transfer among parallel strings of the battery using combined Phase shifted and boost dc converters. The proposed cell balancing is very efficient in parallel charge balancing and can improve over all balancing efficiency of the BMS in achieving both same and parallel limb balancing. The proposed topology has been evaluated using MATLAB/Simulink with the help of inbuilt Li-ion NMC cell model (3.7V, 2.050Ah) and the results are presented.

The dual active bridge (DAB) converter is a prominent topology in DC-DC power conversion. The SC fault across the transformer terminal of DAB converter may result in catastrophic failures. However, the existing literature lacks the details on analysis regarding transient performance of DAB with terminal short circuit (SC) faults. Thus, it is imperative to study the transient over current evaluation during terminal SC fault in transformer of DAB converter. In regard to the above concern, this paper gives the theoretical and experimental study of terminal faults in transformer. The detailed simulation study is carried out using MATLAB/Simscape and experimental results are shown using designed DAB prototype of 1 kW. Based on the analysis, a simple detection technique is proposed for terminal SC faults. This technique use the voltage across redundant winding coupled with the main winding of standalone leakage inductor and thereby reduce extra sensor cost for detection.

Most of the direct and indirect torque control schemes proposed for switched reluctance motors (SRMs) consider equal rotor and stator pole arc. Leading to a linear non-saturating inductance profile. However, actually, in SRM, the rotor pole arc is kept higher than the stator pole arc. Leading to a non-linear saturating inductance profile. And not considering this in control leads to underutilization of the maximum torque producing capacity during the constant torque region. In the proposed novel direct torque control (DTC) scheme, firstly, the rotor pole arc and saturation effect are incorporated by considering it in the sector formation for every electrical cycle. Second, the flux control loop is removed, and sectors are classified based on the actual inductance profile, which is rotor position-dependent. Also, the voltage vector selection rule is modified for torque control. And the proposed voltage vector concerning the sector, allows multiple phases to conduct simultaneously. Wherein each phase conducts according to its actual inductance profile. This also ensures complete energization of incoming phase current while the outgoing phase is maintained at a constant current level. Leading to a reduction in torque ripples during commutation. The proposed DTC scheme incorporating the rotor pole arc and saturation effect improves the operating range for effectively reducing the torque ripples and facilitates a higher torque/ampere ratio.

This paper presents space vector modulation strategy for eliminating the common mode (CM) voltage of a three level five-phase neutral point clamped (NPC) voltage source inverter (VSI). There are two hundred and forty three discrete switching states available for operation and control of the NPC VSI. Out of two hundred and forty three switching states only fifty one switching states gives zero common mode voltage. The method reported in this paper, only thirty one switching states are selected from those fifty one switching states so that the xy voltage vector component is restricted.. The same switching states also give zero neutral point current and hence the dc link capacitor has equal voltage distribution. Simulation results are provided to validate the concept.