A position estimation method for the Synchronous Reluctance Motor (SynRM) based on an inductance model is proposed for light loads operating within the low to medium speed range. Under these conditions, the inductance exhibits a linear relationship with rotor position in specific regions. This linear characteristic of the inductance is utilized to determine the rotor position accurately. Simulations are conducted on a 1.0 kW FEM Model of SynRM prototype, validating the feasibility and effectiveness of the proposed method.

This paper introduces a Reluctance Equivalent (RE) EMF model for sensorless position estimation of synchronous reluctance motors (SynRMs). The unique salient structure of the SynRM results in varying reluctance paths associated with the stator phases. These variations in reluctance cause continuous changes in phase inductance relative to the rotor position, leading to the generation of RE EMF in the stator phase. The RE EMF model is initially analyzed in the abc plane and subsequently transformed into the stationary αβ plane for position estimation. The model’s validity is demonstrated using a Finite Element Model of the developed SynRM prototype

For convenient interconnection with ac/dc grid, Solid State Transformer (SST) is the more preferable solution according to the current literature. Also, recent advancements in the configuration of Modular Multilevel Converter (MMC) shows how the Hybrid MMCs provide superior performance compared to the conventional half-bridge sub-module (HB-SM) MMC. The Hybrid MMC considered here makes the use of HB SMs in addition to Full-bridge (FB) SMs. For secure operation of MMC, the foremost control objectives need to be fulfilled viz., SM capacitor voltage control, circulating current control, output current control. Thus, the article mainly focuses on this primary control objectives for the grid connected Hybrid MMC, which will be acting as back-end converter of the SST. To balance the SM capacitor voltages of MMC, the reduced switching frequency (RSF) voltage balancing (VB) technique is used in this article. The impact of this technique is compared with the traditional VB method. Then based on double line frequency, dq-frame, the closed loop circulating current control is achieved to eliminate the second harmonic components in the arm currents. Closed loop output current control having the same logic as applicable to three-phase VSC is also implemented. Furthermore, open loop power flow control is used for generating the reference for closed loop current control. To evaluate the performance of the controller, a comparative analysis of Hybrid MMC with and without application of controllers, is executed using MATLAB simulation. The impact of RSF - VB and current controllers is also presented.

Induction Machines employed in electric vehicles (EVs) require variable speed and torque combinations which can be achieved by pole-phase modulation (PPM) technique. In this paper, new winding excitation is analyzed using finite element analysis (FEA) of 6-terminal, 36-slot Induction Motor (IM) drive with 1:2 speed ratio using PPM. It also proposes a new winding technique for Multi-Pole Multi-Phase Induction Motor (MPMPIM) drives with higher slots per pole per phase to achieve the speed-torque combination similar to typical Internal Combustion (IC) engine drives. This approach reduces the leakage reactance, torque and current pulsation with the improvement in overload capacity. Accordingly, winding of the considered IM has been modified to operate with either 3-phase/4-pole or 6-phase/2-pole combinations. The proposed winding excitation gives performance required for EV application like high pole mode for high starting torque during hill climbing and low pole mode during high speed cruising operation. The operation of the proposed drive for different pole-phase combinations with two different speeds is simulated and verified through FEA for 3 HP, 6-terminal, and 36-slot IM drive.

The research on multilevel inverter has created a milestone due to its wide application areas starting from industries to smart grid systems. Due to the increase of power demands, the importance of inverters increases in the microgrids and standalone systems. This paper presents a single phase hybrid cascaded structure of active neutral point clamped converter with modified H-bridge multilevel inverter. The five level active neutral point clamped converter is cascaded with nine level modified H-bridge to generate 13 level output voltage. This combinational structure reduces some source count by maintaining higher voltage levels. The mathematical analysis is provided with the simulation and experimental results for validation of the topology. The symmetrical source configuration is implemented for the voltage level generation. The series combination of resistive - inductive is considered in the load side. This structure is well suited for the PV applications where the inverter structure can be cascaded for increased power level.

This paper presents the energy management in a solar PV based charging station integrated with battery energy storage system (BESS). The provision of optional exchange of power by the DC grid with the utility grid has been created here. Power flow through the utility grid is controlled using a voltage source converter (VSC). The loads considered are the Electric Vehicles (EVs) batteries. Load demand was met by the maximum power obtained from the solar PV (Photo Voltaic) using Maximum Power Point Tracking (MPPT) controller. An automated control of energy flow among solar PV, BESS and load battery is proposed using DC-DC converters. The dip in DC microgrid voltage, because of excess load demand beyond the available combined maximum power from solar PV and BESS, is compensated by delivering deficient power from utility grid. PSCAD simulation results are presented here to validate the proposed scheme.

This paper presents the hybrid control of a dc-dc resonant converter for a dc micro-grid. The hybrid control is the simultaneous variation of the frequency and the duty ratio, which can provide excellent voltage regulation and maintain zero-voltage switching (ZVS) over a wide load range. Hence, excellent conversion efficiency is also maintained over the wide load range using hybrid control. However, the conventional control methods for a dc-dc resonant converter using either variable switching frequency or duty ratio have their own limitations. The frequency control requires wide variation in switching frequency for output voltage regulation, which leads to higher switching losses at turn-off of switches and lower efficiency particularly at light loads. The duty ratio control has a limitation of loosing of ZVS at light loads. The simulation and experimental results of hybrid control of resonant converter operating above 100 kHz with maximum duty ratio of 0.48 for 3 kW are presented from full load to no load. The maximum efficiency of the resonant converter is found to be 98%, which was achieved at 75% of the full load.

In this paper, an electromagnetic compatibility estimator is proposed using an artificial neural network with a scaled conjugate gradient algorithm. Neural networks are trained with the help of seven different optimization algorithms in MATLAB. Their performance is evaluated on the basis of number of neurons, desired output, and mean-squared error in offline mode in MATLAB. Among seven algorithms, scaled conjugate gradient algorithm is found to be the best choice. Hence, it is implemented in LabVIEW for online assessment of electromagnetic compatibility issues. Voltage dip, swell, and harmonics are generated with the help of an experimental setup. It consists of 230 V, 50 Hz input voltage supply, microcontroller, variac, and solid-state relays. It is interfaced to the LabVIEW software with the help of an NI USB 6361 data acquisition system. It enabled the continuous online monitoring of various signals. Along with voltage dip and swell, harmonics are also evaluated with the help of spectrum analyzer in LabVIEW. The detailed description of a hardware setup and mathematical modeling of trained network is given in this paper.

This paper presents real-time implementation of a grid interfaced distributed generation (DG) system with modified current control loop using three phase amplitude adaptive notch filter (AANF) based synchronization tool. A grid current feedback based modified dq-current control technique for interfacing inverter is developed in order to achieve constant loading on the grid, transient-free operation, and power factor improvement close to unity power factor (UPF) of the utility grid during sudden load variations. This technique does not require separate calculation of reference reactive component and harmonics component of currents hence reduces control circuit complexity. In addition, it requires only three voltage and three current sensors. Three phase AANF is developed and is used for online extraction of utility voltage phase angle to generate synchronized reference current signals for interfacing inverter. AANF is used because of its adjustable accuracy and amplitude adaptability even under unbalanced voltage sag and swell, frequency variation, and distorted grid conditions. Fast and accurate behavior of three phase AANF improves the dynamic response of entire DG system control performance for sudden load variations. The dynamic behavior of the proposed grid interfaced DG system is experimentally evaluated in maintaining constant loading on grid, transient-free operation, and power factor improvement close to UPF operation of the utility grid, by compensating total reactive power and harmonic current demanded by variable linear as well as nonlinear load.