The research introduces an innovative seven-level inverter design featuring 24 switches, all powered by a single DC source. The topology of this inverter offers benefits in terms of sensor-less capacitor balancing fault tolerance, and increased DC bus utilization with extended linear modulation range till full base speed. In this paper, the balancing of capacitor voltages relies solely on measuring their voltage, eliminating the need for additional current sensors. The capacitor balancing focuses on minimizing the dependencies on current sensors to determine the direction of capacitor currents. By using these measured values, logical variables and equations are created. These logical expressions remain effective across linear and extended linear modulation ranges, eliminating all lower-order harmonics.The modulation technique used is space vector pulse width modulation (SVPWM). The simulation results show how well a state-of-the-art seven-level inverter can operate an induction motor (IM) drive.

An X-ray medical apparatus requires a high voltage to operate and shall be produced from a domestic 3-phase or 1-phase AC supply in hospitals. Along with this comes a power quality issue, as this medical device has become common. Following a typical X-ray datasheet, the voltage level must increase from 400/415 volts mains to 120 kV. Due to the above reason, several stages are required to boost the voltage level to the required level. This leads to the heavy size of the equipment, increased losses, and poor power quality. This paper proposes a methodology to implement the power supply generator circuit for an X-ray device that adopts 1) a 3-phase Boost PFC (Power Factor Correction) rectifier, 2) a High-frequency series resonant inverter, and 3) a Voltage multiplier circuit. ZCS (Zero Current Switching) has been adopted to reduce switching losses due to high-frequency switching frequency.

The electrical rotating machines consist of non-linear magnetic characteristics due to their inductive nature and the existence of different air gaps. The control and stability analysis with this type of magnetic characteristics is a complex task and proper tuning is required. Especially the special machines like switched reluctance machines (SRM) the inductance variation is depending on the reluctance over the traditional machines. Because of this, the controller design with traditional Proportional + Integral (PI) controllers may not give superior results in terms of transient and steady-state operational characteristics. This paper discusses the tuning of PI controllers by deriving the optimized plant transfer function of SRM and integrating non-linear techniques like an anti-windup scheme for an improved and stable response. The mathematical modeling of 8/6 pole SRM is presented. The implementation of 8/6 pole SRM has been carried out using the look tables of torque vs phase currents, rotor angle, and phase inductance vs phase currents, and rotor angle in MATLAB. The look-table data is derived with Finite Element Analysis (FEA) tools like FEMM and JMAG. The detailed steady state and transient response of 8/6 pole SRM with a modified PI controller with anti-windun logic are nresented.

In this paper, an electromagnet rotor based switched reluctance machine (ESRM) is proposed for electric vehicle (EV) applications. The proposed machine is realized with the winding on the rotor. Because of these rotor winding, higher torque density (Nm/kg), reduced input current, wider-torque speed characteristics are achieved. This is done by establishing rotor excitation through innovative power transfer from stator to rotor or extracting power from space harmonics. In the first approach of rotor excitation through wireless power transfer (WPT) system, the stator has transmitting coil fed by resonant converter and the rotor has receiving coil which has high pass filter to allow high frequency signals necessary for rotor excitation. A 50kW ESRM has been modelled and validated in FEM (Finite Element Method) simulations tools like FEMM and JMAG.