Sharmili Das

Enhanced-Boost Quasi-Z-Source Inverters With Two-Switched Impedance Networks

In this paper, two topologies are presented for the enhanced-boost quasi-Z-source inverters (qZSI), namely continuous input current configuration and discontinuous input current configuration of enhanced-boost qZSI with two-switched impedance networks. Similar to enhanced-boost impedance-source inverters (ZSIs), these proposed inverter topologies possess very high boost voltage inversion at low shoot-through duty ratio and high modulation index to provide an improved quality output voltage. Compared to enhanced-boost ZSIs with two-switched Z-source impedance networks, these proposed inverter topologies share common ground with source and bridge inverter, overcome the starting inrush problem, and draw continuous input current and the lower voltage across the capacitors. Moreover, the input ripple current is negligible. This paper presents the operating principles and analysis of continuous input current configuration enhanced-boost qZSI with two-switched impedance networks and compares with ZSI, switched inductor ZSI, DA/CA-qZSI, and enhanced-boost ZSIs. The theoretical analysis is done and is validated through simulation and experimental results.

Two-Tapped Inductor quasi Impedance Source Inverter (2TL-qZSI) for PV applications

This paper presents the topology of Two-Tapped Inductor (TL)-qZSI for the PV systems to get the high boosting factor by freely varying the turns ratio of the Tapped Inductor (TL) cells. This topology is same as that of TL-ZSI, but it has some advantages, like it draws continuous input current from the source, reduced stress across the capacitors, so lower component rating can be used and gives high voltage boost. A very small shoot through period gives high voltage gain, such that high modulation index can be obtained to get better output voltage. This topology is suitable for the application which requires large voltage gain, such as Photovoltaic systems. The steady state analysis is validated for the proposed topology and the simulation results are obtained.

High boosting type Z-source inverter/ improved Z-source inverter for solar photovoltaic system

In this paper, two topologies are presented for solar PV system, namely voltage lifting ZSI and voltage lifting Improved ZSI. These proposed inverters possess very high voltage boost. By replacing the middle diode in one of the switched inductor (SL) cell of SL-ZSI/2SL-qZSI with capacitor (CVL) high voltage gain can be obtained and also number of L, C and diodes gets reduced, which reduces weight, space and cost of the system. Very small shoot through duty cycle results in high voltage boost, thus efficiency can also be increased. Proposed topologies are analyzed in the steady state and their performances are validated using simulated results obtained in MATLAB/Simulink. This paper presents operating principles, analysis and simulation results, and compares them with SL-ZSI/2SL-qZSI.

A Three Phase five level cascaded H-Bridge rectifier with zero current injection scheme

A Three-Phase five level AC/DC Converter with Cascaded H-Bridge (CHB) Converter topology is presented to achieve unity power factor and improve power quality. The CHB active rectifier is an attractive topology that allows feeding of similar or different multiple DC loads. In this paper, the AC/DC converter is controlled in Synchronous Reference Frame (SRF) scheme, such that it draws a sinusoidal line current with unity power factor from the AC source. The SRF is adopted in the system to track line current command and output voltage reference. The system model and control algorithm are described. A Zero Current Injection (ZCI) solution is presented for voltage balancing of distinct dc buses in multi level CHB rectifier. This method ensures that the dc bus capacitor voltages converge to the reference value, even when the loads attached to them are extracting different amounts of power with acceptable load power limits. Multilevel Sine Pulse Width Modulated (SPWM) scheme is used to reduce the current harmonics in the input and obtain regulated DC output. The effectiveness of the proposed control algorithm is verified by the computer simulations and validated with experimental results.

Matrix converter fed PMSM drive with maximum torque per ampere control

This paper proposes maximum torque per ampere control for matrix converter fed interior permanent magnet synchronous motor drive. PI controller has been used in closed loop speed control to obtain the d axis and q axis currents. A matrix converter PMSM drive replaces the conventional voltage-source inverter (VSI) drive due to its advantageous feature like elimination of bulky and life limited dc-link capacitors; inherent bidirectional power flow; the sinusoidal input current drawn; controllable input power factor and compact and reliable all silicon structures. Due to thermal or reliability constraints the maximum permissible current of the inverter or motor is limited. This also limits the torque capability. The MTPA control gives high efficiency as the stator current is reduced as compared to the conventional control. The MTPA control strategy is mostly used in the efficient drive applications. The dynamic performance of the proposed drive is simulated in Matlab/Simulink environment.

Modified switched boost inverter with reduced voltage stress across the switch

This paper presents the novel topology of switched boost inverter for solar photovoltaic systems; which reduces the voltage stress across the switch; minimizes the current ripple; increases system efficiency; reduces the complexity and it uses less number of components with the addition of only one switch. The closed loop control of stand-alone solar photovoltaic systems for modified SBI is carried out in MATLAB/Simulink to validate the theoretical analysis.

Parameter plane synthesis of Matrix Converter fed Induction Motor over wide speed range

In this paper, a new technique for the design of Proportional Integral (PI) controller parameters for wide range operation of vector controlled Matrix Converter (MC) fed Induction Motor Drive (IMD) is presented. The closed loop mathematical model of the IMD is developed in the synchronous rotating d-q reference frame. The current and speed controller parameters are selected by comparing the transient response of torque, flux and speed loop for step variation in reference value. Parameter plane synthesis method (D-partition technique) is used to determine the stable region in the PI controller parameter plane. The small signal stability of the designed controller parameters is also evaluated by investigating the performance of proposed drive scheme in MATLAB/Simulink environment. The drive system is tested for wide speed range operations and the results show that the proposed technique has fast dynamic response and is effective over wide speed range.

Comparative analysis of conventional and IRP theory based Shunt APF for 3P3W system

Harmonics and Reactive current in transmission line causes additional transmission losses in the line. To mitigate this problem, Shunt Active Power Filter (SAPF) is presented for the compensation of harmonics and reactive power with balanced and unbalanced non linear load. In this paper two control topology such as conventional control scheme and instantaneous reactive power theory are presented. Finally, a comparative analysis is made based on the simulation results.