Study of Novel Power Electronic Converters for Small Scale Wind Energy Conversion Systems

This chapter proposes a study of novel power electronic converters for small scale wind energy conversion systems. In this chapter major topologies of power electronic converters that used in wind energy converter systems have been analysed. Various topologies of DC/AC single stage converters such as high boost Z-source inverters (ZSI) have been investigated. New proposed schemes for inverters such as multilevel and Z-source inverters have been studied in this proposed chapter. Multilevel converters are categorized into three major groups according to their topologies which are diode clamped multilevel converters (DCM), cascade multilevel converters (CMC) with multiple isolated dc voltage sources and flying capacitor based multilevel converters (FCMC). Z-source inverters are divided to ZSI, qZSI and trans-ZSI types. Trans-ZSI is mostly used for high step-up single stage conversions

Reliability and Performance Improvement of PUC Converter Using a New Single-Carrier Sensor-Less PWM Method with Pseudo Reference Functions

A new single-carrier sensor-less pulsewidth modulation (PWM) method using suggested pseudo reference functions is proposed for packed U-cell (PUC) converter to improve performance and reliability of the PUC converter. It is composed of one PWM carrier signal and two suggested pseudo reference functions. By employing the proposed modulation method, the PUC dc capacitor voltage ripple is substantially decreased, and faster sensor-less capacitor voltage balancing is obtained. Moreover, the power losses are evenly distributed among all power switches. Consequently, notable reduction of the PUC dc capacitor voltage ripple and even distribution of the power loss among switches enhance the PUC converter\u27s reliability and lifetime. In addition, odd multiples of the switching harmonic clusters are eliminated from the output voltage; thus, the values of output passive filter components are halved. Hence, applying the proposed single-carrier sensor-less PWM method remarkably improves the performance, power density, reliability, and lifetime of the PUC converter and notably simplifies implementation of the switching pattern. Provided experimental results and comparisons as well as reliability analysis verify the viability and effectiveness of the proposed PWM method

A New Constant Switching Frequency Model Predictive Control Method for Grid Connected 5-level ANPC Inverter with Capacitors Sensor-less Voltage Balancing

In this paper, a constant switching frequency model predictive control (MPC) method with capacitors voltages self-balancing is proposed for the 5-level active-neutral-point-clamped (5L-ANPC) grid connected inverter. The proposed MPC provides optimum reference voltage for the 5L-ANPC inverter based on minimizing the derivative of defined cost function with respect to the output voltage of the 5L-ANPC inverter. The generated reference voltage by the proposed MPC is applied to a phase shifted pulse width modulation (PS-PWM) method to provide constant switching frequency and sensor-less voltage balancing of the dc-link and flying capacitors of the 5L-ANPC inverter. Hence, the proposed MPC only needs to measure grid current; thus, the complexity of control system and number of required sensors are notably decreased. The proposed MPC is described and simulation and experimental results are provided for the grid connected 5L-ANPC inverter. The provided simulation and experimental results verify the dynamic and steady state performance as well as viability of the proposed constant switching frequency MPC for the grid connected 5L-ANPC inverter