Power factor corrected rectifiers, active power filters, and grid-connected utility inverters

In this dissertation, Unified Constant-frequency Integration Control (UCI control) based on one-cycle control, is developed to improve the power factor of power electronics converters. The proposed control method employs an integrator with reset as its core component along with a few logic and linear components to control the switch duty ratios of three-phase rectifiers, active power filters, or grid-connected inverters. With the proposed control, all three-phase utility currents are sinusoidal and unity power factor is achieved. No multipliers are required, as used in many control approaches to scale the current references according to the load level. In addition, constant switching frequency modulation that is desirable for industry applications is employed. In general, UCI control can have vector or bipolar operation. For vector operated UCI control, typically the switching losses are reduced by controlling only two switches at high switching frequency. In this case, the input voltage zero-crossing is sensed to determine the vector location, resulting in a slightly complicated control system. For bipolar operated UCI control, the controller can be even simpler and the input voltage zero-crossing sensor can be eliminated. The overall cost can be also reduced. However, the switching losses are higher compared with vector operated UCI control since all switches are operated at high frequency at any given time.; Chapter 1 gives a basic introduction to UCI Control. Three-phase power factor corrected rectifiers with vector operated UCI control are covered in Chapter 2. Chapter 3 introduces the three-phase power-factor-corrected rectifier with bipolar operated UCI control.; Chapters 4, 5 and 6 are devoted to the UCI controlled active power filter. Chapter 4 presents the UCI controlled single-phase APFs. Three-phase APF with vector operated UCI control is explained in Chapter 5, and bipolar operated UCI control is discussed in Chapter 6.; Alternative energy sources such as fuel-cells, photovoltaics, wind power etc. are receiving increased interest recently because they consume renewable energy. Chapter 7 presents the application of a UCI controlled grid-connected inverter for alternative energy sources. Minimum switching losses, and high power factor are achieved with proposed control method.; Chapters 8, 9, 10 and 11 discuss the single-stage Power Factor Correction (PFC) from a topology point of view. Single-stage Power Factor Correction is attractive at low power applications (typically below 200w). (Abstract shortened by UMI.)...