Research Terms
Engineering Electrical Engineering
Keywords
Famu-Fsu College Of Engineering
In this invention, a novel single-phase single-stage grid-interactive inverter based on a discrete Fourier Transform Phase Locked Loop technique is developed to separate the real and reactive power between different energy sources/storages. The hybrid modulation technique and sophisticated power allocation strategy are developed for the power generation system to achieve wide range reactive power compensation and enhance energy conversion efficiency. One distributed energy source and two energy storages are interfaced to the inverter with three cascaded H -bridge cells used to investigate the performance of the proposed system. Different energy source/storages with wide voltage change range can be directly connected in the invention and the single-stage energy conversion can be implemented. The present invention can integrate distributed energy sources/storages in one cascaded inverter. Due to the absence of DC-DC converter, single-stage energy conversion can be achieved. The hybrid modulation technique and power allocation strategy corresponding to the proposed system are developed to achieve the wide range reactive power compensation, voltage boost function, and the optimized power management.
The proposed single-phase single-stage grid-interactive inverter is particularly suitable to meeting the increasing distributed power generation needs. It can facilitate to interface different distributed renewable energy sources or storages such as wind power, solar power, battery, fuel cell, Ultra-capacitor and so on. The switching loss will be decreased due to the cascaded structure and hybrid modulation technique.
In the present invention, different circuit-based implementations of stochastic anti-windup PI controllers are provided for a motor drive controller system. The designs can be implemented in a Field Programmable Gate Arrays (FPGA) device. The anti-windup PI controllers are implemented stochastically so as to enhance the computational capability of FPGA. The invention encompasses different circuit arrangements that implement distinct anti-windup algorithms for a digital PI speed controller. The anti-windup algorithms implemented by the circuit arrangements can significantly improve the control performance of variable-speed motor drives.
Compared with the existing technologies, the stochastic PI controller provides an efficient implementation approach that uses straightforward digital logic circuits but has the advantage of significantly reducing the circuit complexity. Therefore, the present invention notably improves the performance of the stochastic PI controller and saves digital resources in a motor drive control system. The immediate and/or future applications are motor drive controllers for induction motor systems, and more particularly, proportional-integral (PI) controllers. The use of the invention will increase the market of FPGA since the capability will be largely increased and the cost will be relatively reduced.