Method for controlling a direct-drive wave power generation system

Abstract

The invention relates to a method for controlling a direct-drive wave power generation system, comprising the following steps: (1) measuring by using a position sensor and a speed sensor to obtain the position and the speed of a rotor of a power generator; (2) calculating by using other parameters to obtain the control target value of the current current of the rotor; (3) measuring the instantaneous value of a stator of the power generator, and making the current of the stator under the a-b-c coordinate be under the d-q coordinate through coordinate transformation; 4) comparing the measured value of the current of the stator and the control target value, inputting to a proportional integral controller, outputting the control target value of the voltage of the stator under the d-q coordinate by the proportional integral controller, and making the voltage of the stator under the d-q coordinate be under the a-b-c coordinate through the reverse transformation of the coordinates; and (5) inputting the target value of the voltage of the stator under the a-b-c coordinate into a linear permanent-magnet power generator, controlling a transformer, and outputting the target value of the voltage of the stator so that the current of the stator is equal to the control target value. The direct-drive wave power generation system comprises an Archimedes floater and the linear permanent-magnet power generator. The control strategy has a response speed and high efficiency and can be applied to the all sea conditions.

Description

technical field [0001] The invention belongs to the research direction of electric power system and its automation in the field of electrical engineering, and discloses a direct-drive wave power generation system applicable to all sea conditions (regular waves and irregular waves, as well as linear waves and nonlinear waves). optimal control method. Background technique [0002] The direct-drive wave power system (WEC) usually consists of a buoy and a linear permanent magnet generator, which has a simple structure and high efficiency. The wave power system based on the Archimedes Wave Swing (AWS) is the first direct drive wave power system. The purpose of optimal control is to obtain energy from the waves to the maximum, for example, by pressing seawater into or out of the cylinder in the AWS, changing the volume and pressure of the air in the cylinder, so that the AWS can resonate with the waves to achieve the purpose of control , but this method has a slow response speed...

AI Technical Summary

Problems solved by technology

The purpose of optimal control is to obtain energy from the waves to the maximum, for example, by pressing seawater into or out of the cylinder in the AWS, changing the volume and pressure of the air in the cylinder, so that the AWS can resonate with the waves to achieve the purpose of control , but this method has a slow response speed, it is difficult to track the change of the wave, and the control accuracy is not high; for example, based on the analysis of the force on the rotor of the linear generator, the WEC is equivalent to a series resonant circuit, Use the control of the reaction force to maximize the energy in the wave; for example, adjust the damping of AWS through the electrical control of the linear permanent magnet generator to achieve the purpose of control. This method is more convenient and accurate to use

However, these methods are all obtained under the assumption that the waves are regular waves, and in actual working conditions, the waves acting on AWS cannot be regular

Images