Modelling and control of single VSI leading experimental hybrid power system integrating a wind turbine simulator
This paper discusses a hybrid wind diesel system aims to validate wind powered section of the experimental system. The experimental system proposed consists of a wind turbine simulator, a permanent magnets generator, a diode bridge rectifier, a step down converter, a bank of battery, a load and a control unit. An other operation of three-phase, four-wire voltage source inverter (VSI) under unbalanced voltage conditions is also investigated.
THE HYBRID COORDINATE CUTTING-IN CONTROL TECHNOLOGY OF THE DOUBLY-FED VARIABLE SPEEDAND PITCH WIND-POWER GENERATOR
In view of the cutting-in problems of the doubly-fe d wind power generator, this paper deals with it’s control strategies in detail and proposes a coordinate cutt ing-in control method based on the hybrid system th eory, and establishes the hierarchical control model of t he doubly-fed wind power generator around the cutti ngin. On the basis of the model, the model informatio n and structure information of the system are decentralized. On the one hand, the control algorit hm is designed for the continuous variable of the s ystem with the d-axis current and q-axis current as its c ontrolled outputs according to the estimated mechan isms and control strategies. On the other hand, the hybr id automaton is used for the state transition of th e system discrete variable. Simulation results show that com pared with the traditional control methods this new control method can make the d-axis current and the q-axis current of DIFG to the reference values in f inite time and achieve the effective control of the rotor current. What's more important this method can not only improve the no off-grid ability during the grid-vol tage fluctuation, but also prevent the rotor and ro tor-side converter over current effectively. It has importan t actual significance and practical application val ue.
Investigations of dielectric gratings using electrodynamic models based on volume integral equations
Eigenmodes of planar and cylindrical dielectric gratings (DGs) and electromagnetic wave scattering from multiplayer DGs are investigated. The DG characteristics are calculated using numerical-analytical solution of integral equations (IEs).