A control strategy for series connected offshore wind turbines

Abstract

This paper presents a control strategy for HVDC systems based on pulse width modulated current source converters. The strategy is applicable to series connected off-shore wind farms where the line current must be controlled by the on-land converter while the off-shore voltage and power are controlled by converters allocated in each turbine. A threestage hierarchical control based on proportional regulators was designed. Space vector modulation is used in the converter at medium switching frequency. The control and modulation show fast dynamic response and low harmonic distortion. This desirable behavior was demonstrated by simulation on a 16 MW system with an exact switching model of the semiconductor devices. both, short circuit and stationary state were studied.

A Matrix converter-interfaced PM Generator System with Active Filtering Capabilities

“…The inner loop controls the capacitor voltage, c v , and provides the current reference mc i' to the modulation block of the matrix converter. The outer loop controls the current, mc i , injected into the grid at the PCC and provides the capacitor voltage c v reference to the inner loop [4].…”

“…In [3] an indirect triangular carrier-based modulation is used as well as active damping to avoid resonance in the input LC filter. In this paper it is suggested to use indirect space vector modulation and simple proportional control for the input current and capacitor voltage as in [4]. The paper is organized as follows: Following the introduction, the second section presents the matrix converter and the indirect space vector modulation.…”