Admittance-Dissipativity Analysis and Shaping of Dual-Sequence Current Control for VSCs

• This paper analyzes the admittance-dissipativity of dual-sequence current control for grid-connected voltage-source converters (VSCs). The output admittance model of dual-sequence current control is first developed in the stationary reference frame by using complex vectors. Impacts of digital filters used within current control and voltage-feedforward (VFF) control loops, and of the delay compensation at the fundamental frequency, are then evaluated. It is found that the cascaded use of sequence-decomposition filter (SDF) and the low-pass filter (LPF) in the VFF control loop adds a non-dissipative region in the output admittance, and the fundamental-frequency delay-compensation further worsens the dissipativity. An analytical design method for the LPF is then developed to mitigate the non-dissipative region, which lowers the instability risks and improves the stability robustness of dual-sequence current control under different grid conditions. Lastly, simulations and experimental results corroborate theoretical analyses.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Annan elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Other Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Nyckelord

Admittance

Converters

Current control

delay compensation

Delays

Digital filter

dissipativity

Power conversion

sequence control

Stability analysis

Transfer functions

voltage feedforward

Control systems

Digital filters

Electric current control

Natural frequencies

System stability

Analytical design method

Decomposition filter

Dissipativity analysis

Fundamental frequencies

Stability robustness

Stationary reference frames

Voltage feed-forward

Voltage-source converter

Low pass filters

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)