Patent ID: 8060349
Filing Date: 2011-11-15
Classification: H02J,H02M,Y02E

Abstract:
1. A method for controlling current, in an electric power system based on passivity-based control theory, to regulate a load bus voltage with a static synchronous compensator (STATCOM) controller designed using a STATCOM model, comprising: constructing a STATCOM model with a viewpoint of energy balancing as a circuit model constructed in Euler-Lagrange (EL) dynamic frame, wherein the model also considers the dynamic response of a changeable load, and is used to determine a control command for fast adjustment of a load characteristic in an electric power system using a STATCOM controller wherein the STATCOM model is given by where L=the Lagrangian term of the STATCOM EL model, D,M =the Rayleigh disruptive term of the STATCOM EL model, R,R l =the dissipation term of the STATCOM EL model, J,J l =the interconnection term of the STATCOM EL model, ω=dθ/dt=the angular speed of the ac system, θ=the angle of the STATCOM bus voltage, ε=the external force term of the STATCOM EL model, i sd ,i sq =the d-q axis current through a loss resistor ( 114 ) and a loss inductor ( 115 ) under the direct-quadrature rotating frame, i Ld ,i Lq =the d-q axis current through the changeable load under the direct-quadrature rotating frame, V dc =the DC side voltage across a coupling capacitor ( 113 ) and the loss resistor, u d ,u q =the d-q axis control input of converter ( 106 ); designing a STATCOM controller for controlling current in said electric power system on the basis of passivity-based control using said STATCOM model and technologies of energy shaping and damping injection and using controlled current to regulate a load bus voltage; wherein said damping injection changes the STATCOM model to Dż*−M{dot over (w)}+Rz*+J(u)z*−R where and wherein the energy shaping error signal is defined as {tilde over (z)}=z−z*=[i sd −i* sd i sq −i* sq V dc −V* dc ] T ; and controlling current in said electric power system on the basis of passivity-based control to regulate the load bus voltage with the STATCOM controller.