Reactive power limits in distributed generators from generic capability curves

Abstract

Abstract-This paper presents a generic trapezoid-type capability curve for any distributed generation technology. This curve is used to estimate the machine reactive power limits in terms of the actual active power and terminal voltage. The proposed simplification was tested on synchronous machines, doubly fed induction generators and full power converter interfaced generators. This methodology can be implemented in Volt/VAR control schemes when the estimation of DG capability is required.

Combined Local and Centralized Voltage Control in Active Distribution Networks

“…where 1 denotes a unit vector, Q (11) are updated in accordance with the DGU capability curves [24], assuming that the active power will not change significantly over the control horizon. Thus the bounds vary with the discrete time k, but, for legibility, the dependency on active power and voltage is omitted in the notation.…”

Contribution of Distribution Network Control to Voltage Stability: A Case Study

“…The active powers, updated from real-time measurements, are already at their upper limits. The reactive power limits are updated with the voltage and active power as described in [19], based on the information in [20] for the DFIGs. The constraints (4b) are associated with the rate of change of control variables.…”

Voltage profile correction in distribution grids combining single- and two-level controllers

“…where 1 denotes a unit vector, Q (k) are updated at each time step based on the measured active power and terminal voltage, in accordance with the DGU capability curves [10]. In the constraints (11),…”

“…3 is embedded in the differential-algebraic model of the DGU unit, while the centralized controller acts at discrete times only. The quadratic programming problem (4)(5)(6)(7)(8)(9)(10)(11) is solved with the VE17AD package from Harwell [16].…”