Z. Lubosny

Supervisory Control of a Wind Farm

This paper presents a scheme for supervisory control of wind farms. We concentrate on reduction of power output variation, but the proposed scheme can also be used for system-wide controls that are related to power variation, such as frequency control or damping of power swings. The scheme may utilize either a separate (external) energy storage device or a power reserve achieved through part-loading of one or more turbines in a wind farm. The proposed supervisory control scheme has been validated on a model of a wind farm with four turbines. Simulations have confirmed the usefulness of the scheme. The proposed control system is general and could also be used for other types of intermittent generators such as wave or solar.

Identification based Dynamic Equivalencing

Expected bulk connection of renewable energy sources to existing distribution networks may change dynamic properties of power systems and increase the size of power system models used for the analysis of power system operation and stability problems. To reduce the size and complexity of modelling, distribution networks could be replaced by their dynamic equivalents. This paper focuses on identification of dynamic equivalents of distribution network from measured disturbance data. The validity of derived state-space models has been confirmed by simulation.

DUAL INPUT QUASI-OPTIMAL PSS FOR GENERATING UNIT WITH STATIC EXCITATION SYSTEM

Abstract The paper considers dual input Power System Stabiliser (PSS) and Automatic Voltage Controller (AVR) for a generating unit equipped with synchronous generator and static excitation system. The control system uses analytically derived, quasi-optimal values of parameters (time constants) that cause the PSS to produce damping torque component only. Good dynamic properties of the plant equipped with the proposed dual input PSS and AVR are confirmed by simulation using a non-linear, multi-machine model of a power system (part of UCTE power system).

Enhancement of power system stability using fuzzy logic based supervisory power system stabilizer

Under some circumstances, conventional power system stabilizers (PSS) suffer shortcomings and cannot enhance small-signal stability of the power systems especially when it comes to inter-area oscillation damping. This along with the advanced technology in phasor measurement units (PMUs) has lead to an increasing interest in developing global controllers using wide-area measurements to solve the deficiencies of local PSSs. The focus of this paper is to use fuzzy logic principles to develop supervisory power system stabilizers (SPSS) to enhance damping of inter-area oscillations to improve stability and reliability of power systems subjected to disturbances.

PSS design for a small synchronous generator with static excitation system

The paper presents an analytical derivation of parameters for the power system stabilizer (PSS) that produces damping torque component only. The method is applied to a linear single-machine system model equipped with static excitation system. Good dynamic properties of the plant equipped with the proposed PSS have been confirmed by simulation using non-linear, single- and multi-machine models of electric power system. The simplicity of the proposed methodology should significantly simplify the task of designing PSS for small and medium units.