Asma Aziz

Participation of DFIG based wind energy system in load frequency control of interconnected multigeneration power system

Maintenance of system frequency within utility prescribed tolerance band was considered as exclusive responsibility of conventional power plants. Fluctuating power due to varying nature of wind inflict extra power imbalance to the power system leading to frequency deviation from the nominal value. This power generation needs to be balanced with other fast controllable generation sources. With increasing share of wind based energy generation on utility grid, provision of ancillary services from them is also gaining the status of necessity for total system reliability. Frequency regulation makes up as one of the category of these ancillary services for power system security management and quality reliability. Automatic generation control (AGC) is an important function for load frequency control (LFC). This paper addresses design aspects of LFC scheme for minimization of system frequency of interconnected multigeneration power systems in the presence of wind power. Integral of time multiplied by absolute errors (ITAE) has been applied to determine the optimal values for the controller gains of the system. It has been observed from simulations that control area having wind integrated with base load plant gives better AGC performance than the control area having wind integrated with peak load plant.

Intelligent frequency regulation in the wind integrated control area

Abstract Reduction in system inertia due to the higher levels of wind plants in a power system inherently necessitates the frequency regulation investigations and motivates new opportunities for the improvement of active power control techniques. This paper focus on the load-frequency regulation analysis of a control area in the presence of a proposed wind energy technology. The proposed variable speed wind turbine generator model incorporates a dynamic dead-band and moving average frequency filter-based algorithm to provide grid-code compatible power-frequency response. The proposed wind plant model provides better frequency response and increased electrical power generation in comparison to the other frequency responsive wind turbine generator models. This paper also highlights the superiority of gain scheduling concept in fuzzy logic controllers as an improved alternative to various other load frequency controllers under the stochastic conditions in a wind integrated control area.

Fuzzy gain scheduled load frequency controller in presence of grid code frequency responsive wind power penetration

Cumulative wind energy penetration has increased substantial concern on power and frequency regulation in the electrical power industry. Fluctuating power due to varying nature of wind inflict extra power imbalance to the power system leading to frequency deviation from the nominal value. LFC system design must be able to minimize and maintain system frequency in presence of stochastic demand-load and disturbance scenario. Increased penetration of wind generation in interconnected power system intrinsically thus calls for LFC analysis with present and future wind technologies. Grid code frequency responsive wind power plants are new emerging wind technology. Fuzzy gain scheduling of LFC controller is assessed in presence of frequency responsive wind plants and presented in this study as improved substitute to general fuzzy LFC controllers under stochastic conditions.

Modelling and comparison of generic type 4 WTG with EMT type 4 WTG model

Wind system integration can lead to adverse effects on modern electric grid so it is imperative to assess their dynamic performance before actual plant startup. Transmission system operators all over the world stress the need for a proper wind turbine generator model for dynamic performance as well as ancillary service assessment. Due to the bulk power system assessment requirements, development of suitable generic modeling has gained high priority. This paper presents generic modeling of type 4 full converter wind turbine generator system suitable for frequency regulation studies and its comparison with detailed EMT type 4 wind energy conversion system. This paper also analyzes and compares the suitability of simplified vs. detailed aerodynamic models along with mass model by means of simulations in the MATLAB ® Power System Block set.

Modelling and analysis of type 4 wind turbine generator system for utilization in frequency regulation studies

Green energy targets for coming decades advocates high penetration of wind energy in main energy matrix which also pose incendiary threat to stability and reliability of modern electric grid if their dynamic performance aspects are not assessed beforehand. Considering increasing interest in dynamic performance along with ancillary service assessment related to frequency regulation, development of suitable generic modeling has gained high priority. This paper presents modeling of type 4 full converter wind turbine generator system suitable for frequency regulation focusing on active power control. Complete model is a modification of WECC generic model with additional aerodynamic and pitch control model. Descriptions of individual sub models are presented and performance results are compared manufacturer specific GE type 4 WTG generic model by means of simulations in the MATLAB ® Power System Block set.