scholarly journals Enhanced Inertial Response Capability of a Variable Wind Energy Conversion System

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8132
Author(s):  
Jun Wang ◽  
Yien Xu ◽  
Xiaoxin Wu ◽  
Jiejie Huang ◽  
Xinsong Zhang ◽  
...  
Keyword(s):  
Control Strategy ◽  
Maximum Rate ◽  
Rate Of Change ◽  
Frequency Deviation ◽  
Control Coefficient ◽  
Maximum Frequency ◽  
Induction Generators ◽  
Inertial Response ◽  
System Frequency ◽  
Response Capability

An inertial response emulated control strategy of doubly-fed induction generators (DFIGs) is able to arrest their frequency decline following a severe frequency event. Nevertheless, the control coefficient is unchanged, so as to limit the benefit potentiality of improving the inertial response capability for various disturbances and provide less of a benefit for boosting the frequency nadir. This paper addresses an enhanced inertial response emulated control scheme for a DFIG to improve the maximum frequency deviation and maximum rate of change of frequency for various disturbances. To this end, the control coefficient is coupled with the system frequency deviation so as to regulate the control coefficient according to the system frequency deviation (i.e., sizes of the disturbance). Results clearly indicate that the proposed inertial response emulated control strategy provides better performance in terms of improving the maximum rate of change of frequency and maximum frequency deviation under various sizes of disturbance and random wind speed conditions.

scholarly journals An Improved Droop Control Scheme of a Doubly-Fed Induction Generator for Various Disturbances

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7980
Author(s):  
Yien Xu ◽  
Pei Chen ◽  
Xinsong Zhang ◽  
Dejian Yang
Keyword(s):  
Rate Of Change ◽  
Frequency Regulation ◽  
Droop Control ◽  
Doubly Fed Induction Generator ◽  
Control Coefficient ◽  
Induction Generators ◽  
Doubly Fed Induction Generators ◽  
Control Scheme ◽  
Doubly Fed ◽  
System Frequency

Doubly-fed induction generators (DFIGs) participate in the system frequency regulation using a fixed-coefficient droop control scheme. Nevertheless, the frequency-supporting capability of this control scheme with fixed gain is limited for different disturbances. This paper suggests an improved droop control scheme for a DFIG that can both alleviate the frequency nadir and maximum rate of change of frequency (ROCOF) during the frequency regulation. To achieve this, an adaptive droop control coefficient based on the ROCOF is suggested. The proposed droop control coefficient is a linear function of the ROCOF. Therefore, the proposed scheme can adjust the control coefficient according to the varying ROCOF. Simulation results clearly demonstrate that the proposed droop control scheme shows better effectiveness in improving the maximum ROCOF and frequency nadir under various sizes of disturbance, even in a varying wind speed.

scholarly journals Investigation of Inertia Response and Rate of Change of Frequency in Low Rotational Inertial Scenario of Synchronous Dominated System

Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2288
Author(s):  
Francisco Gonzalez-Longatt ◽  
Juan Manuel Roldan-Fernandez ◽  
Harold R. Chamorro ◽  
Santiago Arnaltes ◽  
Jose Luis Rodriguez-Amenedo
Keyword(s):  
Power Systems ◽  
Large Scale ◽  
Power Converter ◽  
Rate Of Change ◽  
Rotational Inertia ◽  
Distributed Energy ◽  
Inertial Response ◽  
System Frequency ◽  
Inertia Response ◽  
System Inertia

The shift to a sustainable energy future is becoming more reliant on large-scale deployment of renewable and distributed energy resources raising concerns about frequency stability. Rate of Change of Frequency (RoCoF) is necessary as a system inertia metric in order for network operators to perform control steps to preserve system operation. This paper presents in a straightforward and illustrative way several relevant aspects of the inertia response and RoCoF calculation that could help to understand and explain the implementation and results of inertial response controllers on power converter-based technologies. Qualitative explanations based on illustrative numerical experiments are used to cover the effects on the system frequency response of reduced rotational inertia in synchronous dominated power systems. One main contribution of this paper is making evident the importance of the governor action to avoid the synchronous machine taking active power from the system during the recovering period of kinetic energy in an under frequency event.

scholarly journals Research on Frequency Fuzzy Adaptive Additional Inertial Control Strategy for D-PMSG Wind Turbine

2019 ◽  
Vol 11 (15) ◽  
pp. 4241
Author(s):  
Mudan Li ◽  
Yinsong Wang
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Control Strategy ◽  
Synchronous Generator ◽  
Frequency Deviation ◽  
Frequency Regulation ◽  
Response Characteristics ◽  
Inertial Response ◽  
Inertial Control ◽  
Fuzzy Adaptive

The traditional additional inertial control (T-AIC) strategy can provide frequency support for the directly-driven wind turbine with a permanent magnet synchronous generator (D-PMSG). However, due to the fixed control coefficients, the frequency modulation effect is poor under load and wind speed disturbances. In order to improve the frequency transient response of D-PMSG, a fuzzy adaptive additional inertial control strategy (FA-AIC) is proposed in this paper. A simplified D-PMSG model is established for the complexity and low calculation speed. A single-machine grid-connected system composed of a D-PMSG and an equivalent synchronous generator set (ESGS) is taken as the background and analysis of the principle of T-AIC. The proportional and derivative coefficient initial values in T-AIC are tuned by simulating the static characteristics and inertial response characteristics of the conventional synchronous generator set, and fuzzy control technology is introduced to adjust the proportional and derivative coefficients adaptively based on the frequency deviation and the frequency deviation change rate under load or wind speed disturbances. The simulation verification indicates that T-AIC, kinetic energy (KE)-based gain-AIC and FA-AIC all can utilize the D-PMSG additional inertial response to provide frequency support for grid-connected systems. Compared with T-AIC and KE-based gain-AIC, the proposed FA-AIC can not only provide more effective frequency support during load disturbances, but also suppress the frequency fluctuation caused by the wind speed variation and displays a better dynamic frequency regulation effect.

scholarly journals Frequency Support from a Variable-Speed Wind Turbine Generator Using Different Variable Droop Characteristics

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4477
Author(s):  
Dejian Yang ◽  
Jingjiao Li ◽  
Xinsong Zhang ◽  
Liang Hua
Keyword(s):  
Frequency Response ◽  
Control Method ◽  
Frequency Control ◽  
Test System ◽  
Ancillary Service ◽  
Load Variations ◽  
Induction Generators ◽  
Doubly Fed ◽  
System Frequency ◽  
Response Capability

Doubly-fed induction generators (DFIGs) are capable of boosting frequency response capability while preventing the rotor speed from stalling during under-frequency disturbances, by employing variable droop characteristics. However, the frequency response capability during over-frequency disturbances is shortened because the potential for storing the kinetic energy is inversely proportional to the variable droop characteristics used for under-frequency disturbances. This paper designs a frequency control method of a DFIG to boost the frequency response capability during over-frequency disturbances while preserving the frequency response capability during under-frequency disturbances, by employing different variable droop characteristics. The effectiveness of the proposed frequency control method is investigated in a test system. The investigation results under five scenarios with different load variations, wind power penetrations and wind conditions clearly demonstrate that the proposed frequency control method suppresses the maximum system frequency deviations. As such, the proposed frequency control method can provide an effective solution for the frequency control ancillary service of a power system with large integrations of wind energy.

Doubly Fed of Induction Generators Wind Turbine Frequency Control Based on Power Curve of Inertia Control and Pitch Angle Control

2014 ◽  
Vol 1070-1072 ◽  
pp. 228-232
Author(s):  
Xiao Ying Zhang ◽  
Si Wen Li
Keyword(s):  
Wind Turbine ◽  
Control Strategy ◽  
Pitch Angle ◽  
Frequency Control ◽  
Wind Farms ◽  
Rate Of Change ◽  
Pitch Frequency ◽  
Inertia Control ◽  
Doubly Fed ◽  
System Frequency

With many grid-connected wind farms of Doubly-fed Induction Generator (DFIG) type taking the palce of conventional synchronous generators, the frequency control ability of the system will decrease. But the existing control strategy based on maximum wind power tracking of DFIG can not response to the deviation of the system frequency. This paper proposes a new hybrid frequency control strategy based on the research of the frequency response to the doubly fed induction wind turbine curves switching inertia control loop and the ability for the pitch angle control participating in the system primary frequency modulation. The strategy reduces the initial rate of change and the steady state error of system frequency with the combined action of the curves switching inertial control and pitch frequency control. Finally, the simulation results of the two areas with four generators validate the effectiveness of the strategy.

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