Provision of Frequency Response from Wind Farms: A Review

Abstract

Renewable sources of energy play a key role in the process of decarbonizing modern electric power systems. However, some renewable sources of energy operate in an intermittent, non-dispatchable way, which may affect the balance of the electrical grid. In this scenario, wind turbine generators must participate in the system frequency control to avoid jeopardizing the transmission and distribution systems. For that reason, additional control strategies are needed to ensure the frequency response of variable-speed wind turbines. This review article analyzes diverse control strategies at different levels which are aimed at contributing to power balancing and system frequency control, including energy storage systems.

Hybrid Deloading Control Strategy in MMC-Based Wind Energy Conversion Systems for Enhanced Frequency Regulation

“…At this wind speed, the proposed control method operates the wind turbine in the over-speeding mode with the prescribed 10% power margin. The performance of the proposed method is then compared with the traditional MPPT method and the MPPT plus frequency droop method presented in [23]. In the MPPT method, the power reference from ( 4) is directly sent to the swing equation block of the VSG.…”

“…In the MPPT method, the power reference from ( 4) is directly sent to the swing equation block of the VSG. In the MPPT plus frequency droop method, the power reference from ( 4) is supplemented by grid frequency droop control, as specified in [23]. The load is initially 9 MW, and then a sudden 5 MW load increment is introduced at t = 35 sec to evaluate dynamic performance.…”

“…On the other hand, while over-speeding control has a faster response, it has a limited control spectrum, especially when the rotor approaches the maximum allowable speed. Given the pros and cons of both methods, hybrid control mechanisms [20,23] are designed to improve the power regulation flexibility of wind turbines and maximize the efficiency and reliability of WECSs. Furthermore, it is crucial to consider the practicalities of implementing such control methods in real-world applications.…”

Estratégias de controle para resposta em frequência na operação isolada entre geração eólica offshore e plataformas de óleo e gás em águas profundas.

“…Em um Sistema Elétrico de Potência (SEP), a oferta e a demanda de energia ativa devem ser equilibradas a todo momento de forma a possibilitar sua operação estável. Caso contrário, a estabilidade e a qualidade do sistema se tornarão progressivamente piores, podendo resultar na desconexão de componentes do conjunto e, eventualmente, causar falhas e apagões em cascata [37].…”

“…Diversos fatores afetam a estabilidade elétrica, incluindo a topologia da rede elétrica, a capacidade dos geradores e dos transformadores, a demanda de carga e a presença de fontes renováveis de energia, como turbinas eólicas e painéis solares [39]. Atualmente, a crescente penetração de energia eólica e de outras fontes de energia renovável, introduz preocupações quanto a segurança na operação de sistemas, uma vez que a variabilidade dos recursos pode resultar em operação com os principais parâmetros do sistema elétrico fora dos limites estabelecidos de forma repentina [37].…”