Frequency response estimation method for high wind penetration considering wind turbine frequency support functions

摘要

To achieve renewable energy targets, more wind turbine generators (WTGs) are being integrated into many power networks around the world. However, unlike traditional synchronous generators, modern WTGs are driven by power electronic devices which provide almost zero inertia and frequency response to frequency related events such as generator tripping. Wind manufacturers and researchers have been working on synthetic WTG inertia support, which can better utilise the rotational nature of WTGs. However, synthetic inertia alone may be insufficient under certain circumstances to prevent automatic under frequency load shedding after generation tripping, which causes security concerns for network operation. Consequently, WTG active power control (APC, similar to governor control) should be activated to improve network security. However, APC will costly reduce WTG output from the maximum power point and result in financial concerns. Therefore when and how much APC service should be activated becomes an extremely important question, which has not been addressed in the literature. This study develops a new method to quickly estimate frequency response caused by generator tripping hence system operators can use this proposed method to continuously evaluate inertia and headroom competency and accordingly activate the amount of WTG inertia and APC required for reliable system operation.