A Performance Evaluation Method for Frequency Response Control of Virtual Control Units

Amidst the rapid expansion of renewable energy sources, the application of virtual power plant technology to integrate distributed resources at the load side into virtual control units for participation in frequency response control can significantly augment the system's limited frequency regulation capabilities. As per established standards, these virtual control units primarily engage in system regulation through feedforward mechanisms, featuring intricate control architectures, rapid response times, and the capacity to intervene at the onset of disturbances. Conversely, conventional static evaluation methods, which concentrate on quasi-steady-state response power, offer an ambiguous depiction of the dynamic response process, thus failing to accurately capture the frequency response control performance of virtual control units. This study introduces an evaluation approach for the frequency response control performance of virtual control units from a dynamic perspective, utilizing transfer functions to ensure precise assessment. Drawing on current research into individual control models for distributed resources at the load side and relevant standards, the evaluation framework incorporates three dynamic parameters: speed of dynamic regulation, amplitude of dynamic adjustment, and cumulative dynamic effect. The actual values of these parameters are determined using the least squares fitting method. By aligning with grid requirements and incorporating convolution calculation techniques, benchmark values for the dynamic parameters are established. Based on a comparison of the actual and benchmark values, a set of evaluation indicators is developed. The viability and efficacy of the proposed method are demonstrated through comparative analysis.