ABSTRACT Currently, reactive power compensation in wind‐photovoltaic (PV) hybrid grid‐connected systems is typically controlled independently by the wind farm and PV station, lacking a coordination mechanism between them. To address this, we propose a reactive power hierarchical control strategy for wind‐PV hybrid systems. Building on an analysis of reactive power source regulation characteristics and reactive power sensitivity, a three‐layer reactive power control structure for wind‐PV hybrid grid‐connected systems is proposed based on the hierarchical control concept. At the system layer, the reactive power compensation requirements for the entire system are determined using the reactive voltage sensitivity of the system collection bus. At the station layer, reactive power allocation tasks for the wind farm and PV station are determined using a hierarchical optimisation control model. At the equipment layer, reactive power allocation tasks for wind turbines, PV inverters, and dynamic reactive power compensation equipment are determined according to the allocation principles governing reactive power sources within the wind farm and PV station. Compared with traditional control strategy, the control strategy in this paper can make full use of the reactive power control capability of the reactive power sources within the system to achieve optimal allocation of the reactive power compensation tasks in the whole system. The average reduction in system network losses reached 8.14%, and the bus voltage at the collection point could be essentially stabilised around 1.0 pu so as to achieve the purpose of improving the stability of the collection bus voltage of the system and point of common coupling (PCC) bus voltage of the station and reducing the system network loss.
Zhang et al. (Wed,) studied this question.