Network-Side Carbon Emission Reduction via Dispatching Power Electronic Devices in AC-DC Hybrid Distribution Systems

Heightened environmental concerns have arisen the urge for low-carbon power systems. Existing literatures on low-carbon dispatching have fully studied how to reduce carbon emissions on generation side or demand side. But, carbon emissions related to network power losses (i.e., network-side carbon emissions), especially in distribution system (DS), significantly affects the whole carbon distributions as well. However, the objective of conventional low-carbon economic dispatching fails to precisely reduce this part of carbon emissions. To address this issue, we propose a network-side carbon emission reduction method. After determining active power flows by the day-ahead economic dispatching, this method innovatively explores utilizing reactive power compensation capability of some emerging power electronic devices in AC-DC hybrid DS for reducing network-side carbon emissions. First, the traditional Var compensation devices and the emerging voltage source converters (VSCs) with specific control strategies are modelled. Second, models of inverter-based PV units and the aggregated feasible power region (AFPR) of PV aggregators are also proposed. Finally, the low-carbon dispatching model for network-side carbon emission reduction is established, and an ALSO-X+ method is used to solve joint chance constraints (JCC) on the AFPR caused by the uncertainties of PV generation. Case studies on AC-DC test systems with different scales verify that dispatching reactive power can also influences carbon intensities among the whole distribution network. Moreover, our proposed method could effectively reduce network-side carbon emissions and demand-side carbon emissions. Note to Practitioners - Optimizing carbon emissions on network side via dispatching reactive power significantly affect carbon distributions as well, which shows great potential on achieving the low-carbon goal in DS. And in practice, it is essential to unlock the reactive power compensation capability of power electronic devices, especially in AC-DC hybrid DS. This paper proposes a network carbon emission reduction method considering dispatching various reactive power devices. This method takes various control modes of VSC into account, and utilizes JCC to deal with uncertainties during the PV aggregation process. Moreover, the novel ALSO-X+ algorithm is adopted to efficiently decompose the JCC constraints. The proposed method not only provides new sights and extends current researches for achieving the low-carbon goal in DS, but also demonstrates the adaptability for AC-DC hybrid DS operation and exhibits significant scalability, which offers the considerable practical values for industry practitioners.