# Development of A Loss Minimization Based Operation Strategy for Embedded BTB VSC HVDC
## 5 Conclusions  
This paper proposes a methodology for determining the operating point of embedded HVDC considering system losses and reliability criterion. In order to verify the effectiveness of the proposed control, we applied the methodology to the Korean power system, as a result, we proved that embedded BTB VSC HVDC can provide more efficient grid service for the AC system as follows. * In normal operation, the system loss is reduced by about 16 MW in the STLM control. This is 1% of the total loss, but an economic benefit can be gained during the lifetime of HVDC. Although we did not perform a detailed economic assessment, it is possible to obtain a loss reduction effect of about 85 million dollars a year considering energy charge and demand charge. * There are about 180 branches in the zone with HVDC. Using sensitivity analysis, the number of monitoring branches can be reduced to 14 lines and three transformers. * If a disturbance occurs in the AC system and there is no appropriate HVDC control accordingly, HVDC may adversely affect the AC system. Using the SCLM control, not only overload and overvoltage problems are solved, but also the system loss is reduced, which is advantageous in economy and reliability. The proposed scheme can be operated well in a real system if a large-enough communication system like Supervisory control and data acquisition (SCADA) is applied. It is possible to reduce the communication burden by reducing the number of monitoring lines by precomputing the line that is greatly influenced by the HVDC control. Future research will need to be done on the overall embedded VSC HVDC operation strategy, not limited to the active/reactive power control, but considering all the other grid services it can provide. [PERSON] and [PERSON] contributed equally to this work. The main algorithm and control scheme were proposed by [PERSON] and [PERSON]. The experiment results were collected by [PERSON], [PERSON] ([PERSON]) and [PERSON] ([PERSON]). The simulation results were analyzed by [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] wrote the paper. This research received no external funding. This work was supported by Korea Electric Power Corporation grant (R17 XA05-4) and \"Human Resources Program in Energy Technology\" of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea. (No.20174030201540). The authors declare no conflict of interest. * [PERSON] and [PERSON] (2015) [PERSON]; [PERSON] Ancillary services in electric power systems with HVDC grids. _IET Gener. Transm. Distrib._**2015**, \(9\), 1179-1185. [CrossRef]
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