Traditional arc-suppression devices have a weak effect on the arc-extinguishing result of earth fault because of increased active and harmonic components of fault current. To solve the problem, in this paper, a flexible arc-suppression device based on a three-phase cascaded H-bridge (CHB) converter with auxiliary sources is further developed; on this basis, an arc-suppression method based on the improved finite control set model predictive control is proposed. The proposed approach, which uses a combination of two voltage levels in a sampling period to reduce the steady-state current error, controls the CHB converter to inject compensation current into the distribution network. Taking into account the reduction of switching losses and balancing heat in each H-bridge cell, a novel method that causes the switching transitions to be distributed evenly among the H-bridge cells is proposed to select the optimal switching combination. The tracking capability of the improved control method is analyzed, and the parameters affecting the arc-suppression performance are obtained. The simulation and experimental results show that the proposed method achieves an excellent performance of suppressing fault current and extinguishing arc. Moreover, the balance of switching transitions is also achieved.

With the promotion of carbon peaking and carbon neutrality goals and the construction of renewable-dominated electric power systems, renewable energy will become the main power source of power systems in China. How to ensure the accommodation of renewable energy will also be the core issue in the future development process of renewable-dominated electric power systems. In this context, shared energy storage (SES), a novel business model combined with energy storage technologies and the sharing economy, has the potential to play an important role in renewable energy accommodation scenarios. This paper systematically organizes the application prospect, development status and key technologies of SES in the renewable energy accommodation scenario in the context of China, providing helpful references for the promotion of the business model. Firstly, a typical SES framework for renewable energy accommodation is described, and three basic forms of SES in this scenario are presented. Moreover, the application prospect of SES in the renewable energy accommodation scenario is quantitatively analyzed based on the renewable energy generation planning under the carbon peaking goal and the current guarantee mechanism of renewable energy accommodation. Furthermore, the rules for energy storage systems that provide the peak-regulation ancillary service in typical regions and provincial administrative regions in China are summarized, and the development status of SES in the renewable energy accommodation scenario is analyzed, combined with the actual market data. Finally, the key technologies to promote the further development of SES for renewable energy accommodation are presented.

Sharing energy storage (SES) is a novel business model in order to increase the profits and improve the utilization rate of idle energy storage facilities. On the other hand, blockchains can be competently applied in the transaction and operation of SES because of distributed network architecture, traceability and tamper proof. In this paper, a management model of SES based on proxy signatures in the blockchain environment is proposed. Many management models including the principal-agent model are analyzed for SES in terms of benefit, cost, resources, and so on. Moreover, a blockchain framework and a typical transaction process of SES is presented. Finally, a proxy signature mechanism based on the ElGamal algorithm is proposed in order to address the problem that the signature power of nodes cannot be transferred on blockchains. Simulation results show that the proposed proxy signature mechanism can achieve the delegation of digital signature power under the premise of security and reliability, which is suitable for the management model of SES on blockchains.

Typhoons and other natural disasters affect the normal operation of power systems thus it is an important goal for strong and intelligent power grid construction to improve the ability of power systems to resist typhoons and other natural disasters. Especially, an effective coordinated and optimized dispatching strategy for a multi-source power system is greatly helpful to cope with the impact of typhoons and other natural disasters on power system operation. Given this background, a typhoon wind circle model considering the temporal and spatial distribution of typhoons is established to obtain the input wind speed of the wind farm at first. Second, based on the initial input wind speed of wind farms, a typical scenario set of wind power output is constructed to reflect its fluctuation and uncertainty. Next, an optimal coordinated dispatching model of a multi-source power system with wind, hydro and thermal power based on the conditional value at risk (CVaR) is established with the target of minimizing the total cost of system dispatching, in which a 72 h pre-dispatching mode is studied to optimize the system operation for 72 h on the day before, on and after the typhoon. Finally, a revised 24-node transmission network system in a coastal area with typhoon is served as a case for demonstrating the effectiveness of the proposed model, and the simulation result shows that the proposed model could take the advantages of the coordination and complementarity of multi-sources power system and decrease the total cost of system dispatching and improve the renewable energy consumption level.

The need to accelerate the innovation and application of the supply chain has been suggested by the State Council of China. To solve the problem of data isolation caused by privacy protection in the power material supply chain, a data traceability and sharing mechanism based on blockchain is designed in this paper. Firstly, the existing problems of the power material supply chain are introduced, and the applicability of blockchain in the power material supply chain in view of these problems is analyzed. Secondly, blockchain-based power material supply deployment and application structures are proposed. Then, considering the problem of data isolation in the material inspection and distribution links between suppliers and the material company, a data traceability mechanism based on blockchain is designed to provide evidence for the data authenticity and a proxy re-encryption method is used to ensure security and privacy in data sharing. Finally, the effectiveness of the proposed data traceability and sharing mechanism is verified using the Hyperledger Fabric platform for power material case studies. The simulation results show that the combination of proxy re-encryption and blockchain technology in the power material supply chain can confirm the validity of the historical data and keep the private data of the material company confidential, so as to realize the traceability and sharing of the power material supply data.