Recently, renewable energy has received considerable attention worldwide due to environmental problems such as climate change. However, there are still many problems to be solved to increase the penetration level of renewable energy sources in a power system. Above all, a power system with a high renewable penetration level requires an entirely novel operational strategy and control approach to achieve reliable operation by considering the intermittency of variable renewable energy sources. This paper proposes power-sensitivities-based indirect voltage control of renewable energy generators with power constraints. The proposed method realizes seamless control of the voltage by compensating with the reactive power if the real power of the distributed generator (DG) is insufficient due to its intermittency. To achieve the proposed method, the real and reactive power references of DGs are initially operated based on the power sensitivities between generation and loads if all the DGs operate within the power constraints. However, if at least one of the DGs reaches its constraint limit, the references can be modified using other sensitivities between real and reactive power generation enabling indirect voltage control of DGs. Therefore, a high level of renewable penetration in power systems can be accomplished with the proposed method. The proposed method is verified with several case studies that are based on a microgrid with practical data from a real island power system. Verification is carried out using the power system computer aided design and electromagnetic transient including DC (PSCAD/EMTDC™) simulation software.

An interleaved zero-voltage zero-current switching (ZVZCS) high step-up DC-DC converter is proposed for modern photovoltaic power generation systems. The proposed converter can achieve high voltage conversion gain without operating under extreme duty cycles. The voltage conversion gain can be readily adjusted by selecting different numbers of the diode-capacitor multiplier (DCM) cells in the circuit at the design stage. Moreover, with the passive snubber circuit in the proposed converter, all power switches and diodes in the DCMs can achieve zero-voltage turn-off and zero-current turn-on, which effectively reduces switching losses and increases the overall converter efficiency. The operational principles and analysis of the performance analysis with two DCMs are presented for demonstrative purpose. The effectiveness of the proposed ZVZCS DC-DC converter is validated using an 800W experimental prototype.

To better predict the high-frequency switching operation of the half-bridge circuit in power converters, the value of the parasitic elements of these devices must be accurately evaluated. A new MOSFET-based half-bridge circuit parasitic inductances extraction method using two-port S-parameters is proposed in this paper. By changing the terminal connection of the half-bridge circuit, we can treat it as several different two-port networks, and then detailed network analysis can be performed on it. The parasitic parameters of multi-terminal actual circuits such as half-bridge can be extracted accurately and quickly through the simple measurement steps and calculations of the proposed method.

With the formation of the concept of Cyber Physical Social Energy System, social and human factors become more prominent and stay at an important position. The interaction between the energy system and the social system will have a huge impact on the development of the energy system. As one of the hot topics in the CPSES area, the influence of the transformational leadership on the team green behaviors has attracted extensive attention of the academics. By influencing the enterprise behaviors through the leadership behaviors, it can promote the development of the Power Energy Internet Platform Technology and accelerate the application of the technology. Based on the Affective Events Theory, this article discusses the influencing mechanism and key factors of the transformational leadership on the team green behaviors. A total of 3 821 employees and their supervisors from 457 work teams in 19 energy enterprises in the Pearl River Delta region were tracked. This article finds that the transformational leadership positively affects the team green behavior. The connectedness to nature plays a positive mediating role between the transformational leadership and the team green behavior. The work features has a negative regulating effect on the relationship between the transformational leadership and the connectedness to nature, while the team task performance has a positive regulating effect. This article expands the application scope of the AET theory, discusses details of the influence mechanism between the transformational leadership and the team green behaviors, and provides a direction for further theoretical exploration.

Named Data Networking (NDN), an extension of the Content-centric network (CCN), is not an unfamiliar word. It is considered as one of the promising future network architecture. NDN focuses on naming the content regardless of end-to-end device addresses. NDN has been adopted for vehicular ad hoc networks (VANETs), and it has promising results. Though NDN has robust architecture, many challenges still exist, including consumer and producer mobility, naming, and Interest and data packet flooding. In vehicular NDN, the consumer vehicle broadcasts an Interest packet for the required content. The producer vehicle or an intermediate vehicle that contains the required content in its cache replies with the data packet after receiving the Interest packet. The data packet reaches the consumer vehicle via simple broadcasting. This data broadcast creates congestion in the network and needs to be mitigated. In this work, we coin a new term called name centrality, and using it along with received signal strength, we have proposed a novel scheme to control data broadcast storm in vehicular NDN. The scheme uses the mentioned two parameters to allow only a subset of potential forwarding vehicles to rebroadcast the data packet instead of all the vehicles which receive the data packets. This reduces the copies of data packets processed and propagated in the network and hence alleviates congestion. The scheme is evaluated through extensive simulation under different scenarios, and it outperforms the legacy schemes. The comparison has been made in terms of copies of total data packets processed, Interest satisfaction delay, and Interest satisfaction rate. Compared to other approaches, the proposed scheme reduced the average copies of data packets processed by 55% and 20% with varying Interest packet rates and 58% and 19% with varying vehicle speed.

The Notarial Office(NO), working on providing various essential certificates, still relies on manual handling and requires paper materials from other government departments. That brings lots of inconvenience. The Notarial Office rejects non-local paper materials for their lower credibility in the local place and then cannot provide cross-borders services. It also easily cause sensitive information leakage as copies of paper materials have been stored. In this case, a blockchain-based system is suitable to address challenges in this scenario because of its advantages (e.g, decentralized, immutability, transparency, auditability). We implemented this system on top of the Hyperledger Fabric. Moreover, we replace manual operations with smart contracts, set extra ledgers to off-load different types of transactions and provide encryption for private information when needed. In the end, we get an expected result. That is, the modification outperformed the unmodified network in experiments.