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Fine grid management is one of the important development directions of transportation planning that has not been fully considered in previous literature. This paper explores the application of the fine grid management method in transportation planning. Based on a case study of Chuanhui, China, this paper proposes a data-driven fine grid partitioning method for determining traffic analysis zones (TAZs). The TAZs are partitioned based on quadrilateral and hexagonal grids. This paper also summarizes a set of criteria for evaluating the impact of different fine grid partitioning methods based on the geographically and temporally weighted regression (GTWR) model. The results show that our fine grid partitioning method for determining TAZs based on quadrilateral grids can achieve a relatively low level of predicted value bias and variable correlation degree bias when the number of TAZs is larger, and it has obvious advantages. Finally, policy implications are proposed to promote the refinement of transportation planning. [ABSTRACT FROM AUTHOR]

Advanced grid technology represented by smart grid and energy internet is the core feature of the next-generation power grid. The next-generation power grid will be a large-scale cyber-physical system (CPS), which will have a higher level of risk management due to its flexibility in sensing and control. This paper explains the methods and results of a study on grid CPS's behavior after risk. Firstly, a behavior model based on hybrid automata is built to simulate grid CPS's risk decisions. Then, a GCPS risk transfer model based on cooperative game theory is built. The model allows decisions to ignore complex network structures. On this basis, a modified applicant-proposing algorithm to achieve risk optimum is proposed. The risk management model proposed in this paper can provide references for power generation and transmission decision after risk as well as risk aversion, an empirical study in north China verifies its validity. [ABSTRACT FROM AUTHOR]

The accuracy of doubly fed induction generator (DFIG) models and parameters plays an important role in power system operation. This paper proposes a parameter identification method based on the hybrid genetic algorithm for the control system of DFIG converters. In the improved genetic algorithm, the generation gap value and immune strategy are adopted, and a strategy of "individual identification, elite retention, and overall identification" is proposed. The DFIG operation data information used for parameter identification considers the loss of rotor current, stator current, grid-side voltage, stator voltage, and rotor voltage. The operating data of a wind farm in Zhangjiakou, North China, were used as a test case to verify the effectiveness of the proposed parameter identification method for the Maximum Power Point Tracking (MPPT), constant speed, and constant power operation conditions of the wind turbine. [ABSTRACT FROM AUTHOR]

• The five functions of government-market dynamics are critical to SG deployment. • China and Japan differ in the ways that government actors engage market actors. • China's approach is hierarchical; Japan's approach is more systemic. • National contextual differences can explain the variety of dynamics and outcomes. • Optimising government-making dynamics is vital to realising SG potentials. Smart grids (SGs) have been increasingly regarded as an enabling technology for post-Fukushima energy transitions. SGs require new policies and market infrastructures to deliver their potential, but the roles of governments in increasingly market based energy systems have not been well conceptualised. Advancing the socio-technical energy transitions literature, this paper proposes five functions of government-market dynamics in an integrated framework, and applies the framework in the field of smart grid developments in two Asian countries, China and Japan. Based on interviews with 38 key stakeholders, this study has three main findings. First, both countries have in common that the five functions of government-market dynamics are critical in developing, diffusing and utilising SG technologies. Second, China and Japan exhibit distinctive characteristics in the ways that government actors engage market actors. While the Chinese approach is more hierarchical, fragmented and homogenous led by two monopolised grid companies, the Japanese approach is a relatively systemic, bottom-up, and heterogeneous system mainly operated through four large-scale SG demonstration projects. Third, national contextual differences, most notably the advancement of electricity market reforms, explain the variety of the dynamics and outcomes. This paper concludes that consideration of optimising government-market dynamics is vital to create conductive conditions for realising the potential that SGs can offer in energy transitions. [ABSTRACT FROM AUTHOR]

An increased use of the high-voltage direct current (HVDC) technologies can have important effects on frequency performance and voltage stability of the receiving-end grid during normal operation as well as during blocking failure. The main reasons are the inherent characteristics of the HVDC such as its much larger capacity than thermal plants and lack of voltage supporting ability to the alternating current (AC) grid. These has led to new challenges for AC/direct current (DC) power grid operators in terms of ensuring power system security. To address these challenges, a unit commitment (UC) of the receiving-end in the AC/DC hybrid grid is presented in this paper. In the proposed model, primary frequency modulation constraints are added to provide sufficient capacity for HVDC blocking. Besides, grid security constraint after secondary frequency regulation is also considered because HVDC blocking failure would cause large range power transfer and transmission lines overload. Meanwhile, voltage stability constraints are employed to guarantee enough voltage supporting capacity from thermal plants at the HVDC feed-in area. Based on the characteristics of the model, Benders decomposition and mixed integer programming algorithm are used to get the optimal transmission power of the HVDC and schedule of thermal units. The study is done by considering the IEEE-39 and Jiangsu power grid in eastern China, containing two HVDC transmission projections respectively. The results are also validated by simulation of different HVDC blocking failure scenarios. [ABSTRACT FROM AUTHOR]

As subsidies continue to fall, the technology and cost performance of distributed photovoltaic (PV) determines the progress of its grid parity. Based on the discussion of technology and cost, this paper analyzed the economic performance of China's distributed PV industry by utilizing the two indicators of levelized cost of energy (LCOE) and internal rate of return (IRR). The results show that: firstly, the current external environment is generally conducive to the development of distributed PV, but there are still some constraints. Secondly, with the decrease of unit investment cost, distributed PV can achieve the goal of parity before 2025. Thirdly, distributed PV projects in the three types of solar energy resources all have high IRR, and the economic performance is better for the projects with high proportion of spontaneous self-use. At the end of the paper, policy recommendations are offered as references for the government. • We comprehensively analyzed the technology and cost performance of China's distributed PV. • We focused on the trend and decline path of China's distributed PV costs. • The LCOE of distributed PV in China is expected to achieve full parity in 2025. • Except 100% grid-connected mode, the IRR of distributed PV power plants in three areas is higher than 8% which has shown good economic benefits. [ABSTRACT FROM AUTHOR]

During the '13th Five-Year Plan period' (2016-2020), one of the main targets for China's energy strategy is to develop a new generation of power system, integrating high shares of renewable energy sources. This implies that the technology industrialisation of microgrid powered by distributed generation of renewable energy is becoming crucial. This paper carries out a comprehensive study of the status and challenges of developing microgrid, based on case studies of demonstration projects of microgrid in China during different developmental stages. The focus is on the effects of government policies, technical innovations and changes in the business model of electricity market on the promotion of microgrid in China and the reformation of electricity market in China. The ultimate target for the reformation of power system in China is to finish the transformation from a linear business model of centralised power system. [ABSTRACT FROM AUTHOR]

Some achievements have been made in the economic development of coastal rural leisure industry in China, but there is still a certain gap between the overall level and the economic development level of international coastal rural leisure industry. This paper puts forward a path selection model of coastal rural leisure industry economic development based on grid sub-regional feature matching, adopts irregular triangulation network planning method to search the economic development path of coastal rural leisure industry oriented to Internet of things technology, and establishes a subregional feature matching model of coastal rural leisure industry economic development path. The adaptive grid block fusion method is used to plan and design the economic development path of coastal rural leisure industry, and the statistical characteristics of node positioning of coastal rural leisure industry economic development path are extracted. Combined with the relevant fuzzy constraint method, the economic development path selection of coastal rural leisure industry is realized, and the adaptive equilibrium ability of coastal rural leisure industry economic development path selection is improved. The simulation results show that this method has good adaptability and high equilibrium level in the economic development path selection of coastal rural leisure industry, and has good application value in the path selection and planning of coastal rural leisure industry economic development. [ABSTRACT FROM AUTHOR]

• The utility death spiral of China power sector due to grid-abandoners is deeply researched. • The Bass diffusion model is applied to evaluate the installation of rooftop PV systems and hybrid PV-BESS. • The utility death spiral is unlikely to occur under low-solar radiation in China's power sector. • Several significant inner drivers of rooftop PV systems and hybrid PV-BESS expansion are investigated. • The high-solar radiation, falling costs of PV and BESS, and increasing retail price can provoke grid abandonment through rooftop PV systems and hybrid PV-BESS expansions. Nowadays, owing to the price and technological advantages, photovoltaic (PV) and battery energy storage systems (BESS) have rapidly developed in China. The self-production and consumption of PV and BESS are causing consumers to abandon the power grid. However, this potential of grid abandonment in China's power sector remains unclear. Therefore, this paper deeply investigates the interaction between grid abandonment and the distribution price of utility, namely the utility death spiral to explore the potential in China. A method based on the innovation diffusion theory is proposed to reveal the causal loop of the death spiral. The Bass diffusion model, an approach of innovation diffusion theory, is applied to estimate the installations of rooftop PV systems and hybrid PV-BESS. After that, the distribution price, grid utilization level, and utility recovery cost based on China's price structure are evaluated. Sensitivity analyses are conducted to investigate several significant inner drivers of the rooftop PV systems and hybrid PV-BESS expansions. Results indicate that the utility death spiral is unlikely to occur in China with low-solar radiation, while it will occur in a high-solar radiation scenario with 57% penetration of rooftop PV systems. Compared with the return rates of the utility requirement, the cost reduction of PV and BESS, and even a 1% growth in the retail price cause the death spiral. When the death spiral occurs, the permeations of PV and BESS in the cost reduction scenario are 51% and 56%, while the permeations are 52% and 51% in the scenario of 1% growth of the retail price. Additionally, several possible solutions to avoid the death spiral are discussed, such as discriminatory prices, business models, price mechanisms, and support mechanisms. [ABSTRACT FROM AUTHOR]

After we developed a saturated iron core type 35 kV/90 MVA superconductive fault current limiter and installed the device in a transmission network at Puji substation of China Southern Power Grid for live-grid operation in 2007, we continued our efforts in advancing this technology. A 220 kV/300 MVA device has been designed, manufactured and factory tested. This device differs from the 35 kV device in its form of electrical insulation even though the two devices have the same working principle and similar core structure. Improvements in the dc magnetization circuit and the cryogenic system were also achieved. This 220 kV/300 MVA superconductive fault current limiter has been installed and has passed all field tests at Shigezhuang substation in Tianjin, China. Trial operation is underway. This paper introduces the major design parameters, key functional specifications and some testing results of the device. [ABSTRACT FROM AUTHOR]

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The Shangdu power plant has four 600-MW turbine-generators connected to the North-China Grid through two 500-kV transmissions, which are compensated with 45% fixed series capacitors. Extensive studies conducted on the system model indicate that the system suffers from multimodal subsynchronous resonance (SSR). To solve the problem, a countermeasure is developed by combining the supplementary excitation damping control (SEDC) and the torsional stress relay (TSR). In this paper, the characteristics of the SSR problem are investigated. Then the developed SEDC is presented. To validate the effectiveness of the proposed SEDC as well as the results of model studies, field tests were conducted under various operating conditions. The tests fully exposed the realistic threat of SSR in the system. Meanwhile, it is demonstrated that the developed SEDC can improve torsional damping significantly, and thus solve the multimodal SSR problem effectively. This is the first time in China that practical SEDCs have been developed and their ability to mitigate multimodal SSR has been verified in a real series-compensated system. [ABSTRACT FROM AUTHOR]

Due to its characteristics of nearby power generation, grid-connection, conversion and use, rooftop photovoltaic power generation has formed the advantages of less investment, flexible, efficient and environmental protection, with broad prospects for development. Therefore, studying its economic performance is of great significance to investment decision and policy improvement. Under the current technical cost and policy conditions of rooftop photovoltaic in China, this paper constructs a cost-benefit analysis model considering the impact of inflation on cash flow. The results show that: For small rooftop photovoltaic in China, first of all, under the existing subsidy price and cost, its investment payback period is short and the risk is low. Secondly, the average internal rate of return is more than 10%, and the levelized cost of electricity is 0.2727–0.5573CNY/kWh, so the economic performance is good. Then, although the subsidy price has been lowered twice in a row in 2018, its economic performance is still relatively good. Finally, in the economic performance analysis of rooftop photovoltaic, besides the influence of power generation capacity, loan interest rate, construction cost and other factors, the time value of capital and inflation are also factors that cannot be ignored. • The analysis is based on current policy and technology levels. • The object of analysis is industrial and commercial household photovoltaic. • The inflation rate is added to the formula for calculating various economic indicators. [ABSTRACT FROM AUTHOR]