The User-defined Modeling Method of Power System Components Based on RTDS-CBuilder

This paper puts forward a method to design the user-defined component based on the user-defined modeling environment CBuilder of RTDS simulator. And also develops the user-defined component model with algorithm described by C language, visual graphics appearance, and the component function. And it generates the dynamic link library which has the same execution efficiency as that of the included model of RTDS. This paper takes the IEEE type EXST1 static excitation system as an example to build the user-defined component. The closed-loop tests on the user-defined component and the included one of RTDS are performed to examine the accuracy of the proposed method. By comparison, the test results show that the external characteristics of the user-defined component and the included model of RTDS are basically the same in the initialization process, the step process of the terminal voltage reference value and the case of the large disturbance.

How do green product exports affect carbon emissions?Evidence from China

Green development has become an increasingly important global initiative.Therefore,this study focuses on the impact of green product exports on carbon emissions in China.Firm-level datasets are used to estimate provincial green product exports between 2001-2016.This study estimates the impact of green exports on carbon emissions using the system generalized method of moments methodology.In addition,heterogeneity and asymmetry of the nexus are explored.The following findings are highlighted:(1)China’s green product exports show a significant upward trend during the study period;(2)increased green product exports,especially those of high-technology manufacturers,can effectively mitigate CO_(2) emissions;(3)the influence of green product exports on carbon emissions is regional heterogeneous but consistent across quantiles;and(4)technique and scale effects are significant mediators,whereas the composition effect is not.These findings provide new evidence supporting methods to mitigate China’s CO_(2) emissions by adjusting green product export structures.

Study on Reproductive Growth Characteristics and Seed Germination of Eucalyptus dunnii in Sichuan Province

Studying the flowering development and seed germination of Eucalyptu dunnii and mastering the reproductive growth law can provide a theoretical basis for seed garden construction. In this study,a blooming plant growing in Zitong County was selected as the experiment subject. The results were as follows： florescence date of Eucalyptus dunnii was Mid-late February to mid to late October. Depending on morphologic change,flowering can be divided into 6 phases： Flower bud differentiation stage,inflorescence formation stage,opercle color change stage,capsule enlargement and shedding ring formation stage,flowering period,seed development stage. The development process of the buds on the same inflorescence was basically the same,the growth of buds near the base of the same branch was faster than that of the top buds,and the development of flower buds in different positions was random. There were 3-4 ovary cavities in a capsule. The number of shriveled seeds was far more than the number of effective seeds,and the average of each capsule contained five normal seeds which could develop into seedlings.

Analysis on the Transfer Characteristics of Rogowski-coil Current Transformer and Its Influence on Protective Relaying

This paper systematically analyzes the transfer characteristics of the Rogowski-coil Current Transformer and its effect on protective relaying through theoretical analysis, experiments and simulations. The frequency characteristics and transient characteristics of Rogowski transducer and Rogowski-coil Current Transformer are deeply analyzed based on the physical structure of the transformer.?It is revealed that broad bandwidth of the transformer can improve the performance of protective relaying, and the bandwidth is determined mainly by the parameters of the Rogowski transducer and signal processing circuits. It is also discovered that the measurement errors of transient current mainly depend on the abilities for the current transformer to reproduce an accurate replica of the decaying dc components, which is mainly decided by the decay time constant of the aperiodic component of transient current and the parameters of the integral unit. Finally, some measures are proposed for the performance improvement of Rogowski-coil Current Transformer to meet the requirements of protective relaying system in terms of structural design and testing standards.