Collusion-Proof Mechanism in Compensation for Failed Generic Technological Innovation Projects: Based on Information Topology

Against the backdrop of innovation fault-tolerance, government compensation for failed generic technological innovation projects is beneficial to stimulate re-innovation behaviour. However, considering the information asymmetry, a collusion tendency exists between the compensated party and the evaluator during the process of compensation. To prompt the government to build collusion-proof mechanisms to reduce collusion loss, the evolutionary game method was used to build replicated dynamic equations and a Jacobian matrix of both sides based on the information topology between the conspirators and regulator. Through the evolutionary equilibrium analysis and numerical simulation, evolutionary stability strategies (ESS) under different topological relationship information (non-intersect, partial intersect, and inclusive type) were found. Results show that the collusion behaviour can be effectively restrained when the government is unaware of collusion information, the net defense income is positive, and the penalty threshold is the product of the net collusive income and the ratio of the collusive and regulatory information. With the increasing amount of collusive information available to the government, the conspirators tend to adhere to moral principles subject to strict regulation. In addition, the moderating effect of penalty factor is positively correlated with the private information possessed by both sides. The conclusion is beneficial to provide theoretical support for optimizing the government-led compensation mechanism for failed generic technological innovation projects

Surface Potential Decay on Material Samples Taken From In-service Aged (U) HVDC Silicone Rubber Composite Insulators

Surface potential decay characteristics of specimens extracted from in-service aged and reference UHVDC composite insulator sheds are reported and analyzed in this paper. In the experiments, surfaces of the insulator samples were charged by dc corona and the decay was recorded utilizing a non-contact technique. In addition, surface and bulk conductivities of the specimens were determined and used for analyzing by means of computer simulations their impact on the potential distribution profiles and its decay. Based on the performed experiments, trap density distributions, mobility of charge carriers and field dependent bulk conductivities are deduced for the investigated samples with the aim to evaluate the ageing severity

Ultrasonic phased array detection of internal deffects in composite insulators

To reduce the risk imposed by use of defected composite insulators on the operation of power grids, this paper introduces a nondestructive ultrasonic phased array (UPA) technique that allows effectively test such insulators. The method offers a great potential by reducing inspection time as well as allowing for analyzing components characterized by a complex geometry. The UPA inspection system utilizes an open-ended rectangular waveguide sensor, operating at frequency of 2.5 MHz. The system is simple, safe and relatively inexpensive. In this work, samples of silicone rubber composite insulators with various types of detects are studied and the obtained results show that void defects in the bulk of the insulator housing are easiest to be detected. Holes under insulator sheds can also be detected by the edge of scanning range. For the defects near the core-shed interface, the detection becomes possible by comparisons with sample without defects

Ultrasonic phased array detection of internal deffects in composite insulators

To reduce the risk imposed by use of defected composite insulators on the operation of power grids, this paper introduces a nondestructive ultrasonic phased array (UPA) technique that allows effectively test such insulators. The method offers a great potential by reducing inspection time as well as allowing for analyzing components characterized by a complex geometry. The UPA inspection system utilizes an open-ended rectangular waveguide sensor, operating at frequency of 2.5 MHz. The system is simple, safe and relatively inexpensive. In this work, samples of silicone rubber composite insulators with various types of detects are studied and the obtained results show that void defects in the bulk of the insulator housing are easiest to be detected. Holes under insulator sheds can also be detected by the edge of scanning range. For the defects near the core-shed interface, the detection becomes possible by comparisons with sample without defects

Surface Potential Decay on Material Samples Taken From In-service Aged (U) HVDC Silicone Rubber Composite Insulators

Surface potential decay characteristics of specimens extracted from in-service aged and reference UHVDC composite insulator sheds are reported and analyzed in this paper. In the experiments, surfaces of the insulator samples were charged by dc corona and the decay was recorded utilizing a non-contact technique. In addition, surface and bulk conductivities of the specimens were determined and used for analyzing by means of computer simulations their impact on the potential distribution profiles and its decay. Based on the performed experiments, trap density distributions, mobility of charge carriers and field dependent bulk conductivities are deduced for the investigated samples with the aim to evaluate the ageing severity

Surface Potential Decay on Material Samples Taken From In-service Aged HVDC Silicone Rubber Composite

Surface potential decay characteristics of specimens extracted from in-service aged and reference HVDC composite insulator sheds are reported and analyzed in this paper. In the experiments, surfaces of the insulator samples were charged by dc corona and the decay was recorded utilizing a non-contact technique. In addition, surface and bulk conductivities of the specimens were determined and used for analyzing by means of computer simulations their impact on the potential distribution profiles and its decay. Based on the performed experiments, trap density distributions, mobility of charge carriers and field dependent bulk conductivities are deduced for the investigated samples with the aim to evaluate the ageing severity

Dielectric Response Characterization of In-service Aged Sheds of (U) HVDC Silicone Rubber Composite Insulators

Investigations of bulk dielectric properties of specimens extracted from in-service aged and aged UHVDC composite insulator sheds are reported in this paper. The program of the study included measurements of DC conductivity and complex permittivity at frequency range 10-4 – 103 Hz at various temperatures in dry and wet (water immersion) conditions. The obtained results are analyzed by considering a combination of relations describing various dielectric relaxation modes in dielectrics, included three Cole-Cole types of responses and a hopping process. The hopping has the strongest impact on the responses in the whole frequency range. Two of the Cole- Cole responses appearing in the low frequency range are attributed to Maxwell- Wagner-Sillars relaxations at macroscopic and mesoscopic levels; first one representing interfacial polarization at the border between specimen and air gap in the electrode arrangement, while the second one is attributed to the charge relaxation at filler boundaries and internal cavities in the polymeric materials. The third Cole-Cole process, active at higher frequencies, is considered as a sign of polymer degradation, as it shifts with the ageing to higher frequencies. Based on the results of this study, it is claimed that dielectric response measurements on specimens of in-service aged composite insulator sheds can provide useful information on the degree of material degradation. In addition, a water immersion test in combination with such measurements may be a good way to enhancing the observed changes

Space charge behavior in silicone rubber from in-service aged HVDC composite insulators

Space charge behavior in sheds removed from service aged 500 and 800 kV HVDC silicone rubber insulators and compared to a stored reference insulator is reported in this paper. The aim of this investigation is to evaluate the material aging. The investigations are made under electric field of \ub120 kV/mm at room temperature using pulsed electro-acoustic technique. Based on the results, the electric field distribution and mobility of charge carriers, considering the contributions of de-trapping process from both shallow and deep traps, are deduced. It is concluded that space charge concentration in the aged material increases compared to that in the reference material and the dynamics of the charge decay changes. The understanding of this behavior provides a means of possibility assessing insulator material aging

Tunable nonlinear conductive behavior without percolation threshold and high thermal conductivity of epoxy resin/SiC ceramic foam co-continuous phase composites

Smart dielectrics with self-adaptive capabilities can exhibit desirable electric field-grading performance as the applied electric field exceeds a critical value. However, the conventional approaches to such dielectrics need heavy doping rate, which will not only increase the interface thermal resistance and limit the improvement of thermal conductivity, but also severely sacrifice the mechanical property. In this contribution, a new type of electric field-grading co-continuous phase composite (EP/SiCcf) composed of epoxy resin and SiC ceramic foam was prepared to realize tunable nonlinear conductive performance, while simultaneously improving thermal and mechanical properties. Results show that there is no percolation threshold for all EP/SiCcf composites. The volume loadings of EP/SiCcf composites range from 8.7 vol% to 15.6 vol%, while the nonlinear coefficient subjected to potential barrier height increases from 2.1 to 4.5 and the switching field tuned by barrier width decreases from 1008 kV/mm to 686 kV/mm. The EP/SiCcf40 still exhibits sharp thermal conductivity enhancement of about 1000% and glass transition temperature enhancement of 10.8 °C. The surface temperature fluctuation over time during heating and cooling has illustrated the prospective application of thermal management capability. In addition, the dynamic mechanical analysis reveals that all EP/SiCcf composites have the significantly improved storage modulus and crosslinking density ascribed to the intact SiC skeleton. The novel co-continuous phase composite provides a new approach for global enhancement of smart dielectric composites in potential applications.This work was supported by the National Natural Science Foundation of China (No. 51977084)