With the wide application of energy storage equipment in modern electronic and electrical systems, developing polymer-based dielectric capacitors with high-power density and rapid charge and discharge capabilities has become important. However, there are significant challenges in synergistic optimization of conventional polymer-based composites, specifically in terms of their breakdown and dielectric properties. As the basis of dielectrics, all-organic polymers have become a research hotspot in recent years, showing broad development prospects in the fields of dielectric and energy storage. This paper reviews the research progress of all-organic polymer dielectrics from the perspective of material preparation methods, with emphasis on strategies that enhance both dielectric and energy storage performance. By dividing all-organic polymer dielectrics into linear polymer dielectrics and nonlinear polymer dielectrics, the paper describes the effects of three structures (blending, filling, and multilayer) on the dielectric and energy storage properties of all-organic polymer dielectrics. Based on the above research progress, the energy storage applications of all-organic dielectrics are summarized and their prospects discussed.

The mechanism of overvoltage formation in the breaking process of a dry-type air-core shunt reactor (DTACSR) is studied in this paper. In addition, the effect of the overvoltage on the interturn insulation characteristics of the DTACSR is also discussed. Based on the actual working condition of a 66 kV DTACSR used in the Chinese power system, a three-phase simulation model and an equivalent circuit are proposed. The maximum chopping overvoltage and reignition overvoltage are obtained through the combination of theoretical analysis, simulation, and data fitting. An overvoltage accumulation test of the interturn insulation specimens is carried out with our established test platform, and the characteristic parameters of the interturn insulation specimens of the DTACSR in different stages of aging are measured. The results show that the combined method is very effective in evaluating the switching overvoltage of the DTACSR. Compared with the traditional single-phase circuit model, the proposed three-phase circuit model obtains a more accurate overvoltage equation. During the breaking process of a DTACSR, a chopping overvoltage with an amplitude greater than 5 p.u. and a reignition overvoltage with an amplitude greater than 8 p.u. may form. The cumulative effect of the overvoltage causes aging of the interturn insulation, and the degree of aging becomes more serious as the amplitude of the overvoltage increases.INDEX TERMS Dry-type air-core shunt reactor, overvoltage, interturn insulation, cumulative effect.

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All‐organic dielectric polymers with excellent capacitive energy storage capabilities have great potential applications in the fields of modern electronics and power systems. However, it is still challenging to achieve simultaneous improvements in both energy density and efficiency in these all‐organic dielectric polymers. This work proposes the all‐organic bilayer composite films with ferroelectric polymer poly(vinylidene fluoride‐hexafluoropropylene) (P(VDF‐HFP)) and linear polymer fluorene polyester (FPE) as the energy storage dielectrics for film capacitors. Compared with pure FPE films, the bilayer composite films exhibit improved dielectric constant. What is more outstanding is that the bilayer composite films has higher energy storage density and energy storage efficiency under the same electric field compared with the pure P(VDF‐HFP) film. Particularly, an outstanding Ud of 7.00 J/cm3 accompanied with great η of 95.9% has been delivered in the resulting bilayer composite films via optimizing the P(VDF‐HFP) content (22.2 vol%) at 520 kV/mm. The compatibility of the two polymers was discussed by simulating the potential distribution of the two polymer molecular chains. This work opens up a new way to prepare compatible polymer flexible capacitor films on a large scale.

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