Dielectric Strength Values Research Articles

Selection of performance indicators on dielectric strength and viscosity for chlorinated polyvinyl chloride with N-Methyl-2-pyrrolidone: Optimization using central composite design-response surface methodology

N-methyl-2-pyrrolidone is a highly polar aprotic solvent that is frequently utilized across a broad range of applications in industry. The composition of chlorinated polyvinyl chloride is commonly flame-resistant and mechanically strong. In this research, the central composite design technique uses response surface methodology to perform a parametric study. The effect of the input variables wt.% (16%, 20%, 24%), stirring speed (300, 600, 900 r/min), and stirring time (20 min, 30 min, 40 min) on the output responses (dielectric strength kV/mm, and viscosity Pascal) were examined. The output responses were recorded during the experiments according to the experimental design. The factors impacting the response were identified through analysis of variance. According to the predicted vs. actual diagram, the confirmed experiments fit well with the predictions. Based on the response surface, the parameter interaction profile was analyzed. According to the contour plots related to each interaction, the maximum value can be achieved within different stirring parameters. Based on the result of optimization, the optimum values of dielectric strength and viscosity were found in (wt.% of chlorinated polyvinyl chloride—18.101%), (stirring speed—664 r/min), (stirring time—21.860 min). The output response obtained from the response surface methodology is the dielectric strength (18.5 kV/mm) and viscosity (37.67 Pa).

The Effect of Humidity and Temperature on Flashover in High Voltage Transmission Line Ceramic Insulators

This research aims to determine the flashover voltage on the surface of porcelain insulators on 150 kV transmission lines located in Payakumbuh, where the insulators are contaminated with dust and moss due to the effects of temperature and humidity. The experiment is carried out with only up to seven insulator plates due to the limitations of the available apparatus. For the further testing, a trend analysis is applied. According to the experimental results, a rise in temperature around the insulator will increase the flashover voltage value and accelerate the potential for a flashover event. This happens because high temperatures can reduce the insulator's dielectric strength and insulation resistance and increase the risk of flashover. The dielectric strength values decreased with an average decrease of 44.62% per insulator plate for dusty insulators and 45.08% for each plate for mossy insulators. The results aim to minimize flashover on transmission lines in hilly areas with relatively high contamination.

STUDYING SOME OF PHYSICAL PROPERTIES FOR POLYMER REINFORCED WITH CHOPPED CARBON FIBERS (CCF) COMPOSITES

The research includes the study of some physical. Properties (thermal conductive and dielectric strength) for two types of polymer composites; epoxy resin (EP) reinforced by chopped carbon fibers (CCF) and unsaturated polyester resin (UPE) reinforced by chopped carbon fibers at different weight percentage (1%, 3%, 5%, 7%). Hand –lay up. Method was used to prepare sheets of composites (EP, UPE, EP/CCF, and UPE/CCF) on. glass mold which were cut according to the standard dimensions of the thermal conductive and dielectric strength tests specimens. The results showed that the. Sample of UPE/CCF have highest values of thermal conductive at weight. percentage (7%) compared with prepared samples at other weight percentage. Also the results showed that the thermal conductive of. Pure UPE and EP increased with increase in weight percentage of carbon fibers addition. On the other hand, the results showed that the polyester composites have higher values of thermal conductive compared with epoxy composites. Also the results showed that higher value of dielectric strength at weight. Percentage (1%) for both types from prepared composites of carbon fibers.In addition, the results showed that the polyester composites have higher values of dielectric strength compared with epoxy composites.

Effect of doping ferroelectric BaTiO3 nanoparticles on dielectric, electro-optical, and ionic properties of antiferroelectric bent-core liquid crystal

Nano-doping in polar bent-core liquid crystals is the topic of current interest for designing multifunctional smart materials. Here, we study the effect of doping of two different-sized (5–15 nm and 50–70 nm) ferroelectric BaTiO3 nanoparticles on the dielectric, electro-optical and ionic properties of antiferroelectric smectic A bent-core liquid crystal. Doping with both the sizes of nanoparticles results in lowering of the transition temperature of the liquid crystal mesophases. Both, the pure as well as doped samples show a soft mode in their antiferroelectric smectic A phase. In comparison to pure liquid crystal, the dielectric strength of the soft mode in doped samples is decreased, while their relaxation frequencies show an increasing behavior. Additionally, a decrement has been observed in the spontaneous polarization of the doped samples. A drop in polarization as well as soft mode dielectric strength values in doped samples, simultaneously point to an antiparallel dipole–dipole correlation between the ferroelectric nanoparticles and antiferroelectric liquid crystal molecules. Higher values of molecular mode relaxation frequencies obtained in nano-doped samples indicate a decrement in viscosity and dilution of pure liquid crystal. An important electro-optical parameter, the response time shows a remarkable decrement for the higher size (50–70 nm) nanoparticles doped sample. An enhancement in direct current conductivity and ion diffusion coefficient is observed for both the nano-doped samples. The smaller size (5–15 nm) ferroelectric nanoparticles reduce the mobile ion concentration and act as ion-capturing agents for the liquid crystal. A systematic investigation of the nano-doped bent-core liquid crystal can catalyze the use of the combined media for faster switching electro-optic applications.

Industrial cutting waste granite dust reinforced cardanol benzoxazine/epoxy resin hybrid composites for high‐voltage electrical insulation applications

AbstractAn attempt has been made to develop hybrid composites from benzoxazine monomer (C‐ddm) hybridized with DGEBA epoxy resin (EP) and reinforced with varying weight percentages (20 wt%, 40 wt%, 60 wt%, 80 wt% and 100 wt%) of glycidoxypropyltrimethoxy‐ silane (GPTMS) functionalized granite dust (GD) obtained from industrial granite cutting and polishing process in order to utilize them for electrical insulation applications. The thermal stability of granite dust reinforced poly(EP‐co‐C‐ddm) composites was studied by TGA analysis. Among the composites samples studied, 100 wt% GD reinforced poly(EP‐co‐C‐ddm) composites possess better thermal stability than that of other neat matrices and composites. Among the composites prepared using varying weight percentages of functionalized GD reinforcement, it was observed that 80 wt% GD reinforced poly(EP‐co‐C‐ddm) composites possesses better hydrophobic character than that of other neat matrices and composites. The value of LOI calculated for neat matrix (poly[EP‐co‐C‐ddm]) and 20 wt%, 40 wt%, 60 wt%, 80 wt% and 100 wt% GD reinforced composites was found to be 22, 28, 34, 40, 43 and 45 respectively. The 80 wt% GD reinforced poly(EP‐co‐C‐ddm) composites possess the higher values of tensile strength and flexural strength of 47 MPa and 140 MPa, respectively than those of their samples. The values of electrical surface resistivity and electrical volume resistivity of all the neat matrices and GD reinforced polybenzoxazine composites were found to be in the order of 1012 and 1013 respectively. The values of dielectric strength obtained from break down voltage (BDV) for neat matrix [poly(EP‐co‐C‐ddm)] and 20 wt%, 40 wt%, 60 wt%, 80 wt% and 100 wt% of GD reinforced poly(EP‐co‐C‐ddm) composites are 15.0, 15.5, 16.5, 17.0, 17.0 and 17.0 kV/mm, respectively. Data obtained from thermal stability, hydrophobic behavior and dielectric studies it was inferred that the hybrid polymer composites developed in the present work can be conveniently used in the form insulators, sealants, adhesives and matrices where application demands at high‐performance industrial and engineering applications.

ANN approaches to determine the dielectric strength improvement of MgO based low density polyethylene nanocomposite

This paper presents the modification occurred to the dielectric strength feature of low density polyethylene compounded with nano magnesia (LDPE/MgO). MgO nanoparticles were prepared using sol–gel technique, MgO filler surface was functionalized to improve the interfacial bonding. Specimen’s groups of composites with different filler concentrations were fabricated by mix blend method. Samples exposed to various salinity media by immersion, dielectric strength test was applied on each set according to relevant ASTM standard with identical testing technique. The results were statistically processed then compared to the pristine material. Tests results utilized to learn Artificial Neural Network in order to acquire the value of dielectric strength of compounds having similar composition but containing different doping amounts or influenced with various salinity level media. The dielectric strength is enhanced by the addition of MgO nanofiller. From the investigation of the obtained results, it is concluded that additives of 1.4% filler concentration by weight is the optimum MgO content for LDPE/MgO nanofiller material. We think that this paper may promote a good researching methodology that gather both empirical work and numerical tools in this field.

Evaluating the dielectric strength of promising SF6 alternatives by DFT calculations and DC breakdown tests

In this paper, a calculation method is proposed to predict the dielectric strength (DS) of gases and the DS of some promising SF 6 alternative gases and their mixtures is further evaluated by DC breakdown tests. The calculation method is based on the density functional theory (DFT), so that the DS of the gases can be obtained by only calculating their molecular parameters, including the average static electronic polarizability and adiabatic ionization energy. The paper also presents the DC breakdown strength of the C 4 F 7 N, C 5 F 10 O, and HFO-type gases, and it is found that the experimental DS values are in good agreement with the calculated values. In addition, DC breakdown tests for gas mixtures are also conducted and their synergistic effect is discussed in detail. The results show that the DS of C 4 F 7 N mixed gases is equivalent to that of pure SF 6 gas even under high pressures, indicating their potential applications in HV electrical equipment. The DS of C 5 F 10 O mixed gas is slightly lower than that of C 4 F 7 N mixed gas. Compared with CO 2 , mixing with air brings stronger synergistic effect in C 5 F 10 O and C 4 F 7 N in our experiment. The DS of HFO mixture is substantially less than that of SF 6 because of the weak synergistic effect when mixed with CO 2 or N 2 . This paper presents an effective method to evaluate DS of SF 6 alternative gases and the results are useful for their future engineering applications.

Interfacial Polarization in Thermoplastic Basalt Fiber-Reinforced Composites.

The aim of this work was to study the interfacial behavior of basalt-fiber-reinforced thermoplastic blends of polypropylene and poly(butylene terephthalate) (PP/PBT). We examined the effect of two compatibilizers and two basalt fiber (BF) sizings: commercial (REF) and experimental (EXP). Differential scanning calorimetry was used to assess the influence of BFs on the phase structure of obtained composites. Furthermore, dielectric relaxation spectroscopy was used for the first time to non-destructively study the interfacial adhesion within an entire volume of BF-reinforced composites by assessing the α relaxation, DC conductivity, and Maxwell–Wagner–Sillars (MWS) polarization. The fiber–matrix adhesion was further investigated using the Havriliak–Negami model. Using complex plane analysis, the dielectric strength, which is inversely related to the adhesion, was calculated. The composites reinforced with EXP fibers showed significantly lower values of dielectric strength compared to the REF fibers, indicating better adhesion between the reinforcement and blend matrix. Static bending tests also confirmed improved fiber adhesion with EXP fibers, while also suggesting a synergistic effect between compatibilizer and sizing in enhancing interfacial properties. Thus, we conclude that substantially improved adhesion of PP/PBT BF-reinforced composites is the result of mutual interactions of functional groups of blend matrix, mostly from blend compatibilizer, and fiber surface due to sizing.

Analysis of Micro-EDM Process of D3 Die-Steel Employing NaNO3 Mixed Deionised Water-An Optimal Approach

In micro-electrical discharge machining, the selection of proper dielectric fluid is one of the important issues regarding the machining rate, geometrical accuracy, as well as surface profiles obtained. Each type of dielectric fluid has their own values of viscosity, flash point, cooling rate and compositions. In addition, depending on the resistivity and other characteristics, dielectric fluid has its own value of dielectric strength. In the present article, an attempt has been made to carryout experimentation during micro-EDM process of D3 die-steel employing NaNO3 salt mixed deionised water. Taguchi-GRA (gray relational analysis) based experimental scheme and optimization technique has been applied to analyze the process parameters to optimize the material removal rate, tool wear rate, overcut and taper of micro-hole generated. Optical microscopic images were also analysed for qualitative assessment of process parameters.

Versatile Paschen's model for the dielectric strength estimation of binary and ternary gas mixtures

The dielectric strength of various binary and ternary gas mixtures is accurately estimated by using the proposed versatile Paschen's model. Unlike the conventional Paschen's models, the new model is based on the improved regression process of the ionization coefficients that results in enhanced accuracy in the dielectric strength estimations of pure gases as well as binary and ternary gas mixtures. Compared to the conventional models, the dielectric strength values estimated by the proposed model and the experimental breakdown measurements show more close and consistent agreement. The results confirm the effectiveness, versatility, and veracity of the proposed Paschen's model in estimating the dielectric strength of gas media.

Realization of high quality silicon nitride deposition at low temperatures

This work demonstrates the low temperature thin-film deposition of silicon nitride (SiNx) for III-nitride-based high electron mobility transistors using inductively coupled plasma chemical vapor deposition. It is observed that the nonlinear dependency of the deposition temperature and gas flow rates have a profound impact on the film quality. The process parameter space is scanned and the optimum film quality is achieved, which is verified with physical and electrical characterizations. The best quality film is achieved at a deposition temperature of 380 °C demonstrating near ideal stoichiometry with negligible hydrogen (<5%) and oxygen (<3%) concentrations. In addition, the optimized film is found to have zero pinholes even at a thickness of 10 nm and is uniform over a large area with an rms roughness of 0.58 nm. The deposited films are characterized by atomic force microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The dielectric strength and dielectric constant of these films are determined from current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the metal-insulator-metal structure, respectively. For the best quality film, the values of dielectric strength and dielectric constant are measured to be ∼8 MV/cm and ∼7.5, respectively. A metal-insulator-semiconductor-heterostructure (metal/SiNx/AlGaN/GaN) capacitor is fabricated with the optimized recipe for interface characterization. The density of slow traps is determined from the hysteresis in the C-V curve and found to be 7.38×1010 cm−2. The frequency dependent conductance method is also used to investigate the trap density. The trap state density is found to be 1.67×1012 cm−2 eV−1 at 0.29 eV below conduction band.

Transport Properties of Thermal Plasma Containing Fluoro-Nitrile (C<sub>4</sub>F<sub>7</sub>N)-Based Gas Mixtures

Gas mixtures containing fluoro-nitriles C<sub>4</sub>F<sub>7</sub>N or fluoro-ketones C<sub>5</sub>F<sub>10</sub>O as minority components (<20%) have been identified as promising alternatives to SF<sub>6</sub> in medium voltage gas-insulated switchgear (GIS) applications, because of their low Global Warming Potential together with their dielectric strength values being comparable to SF<sub>6</sub>. The buffer gases in such fluoro-nitrile or fluoro-ketone based gas mixtures are usually N<sub>2</sub>, O<sub>2</sub>, CO<sub>2</sub>, or air. In this contribution, we provide calculation results of transport properties, assuming local thermodynamic equilibrium (LTE), of thermal plasma containing following gas mixtures: C<sub>4</sub>F<sub>7</sub>N-CO<sub>2</sub> and C<sub>4</sub>F<sub>7</sub>N-CO<sub>2</sub>-O<sub>2</sub>. The modifications in the thermodynamic and transport properties upon the addition of oxygen to the C<sub>4</sub>F<sub>7</sub>N-CO<sub>2</sub> mixtures in the temperature range 300 K-30 kK at 1 bar are provided and discussed. These properties have been utilized to calculate the plasma temperature profile for a free-burning arc in a companion paper.

Influence of test procedure on dielectric breakdown strength of alumina

Dielectric strength testing of ceramics can be performed with various setups and parameters. Comparisons of results from different sources are often not meaningful, because the results are strongly dependent on the actual testing procedure. The aim of this study is to quantify the influence of voltage ramp rate, electrode size, electrode conditioning, and sample thickness on the measured AC dielectric strength of a commercial alumina. Mean values, Weibull moduli, and failure probabilities determined in standardized short time tests are evaluated and related to withstand voltage tests. Dielectric strength values in the range from 21.6 to 33.2 kV mm−1 were obtained for the same material using different testing procedures. Short time tests resulted in small standard deviations (< 2 kV mm−1) and high Weibull moduli around 30, while withstand tests at voltage levels with low and virtual zero failure probability in short time tests resulted in large scatter of withstand time and Weibull moduli < 1. The strong decrease in Weibull moduli is attributed to progressive damage from partial discharge and depolarization during AC testing. These findings emphasize the necessity of a thorough documentation of testing procedure and highlight the importance of withstand voltage tests for a comprehensive material characterization.

IMPROVEMENT OF DIELECTRIC STRENGTHS FOR CROSS-LINKED POLYETHYLENE (XLPE) MEDIUM VOLTAGE CABLES

The electricity distribution companies are interested of the types of polymeric materials used in medium voltage cables which is considered the basis of power grid. In this study, it tried to enhance the electrical properties of cross-linked polyethylene (XLPE) after adding inorganic filler: such as Silica (SiO2) filler with 10%, 20%, 30% and 40% concentration percentages. The dielectric strength of the samples was tested under different thermal conditions (0, 25 and 100 C0) to simulate different types of environments. Thermal aging is simulated for one week in several temperatures (70, 100 and 120 C0) to investigate the effect of variety higher temperature stresses on the electric properties of XLPE in thermal drying oven, after adding Silica filler. Curve fitting is used to choosing the most suitable equation between dielectric strength rates under each thermal condition and variant percentages of Silica filler. It noted that the highest value of dielectric strength for XLPE can be obtained with 30% percentage of SiO2 filler [max. at 70 Co(30.07kV/mm)]. Polynomial regression by MATLAB code has been adopted to find the proper percentages of SiO2 filler and the highest value of dielectric strength. This regression algorithm is a form of linear regression where higher order powers (2nd, 3rd ..) of an independent variable are included, and it describes a relationship between an explanatory variable and a response variable.

Dielectric and Electrical Properties of Poly (?-Caprolactone)/ Organomodified Clay Bionanocomposites Prepared in Open Air by in Situ Polymerization

Dielectric and electrical properties of bio-nanocomposites based on poly (?-caprolactone) (PCL) with different amounts of organomodified montmorillonite clay (MMT-ODA) were investigated by broadband dielectric spectroscopy in the frequency range from 1Hz to 1MHz and in the temperature range from -100 to 25°C. These nanocomposites were prepared by in situ Ring Opening polymerization of ?-caprolactone in open air by using titanium alkoxide as a catalyst. Due to the semicrystalline structure of PCL, the high number of modes and its overlap, the relaxation patterns observed on dielectric spectra were complicated. These relaxation data were modeled using the H-N empirical equation with the contribution of conductivity. The local dynamics of PCL were unaffected by the increase of nano-clay amount, in agreement with the DSC values of glass transition temperature. The PCL/MMT-ODA 3 wt% exhibited the lowest value of dielectric strength, indicating the strongest adhesion between PCL matrix and organo-modified clay. As for PCL/MMT-ODA 5 wt%, the presence of agglomerate made the adhesion between PCL and MMT-ODA very weak. The obtained findings were congruent FTIR and XRD results. The electrical conductivity of PCL was analysed according to the Jonscher’s law. The obtained exponent s values referred to three models corresponding to different temperature ranges.

Dielectric and Electrical Properties of Poly (?-Caprolactone)/ Organomodified Clay Bionanocomposites Prepared in Open Air by in Situ Polymerization

Dielectric and electrical properties of bio-nanocomposites based on poly (?-caprolactone) (PCL) with different amounts of organomodified montmorillonite clay (MMT-ODA) were investigated by broadband dielectric spectroscopy in the frequency range from 1Hz to 1MHz and in the temperature range from -100 to 25°C. These nanocomposites were prepared by in situ Ring Opening polymerization of ?-caprolactone in open air by using titanium alkoxide as a catalyst. Due to the semicrystalline structure of PCL, the high number of modes and its overlap, the relaxation patterns observed on dielectric spectra were complicated. These relaxation data were modeled using the H-N empirical equation with the contribution of conductivity. The local dynamics of PCL were unaffected by the increase of nano-clay amount, in agreement with the DSC values of glass transition temperature. The PCL/MMT-ODA 3 wt% exhibited the lowest value of dielectric strength, indicating the strongest adhesion between PCL matrix and organo-modified clay. As for PCL/MMT-ODA 5 wt%, the presence of agglomerate made the adhesion between PCL and MMT-ODA very weak. The obtained findings were congruent FTIR and XRD results. The electrical conductivity of PCL was analysed according to the Jonscher’s law. The obtained exponent s values referred to three models corresponding to different temperature ranges.

New Details to Relaxation Dynamics of Dielectric Composite Materials Comprising Longitudinally Opened Carbon Nanotubes

The difference between intact and longitudinally opened multiwalled carbon nanotubes (referred to as CNT and OCNT) has been studied in their application as conductive filler in polymer composite materials. The dielectric properties have been studied in a broad frequency range at the temperatures varying from 293 K through 373 K. Introduction of as little as 0.5% and 1.0% of the conductive filler dramatically increased both parts of the complex permittivity. The percolation threshold is registered at ∼1.5% filling fraction. The main frequency dispersion of the dielectric permittivity lies in the low frequency end of the tested spectrum: from 102 Hz through 104 Hz. At equal filling fractions, the permittivity of the OCNT-based samples exceeds that of the intact CNT-based samples. The relaxation dynamics is largely affected by the nanoscale geometry of the filler: the temperature dependence of such parameters as dielectric strength, activation energy, and relaxation time demonstrated significant difference between the charge transfer mechanism in the CNT-based and OCNT-based samples. The obtained activation energy is 150 and 85 kJ/mol for materials comprising CNTs and OCNTs, respectively. The relaxation mechanism is complex, and the exact factors behind the macroscopic dielectric properties of the tested materials cannot be singled out with certainty. Several experimental data points suggest that the individual nanotubes, not their aggregates, play the major role in the observed electrical properties of the composites. At the low loading fractions, we attained the highest dielectric strength values among all the data reported by the present day for the CNT/polymer host systems.

Study of dielectric strength in EPDM by nondestructive dynamic mechanical analysis in high electrical field

In the present work the value of the degree of the area swept by the polymer chain due to an electrical force for a given mesostructure was related to the corresponding value of the dielectric strength. This value was deduced from the electric inclusion formalism applied to dynamic mechanical analysis (DMA) studies conducted under high electric field, which were performed in commercial ethylene-propylene-diene M-class rubber (EPDM); used for the housing of polymeric electrical insulators. EPDM samples with different arrangements of the polymer chains and crystalline degree, promoted by controlled neutron irradiation were studied. Several characterization techniques, as infrared absorption spectroscopy (IR), differential scanning calorimetry (DSC), positron annihilation lifetime spectroscopy (PALS) and dielectric strength (DS) were also used. The relationship between the DS and the degree of movement of polymer chains promoted by electrical forces coming from the electric field applied in a non destructive test as the DMA was successfully established. In fact, a larger empty space in the sample leads to larger areas swept by the polymer chains during bending under the application of the field strength in the dynamic mechanical analysis tests. Therefore, an increase in the capability of movement of charges occurs, corresponding to smaller dielectric strength values. Crystallinity improves the dielectric strength due to the increase in the internal stresses which decreases the capability of movement of the polymer chains and electric carriers by electric forces.

Effect of micro/nano-SiO$_{2}$ on mechanical, thermal, and electrical properties of silicone rubber, epoxy, and EPDM composites for outdoor electrical insulations

In this paper the influence of micro-sized (3 $\mu $m) and nano-sized (10 nm) silica (SiO$_{2})$ on mechanical, thermal, and electrical properties of silicon rubber (SiR), epoxy, and ethylene propylene diene monomer (EPDM) composites is presented. The micro- and nano-sized SiO$_{2}$ particle-filled SiR, epoxy, and EPDM composites were formulated with 20% microsilica and 5% nanosilica by weight respectively. Among these composites, SiR-SiO$_{2}$ amalgamation was performed by mixing using an ultrasonication procedure. Epoxy-SiO$_{2}$ was compounded in two steps, i.e. dispersion of fillers and mixing, whereas EPDM-SiO$_{2}$ compounding was performed with a two roll mill technique. With the addition of micro/nano-SiO$_{2}$, the composites showed enhanced tensile strength of $\sim $2.7 MPa, improved hardness, and reduced elongation at break. Further incorporation of micro/nano-sized particles resulted in high thermal stability for SiR-nano composites (SNCs) as compared to epoxy and EPDM composites. Compared to SiR and EPDM composites, epoxy-nano composites showed the highest value of dielectric strength, i.e. 38.8 kV/mm. Meanwhile, the volume and surface resistivity of SNCs were found higher as compared to other investigated samples. Promising properties of SiR nanocomposites among all the investigated samples suggest that their application is more suitable for utilization in outdoor electrical insulations.

Dielectric investigation of high density polyethylene loaded by ZnO nanoparticles synthesized by sol–gel route

Zinc oxide nanoparticles (ZnO NPs), with wurtzite structure, were synthesized using sol–gel route. Both the microstructure and morphology of the synthesized ZnO NPs were examined using X-ray diffraction, Fourier transform infrared and high-resolution transmission electron microscopy. The synthesized ZnO NPs up to 5 wt% were introduced to high density polyethylene (HDPE) using melt blending technique. The dielectric properties of the fabricated HDPE/ZnO nanocomposites were studied by measuring the dc dielectric breakdown strength at constant 1 kV/s ramp. The dielectric strength values were showed ZnO nanofiller concentration dependency. Enhancement in breakdown strength has been observed with addition of ZnO NPs and reached to 17 ± 3.1 % (for HDPE/1 wt% ZnO) with respect to the pure HDPE sample. The real part of the permittivity ( $$\varepsilon^{\prime }$$ ) and the loss tangent ( $$\tan \delta$$ ) dependency on filler concentration was studied under different applied frequency values from 1 kHz to 1 MHz. As well as the variation of the dielectric parameters ( $$\varepsilon^{\prime }$$ and $$\tan \delta$$ ) was studied throughout temperature range from room temperature to 120 °C.