Epoxy Insulation Research Articles

Analysis of Activation Energy of Epoxy Resin Insulated Transformer Based on Dynamic Method

Epoxy resin insulation transformer is a typical dry-type insulation equipment in power system. The insulation performance diagnosis of such equipment is the current research focus. This paper analyses the basic principles of two typical dynamic methods, FWO method and Kissinger method, and introduces the specific application methods of the two methods in the calculation of the activation energy of epoxy resin insulated transformers, which proves the effectiveness of the method. This article provides theoretical basis and example verification for insulation aging diagnosis of dry-type transformers based on quantitative characterization of activation energy.

Epoxy insulator with surface graded-permittivity by magnetron sputtering for gas-insulated line

To reduce the electric field concentration induced flashover in AC gas insulated line (GIL), a novel concept of surface functionally graded material (SFGM) is proposed in this paper, and the continuously graded high-A layer was fabricated by depositing BaTiO 3 on the insulator surface. The iterative method was introduced to optimize the thickness distribution of the BaTiO 3 layer. After four iterations, the layer thickness distribution almost reaches its optimal solution, and the maximum electric field strength is reduced by approximately 70% compared with that of the conventional insulator. To fabricate the optimized SFGM insulator, a rotatable baffle with the designed gap was placed above the insulator during the sputtering process. For comparison, a uniformly sputtered insulator with the 4μm BaTiO 3 layer and a discretely graded insulator with four gradients were prepared. Both electric field simulations and experiments were performed to evaluate the electrical performance of different insulators. The results show that, compared with the conventional insulator, the sputtered insulators, especially the optimized SFGM insulator, can significantly improve the uniformity of the electric field distribution along the insulator surface under a 50 Hz voltage. Accordingly, the discharge inception voltage and flashover voltage of the insulator both increased significantly. Under negative standard lightning impulse voltage (1.2/50 μs), the sputtered insulators show insulation performance comparable to that of the conventional insulator.

Delamination and current-carrying degradation behavior of epoxy-impregnated superconducting coil winding with 2G HTS tape caused by thermal stress

A thermo-mechanical-electromagnetic model is developed for estimating the delamination and current-carrying degradation of epoxy-impregnated pancake coils. The mixed-mode traction–separation law and the Weibull distribution of delamination strength are considered in simulating the onset and extension of the delamination caused by thermal stress. Because of the considerable differences in thermal shrinkage between the epoxy resin, insulation tape, and second-generation high temperature superconducting (2G HTS) tape, the accumulated radial thermal stress locally exceeds the electro-mechanical delamination strength and even the mechanical delamination strength. The electro-mechanical delamination strength of the 2G HTS tape is the transverse tensile or shear stress level corresponding to an abrupt irreversible critical current degradation. The mechanical delamination strength is the transverse tensile or shear stress limit corresponding to a structural failure. After injecting current into the coil, we obtained the E–I curve of the coil. The critical current and n-value of the superconducting coil indicate a strong degradation after epoxy-impregnation. The current-carrying degradation precedes delamination because the electro-mechanical delamination strength is smaller than the mechanical delamination strength. The degradation is more obvious in large than in small superconducting coils because the radial thermal stress is larger. The onset of degradation depends on the minimum delamination strength, suggesting that caution is required in screening the 2G HTS tape before winding the coil. The simulation results indicate that reducing the thickness of the insulation tape and the amount of epoxy resin effectively reduces the degradation of epoxy-impregnated pancake coils.

Comparative study on direct fluorination and surface properties of alumina-filled and unfilled epoxy insulators

In view of the significant performance improvement of unfilled epoxy insulators by direct fluorination, and the fact that all spacers in SF 6 gas insulated systems are alumina-filled epoxy composites, to promote the application of the method for improving the performance of epoxy spacers, in this paper, alumina-filled epoxy (composite) and unfilled epoxy (pure) samples were prepared with the same formulation and process as those for epoxy spacers. The pure and composite epoxy samples were fluorinated under the same conditions, and comparative studies were performed on their surface physicochemical characteristics and properties. IR analysis and SEM imaging show no obvious influence of alumina particles on the fluorination of the epoxy matrix under the used fluorination conditions, while many nanoparticles and agglomerates appear on the surface and large microsized particles in the SEM imaging depth become less visible after the composite epoxy sample was fluorinated. Contact angle and electrical property measurements indicate that like the pure epoxy sample, surface hydrophilicity and surface conduction of the composite epoxy sample are also increased by the fluorination, while the increase in surface hydrophilicity or surface conduction is more significant or less significant, compared to the pure epoxy sample. All these are associated with the fluorination of the alumina particles and the interface change or reconstruction between the particles and the matrix.

Filler fluorination of nanoTiO2/ER composites and their surface insulation properties: a comparison of dielectric barrier discharge and chemical solution fluorination

NanoTiO2/epoxy resin composites, a kind of dielectric materials with excellent thermal, mechanical and electrical properties, has extensive promise in the insulation area of power system. Although the semiconductor property of TiO2 filler can suppress the electric field mutations in the epoxy insulation devices, the doping of TiO2 will have bad influence on the charge transmission, thus weakening the surface insulation. To solve this problem, filler fluorination with dielectric barrier discharge (DBD) plasma and chemical methods were designed to modify the TiO2 filler. The effects of two fluorination methods on the micro-structures, electrical parameters, and insulation properties of the materials were studied. The results have shown that both DBD plasma and chemical fluorination methods can effectively introduce fluorine into TiO2 filler and its epoxy composites, decreasing its dielectric constant and volume resistivity. Through doping the fluorinated TiO2 nanoparticles, the direct current flashover voltage and charge dissipation rate of the composites can be at best increased to 1.5 times and 4.6 times of the pure epoxy, respectively. The enhanced surface insulation properties were explained by the trap effect and the change of electrical parameters (containing dielectric constant and volume conductivity) brought by fluorination treatments. The study results of two types of filler fluorinations have guiding significance for nano-modification of epoxy insulation composites.

The Attenuation and Propagation Law of Ultrasonic Wave in UHV Gas Insulated Line

Gas insulated transmission line (GIL) is widely used for power transmission in special geographical environment such as river crossing, mountain crossing and city tunnel crossing scenarios. Because of its totally enclosed structure, it is difficult to locate the fault position when the internal breakdown discharge occurs. Fault location by using the ultrasonic wave aroused by discharge is an efficient method for GIL maintenance. This paper reports the experimental and theoretical results of attenuation and propagation law of ultrasonic signal in GIL. An ultra-high voltage (UHV) GIL model was set up to simulate the geometry and material conditions of real GIL. The common lead breaking signal was adopted to generate ultrasonic source, and the propagation velocity and attenuation coefficient of ultrasonic wave were obtained. The experimental results show that the attenuation coefficient of ultrasonic wave on GIL linear unit is about 0.234 dB/m, and its propagation velocity is about 3.3 km/s. But the attenuation level of ultrasonic wave is much higher when it passes through the epoxy insulators or expansion joints. The validity of the method is verified by the creeping discharge test on the GIL model. In order to analyze the propagation path of ultrasonic wave, the relationship between the path and time is calculated and the shortest propagation time is obtained. The results of this research provide support for the fault location of GIL by ultrasonic wave.

Improved Electric Field Distribution Within Bushing Insulation by EP/GO Nanocomposites With Reduced Temperature Coefficient of Conductivity

Field grading within the dry-type bushing insulation presents a major challenge for DC applications due to the highly temperature-dependent conductivity of the epoxy resin insulation. An electric field regulation method based on the epoxy/graphene oxide (EP/GO) nanocomposites with the reduced temperature coefficient of conductivity is proposed and investigated in this paper. DC conductivity of EP/GO nanocomposites with different loadings of 0, 0.05, 0.1 and 0.5 wt% at various temperature are investigated. Trap level distributions are characterized by the isothermal discharge current (IDC) method to clarify the conduction mechanism. Obtained results show that more shallower traps are introduced and the thermal activation energies of the nanocomposites are reduced by the GO nanoparticles, indicating that the temperature coefficient of conductivity of the nanocomposites is reduced. The improvement of electric field distribution within the bushing insulation under operating voltage is verified when the EP/GO nanocomposite with an appropriate content is employed, based on an established ±800 kV valve-side bushing for a converter transformer. However, more defects will be introduced by the GO fillers with excessive content (0.5 wt%), resulting in an obvious reduction of the DC breakdown strength.

Volume and surface memory effects on evolution of streamer dynamics along gas/solid interface in high-pressure nitrogen under long-term repetitive nanosecond pulses

Evolution of the surface streamer and the discharge mode transition from the corona discharge to the surface flashover were investigated by pulse sequence resolved electrical and optical measurements under long-term repetitive nanosecond pulses (RNP). The test sample was a cylindrical epoxy resin insulator attached with a needle electrode in 0.1–0.4 MPa nitrogen. Under positive RNP, the inception phase of subsequent streamer discharges decreases with increasing the pulse repetition frequency (PRF), and a periodical streamer stagnation phenomenon appears at high gas pressure. Under negative RNP, the surface streamer does not illustrate symbolic decreasing tendencies in light intensity and corona inception phase in gas gap. The dependence of the evolution of surface streamer velocity on PRF is correlated with the repulsive force from surface charges and the accessibility of seed electrons. Statistical characteristics of back discharges under negative RNP are qualitatively explained by the local electric field around the triple junction. The reversal phenomenon of polarity effect of the allowable repetitive working coefficient is probably resulted from the corona stabilization effect, the surface electron detrapping process, and the assistance of background electric field. Principal results qualitatively support that behaviors of surface streamer and flashover are dominated by the electric field distribution, volume and surface memory effects as well as their interactions and bidirectional transformations, which are different from the monotonically facilitative tendency predicted by the metastable-species-dominated memory effect mechanism.

Self-Assembled Boron Nitride Nanotube Reinforced Graphene Oxide Aerogels for Dielectric Nanocomposites with High Thermal Management Capability.

Thermally conductive polymeric composites are highly promising in current energy devices such as light-emitting diodes, integrated circuits, and solar cells to achieve appropriate thermal management. However, the introduction of traditional thermoconductive fillers into a polymer usually results in low thermal conductivity enhancement. Here, an ideal dielectric epoxy nanocomposite with ultrahigh thermal conductivity is successfully fabricated using three-dimensional interconnected boron nitride nanotube reinforced graphene oxide nanosheet (3D-BNNT-GONS) aerogels as fillers. The nanocomposite exhibits a nearly 20-fold increase in thermal conductivity with only 11.6 vol % loading fraction. Meanwhile, the nanocomposite possesses excellent insulation performance, including low dielectric constant, low dielectric loss, and high breakdown strength. A heating and cooling process reveals that the nanocomposite has a fast response of surface temperature, indicating high thermal management capability.

Thermal response properties and surface insulation failure mechanism of epoxy resin under arc ablation

Arc ablation during the operation of HVDC circuit breakers can cause irreversible damage to the epoxy resin (EP) insulation pull rod. This is one of the critical factors that affect the reliability and lifetime of a HVDC circuit breaker. In this work, we built an arc ablation experimental platform and studied the thermal response properties of EP insulation under arc ablation. The surface charge evolution characteristics and the dielectric properties were analyzed to reveal the underlying surface insulation failure mechanism of EP after arc ablation. The results indicate that arc ablation can cause severe carbonization to EP insulation. With increasing arc duration, the EP gradually transforms into carbide and pore products. Arc ablation can decrease the molecular moment orientation polarizability and the relative dielectric constant of EP insulation, and thereby increasing the current density formed by Schottky injection. Therefore, when the external electric field is applied, the charge on EP insulation surface migrates from high voltage electrode to the ablating area, causing the regional accumulation of surface charge and the formation of local failure area. This can decrease the surface electrical performance of EP insulation and lead to insulation failure finally.

Overheating decomposition characteristics of epoxy dielectrics in SF6 atmosphere

In this paper, the thermal decomposition characteristics of epoxy resin in SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> was studied using simultaneous thermal analysis (TG/DSC) and gas chromatograph-mass spectrometry (GC-MS). The concentrations of the decomposed gas components were tested, and the method of determining whether the failure of SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> gas insulation equipment is caused by thermal decomposition of the insulating epoxy resin material is proposed. TG-DSC shows that the epoxy resin starts to lose weight sharply at 350 °C, and heating from 350 to 450 °C shows that the main gas products are CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , SO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> S and SOF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> . The concentrations of the four gases are significantly higher than where no epoxy resin is present and only pure SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> is injected. The concentrations of SO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , CF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> and CS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> were all kept below 0.5 ppm in the given temperature range. H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> S is generated at about 325 °C while it can hardly be detected in the decomposition products of pure SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> without epoxy resin at the same temperature. Based on our observations, it is concluded that when the concentration of CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> reaches 5 times the sum of the concentrations of SO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> S, and when the concentration of H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> S is higher than 0.5 ppm, failure of electrical equipment occurs by thermal decomposition of epoxy resin will occur.

Electric Tree Characteristics of Glass Fiber Reinforced Epoxy Insulation Composites with Different Contents

Electric tree aging due to the action of long-term partial discharge stress of epoxy resin casting insulation is a major problem in electrical engineering. On the discharge experimental platform, initiation and culture experiments of the electric trees were carried out at a power frequency voltage of 20 kV. The mass fractions of the spherical glass fibers were 0, 0.5, 1, 2 and 3 %. The results showed that the electrical dendritic process of epoxy resin experienced initiation, growth, lag and burst periods, the phase maps of the corresponding partial discharges in the four periods were all “mountain-like”. The electric tree of pure epoxy resin showed a typical dendritic structure, after the glass fiber was properly added, the electric tree became lighter in color with a more complicated shape, the damage also became more serious, however, the growth of the electric branch was suppressed. The electric tree aging channel of the epoxy resin appeared black and under microscopy the micro-branched channel wall appeared white. When the amount of glass fiber was 2 %, the initiation time of the electric trees was prolonged, the growth rate of the electric trees decreased and suppressing development of the electric tree branches was optimal.

Study on the Influence of Switching Impulse Superposition Phase on AC Partial Discharge of Epoxy Surface in SF6 Gas

In this letter, a test platform capable of generating superimposed voltage with controllable phase is presented. Surface partial discharge(PD) of epoxy insulation was measured and analyzed in SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> . The applied voltage is AC and switching impulse superimposed voltage. Results show that only PD of the negative cycles of the AC voltage is excited or accelerated after impulse. With AC voltage at 90% of partial discharge inception voltage(PDIV), AC PDIV is reduced after imposing the switching impulse. When AC voltage is kept at 110% of PDIV, AC PDs are obviously promoted after impulse.

Surface flashover characteristics of epoxy insulator in C4F7N/CO2 mixtures in a uniform field under AC voltage

This paper reports on an investigation into the surface flashover of an insulator in a C4F7N/CO2 mixture which is used as an alternative to SF6. To date, no studies on this aspect have been reported in the literature. This study was done for a uniform field using a 220 kV AC experimental platform. The influence of molar fraction, gas pressure and creepage distance is reported and compared to that in SF6. The results show that small quantities of C4F7N mixed in CO2 can increase the surface flashover voltage but, as the fraction of C4F7N increases, saturation of the surface flashover occurs. The relative surface flashover voltage of 13.0% C4F7N/87.0% CO2 is approximately 80% that of SF6. The empirical formulae on the critical flashover electrical field has been obtained, which may be referenced in the design of environment friendly high voltage equipment.

Partial discharge characteristics of cavities with different appearances and positions in solid insulation

A cavity is a typical defect in a solid insulator which may cause the appearance of partial discharge (PD) activity in power equipment [1–4]. It is mainly caused by imperfections in the manufacturing process as well as by the creep during equipment operation [5]. In epoxy resin insulators, the creep brings irreversible deformations that increase with time at elevated temperatures and external stress [6,7]. Once a cavity has been formed, the PD can lead to insulation failure. Many studies on PDs in void defects, a type of gas-filled cavity, have been performed by pasting together three epoxy laminates and demonstrated factors that affect their intensity, including void size, shape and interface roughness [8–12]. However, such a test void is quite different in its structure and composition from what we further consider in this article, i.e., cavities appearing during actual insulator operation. Moreover, the pressure in a real cavity is usually very low, because of air leakage and polymerization shrinkage, whereas the test void typically remains under atmospheric pressure. Considering the above mentioned differences, we prepared experimental model insulators, containing various low-pressure cavities. The insulators were manufactured by means of automatic pressure gelation (APG) technique by changing the pressure and temperature during the resin pouring process, which allowed for simulating a more realistic operating environment.

Perkiraan Tegangan Lewat Denyar Isolator Tegangan Menengah 20 kV Keramik dan Resin Epoksi berdasarkan Data Arus Bocor

This paper explains the research results of leakage current data and estimation of flashover voltage on ceramics and epoxy resin as 20 kV outdoor insulator in a chamber with tropical climate conditions. The waveform of leakage current (LC) was measured using a digital oscilloscope. The digital data was transferred to a personal computer using a RS-232 cable. The digital data was analyzed using Fast Fourier Transform. The result showed that LC was affected by various environment conditions like temperature, humidity and pollution. LC of ceramics insulator was higher than epoxy resin insulator in low temperature, high humidity and high pollution condition.

Curing Kinetics and Mechanism Research of E44/T31 Insulation Paint

Epoxy resin insulation paint was prepared with epoxy resin (E44) as binder and with proper inorganic fillers and curing agent (T31) as additives. The isothermal curing reaction process of paint was studied by the differential scanning calorimetry method (DSC), and the curves of curing reaction rate versus time of paint were obtained. The curing reaction kinetics was investigated by using the phenomenological method, and the corresponding parameters of the n-order model, autocatalytic model and Kamal model were determined by fitting the experimental data, respectively. According to the values of R2 and the sum of square due to error (SSE), a suitable curing reaction kinetic model was determined. The curing reaction mechanism of paint was ascertained by the dynamic temperature DSC method and IR spectroscopy (FTIR) method. The results show that the Kamal model can be used to describe the curing kinetics of epoxy resin paint, and the total reaction orders increase from 1.30 to 2.14. The two rate constants increase with the increase of the curing temperature. The activation energy is 90.5832 kJ/mol and 68.3733 kJ/mol respectively, and the pre-exponential factors are 6.521 × 1015 s-1 and 6.3807 × 109 s-1. The curing reaction of paint consists of two steps: the first step is the addition reaction of epoxy group and primary amine or secondary amine; the second step is the etherification reaction of epoxy group and phenolic hydroxyl or alcoholic hydroxyl.&#x0D; Epoxy resin insulation paint was prepared with epoxy resin (E44) as binders and with proper inorganic fillers and curing agent (T31) as additives. The isothermal curing reaction process of paint was studied by differential scanning calorimetry method (DSC), and the curves of curing reaction rate versus time of paint were obtained. The curing reaction kinetics was studied by using the phenomenological method, the corresponding parameters of the n-order model, autocatalytic model and Kamal model were determined by fitting the experimental data, respectively. According to the values of R2 and the sum of square due to error (SSE), a suitable curing reaction kinetic model was determind. The curing reaction mechanism of paint was ascertained by dynamic temperature DSC method and IR spectrogram (FTIR) method. The results show that the kamal model can be used to describe the curing kinetics of epoxy resin paint, the total reaction orders increase from 1.30 to 2.14. The results also show that the two rate constants increase with increasing curing temperature, The activation energies are 90.5832 kJ/mol and 68.3733 kJ/mol, and the pre-exponential factor are 6.521×1015 s-1 and 6.3807×109 s-1. The curing reaction of paint in two steps, the first step is the addition reaction of epoxy group and primary amine or secondary amine. The second step is the etherification reaction of epoxy group and phenolic hydroxyl or alcoholic hydroxyl.

Electrothermal aging characteristics of epoxy resin under bipolar exponential decay pulse voltage and its insulation life evaluation based on Cole-Cole model

The epoxy resin insulation in saturable reactors in a HVDC transmission converter valve is subjected to a bipolar exponential decay pulse voltages under normal operating conditions and its aging mechanism is still unclear. In this paper, an electrothermal aging experiment of epoxy resin was carried out under bipolar exponential decay pulse voltages at high temperature. The dielectric properties of epoxy resin before and after aging were measured using frequency-domain spectroscopy. To quantitatively study the aging characteristics, the double-relaxation Cole-Cole model was used to fit the dielectric spectra. As a result, an exponential function relationship between the relaxation time constant and the aging time of epoxy resin under various aging conditions was obtained. This relationship can be used as an empirical formula to evaluate the degree of aging. Furthermore, a comparison of the aging life characteristics of epoxy resin under pulse and sinusoidal voltages with the same peak value was performed. The results show that the electrothermal aging rate of epoxy resin under a pulse voltage is lower than under a sinusoidal voltage. The effect of the measurement temperature on the insulation life evaluation of epoxy resin was also analyzed.

Electrothermal aging characteristics of epoxy resin under bipolar exponential decay pulse voltage and its insulation life evaluation based on Cole-Cole model

The epoxy resin insulation in saturable reactors in a HVDC transmission converter valve is subjected to a bipolar exponential decay pulse voltages under normal operating conditions and its aging mechanism is still unclear. In this paper, an electrothermal aging experiment of epoxy resin was carried out under bipolar exponential decay pulse voltages at high temperature. The dielectric properties of epoxy resin before and after aging were measured using frequency-domain spectroscopy. To quantitatively study the aging characteristics, the double-relaxation Cole-Cole model was used to fit the dielectric spectra. As a result, an exponential function relationship between the relaxation time constant and the aging time of epoxy resin under various aging conditions was obtained. This relationship can be used as an empirical formula to evaluate the degree of aging. Furthermore, a comparison of the aging life characteristics of epoxy resin under pulse and sinusoidal voltages with the same peak value was performed. The results show that the electrothermal aging rate of epoxy resin under a pulse voltage is lower than under a sinusoidal voltage. The effect of the measurement temperature on the insulation life evaluation of epoxy resin was also analyzed.

A Centimeter Resolution GIS Insulator Strain Distribution Measurement Method Based on OFDR

We proposed a centimeter-resolution insulator strain measuring system based on the optical frequency domain reflectometry to achieve hundreds points distribution measurement. The details of the optical fiber arrangement and signal processing algorithm to obtain the strain distribution on an insulator is presented. A calibration experiment based on a uniform strength beam was carried out to determine the strain sensing factor. Hydrostatic test results demonstrate the accomplishment of 210 points strain distribution measurement with a 1-cm spatial resolution using the proposed system on a 126-kV insulator. Then, the strain distribution on the whole insulator is presented, which is hardly to realized using the conventional strain gauges. The proposed centimeter resolution insulator strain distribution measurement system is suitable for more comprehensive epoxy insulator manufacture processes studies.