Instantaneous Voltage Research Articles

開極タイミング変化時におけるアーク温度の解析

The gas circuit breakers have the problem of re-ignition after current zero. The instantaneous voltage drop causes enormous damage in the case of current interruption failure. Therefore, it is the responsibility of circuit breaker to interrupt the current quickly and reliably. Efficient cooling of the arc temperature is important in order to prevent the re-ignition caused by the transient recovery voltage. In this paper, the arc temperature as a function of opening electrodes timing was analyzed. As a result, the three-dimensional transition of arc temperature to current zero for each current interruption timing at each sine wave time was obtained. In addition, the opening electrodes timing that decreases the arc conductance at current zero was elucidated.

Enhanced models with time‐series coefficients used for electric arc furnace

AbstractElectric arc furnace (EAF) is one of the most disturbing loads in the power system as it is highly time‐varying and nonlinear. In this paper, new models based on the instantaneous EAF voltage and current, recorded from EAFs in Mobarakeh steel company in Isfahan/Iran are proposed. The focus of this paper is on developing efficient models based on the Schwarz model where three modified types are proposed. The original Schwarz model has four constant parameters. Unlike the original Schwarz model which uses invariant parameters, the time‐varying nature of the arc's parameters is considered in the proposed models. The first modified model has two constant model orders and two time‐varying coefficients. Additionally, to further enhance the model's accuracy, in the second modified model, six parameters include three constant model orders, and three time‐varying coefficients exist. The third model uses all the original model's parameters as time‐series parameters. The parameters of the time‐varying model are derived using autoregressive moving average (ARMA) models. The accuracy of the proposed model is evaluated by calculating the active power, harmonics, instantaneous flicker, and short‐term flicker. Finally, three MATLAB codes are provided to generate the model parameters time series.

Optimizing the Connection Diagram and Turns Number for the Three-Phase to Multiphase Transformer Converter Secondary Winding Coils

An approach to determining the optimal connection diagram and the number of turns for secondary winding coils of a three-phase to multiphase transformer-type converter is considered. Each phase of the device’s multiphase winding comprises three coils placed on different core limbs and connected in series with each other. To determine the connection diagram and the number of turns in the multiphase winding coils, it is necessary to solve an optimization problem with taking into account certain constraints that will make it possible to obtain the same number of turns in the series-connected coils of each secondary winding phase, a symmetrical multiphase EMF system, and uniformly distributed symmetrical multiphase load among the three primary winding phases. The formulated optimization problem with constraints is solved using the numerical interior point method. The application of the proposed approach is illustrated by an example of calculating the minimum number of turns in the coils of a three-phase to seven-phase converter, and the converter windings connection diagram is presented. The article gives the calculated apparent power values of the secondary winding coils with a symmetrical resistive-inductive load for a converter with different numbers of coil turns evaluated from solving the optimization problem with various constraints. A prototype three-phase to seven-phase converter has been fabricated on the basis of a three-phase transformer of a standard series. As a result of experimental studies of the prototype, the seven-phase winding instantaneous voltage waveforms, r.m.s. values of currents and voltages, and the primary winding power for no-load and symmetrical load modes have been obtained. The experimental study results have confirmed the calculation results adequacy. By using the proposed approach, it is possible to design a three-phase to multiphase converter with the number of multiphase secondary winding phases more than two. The designed secondary winding coils will have the minimal number of turns, which will make it possible to manufacture a device with smaller mass and dimension indicators and decrease the consumption of expensive electrical materials.

GPS 시각동기 PMU의 대용량 데이터를 이용한 재생 발전설비의 영향 분석

PMUs can acquire time-synchronized large-capacity data through high-speed sampling and linking with GPS, and can receive simultaneous events as unified time series data and use it for WAMS, etc. Therefore, the installation and operation of a PMU-based system that can precisely analyze instantaneous system changes that were difficult to analyze in the past is being sought for monitoring, analysis, protection and control of RPGs. In this paper, to improve the reliability and stable operation of the power grid based on renewable power generation facilities, the effect of PMU large-capacity data are analyzed. First, the large data collected from PMU and F/R installed in Hoenggye and Yeongwol S/S connected with RPGs are acquired. Based on the instantaneous voltage change rate calculation, data analysis techniques such as Boxplot, Correlation, ACF, Kernel density, and Regression were implemented using Python. Finally, the impact and effect of RPGs on the power grid were discussed.

Experimental and Theoretical Study of Corona Inception Threshold in Rod to Plane Electrodes Under AC/DC Combined Voltage: Phase Corresponding to AC Voltage

Under AC/DC combined voltage, the corona inception phase corresponding to AC voltage is not a fixed value and will change within a certain range. In this article, the effects of DC polarity, DC proportion, rod radius, and rod-plane distance on corona inception phase were explored. The results showed that the normalized amplitude under equivalent positive corona conformed to normal distribution. In addition, with the increase of DC proportion, the distribution of corona inception phase under equivalent positive corona was more dispersed, and the dispersion changed more obviously than that under equivalent negative corona. When the DC proportion was increased from 25% to 75%, the interval width of phase under equivalent positive corona and equivalent negative corona increased by at most 50° and 15°, respectively. A fluid model was built to explain the change of phase dispersion from the perspective of space charge. The existence of corona inception phase resulted in the difference between AC instantaneous voltage and AC peak voltage at corona inception time, which was of great significance to the study of corona inception.

Self-Charging Piezo-Supercapacitor: One-Step Mechanical Energy Conversion and Storage.

With the contemplations of ecological and environmental issues related to energy harvesting, piezoelectric nanogenerators (PNGs) may be an accessible, sustainable, and abundant elective wellspring of energy in the future. The PNGs' power output, however, is dependent on the mechanical energy input, which will be intermittent if the mechanical energy is not continuous. This is a fatal flaw for electronics that need continuous power. Here, a self-charging flexible supercapacitor (PSCFS) is successfully realized that can harvest sporadic mechanical energy, convert it to electrical energy, and simultaneously store power. Initially, chemically processed multimetallic oxide, namely, copper cobalt nickel oxide (CuCoNiO4) is amalgamated within the poly(vinylidene fluoride) (PVDF) framework in different wt % to realize high-performance PNGs. The combination of CuCoNiO4 as filler creates a notable electroactive phase inside the PVDF matrix, and the composite realized by combining 1 wt % CuCoNiO4 with PVDF, coined as PNCU 1, exhibits the highest electroactive phase (>86%). Under periodic hammering (∼100 kPa), PNGs fabricated with this optimized composite film deliver an instantaneous voltage of ∼67.9 V and a current of ∼4.15 μA. Furthermore, PNG 1 is ingeniously integrated into a supercapacitor to construct PSCFS, using PNCU 1 as a separator and CuCoNiO4 nanowires on carbon cloth (CC) as the positive and negative electrodes. The self-charging behavior of the rectifier-free storage device was established under bending deformation. The PSCFS device exhibits ∼845 mV from its initial open-circuit potential ∼35 mV in ∼220 s under periodic bending of 180° at a frequency of 1 Hz. The PSCFS can power up various portable electronic appliances such as calculators, watches, and LEDs. This work offers a high-performance, self-powered device that can be used to replace bulky batteries in everyday electronic devices by harnessing mechanical energy, converting mechanical energy from its environment into electrical energy.

Load Voltage Control of a Wind Turbine-driven Three-phase Squirrel-Cage Induction Generator in an Islanded Microgrid

The intermittent nature of the wind resources and reactive power consumptions are major issues associated with squirrel cage induction generator wind power system when operated in an island microgrid mode. The resultant effect of these two issues are continuous fluctuations of load voltage which has adverse effects on electrical devices. This paper proposes a voltage regulation technique based on proportional controller and phase deposition sine pulse width modulation (PDSPWM) for the control of 5-level neutral point clamped multilevel inverter. The instantaneous voltage tracking strategy based on root mean square value of microgrid voltage was adopted to regulate and maintain the output load voltage at 400 𝑉𝑟𝑚𝑠 despite rotor fluctuations with wind speeds. The simulation was carried out in a MATLAB/SIMULINK environment and the performance of the control scheme was found to be excellent.

Teager energy assisted variational mode decomposition‐based fault location technique for STATCOM compensated system

AbstractModern power systems are structurally complex and thus experience transient events. For secure and reliable operation, quick system restoration is required whenever transient phenomenon like line faults occurs. Fault location techniques (FLTs) aid in faster restoration process. However, the accuracy of FLTs gets affected in presence of static synchronous compensator (STATCOM) since STATCOM compensates the dip in measured voltage during fault thereby affecting the fault current signals. Therefore, in this paper, a Teager energy assisted variational mode decomposition (VMD) based traveling wave FLT is developed for transmission lines with STATCOM. The proposed FLT considers two‐terminal instantaneous voltage signals for locating faults. In this FLT, the signals are first decoupled into modal signals and then aerial mode of the signals is chosen for decomposition using VMD. The signals are decomposed via VMD to level three producing mode three signals. Teager energy of the resultant signals is obtained and from the first peak of the energy signals, arrival time of waves (ATWs) is estimated. These estimated ATWs are used to calculate fault location and percentage error. To validate the performance of proposed FLT, several test cases with different fault scenarios are considered and the results are compared with existing techniques. The results prove efficacy of proposed FLT for studied system.

Doubly Fed Induction Machine-Based DC Voltage Generator with Reduced Oscillations of Torque and Output Voltage

The doubly fed induction machine (DFIM)-based DC voltage generator is equipped with a stator-connected diode rectifier. The six-pulse diode rectifier as a nonlinear circuit introduces harmonics in the stator and rotor current and distorts the machine stator voltage, as well as the stator flux. This causes electromagnetic torque oscillations and instantaneous power components oscillations. The torque oscillations adversely impact the mechanical parts of the drive-train and oscillations of the p component of instantaneous power influence DC-bus voltage oscillations. The oscillations can be somewhat cancelled by control methods. However, cancellation of electromagnetic torque is not strictly coupled with cancellation of oscillations of the p component of instantaneous power. The paper presents an analysis of influence of the control methods aimed at a reduction of torque oscillations on the output voltage oscillations level in the stand-alone DFIM-based DC voltage generator. Field-oriented control FOC with current controllers and space vector modulation-based direct torque control DTC-SVM with flux module regulation have been compared with control in which electromagnetic torque is one of the commanded variables, whereas the second variable is the dot product of stator flux and rotor current space vectors. The contributions of this paper are the introduction of a new variable in the second control path in the DTC-SVM method instead of flux vector length and the proof that it can reduce torque and DC-bus voltage oscillations in the DFIG-DC system. Additionally, this paper reveals that for proper stator-to-rotor-turns ratio of a doubly fed machine necessary for reduction of the rotor converter power, lower DC-bus voltage can be obtained than is required for full realization rotor side voltage requested by rotor current controllers. This is the reason why, regardless of the control method, torque oscillations cannot be always fully cancelled, and a comparative study of the methods at these conditions has been conducted in simulation and in laboratory tests.

Calibrated Electrochemical Impedance Spectroscopy and Time‐Domain Measurements of a 7 kWh Automotive Lithium‐Ion Battery Module with 396 Cylindrical Cells

AbstractA 7 kWh automotive battery module with 396 interconnected cells was tested with electrochemical impedance spectroscopy (EIS) and time‐domain pulsing over 260 charge‐discharge cycles. An EIS calibration workflow was developed for low complex impedance values in a frequency range of 1 kHz to 50 mHz. Significant corrections on the resistance and the reactance were obtained from the calibration, particularly at frequencies above 100 Hz. Equivalent circuit parameters were extracted from the EIS spectra and the pulse response and investigated with respect to the cycle number and state‐of‐charge (SoC). Fit parameters were robustly extracted including Rsol, Rct, and L from EIS, and R0, τ1 and τ2 from time‐domain pulsing. The ohmic resistance decreased over the cycling number indicating an enhanced wetting of the electrodes. Charge transfer resistance Rct showed a monotonic increase over the cycles related to cell ageing. From the charge and discharge pulses, the ohmic resistance R0 was determined from the instantaneous voltage step of the recovery pulse, while the two time constants τ1 and τ2 correspond to the slower exponential recovery phase. R0 from the time‐domain showed a similar trend as Rsol plus a contribution of Rct from EIS. Overall, we show that calibrated EIS and time‐domain pulsing are efficient methods to gain insights into the electrochemical processes related to different SoCs and the cycling ageing of battery modules and packs.

Third-Harmonic-Type Modulation Minimizing the DC-Link Energy Storage Requirement of Isolated Phase-Modular Three-Phase PFC Rectifier Systems

A three-phase ac/dc converter with high-frequency isolation can be realized as a monolithic three-phase or as a phase-modular system by combining three single-phase Power Factor Correction (PFC) rectifier modules with individual isolated dc-dc converters. Advantageously, for a phase-modular system the module configuration can be changed depending on the instantaneous input-output voltage ratio (i.e., a star-(Y)- or a delta-(Δ)-arrangement such that wide voltage ranges can be covered without a massive over-dimensioning of the main power components. However, the main disadvantage of a phase-modular converter realization is the fact that the input power of each PFC rectifier module pulsates at twice the mains frequency (which is inherent to single-phase power conversion) such that large dc-link capacitors are required. Recent literature predicts a substantial power pulsation reduction enabled by means of third-(3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> )-harmonic injection modulation which is applicable for the Y-connection (where a common-mode (CM) / zero-sequence (ZS) voltage is injected), and for the Δ-connection of the three single-phase PFC rectifier modules (where a CM / ZS current is injected). This changes the distribution of the power flow in the three-phase system and the power pulsation is shifted to higher frequencies. This paper experimentally verifies and extends the dc-link energy storage requirement reduction of the 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> -harmonic injection modulation concept: In a first step, the derivation of the harmonic injection concept is recapitulated and suitable control methods are discussed for both CM voltage (Y-arrangement) and CM current (Δ-arrangement) injection. Further, an alternative CM voltage injection strategy with simplified reference generation based only on the instantaneous grid voltage measurements is presented and compared to the pure 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> -harmonic injection modulation. Measurement results obtained from a 6 kW prototype reveal a dc-link voltage variation and/or energy buffering reduction by up to 38.6 % enabled by the harmonic injection modulation compared to conventional operation without 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> -harmonic injection modulation.

Harmonic-Invariant Scaling Method for Power Electronic Converters in Power Hardware-in-the-Loop Test Beds

Power hardware-in-the-loop (PHIL) is an experimental technique that uses power amplifiers and real-time simulators for studying the dynamics of power electronic converters and electrical grids. PHIL tests provide the means for functional validation of advanced control algorithms without the burden of building high-power prototypes during early TRL. However, replicating the behavior of high-power systems with laboratory SDC can be complex. Inaccurate scaling of the SDC coupled with an exclusive focus on instantaneous voltages and currents at the fundamental frequency can lead to PHIL results that are only partially relatable to the high-power systems under study. Test beds that fail to represent switching frequency harmonics cannot be used for studying harmonic penetration or loss characterization of large-scale converters. To tackle this issue, this paper proposes a harmonic-invariant scaling method (HISM) that exploits the VA rating of preexisting laboratory SDCs for more accurately replicating harmonic phenomena in a PHIL test bench. Firstly,, a theoretical analysis of the proposed method is presented and, subsequently, the method is validated with MATLAB simulations and experimental tests.

Estimating Average Power of Welding Process With Emitted Noises Based on Adaptive Neuro Fuzzy Inference System

In this study, the average power consumption of an electrode welding machine during the welding process was estimated using the features of the sound emitted during welding. First, the instantaneous values of electrode current and voltage and the sound emitted during the welding process were recorded simultaneously. The minimum, maximum, average, root mean square (RMS), and energy values of the sound data were found and feature extraction was performed, and the instantaneous power and average power values were calculated using the instantaneous current and voltage values. Three Adaptive Neuro-Fuzzy Inference Systems (ANFIS) using the sound features as inputs and average power values as outputs were created, and their results were compared. The average power values consumed during the welding process have been successfully estimated at a rate of 87-95%.

Voltage control and power sharing in DC Microgrids based on voltage-shifting and droop slope-adjusting strategy

• Designed a dynamic droop controller based on average of instantaneous power, droop control and voltage. • Proposed a new distributed control algorithm for DC microgrids. • Accurate power sharing and fast voltage recovery. To overcome the disadvantages of droop control, this paper proposes a novel method of hierarchical distributed secondary control for DC microgrids. With the load changes, distributed energy resources can achieve power sharing and restore the DC bus voltage. Based on the rated voltage and instantaneous power of the DC grid (DG), a hierarchical distributed control method including shift voltage and droop slope adjustment has been developed. By increasing the shifted voltage and adjusting the droop gain, it can effectively compensate the voltage drop caused by the droop controller. In this way, the DC bus voltage can always be adjusted automatically, regardless the load changes. In addition, this paper introduces the design process of the controller in detail and proves the stability of the system. Finally, simulations and experiments have verified the effectiveness and superior performance of the proposed control method.

Preferential perovskite surface-termination induced high piezoresponse in lead-free in situ fabricated Cs3Bi2Br9-PVDF nanocomposites promotes biomechanical energy harvesting.

Lead-free halide perovskites have gained immense popularity in photovoltaic and energy harvesting applications because of their excellent optical and electrical attributes with minimal toxicity. We synthesized composite films of lead-free Cs3Bi2Br9 perovskite embedded in the polyvinylidene fluoride (PVDF) matrix and have investigated their piezoelectric energy harvesting. Five PVDF@Cs3Bi2Br9 composite films were fabricated with varying wt% of the perovskite in the PVDF. The composite with a 4 wt% of the perovskite shows 85% activation of the electroactive β-phase of PVDF. Additionally, this composite exhibits a maximum polarisation of ∼0.1 μC cm-2 and the best energy storage density of ∼0.8 mJ cm-3 at an applied field of ∼16 kV cm-1 among all the synthesized composites. A nanogenerator fabricated using 4 wt% loading in the composite film produced an instantaneous output voltage of ∼40 V, an instantaneous current of ∼4.1 μA, and a power density of ∼17.8 μW cm-2 across 10 MΩ resistance when repeatedly hammered by the human hand. The nanogenerator is further employed to light up several LEDs and to charge capacitors with a small active area demonstrating significant promise for prospective wearables and portable devices and paving the way for high-performance nanogenerators using lead-free halide perovskites. Density functional theory calculations were performed to understand the interaction of the electroactive phase of the PVDF with different perovskite surface terminations to unravel the various interaction mechanisms and their ensuing charge transfer properties.

Universal Equivalent Model for Real-Time CPU/FPGA Co-Simulation of Hybrid Cascaded Multilevel Converters

Real-time simulation is important for ensuring the reliable operation of VSC-HVDC converters in power grids, particularly through the use of rapid control prototyping (RCP) and hardware-in-the-loop (HIL) based converter controllers. While real-time simulation is a common practice for modular multilevel converters (MMCs), it has been less frequently applied to the new class of hybrid cascaded multilevel converters (HCMCs). In this study, a universal equivalent model (UEM) is proposed for a range of HCMC topologies that combines accuracy and computational efficiency through the use of both CPUs and field-programmable gate arrays (FPGAs). The proposed UEM is derived using the hybrid five-level converter (H5LC), a compact, efficient, and fault-tolerant VSC within the HCMC family. The UEM relies on CPUs to simulate the main circuits and controls of the main converter, and utilizes FPGAs to calculate the instantaneous voltages of a large number of full-bridge submodules (FBSMs), flying capacitors, and DC-side pole capacitors. In addition, the FBSMs’ voltage-balancing and switching algorithms are implemented on the FPGAs. The proposed real-time CPU/FPGA-based H5LC-UEM is compared to an offline CPU-based detailed equivalent model to verify its accuracy.

An Enhanced Short-Horizon Integration Actual Voltage Reconstruction Method Based on Inverter Nonlinear Error Inverse-Compensation

In this article, an enhanced short-horizon integration actual voltage reconstruction method based on nonlinear error inverse-compensation (NEIC-SHIVR) is proposed for voltage source inverters. The NEIC-SHIVR method takes into account not only the influence of nonlinear errors in modulation such as dead time addition and narrow pulses elimination on voltage reconstruction but also considers the influence of nonlinear errors in PWM transfer links such as power switch delay and switch voltage drop on voltage reconstruction. First, the real-state driving signal is computed by the output driving signal and the power switch delay time. The auxiliary driving signal is reconstructed to get the auxiliary switching state according to the phase current direction. Second, referring to the auxiliary switching states and the phase-current directions, the instantaneous equivalent bus voltage within each clock pulse is computed by the dc-bus voltage and the switch voltage drop. Finally, the output voltage within each switching period is integrated by the reconstructed instantaneous equivalent bus voltage in each clock pulse. Compared with SHIVR, NEIC-SHIVR provides a more accurate reconstructed voltage. Compared with other methods, NEIC-SHIVR inherits many advantages of SHIVR. For example, it can apply to any PWM method and does not use high-cost high-frequency voltage sensors, which improves system reliability and reduces system complexity. Simulations and experiments verify the effectiveness of the proposed method.

Minimum DC Voltage Ripple Switching Sequence Elicitation for Dual Inverter Through AC Load Error Volt-Sec Computation

In voltage source inverters (VSI), the output voltage is synthesized in an average sense using pulsewidth modulation (PWM) techniques. In space vector PWM techniques, the average realization of the space vector using volt-sec balance results in an instantaneous error that influences the dc bus current. The instantaneous ac load error voltage maps onto the dc bus derive the dc bus current ripple signatures that would be useful to size the dc capacitor. Exploiting concept of instantaneous mapping of ac error voltage onto the dc bus through power factor axis coordinates, in this work, the unprecedented dc ripple voltage computational method is presented. The established synchronous power factor reference frame ensures accurate mapping of ac error voltage onto the dc bus and makes the computational method independent of sensing actual ac load current unlike conventional methods. With the eliminated actual load current dependence, the proposed model can predict the minimum dc voltage ripple yield switching sequence for VSIs at different loading conditions. The efficacy of the proposed model in terms of optimum switching sequence elicitation is demonstrated on the dual inverter configuration experimentally considering the inflated switching stress due to two inverter's switching.

Novel Method for Instantaneous Neutral Point Voltage Balancing for a Stacked Multilevel Inverter-Fed Six-Phase Induction Motor Drives

This article proposes a novel method for instantaneous neutral point (NP) balancing for a six-phase stacked multilevel inverter (MLI)-fed induction motor (IM) drive. A stacked inverter requires as many dc sources as the number of stackings. A single dc source is ensured with instantaneous NP balancing although there are two stackings of MLIs. A single dc-link enables direct back-to-back power conversion and power can be fed back to mains at the desired power factor. Instantaneous NP balancing is achieved by ensuring that at any instant, no midpoint current is drawn from the NP (dc-link capacitor midpoint). This work shows that the midpoint is used only as a tapping point to generate the different pole voltage levels and no current needs to be drawn from it. V/f experiment is conducted on a six-phase IM with a nine-level stacked MLI, which is developed by stacking two five-level inverters where each of the five-level is developed by cascading a flying capacitor with a capacitor fed cascaded H-bridge. The results ensured that the proposed method for zero instantaneous NP current is valid for both steady-state and transient conditions of a six-phase IM drive using stacked MLI.

Experimental study on dynamic response characteristics and performance degradation mechanism of hydrogen-oxygen PEMFC during loading

The instantaneous voltage overshoot caused by current loading is one of the important factors for the performance degradation of hydrogen-oxygen proton exchange membrane fuel cells (PEMFCs). In this study, the dynamic response characteristic parameters, including first-stage delay (FTD), second-stage delay (STD), and voltage undershoot (VU), were studied quantitatively to analyze the voltage changes during current loading. The effects of loading range and operating parameters including temperature, stoichiometric ratio, and relative humidity on dynamic response characteristics were experimentally analyzed. The results show that the FTD and the STD were shortened by a smaller loading amplitude. The FTD under the loading range of 200 mA/cm2-600 mA/cm2 was 0.5 s shorter than that under 200 mA/cm2-1000 mA/cm2, and the STD was shortened by 7.5 s. The STD was reduced by 30.9% with the operating temperature increased from 55 °C to 75 °C. What's more, the FTD and VU reached minimum values with the relative humidity of the anode and cathode controlled at 50% and 70%, respectively. In addition, it was found that after the current loading experiment, the performance decreased by 2.5%, the charge transduction resistance increased by 8.94%, and the electrochemical active surface area decreased by 11.68%. The findings reported are expected to provide guidance for optimizing the working conditions of hydrogen-oxygen PEMFC, to reduce the performance degradation caused by current loading and thus improve its working life.