Abstract Electrochemical impedance spectroscopy (EIS) is widely used for state estimation of energy storage batteries. Currently, EIS typically obtained via frequency sweep methods using electrochemical workstations, which incur high detection time costs. Existing also show limited accuracy in battery estimation. To reduce measurement and improve accuracy, a Transformer--based method utilizing at multiple points proposed. Specifically, by conducting experiments on lithium-ion batteries under...

This article presents a new phase-shifted full-bridge topology using variable inductor. In this topology, inductor is connected in parallel with near-ideal transformer. The zero-voltage switching (ZVS) of the switches achieved over full-load range current provided by And adjustable reduces conduction losses. Under orthogonal dc magnetic potential, has similar characteristics to saturated inductor, which beneficial reduce loss caused current. Since no series and leakage extremely small,...

The junction temperature at the fundamental frequency cannot be ignored in a lifetime evaluation of insulated-gate bipolar transistors (IGBTs) with long-term mission profile. Therefore, it is very important terms calculation speed and accuracy to simplify loss curve when calculating thermal fluctuation frequency. This paper proposes mathematical analysis method for based on an equivalent sinusoidal half-wave loss. dynamic static parameters devices are tested by experimental platform,...

Magnetron is an oscillator with poor phase stability and could not be applied in coherent system. Based on the mutual-coupling injection startup technology, a millimeter wave coaxial magnetron for array application was developed it first time to achieve frequency locking millimeter-band magnetron. Using CST particle studio, model additional coupling port set outer cavity built. Simulation analysis conducted by using bridge connect two ports. The relationship of length lock performance...

A simplified equivalent circuit of electric powertrain system hybrid electrical vehicle (HEV) is proposed to research and investigate into the impact pulse width modulation (PWM) strategies voltage source inverter (VSI) on DC-link capacitor in HEVs. Then, analytical solutions switching function are introduced based space vector PWM (SVPWM) discontinuous (DPWM) schemes. Furthermore, current characterized with solution simulation method quantify various schemes ripple. Finally, both...

Building boundary is of great significance for building reconstruction and digital mapping. The emergence airborne LIDAR technology makes rapid extraction buildings possible. Based on the analysis existing method, article proposes an automatic method extracting 3D boundaries directly from points cloud, which consists three steps: firstly, are segmented by a multi-resolution directional prediction filter roof then recognized series refinement procedure; Secondly, TIN mode built initial...

The dynamic contact voltage of electromagnetic relays are measured in the paper. Both its statistics characteristic and time sequence studied detail. Based on these characteristics, failure diagnostics parameters determined light principle factor method prediction model electrical set up accordance with fuzzy method. By model, can be predicted as reliability relay.

Waterjet abrasive nozzle is the key component for accelerating particle velocity and its diameter has important influence on water jet. The relationship between waterjet cutting performance been studied by experiment. results show: incision depth width of specimen decrease linearly with decreasing diameter; linearity jet moving direction size kerf angle are independent diameter. Under same pressure, reducing make penetration capability to reduce, thus, quality decrease.

Chip solder degradation is one of the main factors affecting reliable operation insulated gate bipolar transistor (IGBT) modules. However, there are still many challenges to get real lifetime chip solder. This paper proposes a consumption prediction method based on failure. First, constant high junction temperature fluctuations applied IGBT modules for power cycling tests. The transient thermal resistance measured monitor process every 1000 times aging And failure degree analyzed by integral...

DC‐link capacitor is one of the most vulnerable passive components in drive system electric vehicle, so condition monitoring capacitors can significantly improve reliability and even driving safety. The existing methods are subject to low accuracy, added hardware irreversible impact on system. Therefore, based Back Propagation (BP) neural network with Improved Gray Wolf Optimization (IGWO), a parameter identification method for vehicle inverter proposed. In this method, capacitance ( C )...

DC-input side of the inverter to balance input and output power, eliminate voltage fluctuation, reduce spike in side. The reliability study on DC-link capacitor under fault state is critical safe operation whole driving system. This builds equivalent circuit source (VSI) with space vector pulse width modulation (SVPWM) strategy analyses current characteristic capacitance normal state. characteristics main Insulation Gate Bipolar Transistor (IGBT) open-circuit states are analyzed differences...

Through the introduction of balanced scorecard, on basis its financial, customer, internal operation, learning and development to improved this paper highlighted "green" increased social environmental factors perfected performance evaluation index green supply chain. Further, it put forward five-level indicators 17 secondary which constitute system chain management, designed a model It provided reference for enterprise's has certain theoretical practical significance.

The transformer is the indispensable important equipment in power system. Optimization design of has become an urgent requirement. This paper takes typical voltage JDCF-110 as research object. Based on deep study structure and basic method, genetic algorithm applied optimization design. model determined, parameters by use are set software developed. realized to achieve anticipated goal.

We take statistics on experimental data, including static contact resistance, bounce time and the max resistance of relay's matching contacts in dynamic closing process. A conclusion is drawn that not obedience to normal distribution function. The further analysis makes clear reliability has correlation with eigenvalues diagnostic parameters figure their density curves. reason for these discussed preliminarily. On ground above work, we develop prediction model based sequence character.

When connecting a large number of generating sets into power grid, there will be the harmonic wave generated in grid causing voltage and current distortion, which affects quality seriously. Based on instantaneous reactive theory, active current, can real-time monitored. The P–Q method adopted to control compensation. By building converter model, variation between photovoltaic grid-connected inverter working under stand-alone mode analysed via simulation system. experimental analysis...

Testing covariance matrices is crucial in high-dimensional statistics. Traditional methods based on the Frobenius and supremum norms are widely used but often treat matrix as a vector neglect its inherent structure. This paper introduces new testing framework operator norm, designed to capture spectral properties of more accurately. The commonly empirical bootstrap multiplier shown fail for norm-based To derive critical values this type statistics, we propose universal procedure, utilizing...

Aiming at the fatigue failure of IGBT module package, evolution process weak link- bond wire and solder layer is studied. For failure, cracks The variation law in analyzed by resistance as characterization parameter crack evolution. growth voids effects on junction temperature stress are analyzed, two void modes given. Taking thermal evolution, analyzed. results show that has little effect initial stage crack, grows to a certain extent, equivalent will expand rapidly, causing fail; under...

This article develops the automatic test system of voltage and current dynamic waveform for circuit breaker. The has monitoring, storage display function contact breaker in switching process. And then, it also designs hardware software monitoring miniature breaker: this mainly consists detection data acquisition voltage. system, which control program, program processing is programmed under condition LabVIEW. At last, carries on real-time monitor to at both ends breaker, especially during...

Through the analysis of stress in ultra high-pressure cylinders, found that its distribution is very uneven. In order to use principle autofrettage for improving design first with Faupel-Furbe formula calculate estimates diameter ratio, and thus are inner outer cylinder block. Then determined parameter on such as optimum radius elastic-plastic junction pressure. Finally, calculation improved cylinder, results show have a greater degree improvement weight, size three areas. Key words:...