Power diode is a special type of semiconductor device mainly used in circuit rectification When the fails, it will have an adverse effect on power system. The study fault prediction essential to improve reliability systems. By analysing failure mode and aging characteristics diodes, forward voltage drop can be considered as characteristic parameter aging. A platform for thermal cycle diodes designed. supports cycling control acquisition, former times temperature, latter obtain during process.

The steady-state output voltage of the currently developed 18 pulse autotransformer rectifier unit (ATRU) does not meet requirements international standard ISO24071 which released in August 2022.To address this issue, paper proposes an optimization method symmetrical D-type ATRU, based on reasonable design number turns and connection windings. Theoretical analysis calculation voltage, input current, equivalent capacity winding current ATRU are conducted. results verified by a MATLAB...

As the core component of an aircraft generator, health brushless exciter is critical to high-quality generation and flight safety. Its stator field winding prone insulation deterioration under various stresses, leading turn-to-turn short-circuit (TTSC) fault. Diagnosing this type fault, especially in early stage, can greatly enhance safety reliability generators. In paper, on basis analysing effect TTSC current, a fault diagnosis method based mean fractional harmonics current was proposed,...

This paper presents a maximum correntropy method of redshift estimation for spectral navigation (SRN). It converts the problem to correntropy. A wavelet transform technique is established denoise signals and fit continuous portions line extraction further construction candidate set. Subsequently, joint by using based on predicted from SRN system equations correct According criterion, acquired as with Simulations comparative analysis demonstrate that in addition possessed real-time...

This paper presents a new adaptive random weighting cubature Kalman filtering method for nonlinear state estimation. adopts the concept of to address problem that filter (CKF) performance is sensitive system noise. It establishes theories estimate noise statistics and predicted measurement together with their associated covariances. Subsequently, it adaptively adjusts weights points based on estimations improve prediction accuracy, thus restraining disturbances noises Simulations comparison...

Abstract The Ms 6.0 earthquake in Changning, Sichuan, China, on 17 June 2019 was the largest recorded stable Sichuan basin. It occurred a complicated region with salt mining and shale gas production. Whether this is induced raises concerns among public scientific community. Furthermore, relation between nearby industrial activities has also been of great interest. To address these questions, we estimated nonstationary background seismicity rate inverted for spatiotemporal stress changes....

When INS/GNSS (inertial navigation system/global satellite system) integrated system is applied, it will be affected by the insufficient number of visible satellites, and even signal lost completely. At this time, positioning error INS accumulates with accuracy decreases rapidly. Therefore, in order to improve performance integration during signals interruption, a novel learning algorithm for neural network has been presented used intelligence article. First all, determine input output...

Abstract The 2017 Mw 6.5 Jiuzhaigou earthquake occurred at the southeastern boundary of Bayankala block in Tibetan Plateau. Here we investigate spatial and temporal seismicity rate changes region using finite‐source epidemic‐type aftershock sequence model stochastic declustering method. background probabilities all events are obtained, cumulative is extracted fitted by a linear function. Following from this, argue that there was decrease immediately after occurrence 2008 7.9 Wenchuan...

The Gaussian filtering is a commonly used method for nonlinear system state estimation. However, this requires both process noise and measurement to be white sequences with known statistical characteristics. it difficult satisfy condition in engineering practice, making the solution deviated or diverged. This paper adopts random weighting concept address limitation of filtering. It establishes estimations characteristics on basis maximum a-posterior theory, further develops new based...

In order to meet the requirements of autonomy and reliability for navigation system, combined with method measuring speed by using spectral redshift information natural celestial bodies, a new scheme, consisting Strapdown Inertial Navigation System (SINS)/Spectral Redshift (SRS)/Geomagnetic (GNS), is designed autonomous integrated systems. The principle this SINS/SRS/GNS system explored, corresponding mathematical model established. Furthermore, robust adaptive central difference particle...

This paper presents a new Strap-down Inertial Navigation System/Spectrum Red-Shift/Star Sensor (SINS/SRS/SS) system integration methodology to improve the autonomy and reliability of spacecraft navigation using spectrum red-shift information from natural celestial bodies such as Sun, Jupiter Earth. The models for SINS/SRS/SS are established. fusion is designed structure federated Kalman filter fuse local estimations SINS/SRS SINS/SS integrated subsystems generate global state estimation...

Due to the disturbance of wind field, it is difficult achieve precise airship positioning and navigation in stratosphere. This paper presents a new constrained unscented particle filter (UPF) for SINS/GNSS/ADS (inertial system/global satellite system/atmosphere data system) integrated navigation. approach constructs speed model describe relationship between velocity using information output from ADS, further establishes mathematical Based on these models, also develops UPF obtain system...

The power electronics technology plays an even more important role in the aerospace applications of More Electric Aircrafts (MEA). AutoTransformer Rectifier Units (ATRU) have been widely adopted aircrafts due to its simplicity and reliability. In this paper, Zero Sequence Blocking Transformers (ZSBT) are employed DC link realize parallel rectifier bridges for ATRU, being proposed 24-pulse rectifier. A star-connected autotransformer is used topology divide primary side voltage into four...

The Kalman filter is an important technique for system state estimation. It requires the exact knowledge of noise statistics to achieve optimal However, in practice, this often unknown or inaccurate due uncertainties and disturbances involved dynamic environment, leading degraded even divergent filtering solutions. To address issue, paper presents a new method by combining random weighting concept with limited memory accurately estimate statistics. avoid influence excessive historical...

ABSTRACT The Kalman filter is an important technique for system state estimation. It requires the exact knowledge of noise statistics to achieve optimal However, in practice, this often unknown or inaccurate due uncertainties and disturbances involved dynamic environment, leading degraded even divergent filtering solutions. This paper proposes a novel method H∞ filtering‐based on adaptive random weighted estimation address issue. combines with concept estimate statistics. Random weighting...

An improved filtering algorithm‐robust adaptive spherical simplex unscented particle filter (RASSUPF) is proposed to achieve high accuracy, induce the amount of computation, and resist influence abnormal interference for MINS/VNS/GNS integrated navigation system. This algorithm adopts transformation (SSUT) approximate probability distribution, employs Kalman (SSUKF) generate importance sampling density filter, applies robust estimation control information on state model observation model....

The small signal transfer function of the Boost converter with Constant Power Loads(CPLs) is derived and condition stability for system obtained. State feedback exact linearization optimal tracking control technique are applied to system. nonlinear law verified using SABER. simulation results show that controller can make operation steadily during large disturbances in power supply loads.

The cubature Kalman filter (CKF) is an estimation method for nonlinear Gaussian systems. However, its filtering solution affected by system error, leading to biased or diverged state estimation. This paper proposes a randomly weighted CKF (RWCKF) handle the limitation. incorporates random weights in restrain error’s influence on dynamic modification of point weights. Randomly theories are established estimate predicted and measurement as well their covariances. Simulation experimental...

According to the essential operational principle of High Power Factor PWM rectifier, a simulation model AC constant power load is proposed. The input current this ensured follow voltage and consistence in their waveforms achieved. This can calculate RMS then generate an appropriate waveform corresponding harmonics contained voltage. Therefore even with influence harmonics. Compared experimental result high factor rectifier behaving as CPL, results Matlab software verify correctness model.

A deep research on the contact line (T)-negative feeder(F) short-circuit impedance is made in this paper basis of analyzing advantages and disadvantages all existing parallel AT power supply system fault location methods . Then, simulation model traction established characteristic under T-F condition simulated analyzed. The results show that subsection method basically corresponds to requirement engineering application. It also provides some theoretical reference for analysis system.

Voltage decrease and power loss in distribution lines of aircraft electric system are harmful to the normal operation electrical equipment, may even threat safety aircraft. This study investigates how gap distance (the between cables skin) voltage frequency (variable supply will be adopted for next generation aircraft) affect impedance cables. To more precise, forming mechanism cable resistance inductance is illustrated detail their change trends with analyzed help electromagnetic theory. An...

Voltage decrease and power loss in distribution lines of aircraft electric system are harmful to the normal operation electrical equipment may even threaten safety aircraft. This study investigates how gap distance (the between cables skin) voltage frequency (variable supply will be adopted for next generation aircraft) affect impedance cables. To more precise, forming mechanism cable resistance inductance is illustrated detail their changing trends with analyzed help electromagnetic...