Abstract Leakage is one of the most serious challenges for safe production high‐pressure gas wells its high risks, including abnormal annular pressure, natural accumulation, and environment pollution, but available methods can hardly accurately measure leakage type depth, which are key parameters rigless repair risk assessment. Therefore, this paper proposes a method to based on characteristics, combines qualitative quantitative measurement together. Qualitative considers tubing liquid...

In order to meet the full load range operation requirement for a semi-dual active bridge (semi-DAB) dc-dc converter working as battery charger, multimode control strategy was presented. Under heavy load, it works with single phase-shifted control. light pulsewidth modulation (PWM) and variable switching frequency. very conditions, PWM constant frequency mode. Light conversion efficiency can be improved significantly by using proposed strategy. Detailed loss breakdown is analyzed compared...

A high-frequency isolated unidirectional three phase (3p) current-fed (CF) semi-dual active bridge (SDAB) dc–dc converter is proposed for power-flow applications suitable wide input and load variations with small current ripple, such as fuel stacks photovoltaic (PV) array. hybrid operating mode control was to handle the stability throughout full range especially light conditions by which, dual-pulsewidth modulation (PWM) shifted fixed clamping voltage implemented over certain kind of while...

Cuckoo Search algorithm is a new bio-inspired algorithm, which describes cuckoo's foraging behavior based on parasitized breeding mechanism of egg and Levy flight search principle. can explore solution space as much possible jump out the local best flexibility. Combined with truncation rounding theory, improved to apply power network planning, introduced solve chance-constrained integer planning model global optimal solution. The effectiveness feasibility solving are verified by taking...

For current-fed dual-active bridge bidirectional dc-dc converters, a PWM plus dual phase shifted (PPDPS) control with varying switching frequency was proposed. To prevent magnetic core saturation, the flux density change of transformer is kept constant in spite battery voltage and load. The detailed loss breakdown implemented by comparing conventional PPDPS fixed frequency. With proposed control, zero performance better lower conversion efficiency can be improved compared control. closed...

With the development of UHV (Ultra-High Voltage) transmission, great changes have occurred for reactive power distribution. Especially transmission varies with different power. Therefore, optimization considering penetration is presented in this paper. The estimation proposed scheme can minimize and hence voltage stability margin whole system transmission. And solved based on improved differential evolution algorithm. An example Huadong grid discussed analyzed. it's proved that present...

As its sampling frequency is independent of the scale system, Monte-Carlo simulation widely applied to reliability evaluation generation and transmission which a complex large system. However, it takes relatively long period obtain higher accurate index. This paper points out that, combination Importance method Discrete Latin Hypercube able reduce variance sample space uniformly simultaneously, improves convergence simulation. Besides, sensitivity analysis linear programming in process...

The conventional ultra capacitor charger uses computer to monitor the capacitor's state of charge(SOC) and adopts different strategy charge capacitor.It makes system expensive control method is also inconvenient.For above problems, a non-microcomputer charging designed.The proposed can achieve two-step modes, constant current limiting voltage(CCLV) mode voltage current(CVLC) mode.Finally, designed presented at last article.

Inspired by an electromagnetic hydropower station that contains reverse polarized magnets, this paper reports a multi-phase bipolar rotary electret power generator (MB-RPH) with DC output current. It is capable of generating almost constant current low crest factor phase coupling caused structure and integrating both positive negative charged into monolayer generators charging to improve performance. Experiments show the each increased about 367% ' performance significantly increases as...

Robotic manufacturing systems are essential in the post-pandemic world because of their high level flexibility and automation when facing a labor crisis. However, it is still challenging to design suitable robotic system for Small- mid-sized enterprises (SMEs), considering both financial burdens SMEs current supply chain disruptions component suppliers.To address these challenges, this study proposes distributed multi-agent collaborative conceptual method involving designers suppliers assist...

Alternating magnetic field (AMF) configurable at a range of frequencies is critical need for optimization nanoparticle based hyperthermia, and their application in targeted drug delivery. Currently, most commercial AMF devices including induction heaters operate one factory-fixed frequency, thereby limiting customized frequency configuration required triggered release mild hyperthermia (40-42°C) ablations (>55°C). Most run as an inductor-capacitor resonance network that could allow to be...

Although acute promyelocytic leukaemia (APL) is a highly curable disease, challenges of early death (ED) and relapse still exist, real-world data are scarce in the ATRA plus ATO era. A total 1105 APL patients from 1990 to 2020 were enrolled categorized into three treatment periods, namely ATRA, ATO, risk-adapted therapy. The rate was 20.2%, 10.1% 7.0%, respectively, while there no significant decline 7-day rate. Consistently, overall survival (OS) disease-free (DFS) markedly improved over...

With the rapid development of Internet Things (IoT) and big-data technology, higher requirement for intelligence bearings has been put forward. This paper reports a novel type intelligent thrust ball bearing, called electret bearing (ETBB), which both self-powering self-sensing capabilities. Due to common characteristics non-contact relative rotational movement, rotary power generator on free-standing mode is embedded into not only maintains mechanical structural integrity but also obtains...