All-order evaluation of weak measurements: --- The cases of an operator A{\bf A} which satisfies the property A2=1{\bf A}^{2}=1 ---

Some exact formulae of the expectation values and probability densities in a weak measurement for an operator ${\bf A}$ which satisfies the property ${\bf A}^{2}=1$ are derived. These formulae include all-order effects of the unitary evolution due to the von-Neumann interaction. These are valid not only in the weak measurement regime but also in the strong measurement regime and tell us the connection between these two regime. Using these formulae, arguments of the optimization of the signal amplification and the signal to noise ratio are developed in two typical experimental setups.Comment: 17 pages, 10 figures (v1); Fig.3 and some typos are corrected (v2); Comments and references are added and some typos are corrected (v3

Temperature rise measurement for power-loss comparison of an aluminum electrolytic capacitor between sinusoidal and square-wave current injections

DC-link capacitors are a major factor of degrading reliability of power electric converters because they usually have a shorter lifetime and higher failure rate than those of semiconductor devices or magnetic devices. Characteristics of the capacitors are usually evaluated by a single sinusoidal current waveform. However, actual current flowing out of the converter into the capacitor is a modulated square current waveform. This paper provides experimental comparison of the power loss dissipated in an aluminum electrolytic capacitor between sinusoidal and square-wave current injections. Power loss is estimated by temperature rise of the capacitor. Experimental results confirm that power losses of the square-wave current injection were always lower than those of the sinusoidal current injection by 10–20%. Moreover, the power losses of the square-wave current injection can be estimated by a synthesis of fundamental and harmonic currents based on the Fourier series expansion, which brings a high accuracy less than 1% when more than fifth harmonic current is introduced. This comparison will be useful for estimating power loss and life time of electrolytic capacitors

Planck Sunyaev-Zel'dovich Cluster Mass Calibration using Hyper Suprime-Cam Weak Lensing

Using $\sim$140 deg$^2$ Subaru Hyper Suprime-Cam (HSC) survey data, we stack the weak lensing (WL) signal around five Planck clusters found within the footprint. This yields a 15$\sigma$ detection of the mean Planck cluster mass density profile. The five Planck clusters span a relatively wide mass range, $M_{\rm WL,500c} = (2-30)\times10^{14}\,M_\odot/h$ with a mean mass of $M_{\rm WL,500c} = (4.15\pm0.61)\times10^{14}\,M_\odot/h$. The ratio of the stacked Planck Sunyaev-Zel'dovich (SZ) mass to the stacked WL mass is $\langle M_{\rm SZ}\rangle/\langle M_{\rm WL}\rangle = 1-b = 0.80\pm0.14$. This mass bias is consistent with previous WL mass calibrations of Planck clusters within the errors. We discuss the implications of our findings for the calibration of SZ cluster counts and the much discussed tension between Planck SZ cluster counts and Planck $\Lambda$CDM cosmology.Comment: 12 pages, 2 tables, 7 figures, accepted to PASJ special issu

ESR and capacitance monitoring of a dc-link capacitor used in a three-phase PWM inverter with a front-end diode rectifier

Condition monitoring plays an important role in estimating health condition of capacitors because the ageing of the capacitors is usually accompanied by an increase in equivalent series resistance (ESR) and a decrease in capacitance. Either capacitance or ESR cannot be a unique indicator of the lifetime of capacitors in some cases. This paper presents a condition monitoring method of a dc-link capacitor used in a three-phase PWM inverter with a front-end diode rectifier intended for motor drives. The monitoring method extracts both the ESR and capacitance of a capacitor under test from the actual ripple current and voltage without disconnecting the capacitor nor injecting an additional current. The monitoring method, therefore, can be implemented online. Experimental results verify that the monitoring method independently obtains the ESR and capacitance changes of the capacitor under test. This contributes to accurate lifetime estimation of dc-link capacitors

On a q-analogue of the multiple gamma functions

A $q$-analogue of the multiple gamma functions is introduced, and is shown to satisfy the generalized Bohr-Morellup theorem. Furthermore we give some expressions of these function.Comment: 8 pages, AMS-Late

Dynamic avalanche free super junction-TCIGBT for high power density operation

Dynamic Avalanche (DA) effects in the Super-Junction Trench IGBTs are analyzed through 3-D TCAD simulations for the first time. A DA free solution for high power density and low loss is proposed and demonstrated in detail. Furthermore, simulation results show that DA results in significant increase in turn-off losses in the Super-Junction Trench IGBTs at high current density operations, which poses a fundamental limit on the power density of IGBT applications. In contrast, the Super-Junction Trench Clustered IGBTs remain DA free at high current density and show low switching losses due to enhanced PMOS action. Therefore, the Super-Junction Trench IGBTs are well suitable for high power density operations with a potential to operate beyond the 1-D unipolar 4H-SiC limit

Turn-off dV/dt controllability in 1.2kV MOS-bipolar devices

Turn-off dV/dt controllability is an essential feature in IGBTs for flexible design in power switching applications. However, the occurrence of Dynamic Avalanche (DA) during the turn-off transients plays a key role on the turn-off power loss, dV/dt controllability and safe operating area of IGBTs. This paper aims to clarify the impact of DA on the turn-off characteristics of 1.2 kV trench IGBTs through calibrated 3-D TCAD simulations as well as experimental demonstrations. Measurement results show that DA is enhanced at high current density and high supply voltage conditions, which aggravates its influence on the dV/dt controllability as well as turn-off power loss. In order to eliminate the DA for high current density and low loss operations, a DA free design is experimentally demonstrated in the Trench Clustered IGBT (TCIGBT). Due to effective management of electric field and unique PMOS actions during turn-off, TCIGBT can retain high dV/dt controllability and low power loss at high current density operations

High dV/dt controllability of 1.2kV Si-TCIGBT for high flexibility design with ultra-low loss operation

High dV/dt controllability of IGBT is an important factor for flexible design as well as low switching loss in power electronics systems. However, Dynamic Avalanche (DA) phenomenon poses a fundamental limit on their dV/dt control range, operating current density, turn-off power loss as well as reliability. Overcoming this phenomenon is essential to ensure their safe operation and high robustness in emerging electric transport. In this work, detailed analysis of 1.2 kV trench gated IGBTs is undertaken through experiments and calibrated TCAD 3-dimensional simulations to show the fundamental cause of the low dV/dt controllability of conventional IGBTs and a method to achieve DA free design by Trench Clustered IGBT (TCIGBT). The potential of TCIGBT for ultra-high current density operation with high dV/dt controllability is also presented