The University of Nottingham Ningbo China

About: The University of Nottingham Ningbo China is a education organization based out in Ningbo, Zhejiang, China. It is known for research contribution in the topics: Computer science & China. The organization has 7491 authors who have published 7153 publications receiving 83555 citations.

A Novel Open-Circuit Fault Diagnosis Method for Voltage Source Inverters With a Single Current Sensor

Abstract: For the purpose of reducing cost and volume, as well as to increase reliability in hostile environments, techniques of reconstructing three-phase current through a single current sensor have been reported for a three-phase alternating current motor vector control system. Based on the phase current reconstruction method, this paper proposes a novel open-circuit fault diagnosis method for the low-power voltage source inverter in the three-phase permanent-magnet synchronous motor drive. Other than sampling the single dc-link current sensor, the zero voltage vector sampling method (ZVVSM) is adopted to implement the fault diagnosis. By placing the single current sensor at a special position, ZVVSM is able to sample current during the two zero voltage vectors and reconstruct the three-phase currents. The reconstructed three-phase currents are used to generate the diagnostic variables that can detect and locate the faulty power switches. The PWM modulation strategy remains unchanged in this method and the reconstructed phase currents are with less waveform distortion and less harmonic contents, which are suitable for the fault diagnosis. The effectiveness of the proposed method is verified by experiments.

What factors influence the organizational commitment of public sector employees in China? The role of extrinsic, intrinsic and social rewards

Abstract: This study investigates the relationship between extrinsic, intrinsic and social rewards, and the organizational commitment of 239 Chinese public sector employees. Hierarchical regression analysis revealed that although variables included to measure extrinsic and social rewards were strongly related to organizational commitment, variables included to measure intrinsic rewards had limited influence. These findings suggest that the antecedents of organizational commitment in the Chinese public sector are significantly different from those in the Chinese private sector and public sector organizations in the West.

Orientation dependent cyclic stability of the elastocaloric effect in textured Ni-Mn-Ga alloys

Abstract: High-performance elastocaloric materials require a large reversible elastocaloric effect and long life cyclic stability. Here, we fabricated textured polycrystalline Ni50.4Mn27.3Ga22.3 alloys by cost-effective casting method to create a texture. A strong correlation between the cyclic stability and the crystal orientation was demonstrated. A large reversible adiabatic temperature change ΔT ∼6 K was obtained when the external stress was applied parallel to direction. However, the ΔT decreased rapidly after 50 cycles, showing an unstable elastocaloric effect (eCE). On the other hand, when the external stress was applied perpendicular to , the adiabatic ΔT was smaller ∼4 K, but was stable over 100 cycles. This significantly enhanced eCE stability was related to the high yield strength, low transformation strain and much higher crack initiation-propagation resistances perpendicular to direction. This study provides a feasible strategy for optimizing the eCE property by creation of the texture structure in polycrystalline Ni-Mn-Ga and Ni-Mn-X (X= In, Sn, Sb) alloys.