Mitigating a transient response of a series stacked AC-DC converter

Wang, Patrick

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https://hdl.handle.net/2142/100044 Copy

Description

Title

Mitigating a transient response of a series stacked AC-DC converter

Author(s)

Wang, Patrick

Contributor(s)

• Banerjee, Arijit
• Huynh, Phuc

Issue Date

2018-05

Keyword(s)

• power conversion
• AC-DC power converters
• generators
• permanent magnet machines
• control systems
• motor control
• power generator control

Abstract

Generator operating at a limited speed range is essential for improving mechanical to electrical conversion efficiency in many high-power conversion systems, such as wind turbines and future ship turbine-generator systems. To meet the power quality requirements while supporting the variable speed operation, ac-dc conversion is required as the interface between the generators and a dc power grid. Therefore, high-efficiency ac-dc conversion is crucial to improve the overall conversion efficiency. An ac-dc conversion architecture integrating power electronics to a multi-port permanent-magnet synchronous generator was proposed for higher ac-dc conversion efficiency and higher system reliability. This architecture series stacks passive rectifiers and one active rectifier to generate a constant dc bus. Each of the rectifiers is powered by one three-phase port from the generator. The efficiency and reliability improvements come from the use of passive rectifiers to process a portion of the total power. A simulation model and a laboratory prototype were built to illustrate the feasibility of the proposed architecture. However, the prototype still has unsatisfactory dynamic performance. The dc bus voltage under a generator speed change still contains unwanted oscillation in the transient response. This thesis focuses on resolving the problem by two methods: (i) study the oscillation mechanism by investigating a realistic generator model and implementing a ramp command in speed change; (ii) achieve a better transient response of the dc bus voltage profile under the changes by appropriately improving the dc bus voltage controller on the experimental setup.

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/100044

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