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Efficiency enhancement to a linear AC voltage regulator: Multi-winding versus multi-transformer design

Electricity distribution companies are required to supply electric power, which conforms to accepted standards, that place limits on voltage fluctuations beyond nominal values. However, it is common for these fluctuations to exceed the specified standards. One solution to this problem is to install stand-alone RMS voltage regulators at the consumer site. Commonly available AC regulators typically have limitations such as slow response time, flattened sine wave output, low efficiency, and limited operating range. The linear AC voltage regulator is a relatively new type of solid-state, single-phase AC regulator for consumer-end, which addresses most of the above issues. It is based on a series transistor-array coupled with a line-frequency transformer that works seamlessly from boost-to-buck mode in the range of 0.8−1.1 per-unit values of line voltage, without a need of any transformer configuration changes. However, previous prototypes exhibited reduced efficiency when the line voltage exceeded the nominal value. This paper presents two alternative designs that achieve efficiencies of 90−95%, usually required in commercial implementation. Analytical and experimental results of a multi-winding versus multi-transformer based prototypes of 300VA output capacity are presented.
Journal Article
Type of thesis
Institute of Electrical and Electronics Engineers (IEEE)
Authorized licensed use limited to: Univ of Waikato. Restrictions apply. This is an author’s accepted version of an article published in Generic Colorized Journal. © 2020 IEEE.