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

authors: Wijesooriya, Priyanwada Nimesha

abstract: 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.

text: 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.

year: 2020-06-18

title: Work-integrated learning gone full circle: How prior work placement experiences influenced workplace supervisors

authors: Martin, Andrew

subjects: work placements

abstract: This article reports of a study of workplace supervision and student experiences and outcomes through insights from semi-structured interviews with 21 graduates who had previously supervised work placement students. The study focused on questions framed from the perspective of the interviewees’ work placement experiences as a student and then as a supervisor (e.g., impact, motivation, insights for future students/supervisors, and graduate attributes). The findings from this study indicate importance of workplace supervisors setting expectations and engaging in initial planning and organizing for effective management of the work placement. Findings also suggest that the supervising can usefully take the form of mentoring, and that this provides the supervisor with professional development in self-management, effective communication and leadership. Implications for future WIL practice include utilizing workplace supervisors, particularly those who are themselves WIL graduates, to help further enhance student WIL experiences, learning outcomes, and legacies

text: Work-integrated learning gone full circle: How prior work placement experiences influenced workplace supervisors This article reports of a study of workplace supervision and student experiences and outcomes through insights from semi-structured interviews with 21 graduates who had previously supervised work placement students. The study focused on questions framed from the perspective of the interviewees’ work placement experiences as a student and then as a supervisor (e.g., impact, motivation, insights for future students/supervisors, and graduate attributes). The findings from this study indicate importance of workplace supervisors setting expectations and engaging in initial planning and organizing for effective management of the work placement. Findings also suggest that the supervising can usefully take the form of mentoring, and that this provides the supervisor with professional development in self-management, effective communication and leadership. Implications for future WIL practice include utilizing workplace supervisors, particularly those who are themselves WIL graduates, to help further enhance student WIL experiences, learning outcomes, and legacies

year: 2019

title: Hei Āwhina Mātua: A kaupapa Māori response to behaviour

authors: Berryman, Mere

abstract: Hei Āwhina Mātua (strengthening parents and other adults), a kaupapa Māori research and development project, sought to capitalise on the strengths available within both whānau and teachers so that both groups could take joint responsibility for students' learning and behaviour. This required professionals trained in delivering learning and behavioural programmes for individual students working in culturally responsive and collaborative ways with adults, whānau, teachers and community members, This chapter returns to this study to reconsider the key findings.

text: Hei Āwhina Mātua: A kaupapa Māori response to behaviour Hei Āwhina Mātua (strengthening parents and other adults), a kaupapa Māori research and development project, sought to capitalise on the strengths available within both whānau and teachers so that both groups could take joint responsibility for students' learning and behaviour. This required professionals trained in delivering learning and behavioural programmes for individual students working in culturally responsive and collaborative ways with adults, whānau, teachers and community members, This chapter returns to this study to reconsider the key findings.

year: 2015