Abstract

Owing to the increasing demand in the urban areas for new technologies such as heat pumps and electric vehicles (EVs), greater power capacity in low voltage (LV) distribution networks is becoming increasingly important. This study will investigate how to improve the power capacity through the implementation of point of use voltage regulation (PUVR). PUVR relies on a power electronics converter at each end-user. Most LV network cabling has a voltage limit of 1 kV, PUVR exploits this voltage rating to increase the network capacity. This study will describe and discuss the results from a viability study using data from a utility company, which shows that the capacity in the LV network could be increased by an additional 500 kVA. However, it was also found that PUVR using present off-the-shelf converters is not as cost-effective as replacing the LV network cables. Two power electronics topologies have been investigated in the simulation studies to date: the AC chopper circuit and the back-to-back inverter circuit. These two topologies were compared and the AC chopper was found to be a cheaper, more efficient topology. Therefore the AC chopper is more suitable for this application and may increase the viability of the PUVR.

Highlights

  • 1.1 Need for point of use voltage regulation (PUVR)In order for the UK to meet the 2020 and 2050 greenhouse gas emissions targets set by the European Union, immediate changes are required across all energy sectors [1]

  • The aim of this paper is to show that end user voltage regulation is a potential solution to this problem

  • This paper proposes two different power electronic circuits to carry out the voltage regulation: the AC chopper and the back-to-back inverter

Read more

Summary

Introduction

In order for the UK to meet the 2020 and 2050 greenhouse gas emissions targets set by the European Union, immediate changes are required across all energy sectors [1]. It is expected that over the 30 years ‘cleaner’ emerging technologies such as heat pumps [2] and electric vehicles (EVs) will be implemented in order to meet these targets. The increasing costs of fossil fuels and of new vehicles are likely to force higher population densities in urban areas, thereby reducing distance of travel to the work place. If the existing urban low-voltage distribution infrastructure is left unchanged, it is unlikely to be ready for this predicted increase in demand in urban areas, which is expected to be in the order of 1–2 GW in magnitude [4]. The concept of PUVR is to set the line-to-line voltage in the three-phase distribution cabling to be higher than the standard 415 V. It is clear that the distribution cabling is underutilised, but in order to make the power usable when it reaches the customer it must be transformed down to 230 V phase

Voltage rise
Distributed generation
Power electronics against transformers
Electric vehicles
Paper outline
Low-voltage distribution cable limitations
Limits of the present urban distribution system
Consideration of losses in a point of use regulation system
Cable loss
Converter loss
Cost benefit
Summary
Proposed technology options for PUVR
AC chopper for PUVR
Filter design
AC chopper results
Second-order low-pass filter design
Switching frequency against harmonic distortion
Back-to-back inverter
Capacitor sizing and design of input and output filters
Back-to-back inverter results
Losses
Power quality
Total harmonic distortion
Non-unity power factor loading
Loading extremes
Complexity and cost
Development of closed-loop control for the AC chopper
Protection
Transient behaviour
Findings
Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call