Electric Power Engineering Centre (EPECentre)

 

Project Number: 2019-23

Project Leader: Michael Hayes, Bill Heffernan

Host Department: ECE (with EPECentre)

Project Title: Instrumentation for groundwater flow measurement

Project outline: As part of the National Science Challenge, UC's ECE Department is involved in a project to try to measure low flow velocities of groundwater in aquifers.   The technique being investigated is based on the concept put forward by Michael Faraday, in which a voltage is induced across water flowing through an AC magnetic field.  Ideally, the intention is to trial the system developed on the Kaitorete spit, which links Te Waihora (Lake Ellesmere) and the Pacific Ocean.

The magnetic field is created by a large electromagnet driven from some power electronics.   The goal of this project is to design and construct an embedded system for controlling the power electronics and synchronising its operation with the measurement electronics.  A critical aspect is that the controlling circuit has low jitter and thus will require a high-performance microcontroller perhaps in conjunction with an FPGA.  The microcontroller needs to remotely communicate with a remote PC and avoid ground loops.

Specific Requirements: 2nd or 3rd professional year ECE or Mechatronics student - preferably a student considering studying towards a higher degree.  Good knowledge of embedded systems and circuit layout fundamentals (e.g., from ENCE361, ENCE461)

Knowledge of PCB layout software, e.g., Kicad, Altium.

 

 

Project Number: 2019-24

Project Leader: Michael Hayes, Bill Heffernan

Host Department: ECE (with EPECentre)

Project Title: Building and testing a novel power converter to drive an induction coil with a trapezoidal current waveform

Project outline: As part of the National Science Challenge, UC's ECE Department is involved in a project to try to measure low flow velocities of groundwater in aquifers.  The technique being investigated is based on the concept put forward by Michael Faraday, in which a voltage is induced across water flowing through an AC magnetic field.  Ideally, the intention is to trial the system developed on the Kaitorete spit, which links Te Waihora (Lake Ellesmere) and the Pacific Ocean.

To produce such an AC magnetic field, a coil is driven with an AC current waveform.  In some instances a flat-topped waveform (approximating a square wave) is preferable to a sinusoidal one.  However, the coil is essentially an inductance with some series resistance and as all electrical engineering students know, you cannot instantaneously change the current in an inductor.  Instead, we have devised a relatively simple and low cost switching power electronics circuit which provides high di/dt to commutate rapidly from negative to positive current half-cycles and constant current to maintain the steady state current during the half-cycles.

This circuit has gradually evolved as the project has progressed, with the result that it is rather large and cumbersome and, most importantly, not readily portable.   The purpose of this project is to design, build and test a new, compact version of the existing circuit, which can be taken out of the lab and deployed in situ.

Specific Requirements: 2nd or 3rd professional year ECE or Mechatronics student - preferably a student considering studying towards a higher degree.

Good knowledge of power electronics and circuit layout fundamentals (e.g., from ENEL372, ENEL471)

Knowledge of PCB layout software, e.g., KiKad, Altium.

 

 

Project Number: 2019-40

Project Leader: Bill Heffernan/Nurzhan Nursultanov, Clemens Altaner, Shusheng Pang

Host Department: EPECentre (with School of Forestry and CAPE)

Project Title: Thermodynamic and economic evaluation of veneer log conditioning processes: a comparison of current and new heating methods

Project outline: The production of laminated wood products, such as plywood and LVL, is achieved by peeling logs on a lathe into thin sheets of veneer, which are subsequently dried, glued and laminated. The process is energy intensive with most of the energy being consumed in thermally conditioning the logs, to soften them before peeling, and then drying of the resulting sheets of veneer. The thermal energy is currently derived from burning wood waste (bark, sawdust, woodchips, veneer waste etc.) to produce hot water and/or steam. The green logs are heated either in hot water bath or in a steam chamber; however, it is observed that both processes have significant heat loss. In some overseas operations the waste wood boilers may also be used to produce electricity, which may be used within the plant, or exported to the grid.

The EPECentre has developed a process for heating freshly felled logs, employing Joule's effect, in which electric current-flow directly heats conductive parts within the timber with subsequent heat flow to less conductive parts. Computational models which predict and control the process reliably have been developed, validated experimentally on full-sized radiata pine logs and reported in the literature.

The result is an energy-efficient and relatively fast process (logs ready to peel for veneer in under 2 hours) compared to existing hot water bath (approximately 20 hours) or steam (of the order of 5 hours) processes. This results in time and energy savings, as well as changing the conditioning process from a batch to a continuous operation, which may also provide some logistical benefits. The energy savings result both from inherently reduced losses from the faster heating process and improved control of the individually tailored final temperature profile of each log.

The purposes of this project are:

  • to model both existing and new processes thermodynamically (heat and mass balance calculation) and economically,
  • to establish the net benefits that could be achieved from adopting this new technology,
  • to identify under what scenarios of equipment investment, electricity cost, alternative uses for currently-burned wood waste and carbon dioxide emissions pricing, economic benefits can be realized.

 Specific Requirements: 3rd professional year student - ideally a student considering studying towards a higher degree.

Good knowledge of thermodynamics and process engineering (e.g. from ENCH292, ENCH392/393 and ENCH494, or from ENME215, ENME315 and ENME405/415)

Knowledge of process modelling techniques (heat and mass balance calculation is essential), process simulators (e.g. HYSYS), and scientific coding (e.g. MATLAB or Python)

 

 

Project Number: 2019-45

Project Leader: Nurzhan Nursultanov, Clemens Altaner

Host Department: EPECentre (with School of Forestry)

Project Title: Electrical characterization of green timber

Project outline: The electrical behaviour of recently felled timber, and indeed of living trees, is of significant scientific interest. It can be used, with suitable measuring instruments, to determine the proportions of the various wood regions inside a tree or log, such as heartwood, sapwood or intermediate wood. The content of these various wood regions has significant impact on the quality, value and best end use for the timber from a given tree and information on the growth rate of the various regions can influence the choice of the best genetics for propagation.

The electrical characteristics can also be used to predict the heating of logs using a process recently developed by the EPECentre, employing Joule's effect, in which electric current-flow directly heats the more conductive parts within the timber with subsequent heat flow to less conductive parts. Computational models which predict and control the process reliably have been developed, validated experimentally on full-sized radiata pine logs and reported in the literature. Logs used to produce veneers for decorative timber, plywood and laminated veneer lumber (LVL) are generally heated to soften the timber before peeling - the new process promises much faster heating than traditional methods.

In general the sapwood is more conductive than the heartwood, but the ratios between electrical conductivity (EC) vary between species, with grain orientation (axial, radial, and tangential), with temperature and with the soil the tree is growing/has been grown in. However, surprisingly little is known about this subject and for some species there is no information at all.

This project seeks to improve this situation, characterizing several thus far unstudied softwood and hardwood species, which are grown for timber in NZ and overseas, both with laboratory and field experiments.

Specific Requirements: 2nd or 3rd professional year student, probably in a science or an engineering discipline - perhaps a student considering studying towards a higher degree.

Prior knowledge of wood, forestry, chemistry or electrical engineering is not essential; knowledge and interest in statistics and the software packages R and/or MATLAB would be helpful but not essential. A positive attitude to practical work is far more important.

 

 

Project Number: 2019-73

Project Leader: Sharee McNab

Host Department: Electrical and Computer Engineering

Project Title: Solar Generation Optimisation Tool and Review of Platforms for Optimisation of Consumer Photovoltaics and Battery Energy Storage Systems

Project outline: Typically residential solar photovoltaic (PV) installations are installed with a fixed mounting of tilt and orientation to optimise generation. Alternatively PV systems (more commonly for commercial or utility-scale solar) can be installed with a tracking system that changes the tilt to optimise generation along one or more axes, however these systems have much greater installation and maintenance costs.

An alternative middle ground is proposed that has a small number of tilt options on a fixed mounting so that the tilt can be manually adjusted throughout the year. The project seeks to develop a tool to optimise generation (or perhaps revenue) for a location using two or three fixed mounting options to take into account the variation in the sun path throughout the year.

A secondary part of the project would be to review home energy management systems available on the domestic market for assisting consumers optimise their PV and battery energy storage system (BESS) by deciding the best times to charge and discharge their BESS. A survey of the level of sophistication employed should be undertaken, for example whether systems use weather forecasting, spot pricing inputs or the ability to provide other paid grid support services to deliver the most economic solution.

Specific Requirements: Engineering student or alternatively Physics/Chemistry