Three years gone, Six months to go… (almost anyway)

I remember being told by my Mum that the road to hell is paved with good intentions. And all my good intentions at the time last year to blog bi-weekly definitely have made my path to the hot place a little bit more easy. So, in penance and to try blogging again here we go.

A lot has happened since September last year, and I'm not quite sure how best to do this, so I've decided to give a bit of photo diary of the last 12 months to give a taste of what's been going on both in PhD-world and my own.

In October/November I was working on the stability analysis of parallel inverters, using small signal stability analysis, the results of the analysis match the simulations relatively well, hopefully these will also match the experimental work as well. Below is the pole-zero plot for the parallel inverters.

Pole-zero plot for parallel inverters

I met one of the founders of Learning Planet, Justin Wickham, in London to discuss the pico hydro scheme they are looking at. You can see more of the area Learning Planet are in here or have a look on their website www.learningplanet.org.uk.

 

The School in Dhawa renovated by Learning Planet

My cousin Helen got married at the end of October, so we headed over to Ireland to celebrate.

Helen and me at her wedding

I helped on the sound desk again with Horfield Theatre Company for their October pantomime, Franky Panky and had a lot of fun - with innuendo and a lot of childish humour. I'm getting a little bit better on the sound, although every so often the wrong person's mic would be turned up… A fun fun week nonetheless!

Franky Panky's Poster

I had a "cruise" to Bruges with my little sister, which was fun - especially all the chocolate!

Me and a bear in Bruges

During November and December I wrote a paper on the experimental turbine work I'd been doing, and submitted it to the Journal of Applied Energy at the beginning of January. It was finally accepted in June, and published here in July! The paper that I presented at WREC was also published in Renewable Energy Journal in July this year as well, here.

A figure from the Applied Energy journal, the slug of water that's ingested by the turbine in one rotation

In the last weekend of November, Hannah and I went to Salisbury to celebrate two years. We had a fun couple of days and saw Stonehenge, the Cathedral, Avebury and the Uffington White Horse.

The Stone Circle at Avebury

I spent Christmas with my parents and sisters, which was great.

With my family at Mount Edgecombe

Back in the lab, I started working on an improved control system to try and reduce any current spikes when the two inverters connected together so that switches won't go bang when the inverters are connected to a grid. This improved control did what it was supposed to in the simulation.

Reduced current spikes on paralleling inverters

I had another family wedding in Ireland, my cousin Gillian got married in early February and Hannah and I headed over for the weekend. Unfortunately snow made our journey back delayed… (I blame Gillian's sister, Jenny, who flew back with us!)

Gillian and Alex's wedding

I found an IEEE conference in Kathmandu that would take place in late September, known as ICSET. I wrote two papers for this conference, one on the turbine testing and the other on a simulation of a off-grid pico hydro network, submitting them by the end of March, which were approved. I'm off to Nepal on the 17th September, which is going to be amazing.

A simple model of an off-grid pico hydro network

I also attended and presented at the EWB research conference at UCL at the end of March, adding to the stress at the time, but really enjoyed it and was interested to hear some of the other projects going on in the EWB universe.

AC grid with distributed generators connected with inverter front ends

After submitting the papers, Hannah and I went off to India for two weeks, and had the most fantastic time. We spent a week in Kerala and a week in Bangalore, and had some amazing experiences, spending a night on a houseboat, riding on an elephant, and visiting some beautiful parts of the countryside.

On a houseboat in Alleppey, Kerala

On returning from India, I started to build some electronics, starting with a simple inverter, four switches and an inductor-capacitor filter. I built a simple control circuit in analogue components to control the output current to a reference sine wave from a signal generator. The circuit managed to produce a relatively good output.

Inverter Mk1 and Output

At the end of April, Hannah and I went to see one of my favourite bands, Feeder, in Cardiff. They were absolutely amazing. Enough said.

At the Feeder gig

By the beginning of May, it was time to do 'Living Below the Line' again (see last years version here). We raised money for MRDF and this time, there were a good 10 of us that did it.

Pasta Dinner during Live Below The Line

Once the original inverter worked, I built a second checking it worked with the basic controller, and then used a real time controller called dSPACE which can use MATLAB models to control things, allowing quick changes to be made to the model and be able to see the result of it. Both inverters worked controlled by the dSPACE which was great.

Parallel Inverters with dSPACE

The Olympic Torch came to Bristol in May, and we went down to the Harbourside to see it. The city was buzzing, and we had a fantastic time watching it arrive.

Olympic Torch arriving in Bristol

I ran a quick tour of the Hydrolab for the University of Bristol's Open Day in June, and showed some of the potential new students around and demonstrated the turbine rig. By the end of the day, my voice was hoarse, but had talked to many hundreds of people.

Turbine rig running

Obviously with London holding the Olympics, I wasn't going to miss going to see some events. We went to see the Beach Volleyball on Horseguards Parade and some Hockey in the Olympic Park, just a most fantastic experience.

Beach Volleyball at Horseguards Parade

Once each of the inverters worked individually, I connected them together, to see how they would work in parallel. They synchronised without blowing up, which was always good, and now in my work I'm trying to improve the performance of the system.

Parallel inverters

Every year Bristol holds an International Balloon Fiesta in Ashton Court, on the outskirts of Bristol. We went to the Nightglow, where the balloons light up to music, and saw a mass take off with Tim, who had come over from New Zealand.

Balloons at the Nightglow

We had a few days in Cornwall, camping. It rained, well it was Cornwall after all, but had a few nice and sunny days, especially down on the Lizard and ate some rather tasty ice-cream too…

Lizard Lighthouse in the sunshine!

A couple of weeks later we returned to Cornwall for a school friend's wedding. Again it rained, and it didn't really let up this time. Argh. Still, we enjoyed an ice-cream in the rain.

Hannah eating an Ice-cream in the rain at Lanhydrock

As well as the Olympics, we also got some tickets for the Paralympics, this time for the swimming, athletics and also saw some judo and table tennis. If anything, we enjoyed this more than the Olympics, the atmosphere was just incredible.

The long jump in the Olympic Stadium

And straight from the Paralympics we headed to the Small is Festival 2012. I had been asked to do a little workshop on pico hydro, and so designed a workshop to build a little crossflow turbine and test it, the workshop went really well and I had a very inspirational weekend. And it didn't rain!

The workshop at Small is Festival

So, hopefully now you're all about caught up with me and my life. I'm really sorry it's taken so long to do this, but I hope I'll be a bit more regular. Not long to go with the PhD now either. Times are scary and fun!

SAM

Back to work again…

After a month off it's been a bit tough to get back in the swing of things. I finished most of the turbine testing before going to Nepal, so now I'm moving on to the electrical side of the project. We have decided to have a power electronic interface between the generator and the grid, so the first part is looking at how to connect inverters in parallel without any central control or stiff grid (like our National Grid). I'm finding this really quite hard, and have started at the basic electrical theory to understand what's going on. There several examples of these control systems in literature - for example here - and I'm using these to start some simulations of inverters connected together in Simulink.

Synchronising parallel connected inverters (the lines are the frequency of two different inverters)

I'm going to be using single phase inverters, as then we won't have to worry about balancing the loads across each phase, as with a three phase system. However, this leads to some problems. With three phase, there are some mathematical transforms that change the 3 sinusoidal voltages into vector quantities, which are much easier to control. With single phase, sadly there is no equivalent. However, there are some ways to get around these problems, so I've been investigating the different solutions to see which will work best.

Buckingham Palace coach

Apart from work, I've been busy and not had a weekend free really. At the end of August, Hannah and I went to see the Queen. Well, we actually we had a look around Buckingham Palace State Rooms. It was amazing, so much gold I have never seen in my life. After the wedding of the year, they had an exhibition in the Palace about the Duchess of Cambridge's dress, and displayed it. I couldn't believe how small she was, I doubt the dress would have been much wider than my thigh… There was also an amazing display of Faberge Eggs and other trinkets. I'm not normally one for jewellery or the like, but they were so intricate, it was just incredible.

Back of Buckingham Palace

We also visited the Royal Mews, where the state carriages and cars are kept. To think of the people that these cars and carriages had carried over the years was just mind-bending. For bank holiday weekend, we went to see my Mum and Dad's new bungalow that there are refurbishing. As it was a really hot and sunny weekend, my Dad had the perfect job for me - remove the insulation from the loft so the electricians could come in and look at the wiring. This was a joyous job, sweating through every pore in a suit that made me look like an Oompa Loompa from Willy Wonka and the Chocolate Factory. At the end of the day, Dad and I managed to clear all insulation - my nose wasn't the same for a few days after though - which was great, and he's now put it back in again with a load on new thicker insulation on top of it. It's going to be one toasty house - energy-saving-tastic! 

Me in the Oompa Loompa suit

The first weekend in September was the Small is… Festival run by EWB-UK and Practical Action. The name of the festival comes from the title of a book written by Practical Action's founder, E.F. Schumacher, Small is Beautiful. It was an interesting festival, looking at different solutions to problems - energy, sanitation, cooking - through a mix of workshops, discussions, panel sessions and practical activities. Some photos from some of the sessions I attended are below (taken from the Small is… festival website).

Playing with a Solar Panel at Small is… (Photo by Nick Holmes)

Watching the charcoal burn

Listening to V3 Power talk about homemade wind turbines (Photo by Nick Holmes)

I found it quite interesting listening to a wind power debate between a manufacturer, Ampair, NGOs, social enterprises and academics. It got quite heated at some points, but I think some interesting arguments on the advantages and disadvantages of locally made equipment compared with mass manufactured certified designs came out above some of the animosity. As the man from Ampair said, they would set up a turbine factory in a developing country, like Peru, if they could be sure that an NGO wouldn't come in with free money and completely undercut them with inferior hand made products. I'm not sure who I agree with, but an interesting discussion none the less. Hannah came along with me, and I think it was quite a shock for both of us to hear some of the statistics to do with smoke inhalation from open fires, and the health problems that it causes.

Every year in September, Bristol opens all the public buildings for a day - even those normally closed. Hannah and I went on a train along the floating harbour down to the SS Great Britain, then onto the Create Centre where they have an Eco-house and a hazard awareness area for children, which we took  a tour around.

The train outside the M-Shed for Bristol Doors Open Day

Then we visited St Stephen's Church, where we booked ourselves on a jaunt up the tower. The tower looks out over the centre of Bristol, and I thought it would be quite fun to climb. The stairs were very awkward, all stone and not very large to fit my size 13 feet on, with the twisty turns. By the time I got to the top, I have to say I was quite relieved. However, my severe fear of heights kicked in and I didn't really manage to see the view!

St Stephen's Church Tower (we climbed up it, all 152 ft!)

Bell ringing in St Stephen's Church

On the way down, even more scary than on the way up as every step we felt we would slip down, we stopped off at the bell ringing level, and I had a go. I've never rung a bell before, and it was really difficult to try and get it in time.

SAM