Solar Grid Inverter Monitoring System - Part 2

The second part of this project requires the RS232 to be signalling at a longer distance than the usual fifteen metre limitations.

To overcome this distance limitation and maintain reliability of the serial network, we use of a special telecommunication device called a RS232 extender. 


The RS232 Extender

The Gefen RS232 extenders will be used to extend the RS232 connection from the Fronius IG grid inverters to the remote location, with over one hundred feet of Cat5e cable.

The Gefen RS232 extenders will perfectly reproduce all 9 pins from one end to the other and have the ability to provide power over Ethernet to the second extender, saving on extra cables and power supplies.

The extender units act as a sender and receiver pair on the RS232 network. Allowing the grid inverter's data logger to send Windows computer information to the Fronius access software.

The RS232 extender sender unit connects to Fronius IG grid inverter at one end and the RS232 extender receiver at the computer terminal at the other end.

Then the Cat5e cable connects the send and receive extender units, over 300 metres away. The sender unit is powered by a 5 volt power supply, which will also power the receiver via the Cat5e cable.


The Fronius IG Access Software

The free Fronius Solar access software is available for download from their corporate website at http://www.fronius.com. The software provides advanced onsite data analysis and archiving options for the PC. As an administrative tool, it offers full setup options for all system components in Solar Net.

The software is easy to install on the Windows system, with a helpful installer wizard.

Once installed, the software is located in the programs section of the windows start menu.

The Fronius access software splash screen displays the general energy output information for the photovoltaic solar power system.

Under the administration menu, the new PV system can be added and configured for the RS232 connection back to the grid inverter's data logger.

In the next part of this series, I will be looking at connecting the monitoring software and data logger to collect information from the school's solar power system, and explaining the features and advantages that computerised power monitoring can have for an organisation.


Other PV Solar Powered Systems and Concepts

A PV solar power system has many other applications apart from grid power installations. One example is NASA's Helios aircraft, remotely piloted to fly at high altitudes.

The electrically powered Helios is constructed mostly of composite materials such as carbon fibre, graphite epoxy, Kevlar, styrofoam, and a thin, transparent plastic skin.

The main tubular wing spar is made of carbon fibre. The spar, which is thicker on the top and bottom to absorb the constant bending motions that occur during flight, is also wrapped with Nomex and Kevlar for additional strength.

The wing ribs are made of epoxy and carbon fibre. Shaped styrofoam is used for the wing's leading edge and a durable clear plastic film covers the entire wing.

The Helios collects a variety of information in the atmosphere, and runs mainly on solar power.

On August 14, 2001, the Helios Prototype, piloted remotely by Greg Kendall, reached an altitude of 96,863 feet, a world record for sustained horizontal flight by a winged aircraft.

The altitude was more than 11,000 feet or more than 2 miles (3.2 km) above the previous record for sustained flight by a winged aircraft. In addition, the aircraft spent more than 40 minutes above 96,000 feet.

Tragically the Helios crashed over the Pacific Ocean on 26 June 2003.

Solar Activity and the Risks to Modern Technology

In the middle of our solar system sits a incredibly large nuclear reaction held together by an enormous gravity pull. Many millions of times the mass of the earth, this star emits solar weather that stretches out past the orbit of Pluto. As with weather on earth, the sun's weather can form destructive storms that stretch out from the sun's surface onto the Earth and further into the solar system.

These solar storms are full of particles (protons, electrons, and plasma), radio waves, x-rays and other forms of energy that come from nuclear reactions.

When these storms reach Earth, they can having varying effects on our planet.


What does this have to do with Technology?

Most technology systems, with the exception of the military and some corporate technology, have no built-in resistance to the effects of extreme solar storms.

This means that most of our electronic devices, electric motors and power systems are very vulnerable to solar activity, which may render the devices partially or totally inoperable.


Why Should we be Worried About the Effect on Everyday Technology?

On September 1–2, 1859, the largest recorded geomagnetic storm occurred. Aurorae were seen around the world, most notably over the Caribbean; also noteworthy were those over the Rocky Mountains that were so bright, the glow awoke gold miners, who began preparing breakfast because they thought it was morning. Telegraph systems all over Europe and North America failed.Telegraph pylons threw sparks and telegraph paper spontaneously caught fire.

Some telegraph systems appeared to continue to send and receive messages despite having been disconnected from their power supplies.

This storm was called the Carrington Event and similar strength storms reach the earth every few hundred years.

A storm like the Carrington Event today would cause most of our modern technology to fail within hours. There would be significant electronic damage, power failures, global financial confusion, and disruption to transport and communications.

Without active help and intervention, areas of the earth could experience famines, civil unrest, and wars.



Recent Solar Storms and Increasing Activity Causing Increased Risk

On the 3-5th of August, we had a geomagnetic storm interact with the Earth, causing a G3 storm event to our magnetosphere.

This storm was impressive, but lucky not a threat to most communication and power systems. However, it posed large issues for satellite operators and space operations.



G3 Solar Storm Effects:

Power systems:  voltage corrections may be required, false alarms triggered on some protection devices. Spacecraft operations: surface charging may occur on satellite components, drag may increase on low-Earth-orbit satellites, and corrections may be needed for orientation problems. Other systems: intermittent satellite navigation and low-frequency radio navigation problems may occur, HF radio may be intermittent, and aurora has been seen as low as Illinois and Oregon.

All the definition for the scales of geomagnetic storms, solar radiation storms, and radio blackouts levels are located at the NOAA (National Oceanic and Atmospheric Administration) website. http://www.swpc.noaa.gov/NOAAscales/index.html

NOAA also has a website devoted to monitoring solar storm activity and contains other excellent information on solar activity. http://www.swpc.noaa.gov/

This current solar cycle is showing signs of the beginning of a very active period for solar storms and risks to the earth.

This cycle will continue to increase in activity for several years before subsiding into a calmer part of the cycle.


What to do About the Risks of a Solar Storm?

The issue needs to be treated like an natural event, similar to earthquake risks. As with earthquakes on Earth, we have built better buildings, invest in detection and prediction, educating people and designing government polices to deal with such a disaster.

Just with earthquake risk management, solar storms need to be addressed to minimise the harm to our way of life.

Possible improvements to solar flare storm risks:

• More EM shielding in electronics devices
• Better designed power systems and grids.
• Better warning and forecast of solar storms
• Understand the sun and it's dynamics better.
• Education of people on the topic in a meaningful way.
• Government polices on the issue, risks and reactions to events.

Through education of the public, better understanding of the sun and laws requiring built-in protection for important devices and systems, the world can become resistant to this type of event.

We may never be able to remove the risk of solar storms, but we can minimise its harm to our technology driven world.

Solar Grid Inverter Monitoring System - Part 1

Solar based power has become an important part of modern strategy for some organisations as they move from carbon based fuel dependence to renewable energy. One of my current projects is looking at a solar power applications for a school that is working towards establishing a carbon neutral power system.

The solar panel array that is currently installed on the school's roof has enough panel area to produce up to 5 kilowatts of electrical power on a sunny day.


Fronius Grid Inverters
 

Three Fronius Grid Inverters

Three Fronius IG 30 grid inverters can feed up to 7.5 kilowatts of power back into the grid, or to the school's AC electrical systems. These high power inverters form the centre of the photovoltaic system, as AC power and access back to the power grid is essential at the school.

Grid inverters are essential for a power system to have mains AC power and photovoltaic power, enabling seamless use of both power sources as a single power source.


The goal of this project is to network the Fronius inverters into a PC system running MS Windows, so that information about the power grid and photovoltaic solar array can be collected for educational and organisational use.



Cabling the Grid Inverters for Computer Monitoring

Inverter, fuse box and Cat5 plate

Blue cables are the serial bus

The three Fronius grid inverters have been mounted on the wall in a way that makes it easy to network the units together.

The three inverter units all have special Com cards, so they can be networked together in a bus type network.

At each end of the Cat5 bus network, special terminator plugs are used to close circuit on the network.

Grid Inverter Bus Network and PC Serial Connection

The last unit has a special data logger card that gives the Fronius grid inverters a data IO port for a computer via RS232.

The data logger card has a DB9 connector, which has been then converted to Cat5 for easy of use in the networking cabinet. 

RJ45 connector in the rack to the Data Logger

The cable run from the DB9 connector on the inverter can be up to 20 metres in length. But for longer lengths of cable, RS232 extenders maybe required. For this example, the Cat5 serial cable is terminated into the network rack in another building.

The Windows PC is connected to the terminated rack connection, which connects back to the Fronius grid inverters with which the Windows PC will be communicating.



For part 2 of this project, I install and setup the Fronius IG access software on the Windows PC.

I will also be explaining the features and advantages that computerised power monitoring can have for an organisation.

Stay tuned.

Latest Projects and Upcoming Articles

Here's some of the new projects that I have been working on. A bit of a mixed bag at the moment, from PSUs and robotics to VMware.

The projects include: VMWare Infrastructure review and tricks. Redundant 48 volts power supply for telecoms equipment. Solar system reporting to computer intergration software. A tracked robot running on Linux and wireless networking.

Stay turned for these informative and useful project updates.

Further project information will be added to the new Burning the Midnight website.

Check it out at http://sites.google.com/site/burningthemidnightproject/