POET Technologies Inc.

This is another example of the very wide spread uses for POET to a diverse set of applications. Many of which they would not even be aware of. This device provides the ability to have extremely fast switching speeds of very high power devices using ether a low voltage control signal or an optical signal.

To give just one example of how such a device could impact industry that POET would likely not even be aware of. The electricity power grid (the interconnected system...i.e. North America) requires very fast detection of faults. A lighting strike on a high voltage circuit causes the insulators to flashover once that flashover occurs it will be sustained through the ionized path over the insulator until the circuit is isolated from its connection to the grid.

Fault detection takes place by line relaying at the main terminals of the line (the big switching stations you often see) and it is a very reactive type of process. The relaying does not know lighting has hit the line causing it to become grounded to earth it just sees the system voltage declining rapidly towards zero and high current flow on the faulted circuit. During electrical storms or other inclement weather you will often see your lights dim for just a moment. That is often associated with a fault condition on the high voltage grid. When a fault occurs on Extremely High Voltage (EHV) lines (i.e. 500kv and higher) the impact can be felt hundreds of miles away across provinces and states. When you see your lights dim for a moment and recover that is often the result of a fault occurring on a high voltage circuit. Because faults are almost always transient in nature (lightning) the industry uses automatic reclosure schemes. The line is isolated by circuit breakers and those circuit breakers close again after 10 seconds to restore the line to service to avoid protracted overlap of outages (restore the circuit to service before another parallel line trips in the same path). If the fault is permanent i.e. the insulator has failed then the circuit has been re-energized into a fault (your lights dim a second time) and the breaker that was used in the automatic reclosure scheme is again tripped to clear the fault off the system. No further energize attempts are made until the fault has been identified.

So at home or at work we have just seen the lights dim but very extreme faults on the (EHV) rocks the power system in a very big way.

When an EHV line becomes faulted to ground voltage on the line drops towards zero. That is why you see your lights dim the closer you are to the fault the more severe the decline in voltage. So if a large area is impacted the power supplied to that area drops very dramatically towards zero the load supplied by the grid has been removed. All the generators on the interconnected grid accelerate because the energy that is being supplied to them no longer equals the energy they are delivering. So this huge power oscillation takes place across the entire system with the most severe effects felt closest to the fault.

All the big power plants supplying the grid begin to accelerate until transient stabilizers recognize that the unit is going out of step. These stabilizers act as quickly as possible to increase the field of the unit (increase the voltage output to load the unit and slow it down).

Everything is reactionary and therefor relatively slow. It takes 3 cycles (.05 seconds) for breakers supplying the fault to open when a trip signal has been applied to that breaker. It has taken the line relaying of the circuit time to recognize that a fault exists. It has to see the voltage decline and recognise where high fault current is flowing into the faulted line and it has to be extremely selective to get it right and not clear for a fault in an adjacent zone. But once the fault has been cleared we now have an unbalance all that massive spinning inertia from all the generators in that part of the continent are now advanced in rotor position (load angle) and all of a sudden the load has reappeared (your lights are no longer dim). So these generators are going through power oscillations and have to regain steady state stability.

The power system is very reactionary. The ability to speed up detection and control would allow the grid to operate so much more efficiently. It would expand system limits to fully utilize the network. The system is constrained by stability limits much more frequently than by thermal limits.

Fast acting control such that would be provided by the POET device described in this patent could have extremely wide spread implications to the bulk power grid.

High frequency switching at high current is enabled by this device both through optical or electrical communication.

The applications would be very far reaching for this type of device in many industries.