Your Questions About Solar Generators Reviews

William asks…

what is Anti islanding protection in inverter of photovoltaic electricity

admin answers:

This is a good question about a popular topic.

First, it is important to understand a few things about the ac power grid, how it works, and how it protects itself when faults happen.

Traditionally, the grid was an interconnection of large generators operated by utilities, who had plenty of engineers, operations, and maintenance personnel. Basically, you could say that all parts of the grid – down to point that it connects to your home or office – were owned and operated by technically skilled people.

“Back then” it was understood that each generator connected to the grid would receive a full engineering review to make sure that it responded as intended when a fault (like a lightning strike) occurred on the grid.

Enter the ‘modern’ times, in which generators can be solar inverters, wind generators, industrial co-generation, etc. It was determined by the electric power engineering community that ‘small’ generators should be required to disconnect from the grid if a fault out on the grid occurs. This would keep the small generators from ‘back-feeding’ into a fault and creating an even more hazardous situation. It also requires that the small generators not operate to serve load in an ‘island’ separated from the rest of the grid.

In reality, intentional islands are allowed, if the appropriate steps are taken to be sure the grid itself is not being back-energized. But, unintentional islands are absolutely forbidden. (They are bad bad juju for the grid.)

Most inverters detect the islanding condition by looking for some combination of the following:
1. A sudden change in system frequency.
2. A sudden change in voltage magnitude.
3. A sudden change in the df/dt (rate of change of frequency).
4. A sudden increase in active output power (kW) well beyond the expected ‘normal’ level.
5. A sudden change in reactive output power (kVAR) well beyond an expected ‘normal’ level.

Depending on their internal control programming, one or any of these events could indicate that the small generator and some amount of load have become disconnected from the grid. (For example, it could be just your home with its PV system, or it could be your whole neighborhood disconnected as a block from the larger grid.)

When this island condition is detected, the small generation sources trip offline.

There are specific performance requirements for distributed generation defined in IEEE Std 1547, which cover the time in which anti-islanding protection should operate, and what levels of parameters define abnormal conditions.

As for the internals of anti-islanding protection in inverters, they specifically use a phase locked loop (PLL) with a small amount of positive feedback in its control loop to quickly and continuously check the grid connectivity. Look for ‘anti-islanding’ protection papers from Sandia National Labs.

Laura asks…

HHO gas injection-?

I live in South Africa. Fuel costs rose by more than 30% this year. Found a lot of negative reviews re HHO gas injection. As a theory it should work same as pushing compressed air (turbo) into the intake for more power. If the power is not used to increase speed would it then not increase consumption. Any one who actualy have installed HHO out there.

admin answers:

Yes, I have and several friends, co-workers and family members.

There are many factors involved in whether an HHO generator will work well or not. The major factors are:
1. What are the electrodes made of, how well will they conduct electricity and how quickly will they corrode?
2. What electrolyte mixture are you using in the water (electrolyte is required to make the water conduct electricity to split the hydrogen and oxygen)
3. How much oxygen are you involving in the gas out to the engine?
4. How many o2 sensors does your vehicle have and how will they react to the extra oxygen they will detect? (sometimes the o2 sensors will detect more oxygen and increase your fuel ratio to compensate for it – I personally have not had this problem, but have heard others record it)

Speaking from my personal experience with the generator I now built, I have literally TRIPLED my gas mileage.

Potential hazards include:
1. Chance of exploding HHO gases if mis-used.
2. Blowing fuses.
3. Water damage to the exhaust over time.
4. Water in the engine – if you are really really careless.

Additional: Common “problems” thrown at you by the nay-sayers, and the narrow-minded smug:

1.*** It takes more electricity to produce than it gives in return with energy.*** = TRUE.=
That is why these are being used along with gasoline engines! (come on folks! Think a little).
The electrolysis here is powered by the alternator from the combustion of gasoline. Because the product is HHO (which is 3 times more combustible than gasoline) – less gasoline is required to achieve the same speeds as before THUS – more MILES PER GALLON.

2. ***It’s a scam*** = False=.
You might as well call Flashlights, Airlines, Solar Power and Refridgeration scams also. All science is first denied by the narrow-minded. Flip through a good history book, then learn some Chemistry! The electrolysis of water produces Hydrogen. Hydrogen and Oxygen (when not combined in H2O formula) are highly combustible. This can be used in internal combustion engines.
Yes, it takes additional battery power if you want to do this solo without gasoline – but doens’t all science require some work on our part? Stop being so Lazy!

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