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Controlling Voltage and Phase Given Variable Source

03/17/2017 12:40 AM

How do you control voltage and phase given a variable shaft or generator speed? What are the basic control for this?

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Guru

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#1

Re: Controlling Voltage and Phase given Variable Source

03/17/2017 1:13 AM

Two main approaches:

1. Convert output to DC and then convert to appropriate voltage/frequency/phase.

2. Doubly fed induction generator.

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#2

Re: Controlling Voltage and Phase given Variable Source

03/17/2017 5:53 AM

Get a working governor.

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#4
In reply to #2

Re: Controlling Voltage and Phase given Variable Source

03/17/2017 11:15 AM

Nah, those boys are all out playing golf. Or was it flog?

If one has a variable shaft, wouldn't have too much wobble in it for a steady state to be reached?

Try using Crisco, it makes good biscuits.

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#3

Re: Controlling Voltage and Phase Given Variable Source

03/17/2017 9:49 AM

If you are paralleling a generator with a bus, increasing the governor setting will advance the phase of the generator with respect to the bus and the generator will accept more of the load (real power).

To increase the voltage of a generator, the excitation is increased by the voltage regulator setting. If the generator is paralleled with the bus and voltage setting of the generator is not the same as the bus voltage, reactive current will flow between the generator and the bus.

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#5

Re: Controlling Voltage and Phase Given Variable Source

03/17/2017 1:23 PM

First you get the answers to the following questions:

Nameplate data and type of generator, Synchronous or Induction; isolated or parallel;

Prime mover type and ratings; hydro, wind, ICE, turbine;

Budget??

Quite frankly if this some form of free-flow energy source; i.e., wind or mini-hydro, your best bet is to get an automotive alternator. Hook the DC output to some car batteries and run everything DC or through an inverter where absolutely necessary for AC load.

Cheap and reliable, and most importantly, does not require any control system or technical skills.

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#7
In reply to #5

Re: Controlling Voltage and Phase Given Variable Source

03/17/2017 11:13 PM

Mini Hydro, RAM. That's a good idea. The only thing I worry is, what if there's no demand and water is at full flow capacity say rainy days. Do I have to deactivate switch the battery from charging? Sounds dangerous if not.

Anyhow converting it to DC and then AC inverter is a good thing.

Any recommended generators about 1~100kW?

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#8
In reply to #7

Re: Controlling Voltage and Phase Given Variable Source

04/22/2017 11:56 AM

When you're driving down the road and your car battery is fully charged, what does the regulator do? Keep charging until the battery acid boils out? (that happened to me. A Fiat. Why am I not surprised). No, it backs-off the charging current. The alternator itself doesn't care what the prime mover is; whether it's an IC engine, a windmill, or a water turbine. Just 'some thing out there' turning the shaft.

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#6

Re: Controlling Voltage and Phase Given Variable Source

03/17/2017 11:09 PM

Thanks guys. I appreciate it.

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