Testing and connecting

EZ Battery Reconditioning Method

Recondition Battery Guide

Get Instant Access

Check that the PMG has no faults before it is put into use. It will be much easier to correct the faults now, than to return the unit to the workshop later.

Mechanical testing

Mount the spine vertically in a vice. The magnet rotors are free to move. The shaft is horizontal, as it will be in a wind generator. Check that the wires are not touching each other, creating a short circuit which makes the PMG harder to turn.

Check that the rotor will spin freely.

Spin the rotor and listen for sounds. There should not be any scuffing or brushing of the rotor, as it turns. It should spin freely for several seconds and gradually come to a halt. If it slows down rapidly then there may be an electrical fault, or the bearings may be over-tightened.

Grasp the stator with both hands. Push one side backward while pulling the other side forward, while the rotor is spinning. It must not touch the rotor. If there is a rubbing sound, then it may be necessary to disassemble the PMG and assemble it more carefully, with more space between the rotor and the stator. Or it may be possible to correct the problem by making minor adjustments to the stator mounting studs.

Stop the rotor with one of the studs in the 3 o'clock position (diagram 43). Hang an object weighing 100 grams on this stud. The rotor should begin to turn clockwise. If it will not turn, then the bearings may be over-greased or too tight.

Checking the balance

The rotors have already been balanced in section 6. The wind turbine blades must also be balanced in the same way. When the unit is assembled, you should check the balance again using the new procedure below. This is necessary because the rotor disk may not be perfectly central on the PMG shaft.

43. HANG A WEIGHT ON ONE OF THE STUDS

Diagram Free Energy Bulb

Repeat the starting test (diagram 43) with each of the four rotor studs in the 3 o'clock position. Try different weights, and find the lightest weight which will start the rotor turning. If one stud needs much more weight than another, then the rotor is not balanced. Fix small weights to the rotor until the balance is correct.

Electrical testing Coil connection test

It would be helpful to have a multimeter when testing the PMG, but it is possible to do some basic tests with a 3 volt torch bulb. See diagram 44.

• Connect the wires 1B to 4A, 2B to 5A, and 3B to 6A. (Series connections of pairs of coils which are in the same phase.)

• Set the multimeter to '10VAC' or similar (if you have one).

• Connect the meter, or a bulb, between the wires marked 1A and 4B.

44. TESTING THE COILS

44. TESTING THE COILS

Paano Test Ang Relay Using Multimeter

• Rotate the PMG slowly by hand, about one revolution per second.

• The meter should give a reading of about two volts, or the bulb should flicker.

• Repeat the test with two more pairs of wires: 2A and 5B, 3A and 6B.

In each case the result should be the same.

If there is no reading, or a very low reading, then check that the series connections (1B-4A, 2B-5A, 3B-6A) are correct. If all these connections are good, then it is possible that one coil has been reversed (placed upside-down).

If any coils have been reversed, then it is necessary to do another test (see diagram 45), to find out which one is at fault. Connect 4B-2A and 5B-3A as shown in the diagram. Now test between 1A and 6B. There should NOT be more than a very small voltage. If there is a voltage, or the bulb lights up, then reverse the connections (swap A for B) on the coils until the voltage drops to a very low level.

When the faulty coil has been found, label the tails again, with A and B at the correct ends.

45. CHECKING FOR A REVERSED COIL

WIRING DIAGRAM

WIRING DIAGRAM

BLOCK ONNECTOR

SERIES CONNECTIONS

BLOCK ONNECTOR

SERIES CONNECTIONS

CIRCUIT

SCHEMATIC

DIAGRAM

^ {

\ BULB OR

Pmg Coils Connection Diagram Windgenkits

2A

\

—©

5B 3A

7 @ ©

/

There will always be a small voltage in this test, because the coils are not perfectly positioned in the mould. If the test gives more than one volt, then it should be possible in future to make a better stator by placing the coils at exactly equal distances apart in the mould.

DC output test

When these tests have been completed and the results are correct, then connect the rectifier, as shown in diagram 46. Connect the tails 1A, 2A and 3A together. Connect each of 4B, 5B and 6B to any three of the rectifier AC terminals (marked with ' S' symbol). This is the 'star' connection. Connect a bulb to the output. If possible, also a multimeter on 10 VDC (or similar).

46. DC TEST

COILS CONNECTED STAR

BLOCK CONNECTOR

46. DC TEST

COILS CONNECTED STAR

Permanent Magnet Moving Coil Instrument

Rotate the rotor by hand as before, approximately one revolution per second (60 rpm). The meter should show a steady reading around 4 volts DC (or 3 volts with the bulb present). The bulb should glow with a steady light, not flickering as before.

If there is no reading, or the bulb flickers, then there is a faulty connection or a faulty rectifier. Check the connections carefully. Try another rectifier.

You can also test the PMG without a bulb or a meter. Simply connect the positive and negative wires from the rectifiers together (all four) in a 'short circuit'. Now try to turn the PMG. It should be stiff but smooth to turn. If it trembles as you turn it then there is a fault.

Connecting the PMG to the 12 volt battery_

Star and Delta connections

For low windspeeds, connect the coils 'star' as above. For high winds, and higher current output, connect the coils 'delta', as in diagram 47.

47. DELTA CONNECTION

CIRCUIT SCHEMATIC DIAGRAM

BLOCK ONNECTOR

SV EbK

CIRCUIT SCHEMATIC DIAGRAM

BATTERY +

BLOCK ONNECTOR

BATTERY +

DELTA CONNECTION GIVES MORE CURRENT WITH BETTER EFFICIENCY AT HIGHER SPEEDS.

TO BATTERY

BATTERY +

BATTERY -

DELTA CONNECTION GIVES MORE CURRENT WITH BETTER EFFICIENCY AT HIGHER SPEEDS.

TO BATTERY

It is also possible to wire a relay (see diagram 48) which will switch the connections from star to delta and back as desired.

Homemade Hydroelectric Generator Diagram

Yet another option for connecting the stator

At the time of writing this document, the above arrangement (using a relay to change the connections) is still under development. Later, an electronic control circuit will be available to automate the changeover. This is all very complex, and it so it can go wrong.

If you do not wish to have to change the connections between low and high windspeeds, then the PMG will still work. However, the efficiency will be slightly less. Three are two options:-

• If you expect mainly low windspeeds, then you can simply use the star connection shown in diagram 46.

• If you also need higher power in higher winds, you can use a 17AWG wire (1.2 mm diameter) to wind coils with 200 turns each. Then you can connect one group in delta and one group in star as shown in diagram 49. Note that you need six AC terminals on the rectifiers so you will need three rectifier blocks.

49. STAR/DELTA CONNECTION

49. STAR/DELTA CONNECTION

Three Phase Motor Star Delta Connection

PMG-to-Battery Cable size

The cable from the PMG to the battery can be either three-phase-AC or DC. If the rectifier is mounted at the wind generator, then it will be DC. This is only slightly more efficient than three phase AC.

At 12 volts, the size of the cable must be large. Even if the current is only 15 amps, it is advisable to use a heavy cable. For a distance of 20 metres, the recommended size is 6 mm2 (10AWG). The diameter (thickness) of each copper wire is about 3mm. A 15 amps current flowing in this cable will lose 15% of the power from the wind generator as heat in the cable. If the cable is longer, it should be heavier, in direct proportion.

Electrical Safety

There is no danger of electric shock from a 12 volt battery. But if the wind generator is disconnected from the battery, and running fast, then the voltage will be higher than 12 volts, maybe as high as 50 volts. Do not run the PMG at high speed without a battery connected.

The battery contains stored electrical energy. When there is a short-circuit fault in the wiring from the battery, for example the positive and negative wires touching each other, this energy is released in a very high current. The cable will heat up and burn. Therefore it is necessary to use a fuse or a circuit breaker on every wire which attaches to the battery positive terminal. Use one fuse for the wind generator and a separate one for the cable to the load (the lights, or whatever uses the power). See diagram 50.

50. CONNECTING THE BATTERY

50. CONNECTING THE BATTERY

Permanent Magnet Generator Free Energy

Battery acid is bad for the clothes and the skin. Do not splash it. Be especially careful of the eyes. If there is an accident, the best cure is to flush with plenty of water.

Batteries produce hydrogen gas, which is very explosive. Do not make sparks near a battery or it may explode, and throw acid in the eyes!

Battery Charging

Lead acid batteries should be kept in a charged condition. In the case of a wind powered system, you may have to wait for a wind to charge the battery. But be careful not to discharge the battery too deeply, or to keep it too long in a discharged state, or it will be damaged (sulphated) and become useless. Stop using a battery before it is fully discharged. If there is a problem with the wind generator, then charge the battery from another source within two weeks.

Charging the battery too hard will also damage it. At first, when the battery is discharged, it is safe to use a high current, but later the current must be reduced or the battery will overheat and the plates will be damaged. The best way to fully charge a battery is to use a small current for a long time.

Watch the battery voltage. If the battery voltage is below 11.5 volts, then it is being discharged too much. If the voltage is high (over 14 volts) then the battery charging current is too high. Use less current or more current in the loads to correct these problems. If there is no voltmeter available, then the user should watch the brightness of the lights and follow these rules:-

• Dim lights, mean low battery. Use less electricity!

• Very bright lights mean too much windpower. Use more electricity!

A good way to use more electricity is too charge more batteries in windy weather, perhaps charging batteries from neighbours' houses.

There are simple electronic circuits which can regulate the battery voltage automatically. They are called 'low voltage disconnects' and 'shunt regulators'. If the user is not willing to watch the battery voltage, then it is necessary to fit a disconnect and a regulator.

Was this article helpful?

0 0
DIY Battery Repair

DIY Battery Repair

You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.

Get My Free Ebook


Responses

Post a comment