This topic is very interesting on it very much any device and it is very contradictory.
Having got acquainted with the work of Mandelstam and Papaleksiparametric resonance, I began to delve deeper into this problem. Although resonance serial and parallel I studied thoroughly, as the education electronics, discovered many interesnogo.Hotya no big secrets in the phenomenon of resonance have not noticed, yet all the while there was a feeling that something is agreed and clearly.
The first question, which is always cool - a system introduced in response capable of donating surplus associated with the oscillatory system Q? Here badly soldered all devices dawned, drop everything and find a theoretical explanation of the normal resonance phenomena, and if the path is correct, then other equally puzzling facts. The wording for resonance makes it clear that capable or that the principle of resonance.
Parallel resonance formed by inductance and capacitance is a closed system, in which all parameters are fixed, and the energy in the system is closed, attempt a direct way to remove excess vibration process will lead to a damping of the oscillations. Realizing at last, it became to investigate the serial - came to the same conclusion.
After talking with friends, experienced electronic engineers, devoted his life to the electric drive, I heard from them a lot of interesting. ... How has the drive in which the years there was a change in the direction of the electric drive design, and with which it was connected. There were many moments of tips, that is, until the 80s asynchronous motors have a massive rotor, very high moment of inertia and a squirrel cage was direct that, at the start, gave rigidity. Somewhere in the eighties began to drive, fundamentally, lured, this is due to the rapid growth of mechanical engineering, took compact powerful motors with soft start-up parameters and a quick stop. The rotors of such machines began to make long, to reduce the motor to coast to a stop after a soft start characteristics applied beveled magnetic rotor system. That investigation prompted the idea to check the correctness of a thought occurred. After earning a total score of 27 asynchronous motors, different years and options to take them apart and count the number of poles of the rotor and the stator. Also, look for massive rotor without bevel rotor poles. Of the 27 engines caught only one very old design, it only managed to see that he is 7.5 kW, speed by measuring were almost 3000 min-1. Resistance windings 1.3 Ohm, the number of poles of the stator 36, rotor 34 (inductance principle do not measure - with the calculation of resonance does not converge). The only drawback of this engine is still slanted rotor magnetic pole. I start the engine under the scheme rotovertera or classical, with phase-shifting capacitor. Working capacity is tuned to resonance. Voltage pick run capacitor to 380 volts. Stops from the powerful sound generator according to the rules removal AFC, rented characteristic and resonance occurs at a frequency higher than 120 Hz. I take out the rotor speed even twenty hertz above. If you make a tuning capacitor 50 Hz frequency response when removing and turn, then he quickly burned. If powered by Lattre, gradually reducing the voltage, it will rotate even at 30 volts. But resonant sine windings at the top of a sine waveform has a bend, one to one ferroresonant stabilizers like. It convinced me that the resonant coil with operating capacitor does not work at the fundamental frequency, but only adjusted to the harmonic multiples. The question arises - what actually interesting, new in my story. And just looking for something a condition of occurrence of parametric resonance .
So what to look for in a ratio of induction motors? First, it was possible to understand that consideration of the engine need only two windings, which operate in resonance. The third is used for consumer loads.
You can overclock the engine in any way. Upon reaching their rated speed, one winding by switching must be electrically disconnected.
Applied to disperse the classical scheme - star connection, two winding through the phase-shifting in the resonance container.After reaching the speed, you need to move quickly onto the output of one winding in places.
The engine is disconnected from the network, to switch windings resonance voltage should be adjusted not lower than 380 volts.After perekidki polarity, the motor is not changing anything externally, also continues to work, but the resonance measurement shows that the voltage has dropped to nearly 170 volts.
Picking up the capacity necessary to restore the original voltage, that is 380 volts, the capacity will increase about three or four times. Here begins the trick - if the inertial mass is sufficient, capacitors have a good quality factor of a small leak. We must take care of the presence of the flywheel, possibly understand all the nuances, you can get rid of it, but at the initial stage it is better to be safe, to stick out was a mass of a few tens of minutes. In his designs used sawmill. Installed on it cutting discs 4-5 large pieces, pulling them faceplate. Even without the effect of spinning for a long time! ...
If the motor winding is quality, has good quality factor, the ratio of stator and rotor poles is chosen correctly, the motor acts as a parametric oscillation mode, at a sine winding plane occurs exactly the same as in ferroresonance stabilizers. And you can safely disconnect from the network, if all motor parameters it is successful, as it were a little faster at the hearing, and continues to work, with slightly heated. You can try to load slowly.
Capacitors for resonance, it is necessary to gain from small - 2 uF. Their few days is desirable to hold in the heat, after charge current from the source 220 and leave the next day with a voltmeter with high impedance input Gaugeable and select the maximum holding a lot of stress. Wires for soldering capacitors, and fed to the engine better make homemade litz wires. Litz apply for a long time, even when engaged in phonics has a very low impedance. When transmitting pulse signals, improving the quality factor of oscillatory systems, doing without thinking, for me it is a rule. But it is possible and simple copper wire, but preferably 2.5 to 3 mm thick.
Litz wire can be dialed from the brand PEL - 0.2 ( d=0.2 mm) veins 8-12. Yet, the most important thing is the engine itself, I have not managed to find one which is derived from theoretical considerations, all modern engines are slanting poles on the rotor a small diameter, and need large-diameter rotor and direct magnetic poles.
Such engines have long surrendered to scrap. C ratio of the two rotor poles are shifted one hundred twenty degrees, relative to the stator must be carried out strictly.
If the top is completely aligned, the left pole is only going to go into the stator pole. This winding, working in resonance, the right coil for the load and its position does not matter.
This circuit has very interesting properties for research. The advantages of it, that it is almost full use of resonance, eating from the network after only one winding. Two coil with the resonant capacitance also produce magnetic flux involved in the work. This allows you to remove the increased mechanical strength. Me converted all machines on the lathe mode, milling, drilling, emery, circular saw, everything works fine from a single-phase network. I am going to alter the compressor. All the equipment as it is operating at full power and a sense that the three-phase network. The scheme used to start the electrolytes in a non inclusion and working coil tuned to resonance with a capacitor type MBGCH with the permissible voltage of 600 V.