SU42199A1 - Device for starting and adjusting induction motor - Google Patents

Description

Already known devices for starting and regulating an induction motor using controlled ion or electronic valves in its primary circuit have the disadvantage that the latter must pass through the full power of the engine. In this case there is a very bad use of the stator windings (primary). In addition, the engine air gap is large, in other words, the machine must have significant magnetic resistance, i.e. be in this respect similar to synchronous machines and direct current machines.

In the proposed device, or electric valves are included in the secondary circuit of the engine, which should allow, firstly, to reduce the power passing through the valve to the slip power, and secondly, to transfer the poor use of the winding from the primary winding of the engine to the secondary one, As you know, always less power and size than the primary and thereby improve the use of the machine as a whole. Finally, thirdly, the new scheme should allow the machine to be executed with a small air gap due to the fact that in it the primary and secondary power circuits are connected by transformer interaction, as in any induction (asynchronous) machine and therefore it is possible not to be imbalanced primary and secondary windings. Reducing the gap leads to a reduction in the size of the weight and dimensions of the machine.

In the case of single-phase execution of the primary winding of the engine, the presence of a valve in the secondary winding should greatly reduce the parasitic effect of the reverse field, since the latter in this case, though, induces an emf in the rotor. double periodicity, but this current emf in windings it doesn’t cause at all (when they have a parasite: the opposite direction) or this current is useful. The latter occurs because the MTOI control valve turns on each part of the motor winding only while the moment created by the winding has the right (useful) direction.

In FIG. 1, 2, 3, 4, 5, and 6 depict various forms of the inventive device for starting and controlling induction motors using controlled ion or electronic valves connected in the usual way of converting a multiphase secondary winding of an induction motor.

|) | 1 a: s% nad vents – mercury – pa} 5p9 au; aYPRYUM with grid, cathode | : Mriai thyratron, etc. (Figs. 1, 2, 3, 4, 5. and 6) are designed to convert the current frequency induced in this winding, the glide of the slide to the frequency of the mains supplying the motor. The energy formed in the secondary winding, the engine, “after that; city governor; frequencies can be in vrasyayy network through a regulated transformer RG (Fig. 3, 4, 5 and b), so that it is possible to regulate the number of revolutions in the gateway without rter in the rheostat from

full CK ipUCtH. hI

In the case of single-phase execution of the primary winding of the engine, in addition to the property of adjusting the speed, this engine receives the ability. start-up in the presence of only the pulsating field of the primary winding without the starting winding required in conventional single-phase induction (asynchronous brushless) motors.

In this case, a start-up / 7P resistor is shown in the secondary circuit of the frequency converter (Figs. 1 and 2).

In the case of the use of a three-phase motor, the UG transformer connecting the secondary motor circuit to the grid includes:. c, the primary circuit of the frequency converter (Fig. 5 and b).

, Delhi B: About the secondary circuits of the regulated engine there were no valves or if the latter were short-circuited, then how: In the embodiments of FIG. 3 And; 4, and so. in the cases of FIG. 5 and b in transformers would flow a different frequency current .; If there are valves controlled by the network in the circuit of these transformers, regardless of whether the latter are connected before (as in schemes FIP 3 and 4) OR after (as in the schemes of Fig. 5 and 6) transformers, the current in the secondary circuit will be flow only when the direction. it coincides with the direction of the current in the primary winding. Thus, ventilated, appropriately controlled images, including and interrupting the low frequency of the secondary circuit, synchronously with the primary current circuit, pass the current of the primary circuit frequency into the secondary circuit of the motor / and transformers. As a result, the jfbpbi TRs in both their primary and secondary windings will flow around the currents of only one frequency-frequency of the power supply7; ,

Predpag ie device; rjoiijfeT find use in electrical ..,; dge; electric motors of single-phase current of normal frequency (and in other cases), rolling mill, miner I | T. d. where SKbHOMrtiiecKafl 1eё1 engine speed is required.

I Subject is shadow.

Claims (4)

1. A device for starting and adjusting the Induction Motor using controlled engines; i-eM or or electronic valves that, in order to pass through the sliding motor energy through the said valves, they are switched on according to the general frequency conversion scheme in the multiphase secondary winding circuit of an asynchronous motor. 2. The form of the device according to claim 1, in the case of its use for start-up without auxiliary winding and adjustment of a single-phase motor, is disconnected so that the starting resistor is switched on in the secondary circuit of the frequency converter. 3. The form of the device according to claim 1, characterized in that, in order to return the slip energy to the network, the secondary circuit of the Frequency Converter is connected to the specified network via a controlled transformer. . 4. The form of the device implementation of p6 p. 3, characterized in that in the case of the use of a three-phase motor, -cv-calling secondary motor circuit with a network transformer is included in the primary circuit of the frequency converter (Fig. 5-b). copyright certificate K. K. Showcase and A. S. Dimitradze № 42199