SU458926A1 - Apparatus for improving commutator commutation of electrical machines - Google Patents

Description

one

The invention relates to the improvement of commutator commutation of electrical electric machines, Tire mains and pulsating power supply, and: m

TOKQM.

A device for improving switching is known, comprising a reversible adjustable amplifier for supplying an additional winding of a supplementary pole, controlled by a multiplying device, according to signals from sensors of rotation speed and current cor.

The power supply is pulsating, which causes a narrowing of the spark-free operation zone with a significant asymmetry of its branches, which impairs the switching capacity and reduces the overload capacity of the machine.

Elimination of these drawbacks is achieved in the proposed device by virtue of the changeover of the sensor of the variable component of the current core and the connection of the latter to the duplicating device through a series of connected switches and a reversible non-switch.

The drawing is shown in the nrnpipial block diagram of the device.

The device consists of a BCiioNora 1A winding 1, located on the cores of the additional poles, a reversible adjustable amplifier 2 for powering this winding, a Hall sensor 3, which is placed in the air gap of the magnetic drive 4. On the magnetic circuit 4 there is an excitation winding 5, which is connected via a rectifier 6 to the tachogenerator 7, articulated with the shaft of the rotor 8 of the machine. The control circuit of the Hall sensor 3 is connected via a reversing switch 9, containing the keys Ki-K4, to a full-wave rectifier 10 with a smoothing P1IM filter. The input | Mittel 10 is connected to the output of the variable-variable sensor Current of the core 11, which extracts only its variable component from the pulsating current. As a sensor for the variable component of the core current, a conventional capacitor can be used, separating the DC and AC components of the voltage taken from the shunt or winding of the additional poles and the compensation of the motor coil, or the magnetic conductor with the winding P1inu with a current box. As keys K | -K4 one can use, for example, contacts of a three-noziopenny polarizer connected to the output of a reversible DC amplifier, operating in a key mode, the input of which is supplied with a voltage removed from the shunt, or the windings of the additional poles and the compressional windings, or transistors, controlled by a load proportional to the total current of the core.

The device works as follows.

In the motor mode of operation of the machine, the keys Ki and K4 are closed, and a constant current flows through the control circuit of the Hall sensor 3 and is proportional to the variable component of the current cor. Since the Hall 3 sensors are located in the mashite field, the induction of which is proportional to the absolute value of the CKQpocTH of rotation, its output voltage is U Ri / ", where i is the proportionality coefficient; n is the speed of the engine. Voltage U is supplied to the input of a controlled reversible amplifier 2, which feeds the secondary winding 1 with a direct current, i, proportional to the product of the rectified neipemen component of the yuk cor and the absolute value of the speed of rotation. The direction of the current in the winding 1 is chosen in such a way that its automating power is directed to the alternating magnetizing force of the winding of the additional poles along which the current of the core flows, i.e., the state of additional pole cooling.

In the reHejpaTOpiHOM mode of the engine, the current shortening of the core is changed, therefore the keys Ki and K4 are produced and the keys K2 and Kz are replaced, which changes the direction of the current in the control circuit of the Hall sensor 3. As a result, the polarity of the regulated amplifier 2 changes. and, consequently, the direction of the current in the auxiliary winding 1 is also determined by changing the coefficient of dripping.

The amount of current otpitki for specific

Maschiny is defined as / n ---, where

Lg 0 - respectively, the currents of water and rations, determined from the zone of non-sparking work.

The required value of the current of the impregnation in winding 1 is set by changing the gain of the amplifier 2, the magnitude of the air gap of the magnetic circuit 4, as well as the inclusion of an adjustable 1potentiometer between the input of the reversing switch 9 and the output of the inverter: I | Mitel 10.

With OTn.HTiKe, the windings of the additional poles of the currents io, the upper and lower limits of the zone, are shifted upwards. In this case, the middle line of the zone is shifted and, thereby, its asymmetry is eliminated, caused by the variable component of the current zhor.

If you need a more accurate analysis of the dependence of the auxiliary current on the product of two control signals, between the input of the amplifier 2 and the output of the Hall sensor 3, a functional core can be switched on.

Subject invention

U1Stroy (Steve for improving commutator commutating electric machines, containing an additional winding of the additional pole connected to the output of a revolvable variable amplifier, the control input of which is connected to the output of a multiplying device made, for example, on a Hall sensor, as well as a rotation speed sensor and a sensor current of the core, connected to the inputs of the M1 multiplier device, characterized by the fact that, in order to eliminate the asymmetry of the spark-free operation zone of the machine while feeding its pulse, driving with the current, as sensors Single current sensor taken ie, variable-releasing component of the armature current, and is connected to the input of the multiplier device through series-connected DC converter and vyp.r

reversing switch.