SU1516763A1 - Transformer pickup of turning angle - Google Patents

Abstract

The invention relates to a measurement technique and provides an increase in the accuracy and sensitivity of a transformer angle sensor by leveling the magnetic flux induction in the working gap by means of a screening element in the form of a short-circuited winding 6 placed on the rotor. The sensor contains a cylindrical stator 1 with an excitation winding 3 placed in its grooves and measuring winding 4. A two-way ferromagnetic rotor 2, one of the poles of which is made with grooves 5, is located coaxially with the stator m In these slots, a three-section winding 6 is short-circuited uniformly, the outer sections 8 of which are connected to the central section 7 in series-counter. The area of the pole sections wrapped around them is almost equal to the area covered by the central section 7. The turns of the rotor windings 6 are unevenly distributed along the slots 5 in the direction from the middle of the pole to its edges, their density in the extreme sections increases, and in the central section decreases. Due to the uneven shielding effect of the winding 6, the induction leveling in the working gap of the sensor occurs and its linearity increases. By performing a three-section closed-loop winding, eddy current losses in the rotor are reduced, which leads to an increase in the sensitivity of the sensor. 2 Il.

Description

The invention relates to a measurement technique and can be used to control the angular displacements of equipment in the oil-producing industry.

The aim of the invention is to improve the accuracy and sensitivity of the transformer angle sensor by ensuring uniform distribution of the induction in its working gap.

FIG. 1 shows the construction of a transformer angle sensor, a slit; in fig. 2 - rotor pole with a short-circuited winding.

The transformer angle sensor contains a cylindrical stator and a bipolar ferromagnetic rotor 2 mounted coaxially with the possibility of angular movement in its cavity. Excitation winding 3 and measuring winding are placed on the grooves on the inside surface of the stator. grooves 5 parallel forming a cylindrical surface. In these slots there is a three-section short-circuited winding 6 with a central section 7 and extreme sections 8 forming the shielding element. The outermost sections of the rotor winding are connected to the middle section in series-counter, and in series with each other in accordance. The total number of turns of the extreme sections is equal to the number of turns of the middle section. The coils of the short-circuited winding 6 are unevenly distributed in the grooves 5. The number of coils per slot is reduced in the middle section, and increases in the extreme sections from the center of the pole to its edges. The area of the pole sections is covered by the turns of the outer sections 8 , approximately equal to the area of the area- (the pulley covered by the middle section 7.

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The angular size of the stator section covered by the excitation winding 3 is approximately twice the angular size of the stator section enclosed by the measuring winding 4. The latter is equal to the angular size of the rotor pole 2.

Transformer angle sensor works as follows.

In the initial position, the surface of the pole with the slots 5 of the rotor 2 is located outside the surface of the portion of the status a 1 covered by the measuring winding 4. In this case, the magnetic flux that crosses the measuring winding 4 is close to zero. Accordingly, the value of the EMF on the measuring winding is approximately zero. When the rotor 2 rotates from the initial position, the surface of its pole partially overlaps the contour of the measuring winding 4, in the latter the electromotive force is induced, proportional to the area of their mutual overlap and, consequently, the magnitude of the angular displacement of the rotor 2.

Due to the edge effect of great; The magnitude of the magnetic conductivity of the equivalent air gap along the surface of the poles of the rotor 2 is not strictly constant. This non-uniformity is compensated for by the inverse non-uniformity of the shielding effect of the short-circuited winding 6, which is due to the uneven distribution of its turns in the slots of the rotor 2. The screening effect of this winding weakens in the middle part of the rotor pole 2 and increases along its edges. Therefore, the resulting magnetic flux density in the working gap of the sensor it becomes almost constant, as a result of which the EMF, induced in the measuring winding 4, increases in proportion to the magnitude of the angular displacement 2 rotor.

Indeed, as follows from FIG. 2 (arrows on dashed lines x

show the direction of the current in the active sections of the conductors of the winding 6 in the rotor slots), in the extreme sections of the rotor pole 2 covered by the greatest number of turns, weakening the floor generated by the secondary flow of the short-circuited winding is greatest, and in the sections of the pole located closer to its middle, this weakening is less. The area is covered by coils passing through the first, second and partially third grooves.

The next section is covered by coils passing only through the second and partially third grooves. The third third of the teeth of the pole pole is even weaker than the second, and even more so in the first teeth. Fourth of the edges of the teeth, encompassed by the part of the middle section 7, oppositely connected with the two extreme sections 8, the secondary flows are already collapsing with the main flow, created by the 1m excitation winding. In the fifth tine, an even larger secondary flow is added to the main flow, due to all the turns of the middle section 7 of the short-circuited winding connected in opposite with the two extreme sections 8.

Thus, the short-circuited winding 6 with non-uniformly distributed turns performs the main task - alignment of the magnetic induction In the working gap. Due to this, the linearity of the operating characteristic of the sensor is increased. However, the availability is in line with and counter to

The subsection of the short-circuited winding 6 significantly reduces losses in it, thereby reducing the equivalent resistance of the screen, which leads to an increase in induction in the working gap and, consequently, to an increase in the sensitivity of the sensor and the accuracy of the angle sensor.

Claims (1)

Invention Formula A transformer angle sensor containing a bipolar ferromagnetic rotor with a shielding element fixed on it and a cylindrical stator located coaxially with it with an excitation winding and measuring winding placed on it, which differs in type and sensitivity, at least one pole of the rotor is complete with grooves evenly distributed along its outer surface in parallel generator, the shielding element is designed as a three-section short-circuit winding placed in the grooves, the outer sections of which are connected to the middle section of the the number of turns of this winding per slot decreases from the middle of the pole to its edges in the direction of decreasing for the middle section and in the direction of increasing for the extreme from the sections, and the areas of the pole sections covered by the turns of the extreme sections are equal to the area of the pole covered by the turns of the middle section. ) - G Phage.g AT