JPH06207972A - Measuring method for rotating magnetic field iron loss at outer core - Google Patents

Abstract

PURPOSE:To easily measure the iron loss of outer core including all effects by measuring rotatory force induced in the outer core. CONSTITUTION:If there is iron loss in an outer core 4 used in a rotating magnetic field, rotatory force is induced in the outer core 4. By letting the iron loss W (W), the induced rotatory force T (Nm), rotation number of the rotating magnetic field n (rpm) and the ratio of the circumference of a circle to its diameter pi, W is expressed as W=2pinT/60, and the iron loss of a magnetic material in a rotating magnetic field is measured only from the induced rotational force. The rotational force is not related with the outer core conditions, it can be evaluated in actually used state including all effects of shape, distortion, magnetic flux distribution, centrifugal force, plate number in the case of plate, layering method, fixing method, etc. For constitution, the two outer cores 4 as the sample are layered and fixed with a sample holder 8, which is rotated with an angle velocity of n0 in the rotating magnetic field of rotation number n+n0 given by three-phase power 1, magnetic field generation coil 2 and iron core 3, and induced rotatory force T and the rotation number n are detected 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring energy loss in an rotating magnetic field of an actuator such as a rotating machine or an outer core used in a generator.

[0002]

2. Description of the Related Art The evaluation of iron loss when an outer core such as a silicon steel plate is used in a rotating machine is generally conducted by the electromagnetic steel plate test method described in JIS C2550. However, this method is not suitable for iron loss evaluation in a place where a rotating magnetic field is generated, such as the outer core inside the rotating machine, where the excitation direction is one direction.

Iron loss evaluation in a rotating magnetic field is carried out by measuring the temperature rise due to iron loss with a thermocouple or thermistor, or by measuring the magnetic flux density and the magnitude of the magnetic field two-dimensionally to obtain the iron loss. There is. These methods can obtain local iron loss and can measure only with a uniform magnetic flux distribution. Further, if it is limited to the inner core, there is a method by measuring the rotational force applied to the inner core in the rotating magnetic field, but the iron loss of the outer core cannot be measured. In addition, it is impossible to make a model of a rotating machine and evaluate the iron loss because the mechanical loss of the rotating machine and the loss due to the winding are too much influence, and it takes time and cost. near.

From the above, in general, in a rotating machine, although the stator has a larger iron loss than the rotor and the stator is often the outer side, the current measuring method actually uses the rotating machine in the rotating machine. It is not possible to fully evaluate the iron loss of the outer core in the state of being installed. Therefore, when the outer core is used in the rotating machine, it is not possible to clearly position the outer core, so that the selection of the magnetic material and the design of the optimum shape cannot be sufficiently performed.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the iron loss of the outer core used in a rotating magnetic field can be determined by the shape, strain, magnetic flux distribution, centrifugal force, plate shape, etc. In the case of (1), the present invention provides a method of measuring iron loss in a rotating magnetic field of an outer core or a method of measuring iron loss in a rotating machine, which includes all effects such as the number of sheets, a laminating method, a bonding method, and a fixing method.

[0006]

According to the present invention, in measuring the iron loss of an outer core used in a rotating magnetic field, which is consumed in the rotating magnetic field, the rotating force induced in the outer core is measured. This is a method for measuring the rotating field iron loss of the outer core, which is characterized in that the iron loss is easily obtained by performing the above.

When the outer core used in the rotating magnetic field has iron loss, a rotating force is induced in the outer core. At this time, the iron loss W (W) is the induced rotational force T (N
m), the rotating speed of the rotating magnetic field with respect to the outer core that causes iron loss is n (rpm), and the pi is π, W = 2πnT / 6
It can be represented by 0, and the iron loss of the magnetic material in the rotating magnetic field can be measured only by the induced rotational force. Rotational force is not related to the condition of the outer core, so the outer core is actually used, including the influence of shape, strain, magnetic flux distribution, centrifugal force, number of sheets in case of plate shape, lamination method, bonding method, fixing method, etc. The iron loss will be evaluated under the condition.

The outer core in the method for measuring the iron loss of the rotating magnetic field of the outer core of the present invention may be either a stator or a rotor, and may be an armature core or a field core. Say that. The magnetic flux distribution when exciting the sample does not have to be a constant magnitude,
A rotating magnetic field should be applied to the outer core.

The rotating magnetic field of the present invention indicates the movement of a magnetic field with respect to an outer core (hereinafter referred to as a measurement sample) for measuring iron loss, and either one or both of the measurement sample and the external magnetic field rotates. The magnetic field rotates relative to the measurement sample, and the external magnetic field may be an electromagnet or a permanent magnet. The external magnetic field does not have to have a constant magnitude and direction, may change depending on the location, and may have a magnetic flux distribution. Further, even if the magnetic flux distribution changes depending on the positional relationship between the external magnetic field and the measurement sample, it is sufficient that the magnetic flux distribution makes one rotation and the same magnetic flux distribution at the same angle.

Relative speed n (rpm) relative to the measurement sample
When measuring the iron loss due to the rotating magnetic field of the outer core stopped in the rotating magnetic field, the outer core is rotated at a low rotating speed n ₀ that does not affect the magnetic characteristics so much that the rotating speed of the external rotating magnetic field is By rotating at n + n ₀ (rpm), measurement error due to frictional force may be reduced. As a matter of course, the rotation speed needs to consider the rotation direction of the external rotating magnetic field. In this case, when the external magnetic field is an electromagnet, the magnetic flux is 0
Leave measuring the rotational force T ₀ when the, or measuring the difference T ₁ -T ₀ of the rotational force T ₁ of the time of applying an external magnetic field, when the external magnetic field by the permanent magnets, the magnetic flux is zero In order to create the state, the rotational force T ₀ ′ is measured by separating the measurement sample so that it is not affected by the permanent magnet, and the rotational force when the measurement sample is inserted into the rotating magnetic field to apply the external magnetic field. The measurement error may be reduced by measuring the difference from T ₁ ′.

The electromagnet is wound around the core to give a magnetic field to the sample. The winding method is the winding method used in the conventional motors or other possible winding methods. But it's okay. The core may be with teeth or without teeth if not required. The number of poles of the permanent magnet or electromagnet is not limited to two, and may be four or more.

The outer core may be any kind of magnetic material, shape and usage, such as silicon steel plate.
From one plate or a laminate of two or more,
It may be a molded product of a composite material with a magnetic material, a ferrite, an aluminum die-cast product, or one or several pieces such as those with accessories.

The applied product of the outer core refers to a case where the outer core is used in a place where a rotating magnetic field is generated, such as an actuator such as a motor or a generator. The laminating method refers to a method of stacking outer cores, in which two or more cores are stacked at different angles when the outer cores are plate-shaped, but the outer cores are stacked.
The sample to be measured and the sample holder may be fixed by pressing, fitting, using a double-sided or single-sided tape, fixing with an adhesive, fixing the actual machine, or a method similar to this, so that distortion does not enter.

[0014]

The present invention will be described with reference to the drawings of the embodiments. Example 1 FIGS. 1 and 2 show a simplified outer core 4 without teeth in a rotating magnetic field of a rotational speed n + n ₀ obtained by a three-phase power source 1, a magnetic field generating coil 2 and an iron core 3.
An apparatus for measuring iron loss due to a rotating magnetic field having a rotation speed n by laminating the sheets and rotating them at an angular velocity n ₀ , and 5 is a detector for detecting the rotation force and the rotation speed induced in the outer core 4 as a measurement sample. , 6 are motors and brakes for rotating or stopping the outer core 4 which is a sample at a constant speed, and 8 is a sample holder for fixing the outer core.

FIG. 2 is a view seen from the direction A in FIG. Also in this case, considering the coordinate axis rotating at the rotation speed n + n ₀ , the rotating magnetic field having the rotation speed n is applied to the outer core 4, so that the rotating force T induced on the outer core 4 is calculated by the relational expression W = 2πnT / 60. By measuring, the iron loss W due to the rotating magnetic field can be obtained. When the outer core 4 is in a stopped state, the rotational force becomes unstable due to frictional force. Therefore, in this embodiment, the outer core 4 is rotated at a rotational speed as low as possible so that the influence thereof is eliminated, thereby improving the measurement accuracy. ing. The sample holder 8 and the outer core 4 may be fixed by fitting the outer core 4 to the sample holder 8 by using an appropriate shape that fits the outer core 4 or by using an adhesive so that the outer core 4 is not distorted. As described above, the outer core 4 may be fixed to the sample holder 8,
The outer core 4 may be fixed by a holding plate that does not affect the iron loss.

Embodiment 2 In FIGS. 3 and 4, a rotating magnetic field is applied to the outer core 12 by rotating one outer core 12 with teeth, which is an actual shape, in a magnetic field generated by a direct current, and It is a device that measures iron loss by rotational force. FIG. 4 is a view seen from the direction B in FIG. 9
Is a DC power supply, 10 is a coil for generating a DC magnetic field, 11 is an iron core for generating a DC magnetic field, 12 is an outer core which is a sample for measuring iron loss due to a rotating magnetic field,
Reference numeral 13 is a detector for detecting the rotational force and the number of revolutions induced in the outer core 12 which is a measurement sample, 14 is a motor and a brake for rotating or stopping the outer core 12 which is a sample at a constant speed, and 16 is a sample for fixing the outer core. It is a holder. As in Example 1, the outer core 12 as a sample is relatively subjected to a rotating magnetic field as the outer core 12 rotates, so iron loss due to the rotating magnetic field of the outer core 12 is required.

Embodiment 3 FIG. 5 and FIG. 6 rotate the permanent magnet in the magnetic field generated by the permanent magnet 18 by rotating one outer core 12 having an actual shape with teeth and wound. With this, a rotating magnetic field is applied to the outer core 12, and the iron loss due to the rotating magnetic field is measured by the rotating force. FIG. 6 is a view seen from the direction C in FIG. Reference numeral 17 is a motor for rotating a permanent magnet, 18 is a permanent magnet for generating a magnetic field, 19 is an outer core that is a sample for measuring iron loss due to a rotating magnetic field, and 20 is a rotational force induced in an outer core 19 that is a measurement sample. And a detector that detects the number of revolutions, 2
Reference numeral 1 is a motor and a brake for rotating or stationary the outer core 19 which is a sample, 23 is a sample holder for fixing the outer core, and 24 is a winding which is not short-circuited so that an induced current does not flow. As in Example 1 above,
Since the rotating magnetic field is relatively applied to the outer core 19 as a sample by the rotation of the permanent magnet 18, the iron loss due to the rotating magnetic field of the outer core 12 is required. When the outer core 19 is in the stopped state, the rotational force becomes unstable due to the frictional force. Therefore, in the third embodiment, as in the first embodiment, the outer core 19 is not affected by the frictional force, and the rotational speed is as low as possible. Rotate by a number to improve measurement accuracy.

Example 4 In the case where two or more outer cores are laminated in a plate shape and are measured in FIG. 1 or 2, when the insulation between layers is broken, the eddy current loss of the measurement sample is increased by ΔW. , ΔW = 2πn
The rotational force increases by ΔT by the amount represented by ΔT / 60.
The rotational force of measurement sample A in which the insulation between layers is not broken and measurement sample B in which the insulation between layers is broken are measured. However, A and B
Is a laminate of two or more measurement samples, and the factors that affect the iron loss per unit volume are exactly the same except the interlayer resistance. When a difference appears in the iron loss per unit volume of the measurement samples A and B, it means that the insulation between layers is broken, and this can be used to detect the insulation breakdown between layers. Table 1 shows the iron loss measured by the measuring method of FIG. 1 when the insulation of the outer core with a frequency of 50 Hz, a magnetic flux density of 1.0 T, an outer diameter of about 17 cm, an inner diameter of about 6 cm, and a plate thickness of about 0.5 mm is broken. Shows.

[0019]

[Table 1]

[0020]

According to the measuring method of the present invention, it is possible to measure the iron loss in the actual machine state, which is not possible by the conventional method, that is, the iron loss of the outer core in the rotating magnetic field under any complicated shape and any usage condition. In addition, it is possible to easily measure the total iron loss consumed in the entire outer core. This may be a rotating magnetic field generated in the product in which the outer core is used, and the total iron loss in the applied state of the outer core can be directly measured. Therefore, it is possible to directly obtain information about the iron loss necessary for designing actuators such as motors and generators.

The present invention can be applied not only to an actuator and a generator, but also to an outer core used where a rotating magnetic field is generated. On the contrary, not only the condition of the outer core of the actual machine but also the actual number of sheets less than the actual machine can be measured, which can be used for a simple test for design and determination of the core shape. Since the iron loss can be measured in the actual machine state, it is possible to measure the effect of strain during core processing and the core loss of the core after strain relief annealing, and it is possible to make a more practical evaluation before assembling the motor etc. It is convenient. This iron loss evaluation method is much more accurate than the iron loss evaluation method found by excluding mechanical loss, copper loss, etc. from total energy loss in conventional motors, etc., because the effects of mechanical loss in motors, etc. can be made extremely small. . The core iron loss can be evaluated before the motor is completely assembled with the core wound and the core fixed to the case. As described above, it is a very effective means for iron loss reduction and design of motors and the like, and search for loss reduction measures for motors and the like.

[Brief description of drawings]

FIG. 1 is an example in which measurement is performed in a rotating magnetic field by generating a rotating magnetic field with an exciting coil.

FIG. 2 is a view on arrow in FIG.

FIG. 3 is an example in which a rotating magnetic field for the measurement sample is generated by rotating the measurement sample.

FIG. 4 is a view on arrow of FIG.

FIG. 5 is an example of an apparatus for measuring iron loss due to a rotating magnetic field by a rotating force.

FIG. 6 is a view seen from the direction C in FIG.

[Explanation of symbols]

1 Three-phase power supply that generates a rotating magnetic field 2,10 Coil that generates a magnetic field 3,11 Iron core 4,12,19 Outer core that is a sample for measuring iron loss due to a rotating magnetic field 5,13,20 Rotation induced in the outer core Detector for detecting force and rotation speed 6, 14, 21 Constant rotation of outer core, which is a sample,
Alternatively, a motor and a brake to be stationary 8,16,23 A motor for rotating a sample 9 A DC power supply 17 A motor for rotating a permanent magnet 18 A permanent magnet 24 A winding which is not short-circuited

Claims (10)

[Claims] 1. When measuring the energy loss of an outer core used in a rotating magnetic field when it is consumed in the rotating magnetic field, the energy loss is measured by measuring the rotational force induced in the outer core. A method for measuring the iron loss of a rotating magnetic field of an outer core, which comprises: 2. The outer core for measuring energy loss in a rotating magnetic field includes all factors that affect energy loss, such as shape, strain, magnetic flux distribution, centrifugal force and the like. A method for measuring a rotating magnetic field iron loss of an outer core as described. 3. The rotating magnetic field iron loss of an outer core according to claim 1, wherein the outer core for measuring energy loss in a rotating magnetic field is in a state of being used in an applied product of the outer core. Measuring method. 4. When using a plate-shaped outer core,
The method for measuring the iron loss of an outer core according to claim 1, 2, or 3, wherein the lamination method is used for an outer core application product. 5. When using a plate-shaped outer core,
The method for measuring the iron loss of an outer core according to claim 1, 2, 3 or 4, wherein the bonding method is in a state of being used for an outer core application product. 6. When using a plate-shaped outer core,
The method for measuring a rotating magnetic field iron loss of an outer core according to claim 1, 2, 3, 4 or 5, wherein the fixing method is a state in which the fixing method is used for an applied product of the outer core. 7. When using a plate-shaped outer core,
The outer magnetic core iron loss measurement of the outer core according to claim 1, 2, 3, 4, 5 or 6, wherein the number of laminated layers is one or less than the number of sheets used in an applied product of the outer core. Method. 8. When using a plate-shaped outer core,
The method for measuring the iron loss of an outer core according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the number of laminated layers is in a state of being used for an outer core application product. 9. In measuring the energy loss due to the rotating magnetic field of the outer core stopped in a rotating magnetic field having a rotating speed of n (rpm), the outer core is rotated at a rotating speed of n _0.
Rotate about (rpm) and change the rotation speed of the external rotating magnetic field to n + n
_{It is set to 0} (rpm), Claims 1, 2, 3,
4, 5, 6, 7 or 8 outer core magnetic field magnetic field iron loss measuring method. 10. When exciting the outer core, exciting is performed by using a permanent magnet or an electromagnet to generate a rotating magnetic field.
A rotating magnetic field iron loss measuring method for an outer core according to 3, 4, 5, 6, 7, 8 or 9.