JPS6010586B2 - Equivalent test method for thyristor motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an equivalent test method for a load commutated thyristor motor, and particularly to a test method for a device having a plurality of three-phase windings.

Traditionally, before shipping from this type of thyristor motor manufacturer, after testing the rotating machine and converter,
It is common to perform combination tests by combining these materials.

In a combination test, a load machine that can carry the load of the rotating machine under test is generally connected, and various characteristics are measured under the actual load to confirm whether specifications are satisfied. Unlike thyristor motors that operate with sinusoidal current and voltage, they are driven with a nearly square-wave current, so harmonic current flows, and in combination tests, emphasis is placed on understanding the mechanical vibrations and losses that are recorded in this.
With the recent expansion in the application of thyristor motors, the need for large-capacity machines is increasing, but systems using rotating machines with multiple sets of ordinary three-phase armature windings also have characteristics due to multiphase. It is increasing from the viewpoint of improvement.

In this type of counterfeiting, a configuration in which each three-phase winding is provided with a conversion device is common. However, as the capacity and demand for thyristor motors increases, the power supplies and costs required for combination tests have become enormous, and it is desired to establish an equivalent test method.

The present invention is based on the above-mentioned viewpoint and aims to provide a general-purpose equivalent test method for thyristor motors.

FIG. 1 is a diagram showing a configuration example of an equivalent test apparatus according to the present invention, in which 1 is a variable speed motor, 2 is a rotating machine to be tested, 3 is an excitation device, 4 and 5 are thyristor order conversion devices, 6 is a DC reactor, 21 is a field winding of the rotating machine under test 2, and 22 and 23 are Hakoisogo windings.

The two sets of armature windings 22 and 23 are electrically wound with a phase shift of 30 degrees from each other, and each output is connected to a forward conversion device 4 or 5 constituted by a thyristor bridge.
Reference numerals 4 and 5 are provided with a current control circuit (not shown).

With such a configuration, the rotating machine under test 2 is rotated as a generator by the variable speed electric motor 1 having a capacity that can compensate for the loss of the rotating machine under test 2.

In this state, an excitation current is applied by the excitation device 3 to establish an AC voltage, and each thyristor bridge is gate-controlled to cause a DC current to flow. When the DC current is constant, assuming that the DC reactor 6 has only an inductance component, the average value of the DC voltage is zero. Ignoring the overlapping angle of each Denki Viscount flow and assuming that the control delay angles of the silice tanning converters 4 and 5 are respectively 2 and 2, since the average DC voltage is zero, the relationship between Q and 2 is as follows. The formula is C.

6QI + COS 2 d.

'.; Generally, there is a relationship between the control delay angle & of the thyristor conversion device and the control advance angle P at that time as follows: Q18=18008}, so from the equation {1}, =82.

For example, when operating with Q = 82 = 45 degrees, the armature winding group is electrically shifted by 30 degrees, so the commutation timing considered with two sets of thyristor bridges is This occurs every 30 degrees.This is similar to the commutation period when 8 and 2 are the same during gourmet gutter operation, and this method is able to grasp the mechanical vibration caused by the commutation phenomenon. In addition, each damper loss of the direct tree and machine shaft due to square wave armature current changes occurs in the same way as during actual load operation.In other words, ``corresponding to 8 during actual load operation, If the operation is carried out in such a manner, the distribution of damper loss within the rotating machine will be almost the same, and the loss can be estimated with high accuracy.Also, the commutation inductance can be estimated from the overlapping angle that occurs in the AC current waveform.
Characteristics during Aoi load operation can be understood. In this example, power is taken out from the armature winding 22 and almost the same power is returned to the armature winding 23.As a rotating machine, only delayed reactive power is output.Therefore, the increase in DC current This causes a demagnetization effect due to armature reaction, but this can be corrected by the excitation device 3.If the armature winding coarseness is n, the control delay angle of each thyristor forward conversion device is Qi. Then, 2 cosQi=01
(3) It is sufficient to perform gate control such that:

In the explanation so far, we have shown the test method when the DC current is constant, but as shown in Figure 2, we use the current control of a thyristor forward converter to give a current reference value that changes in steps to a certain DC amount. We will consider a method to periodically realize the actual load state.

That is, even if a limit value of 3 is set in advance for each control angle of the thyristor forward conversion device with respect to the step-changing current reference value (Fig. 2 shows the case of 30°),
The actual current is changed by symmetrically controlling the control angle of each bridge while maintaining this value. The amount of change in the actual current is determined by the size of the DC reactor and the capacity of the rotating machine under test, but ★8 is a constant value around time A in Figure 2, and the value of 8 is the value during actual load operation. By setting it to , its characteristics can be measured periodically. In this case as well, power fluctuations occur due to the slow rotation of the test object in response to changes in the energy of the DC reactor, but by attaching a flywheel to the variable speed motor, the rotation speed can be approximately reduced without increasing the capacity of the variable speed motor. Can be kept constant. As explained above, this equivalent test method can estimate many of the characteristics in the combination test.

The capacity of the driving rotary machine of the test equipment can be set to a value that can cover the loss of the rotary machine under test, and the thyristor forward conversion device has advantages such as being versatile and requiring less electric power for testing.

[Brief explanation of drawings]

1 is a block diagram of an equivalent test device according to the present invention, and FIG. 2 is a characteristic diagram when performing DC current control to explain the present invention. Tortoise: Variable speed electric motor, 2: Rotating machine under test, 3: Excitation device, 4.5: Cylindrical star order converter, 6: DC reactor, 29: Field winding, 22, 23 ...armature winding. Figure 1 Figure 2

Claims (1)

[Claims] 1 A rotating machine under test having two or more armature winding groups,
An excitation device is mechanically connected to the variable speed motor and applies an excitation current to the field winding of the rotating machine under test, and each set of the armature winding group is provided with a set of thyristor order conversion device. , connect each DC output in cascade and connect a DC reactor as a load, operate each thyristor forward conversion device with symmetrical gate control and asymmetrical gate control, measure the input/output characteristics, and measure the characteristics under actual load conditions. Estimated thyristor equivalence test method.