JPS586378B2 - Field voltage and field current measuring device for brushless rotating electric machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for measuring field voltage and field current of a brushless rotating machine.

An example of a conventionally known method for estimating the field current of this type of rotating machine is shown in FIG.

In the figure, 1 is the stator of the synchronous generator, 2 is its rotating part, 2a is the rotating armature winding of the AC exciter, and 2b is the rotation for rectifying the output of the armature winding 2a of the AC exciter. A rectifier, 2c is a field winding of a synchronous generator, 2s is a slip ring for measuring field voltage, 3 is a field winding of an AC exciter, and 5 is a field of an AC exciter connected via a shunt 4. magnetic ammeter,
6 is a current collecting brush, and 7 is a field voltmeter.

Next, the operation of this device will be explained.

The field winding 2c of the synchronous generator is constantly rotating together with the rotary rectifier 2b and the armature winding 2a of the AC exciter during operation, and its field voltage and field current cannot be directly measured.

Therefore, instead of the field current of the synchronous generator, the field current of the AC exciter, which has a substantially relative relationship, is measured by the field ammeter 5, and the field current of the synchronous generator is estimated.

In order to estimate the field current of a conventional synchronous generator using this method, it is necessary to estimate the error due to the saturation of the magnetic circuit of the AC exciter, the field winding 2c of the synchronous generator, and the armature winding of the AC exciter. 2
There is a large error due to temperature changes in a, and there is a drawback that it is only useful as a guide in practical terms.

Furthermore, it is not possible to directly read the field current of the synchronous generator,
Another drawback was that estimating the current value was time-consuming.

As for the method of detecting the field voltage, there is a method of installing a measuring slip ring 2S on the rotating part, pressing the current collecting brush 6 against it, and measuring it with the field voltmeter 7, but a brushless structure makes maintenance and inspection easier. The drawback was that it did not meet the original purpose of brushless rotating machines.

This invention was made with the aim of eliminating the drawbacks of such conventional devices, and by using a detection rotating transformer, it is possible to directly detect and measure the field voltage and field current of a brushless synchronous machine. This provides a highly accurate device that can perform

Next, one embodiment of the present invention will be described based on the drawings.

In FIG. 2, 8 is a voltage detection rotary transformer for detecting the AC voltage generated in the AC exciter rotating armature winding 2a, 8a is a rotational secondary winding of the voltage detection rotary transformer, 8
b shows the fixed secondary winding of the voltage detection rotary transformer.

9 is a current detection rotary transformer for detecting the current flowing through the rotating armature winding 2a of the AC exciter; 9a is the rotating primary winding of the current detection rotary transformer 9; and 9b is the current detection rotary transformer. The stator winding of the device is shown.

10 is a voltage detection converter for guiding the voltage generated in the fixed secondary winding 8b of the voltage detection rotary transformer to the voltage measuring device 12, and 11 is the fixed secondary winding 9b of the current detection rotary transformer.
2d is a voltage dividing resistor for applying an appropriate voltage to the rotating primary winding 8a of the rotating transformer for detecting voltage; 2e is an AC exciter; A current transformer is used to obtain a current proportional to the current flowing through the armature winding 2a, and 2f is a secondary resistance of the current transformer disposed on the secondary side of the current transformer 2e.

Note that the other configurations are the same as the device shown in FIG. 1, so explanations will be omitted.

Since this invention is configured as described above, a voltage is generated in the rotating armature winding 2a of the AC exciter by excitation of the field winding 3 of the AC exciter, and when current flows, a voltage detection rotating transformer is generated. The rotating primary winding 8a of the device and the rotating primary winding 9a of the current detection rotating transformer each include an AC exciter armature winding 2.
A voltage proportional to the voltage generated at a and the output current is applied.

As a result, a voltage proportional to the line voltage of the AC exciter armature winding 2a is obtained in the fixed secondary winding 8b of the rotating transformer for voltage detection, and a voltage proportional to the line voltage of the AC exciter armature winding 2a is obtained in the fixed secondary winding 8b of the rotating transformer for current detection. 9
A voltage proportional to the output current of the AC exciter armature winding 2a is obtained at b.

The field voltage generated in the field winding 2c is proportional to the line voltage of the AC exciter armature winding 2a, and
Since the field current flowing in is proportional to the output current of the AC exciter armature winding 2a, as a result, the rotating transformer fixed secondary winding 8b for electric current detection and the rotating transformer fixed secondary winding for current detection In the wire 9b, an electric current proportional to the field electric current and the field electric current of the field winding 2c is generated, respectively.

Therefore, the voltage generated in the voltage detection rotating transformer fixed secondary winding 8b and the current detection rotating transformer fixed secondary winding 9b is transferred to the electronic detection converter 10 and the current detection converter 11, respectively.
and its output is sent to the voltage measuring device 12 and the current measuring device 1.
If you measure with 3, you can directly read the field current and field current.

Although this example shows an example in which the field current and field current of a brushless synchronous generator were measured, the field current and field current can be easily measured in the same way in the case of a brushless synchronous motor. It is possible to do so.

Furthermore, it goes without saying that this measuring device can be applied to various control and adjustment devices for brushless synchronous machines.

In this way, according to the present invention, the field voltage and field current of the brushless synchronous machine are configured to be directly detected using a rotary transformer, so the brushless field voltage and field current can be directly read. Therefore, it is possible to obtain a highly accurate measuring device with a simple structure and circuit, which has few errors due to saturation of the magnetic circuit of the AC exciter, and is of great benefit in the operation and maintenance of machines.

[Brief explanation of the drawing]

Fig. 1 is a wiring diagram for explaining a method for estimating the field current of a conventional brushless synchronous machine, and Fig. 2 shows a field voltage and field current measuring device for a brushless synchronous machine according to an embodiment of the present invention. FIG. In the figure, 1 is the stator of the synchronous generator, 2 is its rotating part, 2
a is the rotating armature winding of the AC exciter, 2b is the rotating rectifier,
2c is the field winding of the synchronous generator, 2d is the voltage dividing resistor, 2e is the current transformer, 2f is the secondary resistance of the current transformer, 3 is the field winding of the AC exciter, 4 is the shunt, 5 is the field ammeter of the AC exciter, 6
is a current collector brush, 7 is a field voltage meter, 8 is a rotary transformer for voltage detection, 9 is a rotary transformer for current detection, 10 is a converter for electric current detection, 11 is a converter for current detection, 12 is a voltage measuring equipment,
13 is a current measuring device. In addition, the same symbols in each figure indicate the same or Buddhist priest parts.

Claims (1)

[Scope of Claims] 1. An AC exciter having a rotating armature winding, and a device for rectifying the AC voltage induced in the rotating armature winding to supply power to the rotating field winding of a main synchronous machine. a first rotating primary winding that is energized by the one-phase terminal voltage of the rotating armature winding of the AC exciter and rotates together with the rotating field winding of the main synchronous machine; , a voltage detection rotating transformer comprising a first fixed secondary winding, and a secondary winding current of a current transformer inserted into one phase of the rotating armature winding of the AC exciter. a second rotating primary winding rotated together with the rotating field winding of the main synchronous machine;
a current detection rotary transformer having a fixed secondary winding; and a voltage measuring device and a current measuring device respectively connected to the first and second fixed secondary windings. Field voltage and field current measuring device for plasticless rotating electric machines.