JPS5921264A - Brushless synchronous motor - Google Patents

Abstract

PURPOSE:To simplify the facility by providing an AC exciter, a permanent magnet type sub exciter, and a rotary commutator with a suitable phase connecting mechanism, and detecting the input of the synchronous motor to control the output of the sub exciter by the detection signal. CONSTITUTION:A synchronous motor 1, an AC exciter 3, a permanent magnet type sub exciter 6 and a rotary commutator 14 with a suitable phase connecting mechanism are mounted on the same rotational shaft 2. When a power source 10 is energized, polyphase alternating currents flow through the stator coils of the motor 1, exciting coil 13 is shortcircuited by a discharge resistor 16, and started as an induction machine. The suitable phase connecting mechanism, not shown, detects the current, frequency and phase induced in the coil 13 when becoming near the synchronizing speed, and fires the thyristor of the commutator 14. At this time, the armature coil 17 of the exciter 6 produces a high AC voltage, the exciting coil 5 and the armature coil 15 of the exciter 3 are sufficiently energized, the shortcircuit of the coil 13 of the motor 1 is released to flow a main machine exciting current, and synchronized with the synchronizing speed. In this manner, the exciting facility can be simplified to effectively reduce the cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a brushless synchronous motor device which is designed to rationalize equipment by simplifying a drive system.

[Technical background of the invention]

Synchronous motors have advantages over induction motors in that they can adjust the power factor and are more efficient, but it cannot be denied that they require an excitation device, which is a disadvantage in terms of equipment. Overcoming equipment disadvantages is also required from the standpoint of efficient energy utilization in motor drive systems.

FIG. 1 shows an example of a brushless synchronous motor device according to the prior art. The stator winding (lla) on the stator 01) side of the synchronous motor (1) is energized by multiphase alternating current, and the magnetic pole α on the rotor side is excited on the field winding side. Generally, the field winding (13) of a synchronous motor is connected to the same rotating shaft (2) via a rotary rectifier (I4) provided on the same rotating shaft (2).
It is energized by the armature winding α9 of the AC exciter (3) provided above. Since this AC exciter (3) is a rotating armature type synchronous machine, it is necessary to excite the field winding (5) of its stator magnetic pole (4) with an auxiliary DC power source. A glance at this excitation system shows that the stator winding (ll) of the motor (1) is
It is returned to the power supply room (9) in the same way as the switch u (4) of the multiphase stream current 10) that monitors a)! □Therefore, a long excitation wiring Q41 is required to connect the excitation device (2 increments and AC exciter <3) and a in the power supply room (9). Although not shown in detail in Figure 1, as is well known, the rotating rectifier α on the rotating shaft (2) converts the alternating current generated in the armature winding QS of the alternating current exciter (3) into direct current. In addition to the steady mechanism in which the synchronous motor (1) The circuit of the field winding (03) is short-circuited by the earth discharge resistance (1!) of the rotating shaft (2), and near the synchronous speed, the frequency and phase of the current induced in the field winding (13) are The thyristor in the rotary current device α is activated at an appropriate timing, and the field winding (
2) Supply and excite DC current. and a synchronous motor (1
) has a so-called brushless appropriate phase input mechanism that synchronously draws in the power source 0). Therefore, the exciting current of the field winding (5) of the AC exciter (3) is
) - Even if the power is applied from the beginning of the motor, the synchronous motor (1
) starts after the number of cycles θ, and performs synchronous pull-in and synchronous operation automatically without any special intervention.
Pe de chiru. Furthermore, the excitation device installed in the power supply room has the function of controlling the excitation current of the field winding (5) of the AC exciter (3) in response to load fluctuations during steady operation of the synchronous motor (1). Because of this, stable driving is possible.

[Problems with background technology]

In the above conventional technology, the excitation device Q of the AC exciter (3)
21 is in the power supply room (9), so its excitation wiring (goods)
, the space in the power supply room (9), and even the excitation device 0
'There are drawbacks such as the need for an IJ power source.

[Object of the Invention] ′ □ An object of the present invention is to provide a brushless synchronous motor device with equipment rationalization.

[Summary of the invention]

In the present invention, a tributary exciter is coaxially connected to the synchronous motor,
A permanent magnet shaping exciter and a rotary rectifier with an appropriate phase input mechanism are installed, and an instrument transformer and a current transformer are installed on the power supply line that supplies AC power from the switch panel to the synchronous motor, and the input of the synchronous motor is An excitation control device for an AC exciter that supplies field current to the AC exciter in a controlled manner by controlling the output of the sub-excitation mode using this detection signal, is connected to the AC exciter stator or the synchronous motor stator. By arranging it integrally with the conventional excitation wiring, the
It is possible to streamline equipment by eliminating the need to place the excitation device (a) in the power supply room (9).

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3. In these figures, the same parts as in FIG. 1 are designated by the same reference numerals, and their explanation will be omitted.

In this embodiment, an AC exciter (3), a permanent magnet shaping exciter (6), and a rotating rectifier α4 with an appropriate phase input mechanism are provided coaxially with the synchronous □ electric motor (, 1). Then, a potential transformer 01) and a current transformer C (3) are connected to the main cape /I/(c), which is a part of the power supply line that supplies power from the switch panel @) to the synchronous motor (1). The input of the synchronous motor (1) is detected, and the sub-exciter (1) is activated by this detection signal.
By controlling the output of the fixed side armature and winding ←η of 6), the field winding of the AC exciter (3) (in one phrase, the field current (
An excitation control device for an AC exciter, which supplies the AC exciter while controlling it, is integrally mounted on the stator (3a) of the AC exciter (3). In Fig. 3, (c) in the excitation control device aQ for an AC exciter is a power factor control circuit, (33a) is a power factor setter, and a gate control circuit that generates a gate signal for the zero rectifier circuit (35). I'll go.

Next, the action will be explained. ,
□Switch panel to start the synchronous motor (1) as an induction motor
When :@) is turned on, power source Q to main cape, /I/
Multiphase alternating current flows to the stator winding (lla) of the synchronous motor (1) via (2) □□. At this time, the synchronous motor (
The field winding θ■ in 1) is short-circuited by the discharge resistance αe,
It is started as an induction machine. And when it comes to around the synchronous speed, not shown in the figure.
Appropriate phase input mechanism induces θ rise in field winding of synchronous motor
,: Detects the frequency and phase of the electric current, and ignites the thyristor in the rotary rectifier (14). At around this synchronous speed □, the armature winding Q7) of the sub-exciter (6) generates a sufficiently high AC voltage, and the AC exciter (3) generates a sufficiently high AC voltage.
) is now able to flow sufficient current to the field winding (5) of Therefore, the armature winding of the AC exciter (3) also generates an AC voltage. Therefore, if the thyristor in the rotary rectifier side is fired, the field of the synchronous motor (1) The main machine excitation current (1f) can be passed through the magnetic winding, and the synchronous motor (1f) can be passed through the magnetic winding.
) can be brought to synchronous speed.

The power factor control circuit G [with] in the excitation control device a for an AC exciter is configured to transfer the voltage and current flowing to the stator winding (lla) of the synchronous motor (1) from the main cable (23) to the instrument transformer. C
31) Detected by current transformer 02+, and using the detected signal as input, controls the field current (ife) of the AC exciter (3) so that the edge ratio of the synchronous motor (1) is constant. Furthermore, it has a so-called power factor control function that adjusts the excitation current (1f) of the field winding (13) of the synchronous motor (1), and the power factor setting device (33a) adjusts the excitation current (1f) to the desired power factor. You can. The gate control circuit (2) generates a gate signal based on the signal from the power factor control circuit 03) and controls the G thyristors in the rectifier circuit, so that the field current (ife) of the AC exciter (3) is constant with respect to the set value. It is no secret that it has such a control function.

Therefore, the above embodiment is compared with the conventional one shown in FIG. 1.
As is clear, the only cables that connect the power supply room (9) and the rotating machinery such as the synchronous motor (1) are the main cables (to), and the excitation wiring (24J) is missing, and the Exciter Co., Ltd.'s J-1 Hiso power supply has been eliminated and the equipment has been streamlined.However, as mentioned above, the function as a brushless synchronous motor device is exactly the same.And, the AC exciter (3 ) are all synchronous motors (1) including the sub-excitation (6) where the excitation control device 0 barrel is the power source.
It is incorporated into one piece. The advantages of this are obvious, but can be summarized as follows.

(1) There is no need to worry about placing the excitation device in the power supply room (9), and the excitation wiring 0a connecting the power supply room (9) and the AC exciter (3) can be omitted. Therefore, it is possible to shorten the on-site installation work period.

(11) Since all adjustment tests can be completed at the factory, including the excitation control device for AC exciter 0 barrel, on-site trial run adjustment time can be greatly reduced.

(iii) Another effect of eliminating the need for the excitation wiring C4) is that the failure rate is reduced and the reliability of the device is improved.

(1) Since only the switch panel (21) needs to be placed in the power supply room (9), the power supply room (9) can be made more compact.

Note that the present invention is not limited to the embodiments described above and shown in the drawings; for example, the excitation control device 0Q for an AC exciter may be integrated with a synchronous motor or connected to the terminal box (7) of the synchronous motor. You can put it inside, or use this excitation control device fiH.
It goes without saying that various modifications can be made without changing the gist of the invention, such as adding a reactive power control function to the invention.

〔Effect of the invention〕

As explained above, according to the present invention, the power supply room can be made more compact, economical advantages can be achieved by omitting excitation wiring,
It is possible to provide a brushless synchronous motor device that streamlines equipment by shortening on-site construction and adjustment test periods.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional elevational view of a main part showing a conventional brushless synchronous motor device, FIG. 2 is a vertical sectional elevational view of a main part showing an embodiment of the brushless synchronous motor device of the present invention, and FIG. FIG. 2 is a system diagram of the device shown in FIG. 1...Synchronous motor 2...Rotating shaft 3...
AC exciter 3a... Stator 4 of the AC exciter...
- Stator magnetic pole 6 of AC exciter...Permanent magnet shaping exciter 11...Stator 14 of synchronous motor...Rotary rectifier with appropriate phase input mechanism 18...Excitation control device 21 for AC exciter ... Switch panel 23 ... Main cable 31 that is part of the power supply line
...Instrument transformer 32...Current transformer agent Patent attorney Inoue -Male

Claims (2)

[Claims] (1) A synchronous motor and a sub-exciter are provided coaxially, and
In a brushless synchronous motor device equipped with an appropriate phase input mechanism from startup to synchronous pull-in, an AC exciter, a permanent magnet type exciter, and a rotary rectifier with an appropriate phase input mechanism are installed coaxially with the synchronous motor to open and close the motor. An instrument transformer and a current transformer are installed in the power supply line that supplies AC power from the device panel to the synchronous motor to detect the input of the synchronous motor, and this detection signal controls the output of the sub-exciter to perform AC excitation. 1. A brushless synchronous motor device, characterized in that an excitation control device for an AC exciter that controls and supplies field current to the machine is integrally arranged with an AC exciter stator or a synchronous motor stator. (2) The excitation control device for an AC exciter has at least one of a power factor control function to keep the power factor of a synchronous motor constant and a reactive power control function. The brushless synchronous motor device according to item 1.