JPH09261983A - Activation of synchronous motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain synchronous activation without use of an exclusive synchronous activation line through interconnection of an activation power supply system and a synchronous motor via a non-exclusive bus within the range allowing synchronization. SOLUTION: On the occasion of synchronously activating a synchronous motor system B, a load connected to a first bus 21 is all moved to a second bus 22 to keep a first bus 21 in the vacant condition to provide a non-exclusive line. In this case a bus interconnection breaker 29 is turned off to ratotate a synchronous motor 8 with a turning apparatus 9. Next, a variable frequency power generator 1 is rotated with a turning apparatus 2. Synchronization is established between the variable power generator 1 and synchronous motor 8 to realize control for synchronization so that both frequencies become equal. Thereby, the synchronous motor 8 can be activated via the non-exclusive bus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of starting a synchronous motor using a starting power supply system.

[0002]

2. Description of the Related Art When starting a synchronous motor, a variable frequency power source is used to synchronize the electric power source with the electric motor in a low frequency low speed rotation range, the power source frequency is increased to accelerate the electric motor, and the synchronous electric power is inserted into the system. It is a low-frequency synchronous starting method for a generally used synchronous motor (for example, Electrical Engineering Handbook; Vol. 14, Chapter 5, 5.7 Synchronous motor starting method, JP-A-61-2102179, 61-221588). (See gazette, etc.)

This conventional method will be described with reference to FIG. 3. It is composed of a starting power source system A, a synchronous motor system B and a synchronous starting line C. The starting power supply system A includes a variable frequency generator 1, a turning device 2, a field circuit 3, and an acceleration / deceleration device 4.
And is connected to the bus 21 via the transformer 5, the circuit breaker 6, and the disconnector 7. The synchronous motor system B includes a synchronous motor 8, a turning device 9 and a field circuit 10, and is connected to a bus 21 via a transformer 11, a circuit breaker 12 and a disconnector 13. The synchronous starting circuit C is composed of two circuit breakers 14 and 15.

First, with the breaker 12 turned off, the turning motor 9 rotates the synchronous motor 8 to turn on the field circuit 10. The circuit breakers 14 and 15 are turned on, the variable frequency generator 1 is rotated by the turning device 2, and the field circuit 3 is turned on near the rotation speed of the turning device 9 of the synchronous motor 8. After that, the acceleration / deceleration device 4 accelerates and the synchronous start is completed at the rated speed. These methods are used as starting methods for large-capacity synchronous motors because the starting current is small and the influence on the system is small.

[0005]

However, although the above-mentioned conventional starting method requires the dedicated synchronous starting line C, the synchronous starting circuit C is in the idle state except when the synchronous motor 8 is started. Therefore, there is a drawback that investment efficiency is poor. Also, for multiple synchronous motors,
There was also a problem that a dedicated synchronous starting line had to be provided for each.

An object of the present invention is to provide a method for starting a synchronous motor, which solves the above-mentioned problems of the prior art.

[0007]

According to the present invention, there is provided a method of starting a synchronous motor using a starting power supply system, wherein the starting power supply system is connected via a non-dedicated bus bar within a range allowed by a synchronizing force. A method for starting a synchronous motor is characterized in that the synchronous motor is linked. A variable frequency generator driven by power capable of controlling the speed in the entire speed range may be used for the starting power supply system, or a thyristor frequency converter may be used.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is an electric system diagram showing an example of an embodiment of the method of the present invention. In FIG. 1, reference numeral 21 is a first busbar, 22 is a second busbar, and the breaker 6 on the starting power supply system A side is disconnected via the disconnectors 7a and 7b, respectively, and on the synchronous motor system B side. The switch 12 is connected via disconnectors 13a and 13b, respectively. In addition to the synchronous motor system B, the synchronous motor 23,
A synchronous motor system D including a turning device 24 and a field circuit 25 is connected to a first busbar 21 and a second busbar 22 via a transformer 26, a circuit breaker 27, and disconnectors 28a and 28b. In addition,
Between the first busbar 21 and the second busbar 22, a busbar connecting circuit breaker 29 for connecting and disconnecting both busbars is provided as a disconnector 30.
It is connected via a and 30b.

Duplexing the bus bar in this way is because the frequency of the system to which the variable frequency power source and the synchronous motor are connected is changed in the range of 0 to 50 Hz, so that other loads are normally operated. This is because it is necessary to supply power of a predetermined frequency from the system. In addition, in the extra-high voltage system, a double bus bar is usually provided in consideration of improvement in reliability and ease of maintenance. Therefore, a new bus bar is provided in the practice of the present invention. Instead, one of the existing double buses may be used.

Therefore, when synchronously starting the synchronous motor system B, first, for example, all the loads connected to the first bus bar 21 are transferred to the second bus bar 22 and the first bus bar 21 is emptied. Make it non-dedicated. At this time, the busbar breaker 29 is turned off. Then, with the circuit breakers 12, 27, 29 turned off, the synchronous motor 8 is rotated by the turning device 9 and the field circuit 10 is turned on. Next, the circuit breaker 12 is turned on, the variable frequency generator 1 is rotated by the turning device 2, and the field circuit 3 is turned on.

Further, the disconnectors 7a and 13a are turned on and connected to the same first bus 21, and the disconnectors 7b and 13b are turned off. Then, the variable frequency generator 1 and the synchronous motor 8
While controlling the frequency of the variable frequency generator 1 and the frequency of the synchronous motor 8 in synchronization with each other, the circuit breaker 6 on the side of the variable frequency generator 1 is turned on at the same timing to synchronize the two. To enter. After that, the acceleration / deceleration device 4
Accelerate with to the rated speed. After that, the circuit breaker for busbar communication
After turning on 29 to secure the power supply of the synchronous motor 8, the breaker 6 is turned off.

As a result, the synchronous motor 8 can be started via the non-dedicated busbar. In addition, another synchronous motor 23
Can be started by the same operation. Next, another embodiment will be described with reference to FIG. 2. In FIG. 2, the variable frequency generator 1, starter 2, field circuit 3, acceleration / deceleration device in the starting power supply system A of FIG. The difference is that a thyristor frequency converter 31 is used instead of 4.

Therefore, when the synchronous motor system B is synchronously started, the load is deviated to the second busbar 22 and the first busbar 21 is made non-dedicated in the same manner as above, and the circuit breaker 12,
With 27 and 29 turned off, the synchronous motor 8 is rotated by the turning device 9 and the field circuit 10 is turned on. While turning on the circuit breaker 12 and turning on the disconnecting switches 7a and 13a, the disconnecting switches 7b and 13b are connected to the same first busbar 21.
Off. And a thyristor frequency converter
The circuit breaker 6 is turned on while synchronizing 31 with the synchronous motor 8. After that, the thyristor frequency converter 31 accelerates the speed to the rated speed, and then the busbar breaker 29 is turned on to secure the power source of the synchronous motor 8 and then the breaker 6 is turned off.

[0014]

As described above, according to the present invention,
By using a non-dedicated bus bar within the range allowed by the synchronization power with one starting power supply system, synchronous start can be performed without the need for a dedicated synchronous start line.
You can suppress the investment for installing a dedicated line,
It is also possible to start a plurality of synchronous motors connected to the busbar.

[Brief description of drawings]

FIG. 1 is an electric system diagram showing an example of an embodiment of a method of the present invention.

FIG. 2 is an electric system diagram showing another embodiment of the method of the present invention.

FIG. 3 is an electrical system diagram showing a conventional example.

[Explanation of symbols]

1 Variable frequency generator 2, 9, 24 Turning device 3, 10, 25 Field circuit 4 Acceleration / deceleration device 5, 11, 26 Transformer 6, 12, 14, 15, 27 Circuit breaker 7a, 7b, 13a, 13b, 28a, 28b, 30a, 30b Disconnector 8, 23 Synchronous motor 21 First busbar 22 Second busbar 29 Busbar communication breaker 31 Thyristor frequency converter A Starting power supply system B, D Synchronous motor system C Synchronous starting line

Claims (3)

[Claims] 1. A method of starting a synchronous motor using a starting power supply system, wherein the starting power supply system and the synchronous motor are linked via a non-dedicated bus bar within a range allowed by a synchronization force. And a method for starting a synchronous motor. 2. The method for starting a synchronous motor according to claim 1, wherein a variable frequency generator driven by power capable of controlling the speed in all speed ranges is used for the starting power supply system. 3. The method for starting a synchronous motor according to claim 1, wherein a thyristor frequency converter is used in the starting power supply system.