JPS583582A - Starting method for motor with reducing voltage - Google Patents

Abstract

PURPOSE:To simplify a method of starting a motor with reducing voltage due to a generator by providing an intermediate tap at the armature coil of the generator, employing the voltage of the tap at the first stage of starting and applying full voltage at the second stage. CONSTITUTION:When a motor M is started by an engine generator G or the like, an intermediate tap is provided at the armature coil of the generator G. A switch S2 is closed at the first stage of starting to apply the voltage V2 of the tap to the motor M, and after the speed is raised to a suitable value, the switch S2 is opened, and a switch S1 is closed, thereby applying full voltage V1 of the armature coil to the motor M. Accordingly, the motor M can be started with reduced voltage without necessity of starting compensating transformer, large capacity of starting reactor, thereby reducing the size and simplifying the structure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for starting an induction motor or a synchronous motor.

Conventionally, in equipment that uses an engine generator as a power source, a reduced voltage starting method has been adopted for large electric motors in order to reduce the power generation equipment capacity and improve operating efficiency. However, all voltage reduction means were provided individually on the motor side. The present invention uses a generator with an intermediate tap in the armature winding and utilizes this intermediate tap as a means of voltage reduction, thereby eliminating the need for or installing a conventional starting compensation transformer or starting reactor. Even if it does, the aim is to make its capacity much smaller.

This will be explained with a diagram. To start the electric motor M, first turn on the switch S2. Then, the motor M receives the voltage v2 at the intermediate tap of the armature winding of the generator d, and starts at a reduced voltage. child\
The voltage v2 of the intermediate tap may be 50% voltage or 65% depending on the
% voltage etc.

Next, once the speed of the electric motor M has reached an appropriate level, the switch S2 is turned off, and then the switch S1 is turned on. Then, the electric motor M receives the full voltage v1 of the generator G, and starting is soon completed. If it is necessary to further reduce the rush current or starting current when the switch 81 is turned on, an acdle circuit is provided as indicated by the dotted line in the figure. Then, before turning on the switch S1, the switch Sx is turned on to apply the full voltage v1 of the generator G to the electric motor M through the accelerator X, and then the switch Sl is turned on. Even in this case, the speed of the electric motor M increases and the accelerator X is energized, so the energizing current and the energizing time are small. It's over.

Comparing the reduced voltage starting method of the motor of the present invention with the existing methods, there is an extra loss in Y-Δ because current flows through the switching circuit to Δ even during operation. Unlike the start-up compensator method, a compensation transformer is not required, so costs are reduced, and installation and maintenance costs can be saved. Unlike the reactor starting method, there is no need for an accelerator9, and even if it is needed in some cases, it can be smaller than the conventional glue acudle, resulting in savings in terms of reactor price and installation space. These effects of the present invention become even more remarkable when there are a plurality of motors that are started at a reduced voltage because the means for reducing the voltage is on the power source side and is common.

G Generator, M Motor Sl, S2, Sx Switch % 1. Indication of the case 1982 Patent Application No. 55-0757
60 No. 2, Title of the invention: Motor reduced voltage starting method 3, Relationship with the amended person's case Patent applicant address: 85-14 Tsukushino, Abiko City, Chiba Prefecture
-9-205 4. Date of amendment order: July 9, 1930 5. Subject of amendment: Brief description of drawings in the specification column 6: Contents of amendment: Specification (3), page 11 and line 12 Add the following two lines between.

(4. Brief explanation of drawings)

Claims (1)

[Claims] A method for starting a motor using a generator as a power source, the method comprising: starting a motor using a middle tap of an armature winding of the generator as a power source for the motor in the first step of starting.