High-voltage soft start main circuit

Abstract

The invention relates to a high-voltage soft start main circuit, which belongs to the technical field of high-voltage motor soft starting. The input end of a high-voltage starting switch (2) is connected with a high-voltage grid (1), and the output end is connected with a front reactor (4); a reactor (6) is in parallel connection with a forward transistor (7) and a reverse transistor (8); the parallel-connected end of the reactor (6), the forward transistor (7) and the reverse transistor (8) are connected with the front reactor (4) and the other end is connected with a rear reactor (5); and the other end of the rear reactor (5) is connected with a motor (9). By connecting voltage regulating reactors with antiparallel transistors in parallel and serially connecting phase control reactors in the up-down direction, the high-voltage soft start main circuit provided by the invention can overcome the disadvantages of a variable reactor in the prior art, such as high manufacture cost, complex structure, multiple faults, large maintenance cost, and the content of current harmonics is reduced remarkably. The transistor assembly only needs to bear a lower end voltage and regulate a portion of current, so that the voltage regulator has much lower requirement for the through-current capability of the transistor, thereby greatly lowering the cost.

Description

technical field [0001] The invention relates to a high-voltage reactive power adjustment technology, in particular to a high-voltage soft-start main circuit, and belongs to the technical field of high-voltage motor soft-start. Background technique [0002] The hard start method of directly energizing the motor will cause various hazards. Therefore, since the early 1950s, the traditional self-compensator has been occupying a dominant position in the field of motor starting devices. By the 1980s, soft starters had gradually replaced self-compensators. [0003] The soft start earlier used a reactor or an autotransformer, such as the Chinese patent announcement number: CN 2152343, announcement date: January 5, 1994, invention name: "Motor Reactance Starter", which uses three The reactors are respectively connected in series between the three-phase main circuit and the motor to play the role of step-down starting. However, since this method can only gradually reduce the voltage...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to overcome the deficiencies of the existing soft start mode of variable reactors and anti-parallel thyristors, which have high manufacturing costs, complex structures, many faults, and high maintenance costs, and provide a simple structure, High-voltage soft-start main circuit with easy processing and low production cost

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