CN202009354U

CN202009354U - Discrete frequency soft starting circuit

Info

Publication number: CN202009354U
Application number: CN2011200737876U
Authority: CN
Inventors: 王怡华; 宁国云
Original assignee: DAYU ELECTRIC TECHNOLOGY Co Ltd
Current assignee: DAYU ELECTRIC TECHNOLOGY Co Ltd
Priority date: 2011-03-21
Filing date: 2011-03-21
Publication date: 2011-10-12
Anticipated expiration: 2021-03-21

Abstract

The utility model relates to a discrete frequency soft starting circuit, which comprises six antiparallel silicon controlled rectifiers (T1, T2, T3, T4, T5 and T6), a sampling circuit (F), a controller (K) and a triggering drive system (C). The discrete frequency soft starting circuit is mainly characterized in that: the discrete frequency soft starting circuit is provided with the six antiparallel silicon controlled rectifier modules, wherein the input ends of the silicon controlled rectifiers (T1 and T6) are connected with the phase A of an input power supply, the input ends of the silicon controlled rectifiers (T2 and T3) are connected with the phase B of the input power supply, and the input ends of the silicon controlled rectifiers (T4 and T5) are connected with the phase C of the input power supply. The output ends of the silicon controlled rectifiers (T1 and T2) are connected with the phase U of a three-phase electromotor, the output ends of the silicon controlled rectifiers (T3 and T4) are connected with the phase V of the electromotor, and the output ends of the silicon controlled rectifiers (T5 and T6) are connected with the phase W of the electromotor. Two sets of phase-controlled voltage regulation circuits are connected crosswise and in parallel to operate, the discrete frequency soft starting principle is adopted, the silicon controlled rectifiers are used, and consequently, the discrete frequency soft starting circuit achieves performance close to the performance of an inverter, and has the characteristics of high starting torque, low harmonic current and the like.

Description

A kind of classification variable frequency soft start circuit

Affiliated technical field

The utility model belongs to the electric machines control technology field, is specifically related to a kind of alternating current motor soft starting circuit, is a kind of circuit that is specially adapted to the high-voltage large motor soft start.

Background technology

At present, the alternating current motor soft starter device has autotransformer, water resistance, controlled reactor, magnetic saturation reactor, solid soft start, high voltage converter etc.Wherein the high voltage converter cost is too high, does not need the occasion of converting operation for only needing soft start, and is less economical, uses the long-time running under power frequency of high voltage converter drive motors, owing to the loss of frequency converter self, reduced the efficient of system on the contrary.Solid-state soft starter adopts the Thyristor Controlled voltage-regulating technique, directly regulates motor stator voltage, and control performance is best, uses the most generally, has replaced traditional soft starter device gradually.But adopt phased friendship-intermodulation pressure technology, will produce a large amount of harmonic waves, very big to the pollution of electrical network and motor.Adopt switch control to replace the classification frequency conversion theory of phase control techniques, can solve the harmonic problem of phase control techniques, and can realize high starting torque, but torque pulsation is big, starting current is big, seldom uses in practical engineering application.

For these reasons, the utility model proposes a kind of modified model classification variable frequency soft start circuit, main circuit adopts 6 groups of anti-parallel thyristors, adopt the control of phase shifting control and switch to combine, it is big both to have solved the phase control harmonic wave, reduced the defective of starting torque, it is big also to have solved classification frequency conversion torque pulsation, the defective that starting current is big.Performance with soft start identical, and cost low pressure high voltage converter far away with high voltage converter.

Summary of the invention

Technical solution of the present utility model is: a kind of classification variable frequency soft start circuit, main circuit is made of 6 groups of anti-parallel thyristors, perhaps the anti-parallel thyristor assembly of 6 groups of thyristor series connection constitutes, and 6 groups of anti-parallel thyristor assemblies are respectively (T1), (T2), (T3), (T4), (T5), (T6).Control circuit comprises sample circuit (F), controller (K), triggers drive system (C), its principal character is: 6 groups of anti-parallel thyristor assemblies are arranged, wherein the input termination of (T1) and (T6) input power supply A mutually, (T2) import power supply B mutually with the input termination of (T3), (T4) import power supply C mutually with the input termination of (T5).(T1) with the output termination threephase motor U of (T2) mutually, (T3) with the output termination threephase motor V of (T4) mutually, (T5) with the output termination threephase motor W of (T6) mutually.

The described 6 groups of anti-parallel thyristor assemblies of the utility model technical solution also can be that a plurality of anti-parallel thyristors are composed in series, and have series thyristor all to press assembly, are used for high-tension motor.

The described main circuit topology of technical solution of the present utility model is a kind of improvement phase control circuit, is equivalent to two groups of phase control circuit alter-parallels, has the two-fold advantage of phased potential circuit and ac-ac frequency converter concurrently.Principle based on the classification variable frequency soft start, and improved the deficiency of existing classification frequency changer circuit, when having solved phased potential circuit and being used for flexible starter for electric motor, harmonic current is big, reduced the defective of starting torque, also avoided ac-ac frequency converter to be used for the control complexity of flexible starter for electric motor, defect of high cost.

Description of drawings

Fig. 1 is a main circuit schematic diagram of the present utility model.

Among the figure: T1, T2, T3, T4, T5, T6-anti-parallel thyristor assembly; The F-sample circuit; The K-controller; C-triggers drive system; M-power consumption equipment (motor).

Fig. 2 is another main circuit schematic diagram of the present utility model.

Among the figure: T1, T2, T3, T4, T5, T6-organize the anti-parallel thyristor assembly of thyristor series connection more; The F-sample circuit; The K-controller; C-triggers drive system; M-power consumption equipment (motor).

Embodiment

The utility model is described in further detail below in conjunction with accompanying drawing:

As shown in Figure 1 and Figure 2, the input termination of anti-parallel thyristor assembly (T1) and (T6) input power supply A (T2) imports power supply B mutually with the input termination of (T3) mutually, (T4) imports power supply C mutually with the input termination of (T5).(T1) with the output termination threephase motor U of (T2) mutually, (T3) with the output termination threephase motor V of (T4) mutually, (T5) with the output termination threephase motor W of (T6) mutually.The input voltage synchronizing signal of sample circuit (F) detection equipment and output voltage, electric current, controller (K) is exported control signal later on through computing, through triggering the angle of flow of 6 groups of thyristor assemblies of drive system (C) control, change the frequency and the amplitude of output supply voltage, realize the varying frequency starting of motor.

Claims

1. classification variable frequency soft start circuit, main circuit is made of 6 groups of anti-parallel thyristors, also can be made of the anti-parallel thyristor assembly of 6 groups of thyristor series connection, 6 groups of anti-parallel thyristor assemblies are respectively (T1), (T2), (T3), (T4), (T5), (T6).

2. the control circuit in a kind of classification variable frequency soft start circuit according to claim 1 comprises sample circuit (F), controller (K), triggers drive system (C), its principal character is: 6 groups of anti-parallel thyristor assemblies are arranged, wherein the input termination of (T1) and (T6) input power supply A mutually, (T2) import power supply B mutually with the input termination of (T3), (T4) import power supply C mutually with the input termination of (T5).(T1) with the output termination threephase motor U of (T2) mutually, (T3) with the output termination threephase motor V of (T4) mutually, (T5) with the output termination threephase motor W of (T6) mutually.

3. a kind of classification variable frequency soft start circuit according to claim 1 is characterized in that: be connected on behind 6 groups of anti-parallel thyristor assembly alter-parallels between three-phase input power supply and the three phase electric machine input.

4. a kind of classification variable frequency soft start circuit according to claim 1, its 6 groups of anti-parallel thyristor assemblies also can be that a plurality of anti-parallel thyristors are composed in series, and can have series thyristor all to press assembly.