CN2807607Y

CN2807607Y - Transducer used for low-speed running of AC motor

Info

Publication number: CN2807607Y
Application number: CN 200520091388
Authority: CN
Inventors: 王旭
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-06-20
Filing date: 2005-06-20
Publication date: 2006-08-16
Anticipated expiration: 2015-06-20

Abstract

The utility model belongs to the technical field of electric power electronic and electric transmission, particularly a low-speed running transducer of an alternating current motor. The utility model comprises a direct current power supply (1), an intermediate loop (2), an inversion loop (3) which is controlled by using pulse-width modulation, a drive circuit (5), a protective circuit (6), a control circuit (8) and an operating and displaying part (7), wherein the ports of the drive circuit (5) are respectively connected with the ports of the inversion loop (3) and the control circuit (8); the port of the operating and displaying part (7) is connected with the port of the control circuit (8); the ratio between the peak value of output voltage of the direct current power supply (1) and the voltage rating peak value of the driven motor are in a scope ranging from 1 percent to 50 percent; the ratio between the peak value of output voltage of the inversion loop and the voltage rating peak value of the driven alternating current motor are in a scope ranging from 1 percent to 50 percent; the utility model has the advantages of small volume and low cost, and can drive motors of which the capacity is larger than multiple times corresponding to the capacity of the utility model.

Description

Alternating current motor low cruise frequency converter

Technical field

The utility model belongs to power electronics and electric drive technology field, particularly a kind of alternating current motor low cruise frequency converter.

Background technology

Alternating current motor is a kind of Electric Drive equipment that converts electric energy to mechanical energy, and it just is being widely used in many fields of industry, agricultural and people's lives.The rotating speed of alternating current motor often need be regulated according to actual conditions, it is several that present speed regulating method to it mainly contains frequency control, tandem control, rotor series resistance speed, variable voltage control, pole changing etc., and wherein the effect with frequency control is best.So the frequency converter that is used for frequency conversion and speed regulation of AC motor is used more and morely.The capacity of existing frequency converter is suitable with the capacity of its institute's drive electric motor, and perhaps the capacity of the Capacity Ratio of frequency converter institute drive electric motor wants big.And the peak value of the output voltage of existing frequency converter is the rated voltage that is not less than its institute's drive electric motor.

The utility model content

The purpose of this utility model is to provide a kind of output voltage lower than the rated voltage of institute drive electric motor, and volume is little, cost is low, the alternating current motor low cruise frequency converter that electromagnetic interference is little.

Technical solution of the present utility model can realize according to following mode: alternating current motor low cruise frequency converter, and it comprises: inversion circuit, drive circuit, protective circuit, control circuit, operation and the display part of DC power supply, intermediate loop, employing pulse width modulation control; The port of described drive circuit joins with the port of inversion circuit and control circuit respectively; The port of described operation and display part and the port of control circuit join; Described DC power supply is the inversion circuit power supply, between ratio circle in 1% to 50% of the rated voltage peak value of the peak value of its output voltage and institute's drive electric motor; Between ratio circle in 1% to 50% of the peak value of described inversion circuit output voltage and the alternating current motor rated voltage peak value that driven.

As a kind of preferred version, the utility model can be furnished with overvoltage crowbar at the output of described inversion circuit.

Output voltage of the present utility model can be more much lower than the rated voltage of its drive electric motor, for example is 1/10th of its drive electric motor rated voltage.This is because this frequency converter only is responsible for the low cruise of alternating current motor, and the required voltage of motor is very low when low cruise, so the low speed that this frequency converter only needs output LOW voltage just can satisfy motor normally moves.It is used in the frequency control low cruise of alternating current motor under the various occasions, and for example machine tool chief axis gearshift, elevator standard are stopped, the accurate location of transfer equipment and all need the slowly occasion of operation of alternating current motor.

Because alternating current motor low cruise frequency converter gives the supply power voltage of motor low, it is more much smaller than the electromagnetic interference of existing frequency converter with it motor to be carried out the electromagnetic interference that frequency control causes, and the noise of motor is also little a lot.Because the power output of motor when low cruise is low, this frequency converter can drive the motor with respect to the big manyfold of itself capacity, so its volume is little, cost is low, and can move by short-time overload, the output torque that makes motor is greater than its nominal torque.The peak power output of whole frequency converter be its alternating current motor rated power of driving 1% to 50% between certain numerical value, the maximum output frequency of frequency converter be its alternating current motor rated frequency of driving 0.000001% to 50% between certain numerical value.

Description of drawings

Below in conjunction with the drawings and specific embodiments the utility model is described in further detail.

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

Fig. 2 is the utility model DC power supply partial circuit schematic diagram;

Fig. 3 is the utility model intermediate loop partial circuit schematic diagram;

Fig. 4 is the utility model inversion circuit partial circuit schematic diagram;

Fig. 5 is the utility model overvoltage protection partial circuit schematic diagram;

Fig. 6 is the utility model driving circuit section circuit theory diagrams;

Fig. 7 is the utility model protective circuit circuit theory diagrams;

Fig. 8 is the utility model operation and display part circuit theory diagrams;

Fig. 9 is the utility model control circuit circuit theory diagrams.

Embodiment

As shown in the figure, alternating current motor low cruise frequency converter comprises: inversion circuit 3, drive circuit 5, protective circuit 6, control circuit 8, operation and the display part 7 of DC power supply 1, intermediate loop 2, employing pulse width modulation control; The port of described drive circuit 5 joins with the port of inversion circuit 3 and control circuit 8 respectively; The port of the port of described operation and display part 7 and control circuit 8 joins; Described DC power supply 1 is the inversion circuit power supply, between ratio circle in 1% to 50% of the rated voltage peak value of the peak value of its output voltage and institute's drive electric motor; Between ratio circle in 1% to 50% of the peak value of described inversion circuit output voltage and the alternating current motor rated voltage peak value that driven.Is furnished with overvoltage crowbar 4 at the output of described inversion circuit.

The general structure of alternating current motor low cruise frequency converter as shown in Figure 1.DC power supply 1 among Fig. 1 is single-phase rectifier power supply (as shown in Figure 2), also can be three-phase rectifier power supply or battery, and it can be made in the same casing with this frequency converter, also can be external.Intermediate loop 2 among Fig. 1 mainly is some electrochemical capacitors and over-voltage protection element, plays the effect (as shown in Figure 3) of filtering and protection.Inversion circuit 3 among Fig. 1 adopts three-phase pulse width modulated (PWM) inverter circuits, its circuit structure as shown in Figure 4, the K1 to K6 among Fig. 4 is six electronic switches (as IGBT, IGCT, GTR, GTO or field-effect transistors etc.).Overvoltage protection 4 among Fig. 1 is attempted by U, V, W three ends (as shown in Figure 5) respectively by three piezo-resistances (or three groups of Resistor-Capacitor Units).Drive circuit 5 among Fig. 1 is used to drive these 6 electronic switches of K1 to K6, can adopt the circuit of Fig. 6 to realize.Protective circuit 6 among Fig. 1 is used for when main circuit overcurrent, overvoltage or other fault electronic switch K1 to K6 being turn-offed, and can adopt the circuit of Fig. 7 to realize.Operation among Fig. 1 with show 7 startups that are used for this frequency converter, stop, operation such as frequency modulation, and show its operation conditions, can adopt the circuit of Fig. 8 to realize.Control circuit 8 among Fig. 1 is used for the master control of complete machine, and it is made up of polylith integrated circuit (IC) chip (or microprocessor), and the interface that links to each other with external signal can be arranged, and can adopt the circuit of Fig. 9 to realize.

Peak power output of the present utility model be its alternating current motor rated power of driving 1% to 50% between certain numerical value, its maximum output frequency be its alternating current motor rated frequency of driving 0.000001% to 50% between certain numerical value.

Claims

1, alternating current motor low cruise frequency converter, it is characterized in that, comprising: DC power supply (1), intermediate loop (2), the inversion circuit (3) that adopts pulse width modulation control, drive circuit (5), protective circuit (6), control circuit (8), operation and display part (7); The port of described drive circuit (5) joins with the port of inversion circuit (3) and control circuit (8) respectively; The port of the port of described operation and display part (7) and control circuit (8) joins; Described DC power supply (1) is the inversion circuit power supply, between ratio circle in 1% to 50% of the rated voltage peak value of the peak value of its output voltage and institute's drive electric motor; Between ratio circle in 1% to 50% of the peak value of described inversion circuit output voltage and the alternating current motor rated voltage peak value that driven.

2, alternating current motor low cruise frequency converter according to claim 1 is characterized in that: be furnished with overvoltage crowbar (4) at the output of described inversion circuit.