CN202856628U

CN202856628U - Frequency converter automatically adjusting motor current

Info

Publication number: CN202856628U
Application number: CN 201220369039
Authority: CN
Inventors: 陆磊; 陆音
Original assignee: XUZHOU RIPE FREQUENCY CONVERSION TECHNOLOGY CO LTD
Current assignee: XUZHOU RIPE FREQUENCY CONVERSION TECHNOLOGY CO LTD
Priority date: 2012-07-27
Filing date: 2012-07-27
Publication date: 2013-04-03
Anticipated expiration: 2022-07-27

Abstract

The utility model discloses a frequency converter automatically adjusting motor current, and belongs to the technical field of power electronics and electric drive. Based on an original common frequency converter, the frequency converter adds a signal acquisition circuit which detects three-phase current and voltage in real time. A CPU performs drive signal deviation calculation according to detection values. Through a pulse width modulation method, IGBT drive signals are adjusted in real time, so that current balance and voltage balance of a driven motor are realized. Beneficial effects of the frequency converter are that current and voltage of the driven motor are controlled, and problems of unstable operation of the motor, unbalance of the motor current, and motor overheating caused by different three-phase internal resistance and wire resistance, etc.

Description

The self-regulation motor current-mode converter

Technical field

The utility model relates to a kind of universal frequency converter, and particularly a kind of self-regulation motor current-mode converter belongs to power electronics and electric drive technology field.

Background technology

Since the sixties in 20th century, the advantages such as alternating current machine is simple in structure because of it, easy maintenance, progressively become the capital equipment of mechanical field, then speed regualtion of AC motor just becomes people's problem anxious to be resolved, at present the speed regulating method of alternating current machine mainly contain rotor series resistance speed, fall adjusting velocity by voltage, speed differential clutch speed governing, the speed governing of pole-changing logarithm and frequency control.

Since the nineties in 20th century, along with the development of power electronic technology, so that adopt the variable-frequency control technique of power electronic device to be able to fast development, particularly large scale integrated circuit and computer control occur, and the high-performance AC frequency conversion speed-adjusting system arises at the historic moment.

Current, the ac variable frequency speed regulation control technology mainly adopts vector control technology, Study on direct torque control technology, decoupling zero control technology etc.These technology are in theory very ripe, and are widely used in all kinds of variable-frequency governors.But above theory is to move under the desirable motor status of setting, and in actual applications, the quality of motor varies, the application operating mode is of a great variety, so just have a lot of motors because of the variation of internal resistance, the unknown causes such as fluctuation of load, cause motor to move unstable, the problems such as current of electric is uneven, motor overheating.

The utility model content

The purpose of this utility model provides a kind of self-regulation motor current-mode converter, and it is unstable that it can reduce the motor operation that causes because of reasons such as motor internal resistance variation, the fluctuations of load effectively, the problems such as current of electric imbalance, motor overheating.

The technical scheme that its technical problem that solves the utility model adopts is: a kind of self-regulation motor current-mode converter, comprise rectification circuit, filter circuit, inverter circuit, signal acquisition circuit, cpu control circuit, the IGBT drive circuit, rectification circuit output end accesses filter circuit and switching power circuit simultaneously, filter circuit output access inverter circuit, inverter circuit output access signal acquisition circuit, signal acquisition circuit output access signal processing circuit, signal processing circuit connects cpu control circuit, cpu control circuit output access IGBT drive circuit.

Frequency converter input three-phase alternating-current supply (AC380V-AC440V, 50Hz) is converted to direct current by rectification circuit, makes it become stable direct current by filter circuit simultaneously.Rectification circuit also disposes starting resistance and starting contactor, to reduce the power surges of bringing when the large capacitor charging.

Switching power circuit produces power supply and mainly contains :+5V supplies with the 10G CPU Control Unit power supply, and+24V supplies with outside input/output signal power supply ,+15V ,-15V supply signal acquisition circuit power supply, the four tunnel exchange 22V supplies with the drive circuit power supplys.

The IGBT drive circuit is mainly finished the processing that drives signal, pulse width modulated drive signal after the 10G CPU Control Unit computing, through optocoupler HLP350 isolation, the driving signal that generates about 15V drives the IGBT module, and wherein the IGBT module adopts the product B SM50GP120 of Infineon.

Signal acquisition circuit is mainly finished the data acquisition of frequency converter output current and voltage, and three-phase current signal adopts Hall current sensor, by the isolation of chip TL074C signal, imports respectively CPU into three-phase voltage signal and carries out computing.

Cpu control circuit is the core of system, is used for the functions such as data acquisition, the generation of IGBT driving signal, peripheral input and output, includes control program in the microprocessor.

Signal acquisition circuit Real-time Collection frequency converter output signal of the present utility model, three-phase current and voltage are detected, being fed back into CPU processes, producing pulse width modulating signal interferes IGBT driving signal, thereby it is unstable to have solved the motor operation, the problems such as current of electric imbalance, motor overheating.

Description of drawings

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

Fig. 2 is internal component layout plan of the present utility model;

Fig. 3 is electric current of the present utility model, voltage signal acquisition circuit diagram.

Among Fig. 2: 1, dc filter capacitor, 2, the IGBT Absorption Capacitance, 3, start condenser, 4, the high ripple Absorption Capacitance of direct current, 5, piezo-resistance, 6, binding post, 7, current sensor, 8, voltage sensor, 9, the IGBT module, 10, drive optocoupler, 11, control board gang socket, 12, main transformer, 13, the field effect transistor driving transformer, 14, switching power circuit, 15, field effect transistor.

Embodiment

As shown in Figure 1, at first enter rectification circuit after the three-phase alternating-current supply input, then wave circuit filtering becomes stable direct current after filtration, inputs inverter circuit again.Rectification circuit is input to switching power circuit, switching power circuit provides power supply for 10G CPU Control Unit and drive plate :+5V supplies with the cpu control circuit power supply, + 24V supplies with outside input/output signal power supply, + 15V ,-15V supply signal acquisition circuit power supply, the four tunnel exchange 22V supplies with the drive circuit power supplys.Driving signal is produced by cpu control circuit, cpu control circuit includes microprocessor, internal processes is through computing, produce pulse-width signal and be sent to the IGBT drive circuit, the IGBT drive circuit at first passes through light-coupled isolation, then carries out signal and amplifies, and drives six way switch pipes in the IGBT module, thereby forming three-phase phase poor is 120 ° of sinusoidal waveforms, and the synchronous signal Acquisition Circuit can gather the electric current of output.Output current signal and output voltage signal are sent to CPU through treatment circuit, participate in sequential operation, operation method adopts calculus of differences, adds the difference of current signal and voltage signal on original control signal basis, the output current that makes each road is balance more, and voltage is more stable.

Being illustrated in figure 2 as actual components and parts of the present invention arranges.Input power is connected with frequency converter by binding post 6 and is connected, and after the power supply input, cross-over connection has piezo-resistance 5 between the three phase mains two-phase, as it is too high power supply to occur, piezo-resistance 5 short circuits, thus make the front-end protection switch trip.Dc filter capacitor 1 is used for DC filtering, frequency converter powers on rear first through the starting resistance power supply, slowing down the charging of dc filter capacitor 1 impacts, after 2-3 charges and finish second, assigned the enabling signal of starting relay 3 by 10G CPU Control Unit, starting relay 3 adhesives, the starting resistance short circuit, system enters the normal power supply state.IGBT Absorption Capacitance 2 is mainly used in absorbing the surging that forms because of the switching tube HF switch, reduces the interference of system.Current sensor 7 is used for gathering the current value of output, is converted to the voltage signal input 10G CPU Control Unit of 0-4V.Voltage sensor 8 is used for gathering three-phase output voltage, is converted to the voltage signal input 10G CPU Control Unit of 0-4V.Control board gang socket 11 is used for connecting drive plate and 10G CPU Control Unit.After drive plate receives pulse-width signal, through optocoupler 10 isolation of overdriving, amplify through overdrive circuit again, drive at last IGBT module 9.The power supply of switch power supply system is taken from the internal system direct current, integrated management by chip 2842, produce fluctuating signal, by field effect transistor driving transformer 13 fluctuating signal is divided into two, drive respectively 2 field effect transistor 15, reduce like this voltage that bears of field effect transistor 15, increased its life-span.The voltage of field effect transistor 15 outputs acts on the primary winding of main transformer 12, forms the different voltage of multichannel at secondary coil, by switching power circuit 14 conversions, gives system's each several part power supply.

As shown in Figure 3, the Acquisition Circuit of current signal, voltage signal is as follows:

1, probe power be+15V and-15V, at first pass through inductance DL1, DL2 filtering after the power supply input, then through electrochemical capacitor C21, C22 filtering, pass through electrodeless high frequency capacitance C23, C24 filtering again, make probe power more stable.

2, CS1, CS2, CS3 are current sensor, adopt Hall closed-loop control current sensor, frequency converter output line punching and mistake from current sensor, sensor pin 1 is+15V, sensor pin 2 is-15V, sensor pin 4 is GND, and sensor pin 3 is output current signal, output signal range 0-4V.

3, sensor pin 3 current signals connect respectively 10K resistance R 3, R5, R7, and then accessing DU2(DU2 is the TL074C chip) 2 pin, 6 pin, 9 pin, outputed to respectively after treatment 65 pin, 67 pin, 66 pin of CPU by 1 pin, 7 pin, 8 pin.

4, VS1 is voltage sensor, voltage input end is U, V, W, sensor pin 1 is+15V, sensor pin 2 is-15V, sensor pin 3 is GND,

sensor pin

4,5,6 is output current signal, and range of signal 0-4V, signal after treatment output to 68 pin, 69 pin, 70 pin of CPU.

5, the 4 pin connection+15V of DU2 connect capacitor C 2 filtering simultaneously.The 11 pin connection-15V of DU2 connect capacitor C 3 filtering simultaneously.1,2 pin of DU2,6,7 pin, 8,9 pin connect respectively 15K resistance R 2, R4, R6.

Claims

1. self-regulation motor current-mode converter, comprise rectification circuit, filter circuit, inverter circuit, signal acquisition circuit, cpu control circuit, the IGBT drive circuit, rectification circuit output end access filter circuit and switching power circuit, filter circuit output access inverter circuit, inverter circuit output access signal acquisition circuit, signal acquisition circuit output access cpu control circuit, cpu control circuit output access signal processing circuit, signal processing circuit connects the IGBT drive circuit, it is characterized in that, signal acquisition circuit is to three-phase current and Voltage-output signal Real-time Collection, be fed back into cpu control circuit, produce pulse width modulating signal and interfere the IGBT drive circuit.

2. a kind of self-regulation motor current-mode converter according to claim 1 is characterized in that, described electric current and voltage signal acquisition circuit connecting relation are as follows:

(1). probe power is+15V and-15V, at first pass through inductance DL1, DL2 filtering after the power supply input, then pass through electrochemical capacitor C21, C22 filtering, pass through again electrodeless high frequency capacitance C23, C24 filtering.

(2) .CS1, CS2, CS3 are current sensor, and sensor pin 1 is+15V, and sensor pin 2 is-15V, and sensor pin 4 is GND, and sensor pin 3 is output current signal, output signal range 0-4V.

(3). sensor pin 3 current signals connect respectively 10K resistance R 3, R5, R7, then access 2 pin, 6 pin, 9 pin of DU2, are outputed to respectively after treatment 65 pin, 67 pin, 66 pin of CPU by 1 pin, 7 pin, 8 pin, and wherein DU2 is the TL074C chip

(4) .VS1 is voltage sensor, voltage input end is U, V, W, sensor pin 1 is+15V, sensor pin 2 is-15V, sensor pin 3 is GND, sensor pin 4,5,6 is output current signal, and range of signal 0-4V, signal after treatment output to 68 pin, 69 pin, 70 pin of CPU.

(5) the 4 pin connection+15V of .DU2 connect capacitor C 2 filtering simultaneously, and the 11 pin connection-15V of DU2 connect capacitor C 3 filtering simultaneously, 1,2 pin of DU2, and 6,7 pin, 8,9 pin connect respectively 15K resistance R 2, R4, R6, and wherein DU2 is the TL074C chip.