CN201536334U

CN201536334U - Chopped-controlled three-phase AC motor energy-saving controller

Info

Publication number: CN201536334U
Application number: CN2009200283452U
Authority: CN
Inventors: 孙佃升
Original assignee: Binzhou University
Current assignee: Binzhou University
Priority date: 2009-06-23
Filing date: 2009-06-23
Publication date: 2010-07-28
Anticipated expiration: 2019-06-23

Abstract

The utility model relates to a chopped-controlled three-phase AC motor energy-saving controller which is used for the soft starting control and energy-saving operation of a three-phase AC motor, and comprises a main converting circuit, a drive and protection circuit, a detection circuit, an MC908GP32 singlechip control system and a status display and operation panel circuit, wherein the singlechip control system collects motor operating parameters (current, voltage, power factor and rotate speed) detected by the detection circuit, adjusts the open duty cycle of a switching tube in the main converting circuit through the drive and protection circuit, carries out chopping control to the three-phase input voltage, and properly reduces the input voltage of a motor stator under a certain condition of rotate speed, and the purpose of the energy saving can be achieved. When the system operates, voltage and current waveform are close to sine, does not contain low subharmonic and can filter and remove high subharmonic; and when the motor is started, the chopping duty cycle can be adjusted though detecting the rotate speed and current to realize the purpose of reducing soft start.

Description

Chopper-control three phase alternating current motor energy-saving controller

Technical field

The utility model relates to a kind of control of soft of three phase alternating current motor, energy-conservation device of being used for.

Background technology

Motor is the main dynamics equipment in the industrial production, also is energy consumption equipment main in the electrical network.According to statistics, China has sixty percent motor to move under the underload state that is lower than design rated load 60% approximately, and the power of electric motor factor is below 0.8, even is lower than 0.7, the motor that under this state, moves, and the electricity consumption up to 30% is wasted.Along with fast development of Chinese economy, highly energy-consuming has become very important social concern, and " energy-conservation " is as the theme of advocating in recent years.Simultaneously, most motors in use play, brake the impulse current that causes electrical network is impacted; Problems such as power factor is low, harmonic pollution have also caused the extensive attention of power supply department, and the cry of regulation electric network pollution grows to even greater heights.Two power motors are typically to reach a kind of energy-saving electric machine of realizing the energy-saving run purpose by the transformation of carrying out the motor body structure.This kind motor has respectively corresponding two nominal operation power of two cover windings, moves the switching of winding according to the size of motor load, avoids motor to be in the running status of " low load with strong power ".Two power motors are suitable in servicely having two sizes to differ the big situation of metastable load again, the situation when dragging beam pumping unit such as motor.And under the bigger situation of load instability, mobility scale, two power motors but be not suitable for, and are difficult to reach good energy-conservation effect.Though the reactive power compensation device based on the capacitor switching reactive power compensation technology can improve the motor driving system power factor to a certain extent, improves mains supply, can't reach the purpose of electrical machine energy-saving operation; And the switching of electric capacity is a kind of step type, adjusting that can not be level and smooth according to the running status of motor.The phase control type ac electric motor energy-saving technique is under the low situation of load-rate of motor, reaches the purpose that cuts down the consumption of energy, improves motor power factor by suitable reduction stator winding supply power voltage.But the method for this kind phase control itself will cause the distortion of the voltage waveform that motor asks for to electrical network, and electrical network is brought harmonic pollution, no longer has energy-saving effect under the situation of pressure regulation significantly at needs.Therefore, there is very big defective in the phase control type ac electric motor energy-saving technique.

Summary of the invention

In order to solve the voltage waveform that motor that the phase control type ac electric motor energy-saving technique exists asks for to electrical network is non-sine, and electrical network is brought the problem of harmonic pollution, energy-saving effect difference, and the utility model provides a kind of chopper-control three phase alternating current motor energy-saving controller.Energy-saving run when this controller not only can be realized the motor underloading, the voltage waveform that motor is asked for to electrical network is the sinusoidal PWM ripple of equivalence, reduces motor to greatest extent electrical network is brought harmonic pollution, improves energy-saving effect; Can also realize electric machine soft starting.The technical scheme that the utility model adopted is: this controller comprises following a few part: unsteady flow main circuit, driving and protective circuit, testing circuit, single-chip computer control system, state show and the guidance panel circuit.The input of unsteady flow main circuit links to each other with the inlet wire of three phase mains; the output of unsteady flow main circuit links to each other with the three-phase terminal of three phase alternating current motor; testing circuit links to each other with protective circuit, MC908GP32 single-chip computer control system with unsteady flow main circuit, driving; driving links to each other with unsteady flow main circuit, MC908GP32 single-chip computer control system, testing circuit with protective circuit, and the MC908GP32 single-chip computer control system shows and links to each other with the guidance panel circuit with protective circuit, testing circuit, state with driving.The unsteady flow main circuit has the electronic switch of four groups of two-way break-makes of being made up of IGBT and Power Diode Pumped, wherein three groups are bidirectional electronic switch in mutually, link to each other with the every inlet wire mutually of three phase mains and the three-phase terminal of alternating current machine respectively, each is made up of an IGBT and four Power Diode Pumped, in addition one group is alternate bidirectional electronic switch, be connected between the three-phase terminal of three groups of interior mutually bidirectional electronic switch and alternating current machine, form by an IGBT and six Power Diode Pumped.Parameter when testing circuit detects the motor operation comprises electric current, voltage, power factor, rotating speed.The parameter of the motor operation that single-chip computer control system acquisition testing electric circuit inspection arrives; according to the open duty ratio of control needs by switching tube in driving and the protective circuit adjusting unsteady flow main circuit; three-phase input voltage is carried out copped wave control; satisfy the suitable motor stator input voltage that reduces under certain speed conditions, reaching the purpose of energy-saving run.Owing to be chopper control on the basis of sinusoidal voltage, and chopping frequency height, duty ratio height, voltage, current waveform do not contain low-order harmonic, but the high order harmonic component filtering can reach the purpose that reduces harmonic wave, energy-saving run near sinusoidal during the system operation.During electric motor starting, can regulate the purpose that the copped wave duty ratio realizes soft-start by lowering voltage by detecting rotating speed and electric current.

Energy-saving run when the utility model can be realized motor soft-start by lowering voltage, underloading, reduces motor and brings the harmonic pollution effect obvious to electrical network the power factor when improving the motor operation.

Description of drawings

Below in conjunction with accompanying drawing and example the utility model is further specified.

Fig. 1 is that system of the present utility model forms theory diagram.

Fig. 2 is an outside drawing of the present utility model.

Fig. 3 is a unsteady flow main circuit diagram of the present utility model.

Fig. 4 is IGBT drive circuit figure.

Fig. 5 is buffering discharge circuit figure.

Fig. 6 is the SCM peripheral circuit diagram.

Fig. 7 is the current acquisition circuit diagram.

Embodiment

Fig. 1 is described to be the theory of constitution block diagram of the utility model each several part, and each several part signal circulation relationship as shown in the figure.

In Fig. 2, the corresponding electrical network three-phase input voltage of 1,2,3 difference, 4,5,6 is three-phase output, and 7 for connecing motor speed detection line socket, and 8 is that state shows and guidance panel.To the less demanding motor of rotating speed, can gather during operation, only carry out rotating speed open loop Energy Saving Control and get final product rotating speed.State shows electric current, voltage, the power factor that can show current operation motor.Guidance panel can be set the rotating speed of motor operation within the specific limits, and system falls and carry out energy-saving run under this rotating speed.

Fig. 3 is unsteady flow main circuit component annexation figure of the present utility model, and V1～V4 is IGBT, and diode adopts fast recovery diode.Realize chopping depressuring by the synchro switch control to V1～V3, V4 is open-minded at V1～V3 blocking interval, realizes the afterflow of motor windings electric current.

Fig. 4 is driving and the protective circuit that adopts the IGBT of EXB841 formation in the utility model main circuit, and this circuit can be realized driving and the protection of an IGBT.Need No. 4 drive circuits in this circuit, their input pwm signal altogether, and the power supply of 20V is not altogether.Optocoupler adopts TLP521 among Fig. 4.

Figure 5 shows that the buffering discharge circuit of IGBT, diode adopts fast recovery diode among the figure, and resistance adopts noninductive resistance, and electric capacity adopts the noninductive electric capacity of high pressure.

Fig. 6 is the SCM peripheral circuit.Shown in the figure method of attachment of crystal oscillator, keyboard, indicator light and the input and output pin of relevant signal.

Fig. 7 is the current acquisition circuit.The voltage signal that this circuit collects Hall current sensor amplifies after the A/D switched pins of input single-chip microcomputer after the absolute value rectification, filtering voltage regulation.

Claims

1. control of soft that is used for three phase alternating current motor; the chopper-control three phase alternating current motor energy-saving controller of energy-saving run; by the unsteady flow main circuit; drive and protective circuit; testing circuit; the MC908GP32 single-chip computer control system; state shows and the guidance panel circuit is formed; the input of unsteady flow main circuit links to each other with the inlet wire of three phase mains; the output of unsteady flow main circuit links to each other with the three-phase terminal of three phase alternating current motor; testing circuit and unsteady flow main circuit; drive and protective circuit; the MC908GP32 single-chip computer control system links to each other; driving and protective circuit and unsteady flow main circuit; the MC908GP32 single-chip computer control system; testing circuit links to each other; MC908GP32 single-chip computer control system and driving and protective circuit; testing circuit; state shows and links to each other with the guidance panel circuit; it is characterized in that: the unsteady flow main circuit has the electronic switch of four groups of two-way break-makes of being made up of IGBT and Power Diode Pumped; wherein three groups are bidirectional electronic switch in mutually; link to each other with the every inlet wire mutually of three phase mains and the three-phase terminal of alternating current machine respectively; each is made up of an IGBT and four Power Diode Pumped; in addition one group is alternate bidirectional electronic switch; be connected between the three-phase terminal of three groups of interior mutually bidirectional electronic switch and alternating current machine, form by an IGBT and six Power Diode Pumped.

2. three phase alternating current motor energy-saving controller according to claim 1; it is characterized in that: in service by MC908GP32 single-chip computer control system acquisition testing electric circuit inspection to electric current, voltage, power factor, the rotary speed parameter in motor when operation; by the duty ratio of opening that the driving that is made of EXB841 and protective circuit are regulated switching tube IGBT in the unsteady flow main circuit, three-phase input voltage is carried out copped wave control.