The generator brush sparks the cause of the problem is?

1,brush current density is too large.In the actual operation,if one or two brush jamming due to

mechanical trouble,lack of spring pressure don't output,in order to maintain the normal load,by other brush of current will increase,if there are in the increasing flow of the brush the slant of the

brush,because with the slip ring contact area is reduced,surface flow density increases.According to Q = I * IRT,calorific value and is proportional to the square of the current,the accumulation of heat to send out,the temperature rise sharply,the brush and slip ring interface can produce sparks.Also spark,after the creation of the brush work environment more bad,so a vicious circle,make brush sparks more serious,a few have this severe cases will occur when the three phase induction motor ring of fire.2,uneven brush pressure,or do not conform to the requirements.

Brush factory manufacturers are related: brush spark does not occur to the lowest pressure,pressure adjustment go through scientific argumentation and practice summary,minimum pressure generally is 200 ~ 300 ㎡ ɡ / c,is 0.02 ~ 0.03 MPa,the pressure between each brush also wants even,its difference is not more than 10.The generator in the long run if a brush friction are too short,or brush in the brush frame www.dongfeng-motor.com delay CARDS,pressure will be uneven.Moreover by machinery,heat soft spring itself and other factors affect the pressure can not meet the brush doesn't happen spark theory of minimum requirements.And we are compaction,tyra carbon brush,sometimes feel,no accumulation of experience,operating error is very great.3,the surface of the brush is not clean.

This is the most let people ignore,normal operation of the generator brush seal inside the airtight cabinet,there are set on the shaft gear shape among the poles brush axial flow fan,depend on rotor rotating grinding of graphite carbon powder,heat away in time,brush to clean ac geared motor the cooling effect.If the cupboard door closed lax,or forget to close the door,when checking out the dust with the hot air into the brush,brush attached to the column,on the one hand brush heat dissipation.On the other hand brush spark occurs due to brush the column surface impurity,brush column insulation strength between ring fire easily.Besides slip ring on have spiral groove,this is in order to increase the brush the cooling area,improve with brush contact,makes the brush more fully cooling,at the same time are more likely to make carbon powder.If cupboard door closed lax,lack of draught fan outside dust very easily also adhere to the spiral ditch,consequences was palpable.Excitation single phase capacitor start induction motor electrical and mechanical brush consider its bare outside,the lower voltage level in this also suggests the maintenance regularly clean.A few days ago excitation brush sparks was forced to stop incidents happened in our factory,the reason of many sided,often small disaster.We should cause enough attention.

The working principle of motor

Motor (Motors) is a device converts electrical energy into mechanical energy.It is using electric coil (that ac electric motor is,the stator winding) to diesel generator produce a rotating magnetic field and try to turn the mouse cage form magnetoelectric dynamic rotating torque closed aluminum frame.Motor by using the power divided into dc motor and ac motor,electric power system in most of the motor is ac motor,can be synchronous motor or induction motor (motor stator magnetic speed diesel generators prices and rotor rotating speed is not synchronized rate).Motor is mainly composed of stator and rotor,the direction of motion of the wire in the magnetic field force with the direction of current and magnetic induction line in the www.dongfeng-motor.com direction of magnetic field direction.Working principle of the motor is a function of magnetic field on the current stress,to rotate the motor.

Three automatically adjust the excitation current method

Three automatically adjust the excitation current method In the change of generator excitation

current,generally does not directly in the rotor circuit,because the loop current is very big,is not

convenient to adjust directly,usually adopted method is to change the excitation exciter Magnetic current,to achieve the purpose of regulating the generator rotor current.The commonly used method is to change the electrical resistance of the exciter excitation circuit,change the additional exciting current exciter,changing the conduction Angle of silicon controlled rectifier,etc.There are primary

change the thyristor turn-on Angle Method,which is based on the change of the generator three phase induction motor voltage,current,or power factor,accordingly change the conduction Angle of silicon controlled rectifier,so generator field current can change accordingly.The device generally by the transistor,thyristor electronic components,has a spirit Sensitive,rapid and no wholesalemotor.blogspot.com failure zone,big output power,the advantages of small volume and light weight.In accident cases can effectively inhibit overvoltage and achieve rapid out magnetic generator.

Automatically adjust the excitation device usually by measuring unit,synchronous unit,amplification unit, Controlled unit,stable unit,the limited unit and some auxiliary units.Be measured signals (such as voltage,current,etc.),compared with the given value after measurement unit conversion,and then compare the results (bias) the preamplifier unit and power amplifier unit Amplifier,and is used to control thyristor conduction Angle,in order to achieve the purpose of adjusting ac geared motor the generator excitation current.The function of synchronous unit is to phase shifting part of the output of the trigger pulse synchronization with silicon controlled rectifier ac excitation power supply,to ensure the correctness of silicon control triggering.Controlled unit is used in order to make the parallel operation of generator can be stable and reasonable allocation of reactive load.Stable unit is in order to 220v ac electric motor simprove the stability of power system and the introduction of unit.The excitation system stable unit To improve the stability of excitation system.limit Unit is in order to make the generator is not under the condition of excitation or underexcitation run.It must be noted that not every kind of automatic regulating excitation device has the various units,a regulator device of unit with its specific tasks The relevant.

Induction motor drive system

Asynchronous motor is characterized by simple structure,strong and durable,low cost,reliable operation,low torque ripple,low noise,do not need to position sensor,high speed limit.Induction motor vector control speed regulation technology is mature,the asynchronous motor drive system has obvious advantages,so the earlier was applied in electric vehicle drive system,the current is still the mainstream of the electric vehicle drive system products,but have been other new type of brushless permanent magnet traction motor driving system is gradually replaced.Biggest disadvantage is that driver circuit is complex,high cost; Relatively permanent magnet motor,induction motor efficiency and power density is low.2.The brushless permanent magnet synchronous motor drive system three phase induction motor Brushless permanent

magnet synchronous motor can use cylindrical radial magnetic field structure or disc axial magnetic

field structure,due to the power density and high efficiency and magnet prices wide speed

range,development prospect is very broad,is a strong competitor in the traction motor of electric

vehicle,had been used in a variety of electric vehicles at home and abroad.

Built-in permanent magnet synchronous motor,also known as hybrid permanent magnet reluctance motor.The motor on the www.dongfeng-motor.com basis of the permanent magnet torque superposition of the magnetic resistance torque,the existence of the magnetic resistance torque to improve motor overload capacity and power density,and easy to weak magnetic speed regulating,expanding the scope of the constant power operation.Built-in permanent magnet synchronous motor drive system design theory is increasingly perfect and further,with flexible structure,design degrees of freedom,is expected to get high performance,suitable for electric

cars,high efficiency,high density and wide speed traction drive.These cause the attention of the

peers in the major car companies,especially the Japanese car company colleague's favor.

At present,the American car companies peers in new model design mainly USES the built-in permanent magnet synchronous motor.generator stator Surface; also called permanent

magnet torque motor type permanent magnet synchronous motor,against the built-in permanent magnet synchronous motor,its weak magnetic speed range is small,low power density.The structure of the motor dynamic response is fast,and is expected to get low torque ripple,suitable for used in automobile electronic servo drive,such as automotive electronic power steering servo motor.Sensorless permanent magnet synchronous motor drive system is currently a hot topic in the research of permanent magnet synchronous motor drive system,will become the development trend of the permanent magnet synchronous motor drive system is one of the potential competitive advantage.Permanent magnet synchronous motor drive system often adopts vector control at low speed,high speed with weak magnetic control.

Structure and working principle of the generator is what?

Generators are usually made of stator and rotor,end cover and bearing www.facebook.com/guohong.trading components.By the stator core,stator line winding,stand and fixed the parts of other structures.Rotor by the rotor core (or a magnetic pole,the conjugate) 220v electric motor winding,retaining rings,central ring,slip ring,fan and shaft parts.The generator rotor rotate by the prime mover,when direct current (dc) after the rotor winding for carbon brush and slip ring access,rotor can produce magnetic fields.Due to the rotor is constantly perkins diesel generator rotating,so the diesel generator magnetic field is a rotating magnetic field,it and the relative motion is formed between the stillness of the stator winding,equivalent to the stator winding in constant cutting lines,and will in the stator winding induction electromotive force.The direction of the induced electromotive force of the stator,is decided by the right-hand rule.For Ren Yigen of coil wire,in the process of the rotation of the rotor,sometimes N pole toward it,S very on it,sometimes different polarity in the winding induction electric potential orientation is not the same.Back and forth direction change,this is an alternating current.

Efficiency more than eighty percent of the permanent magnet motor

Efficiency more than eighty percent of the permanent magnet motor product 2~3% lower than the foreign advanced level,the expert suggests to improve Chinese permanent magnet motor 220v ac electric motors system energy efficiency.At present in China,permanent magnet motor power consumption accounted for about 60% of the national power consumption,small and medium-sized motor account for 80% of the national power of the motor. China's motor system energy saving a huge promotion potential,improve the energy efficiency of acmotor2.blogspot.com small and medium-sized motor,is an important aspect of an industrial terminal equipment and energy

saving.

China will become the world's largest production base of system components,motor and motor

improve motor system energy efficiency,China is not only beneficial to China's economy,as well as

sustainable energy supply in the international market. ac geared motor If China in 2020,all use high efficiency motor,can reduce 20.8 billion tons of carbon dioxide emissions into the atmosphere each year and 78.09 million tons of sulfur dioxide. The national development and reform commission energy research institute,the renewable energy development center,deputy director of the proposal,countries should speed up related policy incentives and punishment measures,make enterprise 220v ac electric motors need to weigh the efficiency in using the motor.

To promote efficient motor facing difficulties and solution:

Motor system in our country the total capacity of about 700 million kilowatts,but market is less than

3% efficient motor,motor drive system as a whole running efficiency is 20% lower than in developed

countries.Domestic production of highly efficient motor exported to abroad,long-term facing

"foreigner to eat meat,people drink soup".The cause of such an awkward situation mainly include: 1,the purchaser without the consciousness of energy conservation and environmental protection.220v ac electric motors Most of the current domestic buyers include companies and government agencies,not the consciousness of energy conservation and environmental protection,in the process of purchasing,will purchase cost as the main factors of choosing products.In addition,due to the separation of buyers and users of the motor is,don't understand the life cycle cost of motor and the importance of motor efficiency,it also caused the motor when the choose and buy focusing only on the initial cost,choose the cheap products.

2,more efficient motor due to the raw materials used,the cost about 20% higher than normal

motor.Efficient motor efficiency mainly depends on its use more materials,such as copper and

steel,and raw material prices are rising,caused the high efficient motor manufacturing costs,which creates a situation of the buyers tend to general motors.3,although our country also made the energy efficiency standards of ordinary three-phase asynchronous motor,the allowable value of the small magnet prices and medium-sized three-phase asynchronous motor efficiency and energy conservation value "(GB18613-2006),file regulation,below the level 3 energy efficiency of motor lock-up,and set a transition period of four years,after July 1,2011,ban to level 3 energy efficiency motors.Standards for nearly four years,the effect is not ideal.Country's implementation of the mandatory energy efficiency label,but also hope that the user can like to buy home appliance products,electrical products of choose and buy,according to the level of energy efficiency in order to impel the promotion of high efficiency and energy saving motor.In fact,the vast majority of terminal consumers generally can't see the logo of energy efficiency of the machine.At present,the energy efficiency label system in small and medium-sized motor enterprise promotion effect is very poor.

The deputy secretary-general of China energy conservation association Song Zhongkui hit the nail on the head to point out:"mandatory standard is not mandatory standard itself,but in the implementation of standards,should be clear which department is responsible for the

implementation of the provisions of the relevant also to refine and maneuverability,otherwise,the

mandatory is impossible".Experience from abroad,the implementation of the compulsory standards relating to both positive and negative aspects,one is the positive energy efficiency label system,2 it is to reverse the acmotor2.blogspot.com disciplinary system.For illegal behavior,energy efficiency label management center to China academy of standardization related businesses face fines of up to 100000 yuan,weaker penalties.At the same time,relevant departments of the enterprises to carry out energy efficiency label check mainly for motor,failing to strengthen inspections of motor products on the market.To continue production generator stator after 4 years of protection level 3 energy efficiency of the motor companies to adopt what kind of punishment measures,is still not clear.

In addition,recently,the national development and reform commission jointly issued by the

ministry of finance on the huimin engineering efficient motor energy saving products promotion notice of the detailed rules for the implementation,some enterprises put forward:in the notice requirements apply for promoting enterprise in domestic low-voltage three-phase asynchronous motor and the high voltage three-phase asynchronous motor promotion amount not less than 300000 kilowatts,or rare earth permanent magnet motor promotion amount not less than 10000 kilowatts.According to the condition,in the domestic promotion quantity is difficult to provide.In addition,there are enterprises to increase subsidies.Mentioned in the notice,within 30 days after the end of year,promote enterprise liquidation report on the annual subsidy funds are put forward,step by step to the Treasury.There are business people think that the cycle is too long,the enterprise capital is not drained in time."Visible,maneuverability of policies on promoting efficient motor remains to be improved.

The main structure of a generator?

Generators are usually made of stator and rotor,end cover and bearing components.By the stator core,stator line winding,stand electric motors price and 220v electric motor fixed the parts of other structures.Rotor by the rotor core (or a magnetic pole,the conjugate) winding,12v motor retaining rings,acmotortrading.blogspot.com central ring,slip ring,fan and shaft parts.By bearing and end cover of generator stator and rotor connected together,can make the rotor spinning in the stator,do the exercise cutting lines,thus induced potential,through terminal lead,in the circuit,the electric current is produced.

After motor starting speed is lower than the rated speed:

If several motor also appear such problems tend to power grid voltage is too low.If an electric motor parts electric motor starting a buzz and some vibration,to check whether the stator winding is a power,whether can measure three phase current balance and a buzz vibration check whether the three-phase voltage is too low,but not when no-load motor speed is normal,and the permanent magnet motors for saleloaded speed down.Check the steps: First will start motor racing,such as rotating speed is normal,can clean the motor with light load,such as low speed,load mechanical parts have cut living phenomenon,if no fault in the mechanical parts,motor speed not reduce,can make the motor in the rated load within the scope of operation,if the motor speed dropped,give a person a kind of not move feeling,it is proved that motor has a fault,the cause of this failure is that the extended delta connection of single phase capacitor start induction motor motor into a star,squirrel www.facebook.com/guohong.trading cage rotor broken bar,if it's just around the motor,is likely to be a very like a phase.

Compressor excessive current when the motor running,the cause analysis and elimination method

A,reason analysis Generally considered A refrigerator at work current value,more than normal working current 1.1 1.2 A,which is to think too much electricity.Here's why: 1,refrigerators and other high- power electrical equipment on the same power supply cord.2,the power of the input voltage is too low,lower than allowed work voltage on duty,starting current is too large.3,refrigeration systems affected by external factors,such as condenser clingy wall,there is too much dirt on tube,natural air flow effect is poor,the hot air send out not to go out; Or refrigerator near the heat source too,the refrigerator to store too much hot food,these factors will make the condensing pressure,cause the compressor start is difficult,the motor current is too large.4,compressor internal assembly is not in conformity with the technical requirements,cause movement friction is too large,ac synchronous motor lead to electric reach rated speed,or even halt.

Motor current is too large.5,all of a sudden power failure,suddenly calls,time interval is short,high and low pressure in the system haven't balance,cause big start difficult,current is too large.6,refrigerator system refrigerant leakage,temperature to drop,motor operation,cause too much electricity.7,start relay failure,the thermal protector lost ability,cause too much electricity.Second,the elimination method 1,shall set up special diesel generators prices line power supply.2,install the coupling voltage regulator,voltage regulator to the electrical ratings.3,the refrigerator should be put in the place where the air circulation.4,cut casing,reassemble the parts according to the technical standard.5,when a sudden power failure found,shall be immediately disconnected refrigerator power head,when the power is www.dongfeng-motor.com on,then use the refrigerator.6,by check,confirm the refrigerant in the system has been leaking,shall promptly repair and add freon.7,start relay failure,should be timely repair or replacement.

Stanley portable power station

A lot of size is smaller than air compressor power station,there is only one trolley so big,can drive the efficient tool.For example,we a GT18 hydraulic power station to drive samples of all the tools,from the 90 # hydraulic drill picks wholesalemotor.blogspot.com to small. Our hydraulic power station using the latest technology of the engine manufacturer.Use air-cooled engine,high combustion efficiency,light weight,strong and durable,its produce power to drive the cause of most of our tools,and acmotortrading.blogspot.com engine load.Hydraulic power station look for air and also or internal combustion is a tool perkins diesel generator set has the following characteristics. 1.Diversity: we have more than 50 types of tools you can use this power station 2.perkins diesel generator set Air cooling: not freeze in winter 3.High efficiency: 1 disappeared 4 litres of fuel consumption 4.Low noise 5.Light weight: 150 kg 6.Size: can be put into small truck or train 7.Portability: can work in the field to the mobile trolley 8.Convenient maintenance: can the dealer maintenance engine

Fault phenomenon:motor vibration is too large

Reason and solutions:1.The electric motor cooling fanrotor imbalance www.dongfeng-motor.com-leveling balance 2.Belt wheel unbalance or axis stretch bending-check and correction 3.Motor is not aligned to the load axis-check to adjust the axis of the unit motor fan4.Wrong-check the motor installation and foot screws 5.The heavy load suddenly, lighten the load

Capacitor start motor

In capacitor start motor,start capacitance and start winding string together,thus forming a LC circuit,the circuit has good phase shift (and thus have a very good starting torque).The resistance for the motor will also increase the cost.Fixed phase capacitor motor Another motor is fixed phase capacitor (PSC) motor (i.e.,capacitor motor) up and running.This kind of motor operation mode is similar to the capacitor start motor described above,but it does not have the centrifugal switch,so

its secondary winding is connected to the grid.PSC motor is usually used in hair dryer,electric fans,blowers,and other need to change.Under the condition of invariable load by changing www.dongfeng-motor.com the running winding signal to achieve the purpose of make the motor run at different speeds.All six winding connection respectively,a three-phase motor can connect two winding together through the rest of the a winding capacitance connected to start winding to run into one capacitor start motor.The repulsion motor Repulsion motor is single-phase ac motor rotor winding,it is similar to ac/dc motor.In the repulsion motor armature with brush nipple rather than and in series with the magnetic field.

Already have a few kinds of repulsion motor into production use,but most of all,with repulsion start sensing (RS)-IR motor operation.RS-IR motor with a centrifugal switch all the short commutator connect together,so when it is up to full speed it will run in the form of induction induction motor sales motor.RS-IR was used in the motor under low temperature and low voltage per ampere provide large starting torque.In 2005,almost did not sell any type of repulsion motors.Single-phase ac synchronous motor Small single-phase motor can also be designed to be magnetized rotor.This does not require any motor in the rotor induction motor,so they will not be lower than the main frequency.Instead,they will be as the rotation frequency synchronization.Because of their high speed precision,this kind of motor is typically used in electric power mechanical clock,record machine and tape recorder; They are also used in such as ribbon machine and telescope driving mechanism requires precise time of equipment.Shaded pole type synchronous motor is one of them.Because of inertia,so it is difficult to the rotor from state stopped immediately accelerated to synchronous speed.This kind of motor usually need some special way to start.A variety generator rotor and stator of different Design with a small induction motor (it will share the same and the synchronous motor excitation coil and rotor) or one- way speed (guarantee the rotor startup positive speed) as the very light of the rotor.

The characteristics of variable frequency motor

1,the electromagnetic design For ordinary asynchronous motor,and the design main consideration of the performance parameter is the overload capacity,starting performance,efficiency and power factor. And frequency conversion motor,because of the critical slip inverse ratio at power frequency,you can directly start when critical slip is close to 1,therefore,overload capacity and startup performance is not need to think too much,and to solve the key problem is how to improve the ability to adapt the motor of the non sine wave power. Generally as follows: 1) as far as possible,the reduction of the stator and rotor resistance. Reduce the stator resistance can reduce the fundamental wave copper consumption,to compensate for wholesalemotor.blogspot.com higher harmonic caused by copper consumption increase 2) to suppress the higher harmonic current,should be appropriate to increase the inductance of the motor. But rotor slot leakage resistance is larger the skin effect is also big,higher harmonic copper loss also increased. Therefore,the size of the leakage reactance of the motor should give attention to two or morethings arrives the rationality of the impedance matching within the whole speed range. 3) the main magnetic circuit of frequency conversion motor generally designed to unsaturated state,one is to consider will deepen higher harmonic magnetic circuit saturation.

2 it is to consider at low frequency,in order to improve the output torque and appropriate to increase the output voltage of inverter. 2,the structure design Structure design,main is also considering the non-sinusoidal power characteristics of variable frequency motor insulation structure,the influence of vibration and noise cooling mode,generally pay attention to the following questions: 1) the insulation class,generally for perkins diesel generator set F or higher,strengthen the insulation and line turn insulation strength,especially want to consider the ability of impact resistance voltage insulation. 2) to the problem of vibration and noise of the motor,the motor should be fully considered component and overall rigidity,trying motor lamination to improve its natural frequency,in order to avoid and every force wave resonance phenomenon. 3) cooling method: generally adopts the forced ventilation cooling,namely USES the independent main motor cooling fan motor driver. 4) measures to prevent shaft current,the capacity of more than 160 kw motor bearing insulation measures should be adopted. Mainly produces magnetic circuit asymmetry,also can produce shaft current,while the rest of the high frequency component generated by the current role in combination,shaft current will increase greatly,which can lead to bearing damage,so often insulation measures. 5) www.facebook.com/guohong.trading to the constant power variable frequency motor,when the rotation speed of more than 3000 / min,high temperature resistant special grease should be adopted,to compensate for the temperature of the bearing

Single phase ground fault definition

Three-phase electric power system,only in the insulation between the phase conductors and ground (to appear.Broadly,single-phase earth fault,including single phase grounding short circuit,single phase grounding short circuit is a special phenomenon of single phase ground fault,only the transformer neutral point grounding system will be.Narrowly speaking,single-phase earth fault and single-phase grounding short circuit are two concepts.One is a failure,is an accident.Power system www.dongfeng-motor.com fault and accident is divided in narrow sense.Refers to the one-phase ground fault line (electric) any phase without load and earth wire connected directly,in the 380/220 power supply system or other grounding system.

due to the transformer neutral is grounded,and grounding resistance is very small,wire (electric) any phase without load ground connected directly,and instant will produce very big current,burn out the wire,power distribution equipment or tripping,etc.,so is a serious accident,one-phase ground fault power system is to avoid as far as possible.In power system,there are many places not grounded system power supply,such as dust,inflammable and explosive special field,such as our country all 6-10 kv,35 kv power supply system,etc.,is the neutral point grounding are used or through big resistance earthed power system,this system after the single phase grounding,because there is no loop or that do not produce a large current in the pumps circuit without earth current or large

grounding current,so does not affect the normal operation of the system.Although does not affect the

normal operation of the system,single phase grounding is a failure,in order to guard against ground

for the extension of two phase ground or make the grounding device further damage,such ac alternators 220v as rules of single- phase earth fault happened,to find out the reason,in 2 hours to make processing,2 hours to check out reason or can't handle,would power outage after processing.

different two-phase hybrid stepping motor

4.1 different two-phase hybrid stepping motor control precision interval Angle is 1.8 °,commonly the control precision of the ac servo motor by the motor shaft after the rotary encoder.Grows with a letter fully digital ac servo motor as an example,For the line with a standard 2000 encoder of the motor,drive due to the internal used four frequency multiplication technology,the pulse equivalent to 360 ° / 8000 = 0.045 °.4.2 low frequency characteristics of sync motor at low speed is easy to appear low frequency vibration phenomenon.Vibration frequency is associated with load and drive acmotortrading.blogspot.com performance,it is generally believed half frequency vibration frequency for the motor no-load takeoff.This kind of Determined by the working principle of stepper motor in low frequency vibration phenomenon is very bad for the normal operation of the machine.When the stepper motor work at low speed,general damping technology should be adopted to overcome the low frequency vibration phenomenon,for example Add damper on the motor,or drive the segmentation technology,etc.Ac servo motor running smoothly,even in the low speed also won't appear when the vibration phenomenon.Ac servo

system has a resonance suppression function,can Covers mechanical rigidity is not enough,and the

6.5hp gasoline generator set system has the function of frequency resolution (FFT),can detect the mechanical resonance point,is advantageous for the system adjustment.

The torque-speed characteristic in 4.3 is not synchronous motor output torque increases with speed decreases,and at a high speed when they fell sharply,so its

maximum working speed is in commonly 300 ~ 600 RPM.Ac servo motor for constant torque Output,that is,at its rated speed (generally is 2000 RPM and 3000 RPM) of less than,can be rated output torque and constant power output above the rated speed for.4.4 overload capacity of sync motor do not generally have overload ability.Ac servo motor has a strong ability of overload.Strong ac servo system with the letter as an example,it has the speed overload and torque overload capacity.Its biggest For more than three times the rated torque and torque can be used to overcome inertia load at startup moments of inertia moment.Stepper motor because there is no this kind of overload capacity,in the selection in order to overcome the inertia moment,often need to choose from Big torque motor and machine during the normal work and does not need so big torque,there is a moment of waste phenomenon.4.5 performance not synchronous motor control for the open loop control,start frequency is too high or too much load step easy appear lost or blocked,stops frequently occur high speed overshoot phenomenon,so as to pumps ensure its control Accuracy,should handle up,slow down.

Ac servo drive system for closed-loop control,the actuator can be directly to the motor encoder feedback signal sampling,internal position loop and speed loop,general won't appear step Motor lose step or overshoot phenomenon,more can * control performance.4.6 response performance of the asynchronous motor speed accelerate from 0 to work speed (generally for a few hundred revolutions per minute) 200 ~ 200 milliseconds.Better acceleration performance of the ac servo system,grows with a letter HO CC 400 w ac Servo motor as an example,from static accelerated to the rated speed 3000 RPM it takes only a few milliseconds,can be used for quick start-stop control occasions.To sum up,the ac servo system in many performance is superior to step into electricity Machine.But in some occasion not high demand also often use stepper motor to do perform motor.So,in the process of the design of the control system to a comprehensive,with consideration of many factors such as cost control requirements,choose the appropriate Control the motor.

The main points of the motor maintenance inspection

Motor maintenance inspection is the main points of the early found abnormal state of equipment and handled in time,prevent accident expanding.Maintenance personnel according to the action of relay protection device and the signal can be found abnormal phenomenon,also can rely on the experience of the maintenance staff to diagnose accident.1,the first is a visual inspection Visual can be found on the acmotortrading.blogspot.com following anomalies: if there's any loose for motor external fasteners,parts whether have damage,equipment surface whether there is oil pollution,corrosion phenomena;The contact point and connection of the motor have become angry phenomenon such as mark,burn mark and smoke.Causes for this phenomenon is due to the local overheating or poor conductor or motor winding burned down,etc.;The instrument is normal.Voltmeter without instructions or is not normal,suggests that gear motor the power supply voltage imbalance,fuse,rotor resistance unbalanced three-phase,single phase operation,and poor conductor,etc.Ammeter indication is too big,suggests that motor overload,bearing fault,winding interturn short circuit,etc.;Motor stalling,caused by the reasons are: the power blackouts,single phase operation,low voltage,torque of the motor is too small,heavy load,the voltage drop is too large,bearing burning,mechanical jam,etc.

2,USES the auscultation rods by ear can hear the motor all kinds of noise Including electromagnetic noise,ventilation,noise,mechanical friction,bearing noise and so on,which can judge the motor of the cause of the problem.The cause of large noise has: in mechanical bearing fault,mechanical imbalance,fastening screw loosening,diesel generators prices shaft coupling phase does not conform to requirements,stator core brush,etc.;Have: electric voltage imbalance,single phase operation,winding circuit or breakdown failure,starting performance is bad,bad acceleration,etc.3,by the sense of smell can be found burnt taste,smell The causes of this phenomenon is: motor overheating,winding burned,single phase operation,winding fault,bearings,etc.electricalmotor1.blogspot.com 4,by touch with the hand to touch the surface of the casing can be found that the temperature of the motor and vibration phenomenon The cause of vibration is: mechanical load imbalance,fastening components have loose phenomenon,improper motor base strength is not enough,shaft coupling and uneven air gap or mixed with perkins diesel generator set sundry,voltage imbalance,single phase operation,winding fault,bearings,etc.

Is the cause of the motor temperature too high overload,cooling air duct blockage,single phase operation,turn-to-turn short circuit,voltage too high or too low,unbalanced three-phase voltage,speed characteristics not make starting time is too long,stator and rotor phase wipe,starter poor contact,frequent starting and braking,reverse connect braking or imported high wind temperature,mechanical jam,etc.With the hand touch the estimate motor surface temperature,due to the feeling of everybody is different,subjective,so should be determined by experience.Routine maintenance inspection is divided into daily check,monthly or regular Tours of inspection and check every year.In daily inspection,mainly check the lubrication system,appearance,temperature,noise,vibration and abnormal phenomenon,also check ventilation cooling system,the start capacitor condition of sliding friction and fastening situation of parts,do check and record.Monthly or regular inspection of the main check grounding device switch,wiring,whether there is loose phenomenon,such as presence of damaged parts,if you have to plan and repair measures are put forward,check the dust accumulation,to timely cleaning,check for damage and aging lead wire and the wiring problem.Testing the motor winding insulation resistance and record.Annual check content in addition to the above project,and the collapse of the motor pumping heart checks,cleaning or washing oil dirties,check the insulation