The difference between the speed reducer and frequency converter speed control

Electrical engineers Through the difference between the speed reducer and frequency converter speed control of mechanical devices often need to adjust the speed of three-phase asynchronous motor,often use reducer adjustment change frequency reduction ratio or transducer to adjust the speed of the motor. But by what is the difference between the speed reducer and frequency converter speed control? Together (see electrical engineer) to take us to get to know it.Reducer speed:Reducer is through mechanical transmission device to reduce the motor (motor) speed,such as common gear deceleration,turbine worm reducer,etc.Through the reducer to adjust the speed of the motor general need to make sure the following information:1,the types and specifications of the motor,speed,power (or torque),starting characteristics,short-term overload capacity,the moment of inertia,etc.2,the types of mechanical work,specifications,purpose,rotational speed and power (or torque). Working system: constant load or changing load,variable load load diagram; Rev.,braking and short-time overload torque,start frequency; Shock and vibration levels; Direction of rotation,motor and reducer coupling way,whether the shaft extension with radial force and axial force.3,installation type (reducer and motor,the relative position of working machine,vertical and horizontal).

4,transmission ratio and the margin of error.5,environmental temperature,air velocity,dust concentration and environmental conditions such as ph value; (if there is a circulating lubrication and cooling conditions,lubrication station) and the limitation on the vibration and noise.6,to the degree of service life,Motor vehicle safety and reliability requirements.7,the requirement for the size and weight.8,the demands induction motor price of operation and control.9,the source of material,blank,standard parts and inventory.10,on volume,cost and price requirements.11 and delivery term.Frequency converter speed control:Inverter is by changing the frequency of alternating current motor (motor) in order to achieve the purpose of speed regulation. Reduce the motor speed by the frequency converter,you can achieve the goal of energy saving. But generally within 0-50 hz frequency conversion motor to realize the constant torque speed control,within the scope of 50-100 hz to realize constant power speed regulation,and stepless speed regulation,wide speed range.To sum up,through the difference between the speed reducer and frequency converter speed control is mainly: reducer speed a wider range of speed (slow),but generally not stepless speed regulation,speed regulating motor after a lot of physical and electrical parameters can be continued,in addition to the speed loss; And use frequency converter speed control can realize stepless speed regulation,but limited range of speed (only within 3 -- 100 hz speed),speed when affected by a lot of electric parameters,and can't guarantee the original motor of the number of parameters,and fever more serious.

WTD/YBT/YTD series elevator motors

Using permanent magnet synchronous motor of elevator traction system,usually a gearless traction.Highlight the permanent magnet synchronous motor is easy to make the advantages of low speed and high power.Its compact structure,complete functions,traction motor,traction wheel,electromagnetic brake,in a photoelectric encoder,and easy to install,easy to use.Especially in the development and application of machineroomless elevator,the permanent magnet synchronous electrical motor 12v 1000w traction motor installed in the hole of the lift,the room of construction cost is saved,and beautify the appearance of the building.The wholesalemotor.blogspot.com control chart is shown in figure 4.When the load changes,the permanent magnet synchronous motor by adjusting the Angle between 8 to adapt,its response is fast.


In order to make the elevator has the good comfortable starting and brake and leveling accuracy,joined the accurate rotor and stator rotor position in the system unit and voltage current detection device,determine the size of the motor magnetic field,direction at any time.Position detection device using rotor position sensor (photoelectric encoder or rotating transformer,etc.).Capsules load detection device can ac motor wind generator use a variety of forms such as position,pressure,to measure and calculate in advance,the elevator load given proper direction and the size of the moment,can switch output,analog (voltage) and frequency (hf anti-jamming is strong,can remote transmission),etc.The feedback signal is compared with the given signal,computing,according to the predetermined control mode control,can get better than that of the other performance of the drive system.

Currently there are 5 kinds of electric vehicles

Brush series brushless dc motor,permanent magnet dc motor,ac motor (induction motor),permanent magnet synchronous motor and BLDC motor FM.Brushless dc series motor are: the advantage is that big start torque,overload capacity is strong,the disadvantage is that need to change the carbon brush,high speed has the ring of fire,not suitable for high speed running,low efficiency,large volume,protection and energy feedback is poor,mainly used in electric tricycle.Brush with permanent magnet dc motor: advantage is better than brushless diesel generator dc series motor has high efficiency,energy feedback is good,starting torque and overload ability general,defect is need to change the carbon brush,high speed has the ring of fire,not suitable for high speed operation,efficiency,large volume,moderate protective ability is poor,mainly used in electric tricycle.

Ac motor,the advantage is simple structure,high reliability of motor itself,the disadvantage is that starting torque is small,large starting current,motor depends on increasing the starting current to produce a large torque,but due to the battery characteristics,the battery provides large current,affects the motor torque,the motor efficiency is low,the control of complex,energy feedback performance is poor.Switched reluctance motor: advantage is in low speed with large torque,defect is low speed vibration,noise,low efficiency,poor energy feedback,rarely used.Permanent magnet synchronous motor,the advantage is with high efficiency,energy feedback acmotortrading.blogspot.com is good,the disadvantage is that when the low speed torque cannot ascend,lose the step problem,rarely used.Brushless dc motor: advantages are: (1) motor external characteristic is good,very accord with the load characteristics of electric vehicles especially motor has low speed high torque characteristics of the precious,can provide large starting torque,satisfy the requirement of the vehicle acceleration.(2) the wide speed range,the motor can run tall in the low speed range,due to mechanical commutator and brush motor,the motor can run under low.(3) motor with high efficiency,especially under the light load cars,motor can still keep high efficiency,it is very important for precious battery power.(4) overload capacity is strong,this kind of motor than Y series motor overload capacity can be improved more than 2 times,can meet the needs of the vehicle bumps blocked.(5) regenerative braking effect is single phase generator good,because of the permanent IE2/IE3 electric motor magnetic motor rotor has the very high,when the car downhill or brake motor generator can be completely into the state,to recharge the battery,the electric braking effect at the same time,reduce the financial burden on mechanical brake.

6.Motor small volume,light weight,high power,can effectively reduce weight,save a space.7 no mechanical commutator motor,USES the totally enclosed structure,prevent dust from entering the motor internal,high reliability.Simple than asynchronous motor was motor control system.Faults is more complicated than the ac motor motor itself,brushless dc motor controller than there are complex.

Turbine check before starting the project?

1) steel pipe pressure is normal;(2) the guide vane and the butterfly valve seated;(3) 220v ac electric motors water machine room without obstruction of rotational sundry,shaft seal intact,check the top discharge valve fully open; (4) cooling water pressure is normal,ling oil inlet and outlet valves,air cooler wholesalemotor.blogspot.com inlet valve open to a third opening;(5) the airlock have low speed permanent magnet generator withdrawn,the brake pressure is normal; Electrical engineering network (6) check back to the fuel tank and gravity tank oil level,oil color normal;(7) ac geared motor governor system,butterfly is normal;(8) carbon brush,brush holder,slip ring is in good condition,all the fuses and connecting screws not loose phenomenon;(9) check speed measuring device,temperature checking device,temperature indicator and shearing pin signal device indicates normal,gratuitous barrier signals.

China motor network, increase the stepper motor dynamic torque method

Step 1, select from the Angle of small stepper motor at low speed torque gets bigger with the increase of rotor teeth. Choose small step away from the Angle of step motor can obtain high torque. A dozen HB type on the rotor teeth like 50 tooth, permanent magnet magnetic flux leakage will increase, but will step in proportion, this conclusion in 100 teeth of the following are valid. Type three-phase HB stepping motor from 1.2 ° 50 tooth (rotor) change 0.6 ° 100 teeth (rotor). About 1.4 to 1.8 times the torque at low speed. 2, bipolar rotor cutting machine connection efficiency can cover 2 times. It is easy to buy on the market two phase unipolar or bipolar stepper motor, but bipolar drive power tube is larger than that of unipolar. Stepper motor in high speed way to increase the torque: 1, to reduce the number of turns, reduce L in motor manufacturer's standard products choose small inductance L, rated current. 2, a permanent magnet flux is smaller Can't ac synchronous motor reduce the permanent magnets, such as production maternity leave can increase the air gap, reduce the high speed counter potential, increase current, make the torque increases, the speed - torque characteristic from low speed to high speed into a straight line, increase the torque, frequency response also increases at the same time. Step 3, choose from the Angle of motor. , step motor running at a high speed in the drive circuit improve the method of torque: 1, improve the drive current voltage to maintain high speed large torque, to keep the current constant, make the chopper work in constant current state. To make a constant current can only improve the pulse frequency. When as a stepping motor velocity must be high speed, because the voltage limit, can only work in constant voltage state, if the input voltage, then you can make it at a high speed still can work in constant current state, if the input voltage, then you can make it at a high speed still can work in constant current state, thus improve the speed torque. 2, to reduce the driving circuit shut off when the current in the coil current at the time of power tube shut off, due to the current rate of change is big, coil produced very big induced voltage, power tube will have a risk of being www.facebook.com/dongfeng.motor breakdown, there is often a protection circuit.

Three-phase asynchronous motor starting method

Squirrel-cage three-phase asynchronous motor in the widely used now. This kind of motor in the design process focuses on at work can not only realize good use of intelligent control, and in the process of use and not due to the use of a lot of power to grid used in daily life, work, a certain power impact. The squirrel-cage three-phase asynchronous motor in use process, by the use of gf in use process is usually via step-down start to start the motor, now use the step-down start there are two main ways, one is step-down motion, while another is called soft start. Soft start is also called electronic soft start, the startup mode generally adopts 16-bit single chip microcomputer to be responsible for rotor and stator the control of the motor, through the intelligent control system, the motor at work can ensure that the motor in the load it can achieve a smooth start, still can reduce because click use too much power and cause certain impact to the grid. Including the squirrel-cage three-phase asynchronous motor in before and now, the grid has always maintained a in the process of running with the characteristics of volatility, often at the time of peak electricity consumption, electricity in use process found obvious battery is low, but in the case of electricity consumption is very low, there will be a power's use of power is very high. In order to some of the production process can fully more rational use of electricity, people invented the electric motor electronic soft starter, this product motor fan with this product, the squirrel-cage motor is applied. The squirrel-cage motor such as the electromagnetic brake is also need in step-down startup conditions. In the process of this kind of motor start, machine can't work under full pressure start mode, and when it starts, terminal voltage can't realize the characteristics of the specification requirements.