The motor star triangle start the advantages and disadvantages

Star triangle start the advantages and disadvantages of the 2009-11-23 and motor When star triangle starting method is suitable for the normal operation of the winding for the triangular connection of the motor,the three-phase winding of the motor will lead to six outlet end,and the switch.When starting,will run normally when the delta connection of the stator winding connector for star connection,change again after the starting of triangular connection.This method is only applicable to

small and medium-sized squirrel-cage asynchronous motor.Star connection,the stator winding of the stator voltage drop for 1/3,square root triangle connection is provided by the power of starting current is only 1/3 of the stator winding connection triangle.Is the ability to reduce the starting

current,this is the advantage of it.However,because the starting torque and each phase winding is

proportional to the square of the voltage and winding voltage at y connection reduces the 1/3 times

square root,so the starting torque will drop to 1/3 of the delta connection,this is its shortcomings.Since the principle of decoupling step-down start and reduce the startup of the stator

voltage,star delta starter is by changing the winding connection to change the start voltage,so the

ratio is fixed,but since the lotus root transformer ratio is adjustable,follow the same voltage drop

K,the law of the current decline in K square.Star triangle start belongs to step-down start,step-down

start the purpose is to reduce the starting current,reduce impact on other electrical appliances.Relative to the wholesalemotor.blogspot.com self coupling Motor vehicle step-down start,start star triangle is suitable for small motor capacity,widely used in 4 ~ 100 kw of asynchronous motor,the advantages of small volume,low cost,long life,reliable operation,etc.1,the same motor,wind can be installed in Y type winding and wind can also be installed in the delta type winding;

2,the same motor,the installation,type into delta winding around conductor cross section is small,serial number of turns,high work phase voltage,phase current is low;3,the same motor,the installation of Y type winding,wire section,serial number of turns small,low work voltage,phase current is high;4,delta type winding required three phase symmetry,rotor balancing machine power symmetry is higher also,so as not

to appear circulation,otherwise will be fever,increasing loss;5,Y type winding in three-phase symmetry is bad,the power symmetry is not high,there would be no circulation,but there will be zero

drift,three-phase work serious asymmetry;6,in use,delta type winding can use Y - delta start way to start,but can't use Y Y type winding - delta start way start;7,the resistance is directly

proportional to the square of the heat loss and current,so the same motor,installation into delta

type winding around heat loss is small

Delta connection of the motor and the difference between y connection

Under the small motor (4 kw) most using Y type connection, large motor usually adopt delta connection, star triangle decompression can also be used as a large motor starting, motor spare parts when starting torque motor coil Y type runtime is only half of the delta connection, but the current is only starting about a third of the triangle. Triangle when starting current is rated current of 4 to 7 times, but the torque is big. Speed is the same, but different torque For ordinary three-phase electricity, the phase voltage 220 v, line voltage 380 v. Y connection is three-phase power electricalmotor1.blogspot.com to one end of acmotortrading.blogspot.com each winding, the other three phase asynchronous motor end connect together. That each winding can gain phase voltage of 220 v. Delta connection is each winding end to end in order to form a triangle, three phase electricity in the Angle of the triangle. That each winding can gain line voltage of 380 v. If the phase voltage is 220 v, the rating of the motor is in y connection. If it is 380 v with delta connection. In particular, if the motor is belong to the rated voltage 380 v, you can use 220 v y connection step-down start, start to finish to switch to the delta connection

of the rotor (rotating)

1,the three-phase asynchronous motor rotor core: Role: as part of motor magnetic circuit and rotor winding is placed in the core slot. Structure: the materials provided with the stator,by 0.5 mm thick silicon steel sheet coining,overlying and become,silicon steel cylindrical blunt with uniform distribution of holes,used for rotor winding. Usually lagging in the silicon steel sheet electric vehicle motor with the stator iron core circle to punch the rotor core. General small asynchronous motor rotor core being connected directly on the shaft,large and medium-sized asynchronous Motor rotor (more than in 300 ~ 400 mm in diameter) of the rotor core,with the aid of and pressure on the axis of the rotor bracket. 2,the three-phase asynchronous motor rotor winding Function: cutting the stator rotating magnetic field induced electromotive force and the current,and form the electromagnetic torque and make the motor rotation. Structure: divided into squirrel cage rotor and rotor winding.www.dongfeng-motor.com (1) squirrel cage rotor,rotor winding by the insertion of the rotor slot dogan conducting bar and two circular end ring. If remove the rotor core,the appearance of the whole winding like a cage, Therefore calls cage windings. Small cage motor adopts cast aluminum rotor winding,for more than 100 kw motor adopts copper bar end ring and copper welded together. 2 wound rotor type: winding and rotor winding of the stator winding is similar,is also a symmetrical three-phase winding,generally pick a star,three line received a shaft head of collector Ring,and then through the brush with the external circuit. Characteristics: the structure is complex,so the application of wound rotor motor is widely squirrel-cage motor. But through the collector motor fan ring and brush in series with rotor winding circuit in the additional resistance and so on Components,to improve the asynchronous motor,braking performance and high performance of reason in smooth speed regulation requires a certain range of equipment, such as cranes,elevators,air pressure Shrink machine such as above.