The three-phase compound stepper motor is adopted with the rare earth material, with little

exhaustion of electromagnetism, high coversion efficiency and excellent dynamism compared to

other reaction stepper motor. The three-phase compound stepper can stably run with low noise, big

output and without stepping out. The three-phase stepper motor greatly improves the vibration and

noise driven by the sine wave current, and is the top grade motor.

Latest innovative technology

It  is  employed  with  the  micro-electronic  technology  to  embed  the  new  generation  high  speed

monolithic  processor  into  the  drive  unit  to  improve  the  control  performance  and  simplify  the  circuit;

employed with AC servo control method to get AC servo run characteristics, and the three-phase sine

current drive output; the low voltage DC power supply in the drive unit use the switch power supply to

reduce the volume of power circuit and to get the reliable stability.

Micro step angle

It is employed with the vector division technology to control the min. angle of the motor rotating to

be 1/20（0.03°）of the step angle of motor. The mircro step control can ensure the stepper motor can

stably run with low speed, and its run effect approaches that of AC servo. The micro step drive unit is

matched with μm（0.001mm）  grade CNC control device to realize μm grade min. movement, used for

machining  the  cambered  surface,  conical surface,  thread and other  workpiece, which  can obviously

improve the fine effect of workpiece’s surface.

High torque

The  output  torque  of stepper  motor is  in direct  proportion, the  input  current capacity is in direct

proportion of voltage  used  by the amplifier  of  drive unit  when it  runs  with the high speed. Presently,

the used voltage  of most stepper  motor is below  DC150V, but that  of DY3F reaches DC310V, so,  it

still has the high torque output when it runs with the high speed.

High reliability

The  control parts are high  integrated,  the amplifier  is  employed with  Mitsubishi  new  intellective

module  with  tight  structure,  terse  circuit,  few  connectors,  external  wind  cooling  heat  dissipation  to

protect  the  dust  from  the  machine  inner,  and  with  the  over-temperature,  overvoltage,  low-voltage,

protection and alarm signal output.

 Advanced stepper motor control method

The  AC  servo  control  method is applied the drive  unit of three-phase  compound stepper  motor,

its  input  AC220V  becomes  to  DC  310V  after  commutating,  and  then  becomes  three-circuit  310V

stepping  sine  wave  current  after  pulse  width  modulation,  and  their  fixed  time  sequence  separately

flows through three-circuit wind, and each step corresponds to one step of motor rotating. Change the

motor’s speed by changing the frequency of sine current output by drive unit, and step amount output

by per rev confirms the angle of every step rotating.

According  to  the  present  electronic  technology,  the  step amount of  sine  current  is  divided  into

many. According to the theory, the step amount per rev is many, which is the  subdivided technology.

The theory analysis and much experiement verify: when the subdivision amount exceeds 10, the skip

and the step-out appear after the motor has the load. So it is no actual meaning when the subdivision

amount exceeds 10. Presently, only three-phase sine current subidivision technology can ensure that

the motor output torque does not drop after subsidivision, and each step can be precisely positioned.

When the three-phase wind is connected with the sine current(three-phase current phase shift is

120°）,  the  current in  the air  gap  of  motor creates constant  rotary  maganetic  potential of one space

maximum  value,  the  space  maganetic  potential  power  and  direction  are  related  to  the  current  ‘s

sequence and power  of each phase,  the  current  of  drive  unit in the motor wind is bidirectional grade

step wave(the current wve forms the sine wave when the grade amount increases infinitely), and the

phase  difference  of  each  current  is  120°.  The  maganetic  rotor  tracks  the  rotor  space  maganetic

potential face to move  to  form the motor rotating, and when the  space maganetic  potential  positions

When some phase current changes one full period(other phase current also separately changes

one full period, only their step angle is different), the rotor of stepping motor rotates one pitch, and its

corresponding mechnical  angle  is  360°/Z2(Z2 is the teeth number of rotor). When the phase current

is divided into N step current value in one period, the rotor is located at the different positioning point

when  it  is  in  each  step  current,  so  the  step  angle  of  stepper  motor  is  :а=360°/(NZ2),  or  the  step

number per rev  of motor is S=N×Z2. W hen  each  sine period is composed of 20 current step  N, and

the teeth number Z2 of rotor is 50, the step angle of motor isа=360°/(NZ2)=360°/（20×50）=0.36°, the

needed pulse number per rev is S=N×Z2=20×50=1000.

CNC_Retrofit_Kit