DC motor winding parameters

Jane Medium ： It is more complicated to analyze the mutual inductance between these coils . Let's leave the discussion about them for the future .

key word ： mutual inductance , rotor

 

§01 straight Current motor rotor

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   hand There is a rotor of DC motor on the side ,  You can see that it has five magnetic poles ,  There are also five rotor coils ,  Each coil is wound on two adjacent magnetic poles .  In this way, there should be mutual inductance between each coil .  Now let's measure the parameters of these coils .

  
   Lead out five leads from the motor rotor converter ,  This makes it easy to use SmartTweezer To test .  There are five windings in total ,  Next, measure them respectively   Inductance and resistance between two .

  
   Here is the measurement result .  From the first node ,  Measure the inductance and resistance with the other four nodes ,  It can be seen that these results meet the form of ring connection composed of five inductors .

  
   In order to further confirm the parameters of two windings ,  The inductance and resistance between the five nodes are given below , SmartTweezer The measurement frequency is 1kHz.  According to the measurement results, we can see the resistance and inductance   The values of are mainly divided into two categories .  since childhood , A large .

  
   These two types can actually be seen from the perspective of equivalent series parallel .  One comes from the parallel connection of a single inductor and four inductors ;  The other kind comes from the parallel connection of two inductors and three inductors .  They should differ in value 1.5 times .  Actual measurement results ,  It can be seen that the inductance difference is more than twice ;  The resistance difference is less than twice . But it's bigger than 1.5 times .

  
   Because the resistance of the coil is affected by the measurement frequency , Next SmartTweezer The measurement frequency of is changed to 100 Hz.  Re measure the coil resistance in both configurations ,  You can see that the ratio between them is close 1.5 The Times .  From this, we can know that the above analysis model is correct .  For the inductance measurement results ,  The ratio of its two cases is greater than 1.5.  The reason for this situation can only be explained by one phenomenon ,  That is, there is mutual inductance between coils .
  
 

※ total   junction ※

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   have Volume analysis of mutual inductance between these coils is more complex . Let's leave the discussion about them for the future .

  

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