MCE Wizard RMS current Rating & DC Bus under Voltage Error

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sohail
Level 3
Level 3
50 sign-ins 10 questions asked 10 replies posted

Hi@Krupashanka

                                        I am making project by using Eval-M1-101TF & Eval-M1-IM535 power board to Run air-condition inverter Compressor having BLDC DC motor.  I am Getting 2 Error in Mce designer  

1. RMS Current as per compressor Catalogue Gmcc 1.5 attached also.  Current Compressor input is 4.2A, RMS will be 4.2*.707 is 2.96. but MCE Wizard Accept value 1.5  or Below as RMS current.

2. Parameter give Error same in DC Bus under Voltage level I try to Enter 260V but it give Error only

 

compile Error.png

Accept 6V or Less Value.

 

Compressor Manufacturer Catalogue is also Attach. Pl Guide what I am doing Wring.

 

Thanks 

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1 Solution
psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello @sohail ,

    The value of input voltage and currents fundamental frequency is determined by the reference speed, and it comes from the equation Ws = (120*f/P) (Ws = synchronous speed, P = no of poles, f = input frequency). 

Please create a new thread in case of any query deviating from the title and content of the thread so that each thread serves as a discussion and resolution page for a specific topic mentioned as its title. 

Best Regards,
Sai

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6 Replies
Mahimc2020
Level 2
Level 2
10 questions asked 10 replies posted 10 sign-ins

Hi,
First, the range of input voltage changes in the design and related protections should be known.
Then adjust and tune the parameters.

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psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello @sohail , 

  1. The values of DC Bus voltage levels for protection are not appropriate. Along with their definitions in the MCE Wizard software, it must also be duly noted that max dc bus voltage > DC Bus Critical Overvoltage > DC Bus Overvoltage > DC Bus Nominal Voltage > DC Bus Under voltage.  This relationship must be maintained. Kindly reverify and enter the correct values.
    psb_0-1660902100744.png
  2. The current sensing in general for the eval boards is shown below. The final value of the sensed current which goes to the ADC must not exceed the full scale value which is Vdd (3.3 or 5V). This is verified by calculating the value of scaled current using the parameters in Questions 83, 84, 85 of MCE Wizard. Reverify the values entered from the current sense circuits of the EVAL-M1-101TF and EVAL-M1-IM535 boards by recalculating the gains and offsets of the circuits. Feel free to revert in case any discrepancies are found with respect to the calculations.

    psb_1-1660902969419.png

Best Regards,
Sai
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sohail
Level 3
Level 3
50 sign-ins 10 questions asked 10 replies posted

Hi,

          Thanks for Reply, one more confusion in Compressor allowable frequency is 1600-7200min-1 which HZ is 26.66 to  120Hz.

freq.png 

But In MCE Wizard  frequency Range is 2KHz to 80KHz  how can we adjust this parameter.

 

Thanks 

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psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello @sohail ,

 The range 2kHz - 80kHz is the range of allowed PWM switching frequencies of the inverter, not the  range of input voltage fundamental frequencies to the motor. The values 1600/min - 7200/min correspond to the range of input voltage fundamental frequencies to the motor.

The range of allowable frequencies mentioned by you is acknowledged by the software from the minimum speed, maximum speed, number of poles values entered in the MCE Wizard. 

Best Regards,
Sai
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sohail
Level 3
Level 3
50 sign-ins 10 questions asked 10 replies posted

hello Sai,

                      I am just a Beginner in this field can you explain little bit more input voltage fundamental frequencies to the Motor. My understanding is U,V,W phase of motor  when we change frequency will change the RPM  of Motor. e.g. My Motor RPM is Min 500RPM Max 4020RPM.

when I command 4000RPM what will be frequency?

What is Role of allowable frequencies ?

Thanks

 

Kind Regards

 

 

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psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello @sohail ,

    The value of input voltage and currents fundamental frequency is determined by the reference speed, and it comes from the equation Ws = (120*f/P) (Ws = synchronous speed, P = no of poles, f = input frequency). 

Please create a new thread in case of any query deviating from the title and content of the thread so that each thread serves as a discussion and resolution page for a specific topic mentioned as its title. 

Best Regards,
Sai
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