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Reference Number: AA-01947// Views: AA-01947// Created: 2020-09-15 22:33:07// Last Updated: 2020-09-16 16:19:14
HowTo
HYPERSIM: How to control the tap positions for the Saturable 2 Winding 3 Phase Transformer with Tap Changer


The tap positions of the Saturable 2 winding 3 phase transformer (XFMR) with tap changer block can be controlled from signals external to this XFMR block by following these steps:


  1. In Control tab of this XFMR block, please set the Control Type to " External (input pins)"

  2. The two pins U and D are used to change the tap position.
    The simulation starts at Tap number defined by 'Manual Tap position' in the Saturable 2W, 3phase with tap changer XFMR block.
    The mechanical delay for tap changing operation can be set directly in the block, by using the "operation time" option in the control tab of the block.



  3. The tap position can be changed by applying a pulse of a duration greater than the "temoporization time" defined in the control tab of the block to either the U or the D pin.
    If such a pulse is fed to pin U, the tap position will increase by 1 and if the pulse is fed to pin D, the tap position will decrease by 1

  4. To give the pulse input to either U or D pins, we can use programmable DO events, which is the Target Output, Digital 4 block present in the Targets Input and Output Library.



    1. Add the target output digital block to your model and right click on it to select the option 'Observables' Then choose the CMD01 control signal. 



    2. Now configure the times T1 and T2 inside the  target output digital block  (ensure that the status is "Enable" and the 1st DO is selected in the "DO Operated" column)

                 

    3. Set the time T1 for when the pulse starts and T2  for when the pulse stops. (T2-T1) should be greater than or equal to the temporization time we set earlier in the Control tab of the Saturable 2W, 3 Phase with tap changer XMFR block.

      Tap change operation on running the model is as shown below:



  5. We can also set multiple times, for example, (T1,T2) (T3,T4), (T5,T6) to create multiple pulses for changing the tap at preset times. The time values  (T1,T2) etc can be modified when the simulation is running.

                  


Other considerations:


A. When using a Pulsed Delay block to change tap positions

- The input that we provide to pulsed delay block will not directly become the actual tap position. Note that a pulse of duration greater than the temporization period is required to change the tap position.
In the pulsed delay block, we have to define the "Ton" to be more than the temporization time

- Whenever we change the input constant fed to the pulsed delay block, it helps in crating a pulse signal. 

- The first time we do so, the tap will change by + or - 1, depending on the pin U or D  to which the output of pulsed delay block is connected.

- If the input constant is greater than 0 when the simulation starts, the tap position will increment or decrement by 1 since a non zero input creates a pulse.

- Subsequently increasing the input constant value fed to the pulsed delay will again create pulses which will increment/decrement the tap position by 1 each time a change is made.

Consider this example, where the constant input to the pulsed delay block is 0 before the simulation starts.



In the Pulsed delay block, we set the Ton to 0.6s which is greater than the temporization time of 0.4s set in the XFMR block.



After the simulation starts, the input constant to the pulsed delay block is changed from 0 to 1 and we can then observe the tap change operation.

The tap position changed after (Td of pulsed delay)+(Operation time of XFMR block)






B. When feeding a constant value to U or D pins

If a constant greater than 0 is fed to either U or D pin, the tap position will keep changing until it reaches the maximum or minimum position as defined in the Control tab (based on the pin used: U or D)

For example, consider when a constant is connected to the U pin of the XMFR block and its initial value is 0. Now after the simulation starts, we change the constant value to 1.



We can then observe that the tap position goes up to the maximum position while accounting for the operation time delay of 2s set in the XFMR block.




A simple example model is attached for reference.

 


HVAC_500kV_6Bus.zip 99 Kb 99 Kb