I want to model a three-phase four-winding transformer YNyn0yn0+d5 with two low voltage windings (yn0yn0) and a compensation winding (d5) using Simscape Electrical. The transformer is a 5 limbs transformer. Since the transformer has four windings, I had to connect three single-phase transformers (model in Simulink: multi-winding transformer) in star and delta configurations respectively.
From the transformer test report, I have calculated the parameters of the T-equivalent circuit diagram. Here, I had to calculate the longitudinal impedances of the compensation winding using the measurement of zero sequence component, because it was not measured in the short-circuit test.
The simulated values of the open-circuit and short-circuit tests in the positive sequence component agree very well with the values from the transformer test report.
My problem:
In the measurement of zero sequence component, I only get matching values for the measurement that I used for the calculation of the compensation winding (HV supply, compensation winding short-circuited). In the further zero sequence measurements (additionally, one LV winding short-circuited), the short-circuit voltage is five times too high.
Questions:
Is there possibly a coupling in the transformer only in the zero sequence component?
Or does anyone already know this problem?
Or does anyone have an idea of how I can model the transformer using other Simulink models?I want to model a three-phase four-winding transformer YNyn0yn0+d5 with two low voltage windings (yn0yn0) and a compensation winding (d5) using Simscape Electrical. The transformer is a 5 limbs transformer. Since the transformer has four windings, I had to connect three single-phase transformers (model in Simulink: multi-winding transformer) in star and delta configurations respectively.
From the transformer test report, I have calculated the parameters of the T-equivalent circuit diagram. Here, I had to calculate the longitudinal impedances of the compensation winding using the measurement of zero sequence component, because it was not measured in the short-circuit test.
The simulated values of the open-circuit and short-circuit tests in the positive sequence component agree very well with the values from the transformer test report.
My problem:
In the measurement of zero sequence component, I only get matching values for the measurement that I used for the calculation of the compensation winding (HV supply, compensation winding short-circuited). In the further zero sequence measurements (additionally, one LV winding short-circuited), the short-circuit voltage is five times too high.
Questions:
Is there possibly a coupling in the transformer only in the zero sequence component?
Or does anyone already know this problem?
Or does anyone have an idea of how I can model the transformer using other Simulink models? I want to model a three-phase four-winding transformer YNyn0yn0+d5 with two low voltage windings (yn0yn0) and a compensation winding (d5) using Simscape Electrical. The transformer is a 5 limbs transformer. Since the transformer has four windings, I had to connect three single-phase transformers (model in Simulink: multi-winding transformer) in star and delta configurations respectively.
From the transformer test report, I have calculated the parameters of the T-equivalent circuit diagram. Here, I had to calculate the longitudinal impedances of the compensation winding using the measurement of zero sequence component, because it was not measured in the short-circuit test.
The simulated values of the open-circuit and short-circuit tests in the positive sequence component agree very well with the values from the transformer test report.
My problem:
In the measurement of zero sequence component, I only get matching values for the measurement that I used for the calculation of the compensation winding (HV supply, compensation winding short-circuited). In the further zero sequence measurements (additionally, one LV winding short-circuited), the short-circuit voltage is five times too high.
Questions:
Is there possibly a coupling in the transformer only in the zero sequence component?
Or does anyone already know this problem?
Or does anyone have an idea of how I can model the transformer using other Simulink models? multi-winding transformer, compensation winding, simscape electrical, transformer, transformer coupling, zero sequence MATLAB Answers — New Questions

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