What is ratio error of current transformer?
The ratio error of a current transformer is due to a change in the actual current ratio from the turn ratio. We know that for a current transformer the current ratio must be equal to the turn ratio i.e., I 1/I 2 = N 2/N 1.
What are the errors in current transformer?
Cause of Error in Current Transformer One part of the primary current is consumed for core excitation and remaining is actually transformers with turns ratio of CT so there is error in current transformer means there are both ratio error in current transformer as well as a phase angle error in current transformer.
What is composite error and ratio error in current transformer?
Accuracy of a current transformer is measured by the composite error. This is defined as the difference between the ideal secondary RMS current and that of the actual secondary current. The ratio of the accuracy limit current to the rated current is the ‘accuracy limit factor’.
What is phase angle error transformer?
Current transformers introduce a phase angle error between the current being measured and the voltage signal they generate. Most CTs have a leading phase angle error, where the voltage signal from the CT leads the actual current waveform by a small amount, typically 0.5° to 2.0° (larger for some models).
What is CT error ratio?
Explanation: Ratio error of a C.T. is defined as the ratio of the magnitude of the difference between the nominal and actual ratio with respect to the actual ratio.
How do you calculate current transformer error?
IP = NS / NP x (IE + IS). IP = 40 x (. 013 + 3.75) = 150.52 A7. To calculate the percentage ratio error,divide the exciting current by the secondary current times 100.
What is ratio error?
How do you calculate ratio error in CT?
To calculate the percentage ratio error,divide the exciting current by the secondary current times 100.
How do you calculate CT ratio?
When analog ammeters are installed, we can easily determine the CT ratio by observing the meter full scale value and then divide that value by 5. Figure 3. Ammeter with a full scale of 150 amps. The meter in Figure 3 has a full scale of 150 amps.