Improved Expression for Estimation of Leakage Inductance in E Core Transformer Using Energy Method

Table 1

EE core transformer with interwinding insulation.

Sample no.	1	2
Core type	EE42/21/15	EE65/38/13
𝐹	14.45 mm	22.65 mm
𝐶	15.20 mm	13.45 mm
𝐵	21.10 mm	32.59 mm
𝐸	12.05 mm	19.77 mm
ℎ1 thickness of primary	3.20 mm	3.81 mm
ℎ2 thickness of secondary	1.90 mm	1.55 mm
𝑡 thickness of insulation	1.27 mm	2.00 mm
𝑁1	34	48
𝑁2	17	24
Photograph
Leakage inductance 𝐿leak,earlier from (5)	11.91 μH	22.52 μH
Leakage inductance 𝐿leak from (3)	15.32 μH	28.21 μH
Leakage inductance 𝐿exp at 10 kHz measured	14.13 μH	26.76 μH
% deviation of 𝐿exp from calculated 𝐿leak,earlier	15.71%	15.84%
% deviation of 𝐿exp from calculated 𝐿leak	8.38%	5.12%