Release date : 2019-03-06 15:26:13
Friends who are constantly in contact with three-phase dry-type transformers should find that the three-phase dry-type transformer is overheating. I believe many of my friends would like to know the factors that cause the three-phase dry-type transformer to overheat. Here, Shanghai Yupeng Company will introduce the three-phase dry-type transformer overheating factor for everyone. I hope that my friends can understand the problem and understand the cause in the future, so as to solve the problem quickly and avoid the three-phase dry-type transformer. Bad consequences caused by overheating.
? ? Leading to three-phase dry-type transformer overheating factors:
? ? 1. △B is selected too high, core heat (no load check if the core is hot);
? ? 2. △B is not selected high, the core itself has high frequency loss, and the core is hot (the no-load check is whether the core is hot);
? ? 3. The line current density is too large, the winding heat is hot. If the no-load core is not hot, it should be that the winding current density is too large. Of course, the high-frequency harmonics generated by the distribution parameters are excluded to cause the core to heat up;
? ? 4. Winding current density and core △B selection are not suitable, both the winding and the core are hot.
? ? 5. In the boost type transformer (output high voltage), the distribution parameters are large, and high frequency oscillation is generated to make both the core and the winding heat.
? ? 6. Design transformer power density is large but heat dissipation measures should not be increased when the transformer temperature rises. For example, the planar transformer should have good heat dissipation measures. The current density is selected according to power and volume: small power relative surface area, large heat conduction path, short current density can be selected larger The power is large, the heat conduction path is long, and the selected circuit density is small. After the high frequency, generally 200 kHz or more should pay attention to the convergence effect to select the appropriate wire diameter, and the current can be used to join the strand. The temperature rise empirical formula △ T = [total transformer loss mW/transformer surface area (CM^2)]^0.833 The surface area volume ratio of the planar transformer is smaller than the conventional iron loss/surface area value, so a higher ΔB can be selected.
