小功率工频电源变压器(国外英文资料).docVIP

小功率工频电源变压器(国外英文资料) Design of small power frequency power transformer according to voltage regulation rate -------------------------------------------------------------------------------- Http:// 2004, 04, 29, 11:35 Design of small power frequency power transformer according to voltage regulation rate Design, commercial, frequency, mini, power, transformers, on, voltage, rate, regulae Small power frequency power transformer, small size, thin coil, good heat dissipation conditions. When calculating this kind of transformer, the higher current density can be adopted, but the temperature rise will not exceed the specified value. Therefore, in order to reduce the cost of transformer, increase the output power of transformer and reduce the volume of transformer, the low power frequency power supply transformer under the output power of 60W is usually designed according to the voltage regulation rate. According to the definition of IEC 1007, the voltage regulation rate is defined as: Formula 3 - U - voltage regulation (%); U20 - transformer no-load output voltage (V); U2 - transformer load output voltage (V). Voltage regulation rate is generally not more than 30%. Excessive voltage regulation will cause the transformer to rise above the specified temperature and increase the output voltage, which will affect the load characteristics. Especially in the case of large load change or great change of working environment temperature. Table 1 provides the regulation of voltage regulation for small power frequency power transformers in Japanese standard JIS C6436-1995 for reference. Relationship between 1 voltage regulation rate and power capacity of transformer The relation between the transformer input power P1 and the voltage regulation Delta U is shown in the formula (3) Type P1 - transformer input power (W); F - power frequency (Hz); B - magnetic induction intensity (T); Km - iron core window utilization factor; SC - effective cross sectional area of iron core (cm2); SM - cor