工频炉感应变压器
Mains Frequency Induction Furnace Transformer
工频炉原理：
I. The Theory of Mains Frequency Induction Furnace
使用50Hz的工频电源，利用电磁感应原理熔化金属的电炉称为工频感应炉。大工频感应炉中，根据炉子的结构有无铁心穿过被熔化金属的熔池这一显著的特点，分为无芯工频感应熔化炉及有芯工频感应熔化炉。
The electric furnace that uses 50Hz mains frequency power supply and utilizes electromagnetic induction theory to melt metals can be called Mains Frequency Induction Furnace. We divide the large Mains Frequency Induction Furnace into mains frequency coreless induction furnace and mains frequency induction furnace according to the prominent characteristic that if the furnace's structure has the core to pass through molten metal's pool.
工频感应炉变压器的负载特性：
II. The Load Characteristic of Mains Frequency Induction Furnace Transformer
工频感应炉变压器是感应器的供电电源，其负载平稳，一般没有过载要求。为了提高效率常要求低的阻抗电压，硬的外特性。其结构、设计特点与同容量电力变压器相类似，只是调压方式、调压范围不同。
为了获得高效率和较高的功率因数，感应器几乎都设计成单相的。大容量的单相负载将会破坏三相对称，为此工频感应炉变压器一般做成三相的，3个输出端子接到功率平衡器上，这种功率平衡器通常是由电抗器、电容器、感应器各做一臂D接而成，从而使单相负载变为三相对称负载。
Mains Frequency Induction Furnace Transformer is the inductor's electric power supply. It has smooth load and generally has no overload requirements. In order to improve the efficiency, Mains Frequency Induction Furnace Transformer always need low impedance voltage and hard external characteristics. Its structure, design characteristics is similar with that of the same capacity electric transformer. Only the voltage regulation and voltage regulation scope has some difference.
In order to gain high efficiency and relatively high power factor, the inductors are almost designed to be single phase. The large capacity's single phase load will destroy three phase symmetry, so Mains Frequency Induction Furnace Transformer is generally made into three phase. Three output terminals are connected to power balancer. This power balancer is usually connected by reactor, electric capacitor and inductor, so the single phase load can be changed into three phase balanced load.
技术数据：
III. The Technical Data of Mains Frequency Induction Furnace Transformer
注：1.额定容量为1250KVA 及以下时，前三级输出二次电压时为恒容量输出，其它各级为恒电流输出，
2.额定容量为2000KVA及以前时，均为恒电流输出。
Notes: 1. When Rated Capacity is 1250KVA or below, the secondary voltage that the former three level output is the constant capacity output, the other levels are constant current output.
2. When the rated capacity is 2000KVA and before, it is constant current output.
