2020-10-13
Compared with ordinary inverters and converters, wind power converters have the following characteristics:
High power density, high DC side voltage;
(2) The use of harsh environment, domestic wind farms are generally concentrated in the northeast, North China, northwest and coastal zone. Northeast China and North China are cold and have large temperature difference; The northwest wind sand, dust; The air humidity in coastal areas is high and corrosive.
(3) Long continuous working time, in the season of good wind, the converter is often in full load operation for several months;
Inverter may appear gust, typhoon and other bad weather. These characteristics put forward higher requirements for the main circuit design of wind power converters, especially for the bus design of power module units. If the bus design is not reasonable, and the special requirements of wind power converter are not taken into account, the following problems may occur: (1) The bus overheating, which is due to the wind power converter dc side of the current is large, the voltage is not stable, coupled with the wind season time in full power operation state, easy to lead to the bus overheating; (2) The bus inductance is too large, produce too high peak voltage, resulting in a small safety margin, when encountered gust, typhoon and other bad weather, the converter DC side voltage will be sharply increased for a short time, the power device is likely to appear overvoltage, serious may lead to the power device blow up, causing heavy losses; (3) for manufacturing and assembly errors, busbar and capacitor, such as gravity itself lead to power component force is inevitable, if not in the bus design phase will these factors into consideration, is likely to lead to power devices under too much stress, inverter power is larger, bus is compared commonly big, capacitance number, and increased the risk; (4) Bus protection is not enough, with the invasion of dust, moisture, resulting in insulation failure.