Italy the switching frequency of the AC-DC switching power supply module?(5)

Internationally, the inverter power supply series products below 400kVA have come out. In the early 1980s, Toshiba Corporation of Japan was the first to apply AC variable frequency speed regulation technology to air conditioners. By 1997, its share had reached more than 70% of Japan's household air conditioners. Inverter air conditioners have the advantages of comfort and energy saving. In the early 1990s, domestic research on inverter air conditioners began. In 1996, the production line was introduced to produce inverter air conditioners, which gradually formed a hot spot for inverter air conditioner development and production. A climax is expected around 2000. In addition to the variable frequency power supply, the inverter air conditioner also requires a compressor motor suitable for variable frequency speed regulation. Optimizing the control strategy and selecting functional components are the further development direction of the inverter power supply for air conditioners.

At present, the power carrier is mainly used for intelligent carrier in the home, remote meter reading system, and remote street lamp control system. The use range of the carrier frequency of power lines in my country is 9KHz ~ 500KHz, and the carrier bandwidth is 4KHz. The development of power carrier is very limited due to the change of power line impedance and the interference of power line noise. In order to increase the communication distance of the power carrier, we must move away from the power switching frequency of the circuit carrier unit. The carrier frequencies currently used in China are 115KHz and 132KHz. In this case, the switching frequency is around 60KHz for the LED advertising screen power supply.