The inverter power supply circuit is easy to produce a lot of heat under the condition of high voltage, high current and high frequency, in addition to taking appropriate cooling measures (such as control of room temperature, adding heat sink, itd.) , but also must have over-temperature protection circuit.
The over-temperature protection devices are mainly thermistors, temperature switches and temperature fuses. NTC thermistors are often used in the design of power supply for over-temperature protection, because of its ability to suppress surge current and ordinary resistance, but on the resistance of power consumption can be reduced by dozens to hundreds of times.
The main methods to reduce the external interference of inverter power supply are as follows:
In order to reduce the external interference caused by the inverter power, there are three methods: to make the inverter power itself to send out as little interference signal as possible, to improve the anti-interference ability of the object being interfered with, and to use isolation measures, the interference signal transmitted by the inverter to the interfered object is weakened.
Because the inverter power supply in the inverter uses high-speed semiconductor switches to generate a certain width and SPWM control signal, the pulse signal with sharp change edge will produce strong electromagnetic interference, especially the output current, they will transmit their energy in a variety of ways, causing interference with other equipment and seriously exceeding the limits of Electromagnetic compatibility standards.
Zato, the manufacturers of frequency converters for users to make some special equipment to reduce the electromagnetic interference generated by the inverter, in order to meet the quality inspection standards and ensure the operation of the equipment.