A frequency converter is a control device that uses the switching action of power semiconductor devices to convert industrial frequency power into electrical energy of another frequency. With the rapid development of modern power electronics and microelectronics technologies, high-voltage, high-power variable frequency speed control devices have become increasingly sophisticated. Previously difficult-to-solve high-voltage problems have been effectively solved in recent years through device series connection or unit series connection. High-voltage, high-power variable frequency speed control devices are widely used in various fans, pumps, compressors, rolling mills, etc., in large-scale mining plants, petrochemical plants, municipal water supply, metallurgy, steel, and power energy industries.
In the future, high-voltage variable frequency speed control technology will be developed in the following eight aspects, which are mainly manifested in:
① High-voltage frequency converters will develop towards higher power, smaller size, and lighter weight.
② High-voltage frequency converters will develop in two directions: direct high voltage of devices and multiple superposition (device series and unit series).
③ New types of power semiconductor devices with higher voltage and greater current will be used in high-voltage frequency converters.
④ At present, IGBT, IGCT, and SGCT will still play the main roles, while SCR and GTO will be phased out of the frequency converter market.
⑤ The application of sensorless vector control, flux control and direct torque control technologies will become more mature.
⑥ Fully realize digitalization and automation: parameter self-setting technology; process self-optimization technology; fault self-diagnosis technology.
⑦ By using 32-bit MCU, DSP and ASIC devices, the frequency converter achieves high precision and multiple functions.
⑧ Related supporting industries are developing towards specialization and large-scale operation, and the social division of labor will become more obvious.
