The difference between high frequency equipment and power frequency machine
High-frequency equipment uses high-frequency switching technology to replace the UPS of power frequency transformers in rectifiers and inverters with high-frequency switching elements, commonly known as high-frequency machines. High-frequency machines are small in size and high in efficiency. Power frequency machine: UPS that uses power frequency transformer as rectifier and inverter components is commonly known as power frequency machine. , The high-frequency machine does not have an isolation transformer, and its output zero line has high-frequency current, mainly from the harmonic interference of the mains grid, the pulsating current of the UPS rectifier and the high-frequency inverter, and the harmonic interference of the load, etc. The interference voltage is not only Values are high and difficult to eliminate. However, the output zero-ground voltage of the power frequency machine is lower, and there is no high-frequency component, which is more important for the communication security of the computer network. The output of the high-frequency machine is not isolated by a transformer. If the inverter power device is short-circuited, the high DC voltage on the DC bus (DC BUS) is directly applied to the load, which is a safety hazard, but the power frequency machine does not have this problem. The power frequency machine has strong anti-load impact ability.
High-frequency equipment refers to the X-ray machine with the high-voltage generator operating frequency greater than 20kHz, and the power frequency machine refers to the X-ray machine with the high-voltage generator operating frequency less than 400Hz. The power frequency machine has a 100Hz sine ripple after the 50Hz power frequency power supply is raised and rectified. After filtering, there is still more than 10% of the ripple. The high frequency machine has a high working frequency, and the voltage after high voltage rectification is basically constant DC , the ripple can be less than 0.1%. Different high-voltage voltages correspond to electron beams of different energies, thereby generating X-rays of different wavelengths. The more single the X-ray spectrum is, the less scattering, and the clearer the imaging. The output line spectrum of the power frequency machine is complex, the amount of X-rays at the characteristic frequency at the same time is small, the stray scattered lines are many, and the imaging is blurred. The high-frequency machine has simple outgoing spectrum, less stray scattered lines, clear imaging, and reduces the total outgoing line quantity by more than 50% compared with the power frequency machine.