Design of High Frequency and High Power Supply for Ohmic Heating Based on ARM

When power frequency alternating voltage was used to heat soybean milk, electrode surface was corroded. Aiming at this problem, a high frequency and high power supply based on ARM microprocessor was designed. This power supply consists of ARM microprocessor, human-computer interaction interface, direct current power module, inverter device and data acquisition device. And it could change direct voltage into intermittent square-wave alternating current, in which voltage amplitude was continuous adjustable from 0 V to 400 V, frequency was adjustable from 50 Hz to 30 kHz and duty ratio was adjustable from 10% to 90%. Under the control of ARM microprocessor, data acquisition device would collect root mean square of voltage and current and temperature of soybean milk. Experiments showed that this power supply could heat soybean milk stably and reduce electrode corrosion effectively by adjusting voltage frequency.