Three technical features of high frequency heating equi […]
Three technical features of high frequency heating equipment:
1. The high-frequency heating device adopts the principle of magnetic field induced eddy current heating. The current is generated by the current through the coil. When the magnetic field lines pass through the metal material, the boiler body itself heats up at a high speed, and then the material is heated and can be reached in a short time. Satisfactory temperature.
2, the main advantages of high-frequency heating equipment is magnetic heating, energy saving, environmental protection, zero emissions, unattended, water and electricity separation, no scaling, no open flame, easy to operate, safe and reliable, durable, clean and environmentally friendly, easy to install, Beautiful appearance, wide application, no noise, odor, open circuit, there is no danger of explosion at all.
3. High-frequency heating equipment has multiple intelligent protections such as anti-overheating, no leakage, anti-water and anti-dry burning, anti-undervoltage, anti-overvoltage, anti-freezing, automatic high-temperature heat storage at night when electricity is low, no fumes, no heat radiation, etc. Many advantages. The use of backwater control to control the high-power radiator for heat dissipation can fully utilize the recovered heat source to improve thermal efficiency and adapt to various harsh environments.
Induction heating power supply is an indispensable part of high-frequency heating equipment. The worker of Zhengzhou Xingchuan Induction Technology Co., Ltd. said: The power-regulating method of induction heating power supply is usually divided into DC power adjustment and inverter power adjustment.
A DC power adjustment mode that adjusts the output power of an induction heating power supply by adjusting the output voltage of the DC/DC converter. There is also input controllable rectification to regulate power. DC power adjustment can adjust power in a wide range, and the linearity of power adjustment is better. However, a controllable circuit must be added to the front of the inverter bridge. Moreover, when it is necessary to add power factor correction, DC power adjustment is more difficult to achieve.
The other is the inverter power adjustment mode, and the inverter power adjustment can be divided into three categories:
1) Frequency Modulation (PFM)
The method of frequency modulation is to adjust the switching frequency of the inverter switch tube, thereby changing the output impedance to achieve the purpose of adjusting the output power. This type of power adjustment is more common, and the advantage is that the adjustment method is relatively simple, and it is easier to implement soft switching. However, the power regulation is not linear and the adjustment range is not large.
2) Pulse Density Modulation (PDM)
PDM is to control the power by controlling the pulse density to control the average output power. This control method is easier to implement, but the heating effect is not good because it is intermittent heating.
3) Pulse Width Modulation (PWM)
The PWM adjusts the output power by adjusting the on-time of one cycle of the inverter switch. This method is equivalent to the modulation method of the ordinary switching power supply, and the adjustment linearity is good, and the range is large, but it is not easy to implement soft switching.
Of course, the load of induction heating usually changes characteristics as the operating conditions change. This will require the power supply to monitor changes in the load and make adjustments, such as using frequency tracking.