Origin	China
Model Number	Atec
Brand Name	Atec
Output Power	>500W

1.     AtecD high frequency and AtecF middle frequency series products

AtecD high frequency and AtecF middle frequency series inductive heat powers are the new type(DSP+IGBT structure) and high efficiency energy conservation products. Base on IGBT inverter, all devices adapt DSP digital precision control to ensure all IGBT’s operations in ZCS condition. The full air cooling structure can decrease the system loss and avoid any fault caused by water system. Perfect limit and protection functions ensure device’s continuous and safe operation in all working conditions. Non-polarity capacitors are designed for long service duration and safe operation. And the devices have DC side chopping or filtering circuit that increases the system power factor. Therefore, the devices have great advantages of high-reliability and high efficiency.

2.     Inductive heat power

Inductive heat powers are widely used in the fields of metal heat treatment, full heating, quenching, annealing, melting, welding, shrink fitting, degassing and heating of electrical vacuum elements, semiconductor material refining, plastic sealing, roasting and purifying, and etc. The work theory of devices is that in a high frequency magnetic field a conductor can be affected by its inductive current and gives out heat itself. Comparing with gas burning or electrifying, inductive heating type has many strong points: energy conservation, non-touch, high speed, efficient, simple-process, easy automatization, and etc.

3.     Common probles in current similar products

Although IGBT has replaced thyristor and SCR during the development of inductive heat powers, there are still common problems in devices developed and manufactured by most supplier, including:

Low efficiency, large consumption of electric energy and cooling water

Easy damage of IGBT

Easy damage of output transformer

More fault in cooling water system

Easy misacting of device protection, low reliability

Low power factor, high harmonic wave pollution

The above problems are mainly caused by the design defects, now we can list out some:

IGBT operate out of the ZCS condition because the control circuit can not work well under different operation conditions. This cause more switch loss and IGBT easy damage by over-temperature.

Wide usage of water cooling in output transformer easily lead to the transformer burning caused by scale jam in the copper pipes. Further more, large eddy current loss of water cooling type transformer under high frequency working condition causes low efficiency and more water consumption.

Soft ON and forced OFF(or forced OFF with buffer) circuit designed in some devices cause more IGBT loss and easy damage of IGBT in overload condition.

There are more leak and jam faults in IGBT cooler, resonance capacitor, transformer and reactor with water cooling type.

Devices are easily damage by bad limits and protections in conditions including over voltage, under voltage, overload, inductor short circuit, over temperature, water cut off and etc.

Protection misacting and bad EMI resisting ability in the control circuit cause low device reliability.

Large capacity and electric capacitor type filter, none filtering inductor or DC side IGBT chop circuit designed directly after converter part lead to low power factor and high harmonic wave in input current. More heat, more in series and short life are also the defects of electric capacitor.

4.     Main measurements to solve the above problems in Atec series inductive heat power design

1). Precise and reliable ZCS-IGBT inverter in DSP control

2). Full air cooling structure, including IGBT inverter and output transformer

3). Automatic and accurate tracking of resonance frequency and phase

4). Perfect limit and protection functions

5). Dual channel control technology of middle frequency and high frequency inductive heat