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Pulsed electric field (PEF) helps to keep food pasteurized and fresh with the supply of intermittent energy supply. In the following article, we are going to discuss the effects of Step Up transformer and how it works perfectly for Pulsed Electric Fields.

What is Pulsed Electric Field?

Pulsed Electric Field (PEF) is a system that gives a high voltage of electrical energy in a short time (Pulses) for sterilization of food. PEF is a more beneficial and advance way of keeping the food fresh without the loss of taste, odor, and color. With its high voltage supply, it causes a deliberate disintegration of microbes and makes the food safe for consumption.

It’s a successful non-thermal method for pasteurization of semi-fluid and liquid food and it's far more beneficial than various thermal processes though these methods are very effective in eradicating bacteria it reduces the nutritional value, color, and taste of the food. Hence Pulsed Electric Field was introduced as it manages to heat food in a few seconds without the loss of the nutrition value. 

Pulsed Electric Field causes intent electric energy that causes the breakdown of microbes like bacteria in a very short time but the temperature rise is significantly high. PEF effective working depends on the electric field in the treatment chamber, total timing, amount of energy and pulse width. It needs high voltage and various methods have been used for generating optimum intensity it needs.

• Vacuum Tubes
• Solid State Devices
• Pulse Forming Network
• Use of the Marx Generator

These all were used but since this task is hard to attain several devices failed due to overvoltage or voltage drop and many other issues. So Step Up transformers were used for this process as people faced various problems with switching on high voltage as it required complicated driving circuits. In case you are not aware of Step Up transformers, we’ll explain it.

Step-up transformers increase the voltage from the primary system to the secondary one. Instead of switching to the high voltage you can work with low voltage and then amplify the voltage level with the step transformer. The high voltage generator switches voltages at 1000 VDC and increases the current 12 times to produce 12kV voltage. There are few IGBTs used in parallel to direct high current on the primary winding.

The productiveness of PEF depends on the generated pulse shape as ideally the pulse should be squared shape which contributes short rise time and less voltage drop. An effective PEF needs the electric fields in the range of 20-50 kV/cm and energy should 50-1000kJ/kg and the pulse width should be between 1-10 µs.

It is the main work that the energy from the high voltage source should be efficiently transferred to the food in the chamber. Those output parameters are affected by various factors, such as magnetizing inductance, parasitic components, and the amount of energy available in capacitor banks.