Sneak Circuits of Power Electronic Converters

Chapter 1Sneak Circuit and Power Electronic Systems

1.1 Reliability of Power Electronic Systems

Power electronics has already found an important place in modern technology, because it helps to meet the demands of energy, particularly in electrical form and efficient use of electricity. Application of power electronics is expanding exponentially in many areas, from computer power supply to industrial motor control, transportation, energy storage, electric power transmission, and distribution. Nowadays, over 70% of electrical loads are supplied through power electronic systems in the United States and Europe, and almost all electrical and electro-mechanical equipment contains power electronic circuits and/or systems. In the next 5 years, renewable energy systems (wind and solar, etc.) will show a sharp increase throughout the world, the needs of power electronic systems grow rapidly as a result. Therefore, the reliability of these systems should be a concern in its fundamental place in energy conversion and management.

A basic concept in reliability engineering is that part failure may cause system failure, and preventing part failure is effective in preventing system failure. Likewise, in power electronic systems, it is found that many system failures do result from component failures. The main factor affecting reliability at part level is the electrical and thermal stress of a component, such as device voltage, current, temperature, or temperature rise due to power dissipation, ...