**6. Charge accumulation behavior in the PAI bulk under simulated high voltage PWM application and high temperature (80 °C)**

Recently, the needs of fast measurement are demanded, day by day [5–7]. It is because that many high-speed voltage applications are widely used all over the world. The motor system is one of the examples. The PWM signal is driven by over several tens of kHz. Therefore, under the above situation, the space charge measurement is also required under such high frequency rectangular voltage. Therefore, we can solve such requirement by cooperatively controlling the pulse voltage and the application high voltage.

In this chapter, measurement results in PAI using cooperative operation system between the pulse voltage and the application voltage are introduced.
