Linearization of gain

The linearization is done by multiplying the proportional gain by a factor G(α) depending on α as shown in the figure below:

Correction Factor for Proportional Gain of PI Regulators

This linearization is necessary to have the regulation respond with the same speed at different values of α.

On the inverter side, the linearization is applied on the β=180°-α and G(β) looks the same as G(α).

The linearization of the gain does not apply to the integral part of the PI regulator because this part of the response is slower.

The regulator output goes through two limiting functions before being sent to the firing unit.

These functions are:

• α limiter
• Δα limiter