PID Controller for Piezoelectric Actuators

[rockbassist90]

I understand a brushless motor (DC) is analogous to an inductive load
and a piezo is that to a capacitive load...

This servo amplifier http://www.copleycontrols.com/Motion/pdf/Accelnet_MACRO.pdf

I've used for various applications with Brushless motors and it uses a three phase PWM inverter that converts the bus voltage into a sinusoidal waveform to drive the motor coils.

Since the piezo is capacitive load...this would obviously short circuit the drive...how should I tackle this problem with a 4 phase piezo motor?

Scratching my head on this one.