Damper for power train
A damper for a power train, comprising a piezoelectric transformer and a load element connected across the output of the piezoelectric transformer.
1. A power train for a high impedance load, comprising:
an input EMC filter for connection to a power supply;
a pulse width modulation (PWM) converter connected to an output of the input EMC filter and configured to provide a PWM output to drive the high impedance load; and
a damper connected between an output of the PWM converter and terminals of the high impedance load, wherein the damper comprises:
a piezoelectric transformer; and
a load element connected across an output of the piezoelectric transformer.
2. A power train according to claim 1 wherein the damper further includes:
a piezoelectric transformer for each of one or more phase lines of the power train, each piezoelectric transformer having a respective load element connected across its output.
3. A power train according to claim 2 , for a three-phase power train, wherein the damper has three piezoelectric transformers, one associated with each phase line, and three load elements, one for each transformer.
4. A power train according to claim 2 , for a two-phase power train, wherein the damper has two piezoelectric transformers, one associated with each phase line, and two load elements, one for each transformer.
5. A power train according to claim 2 , for a single-phase power train, having a single piezoelectric transformer, and a single load element.
6. A power train according to claim 1 , for a three-phase power train, wherein the damper comprises three piezoelectric transformers, one associated with each phase line, and a single load common to all piezoelectric transformers.
7. A power train according to claim 1 , wherein the load element is a resistor.
8. A power train according to claim 1 , wherein the load element is a power converter configured to regenerate switching energy.
9. The power train of claim 1 , further comprising the power supply.
10. The power train of claim 1 , further comprising the high impedance load, wherein the high impedance load is connected to an output of the damper.
11. The power train of claim 10 , wherein the high impedance load is a motor.