PWM-Converter for Travelling Wave Type Ultrasonic Motors.

For feeding piezoelectric ultrasonic motors different kinds of resonant converter concepts are well proven, but a common problem are their bulky and expensive resonant inductors. Therefore, power converters which do not require heavy inductors are of great interest. In this contrbution power converters with non-resonant output filters are investigated fpr reducing weight and volume ofe the magnetic components. The design of such a power converter for a travelling wave type ultrasonic type motor is presented. Implementation highlights like the design of the filters and the concept of an universal digital modulator are outlined and measured results are presented. Finally the concept is compared to resonant converters under consideration of weight, volume and efficiency

PWM-Converter for Travelling Wave Type Ultrasonic Motors.

For feeding piezoelectric ultrasonic motors different kinds of resonant converter concepts are well proven, but a common problem are their bulky and expensive resonant inductors. Therefore, power converters which do not require heavy inductors are of great interest. In this contrbution power converters with non-resonant output filters are investigated fpr reducing weight and volume ofe the magnetic components. The design of such a power converter for a travelling wave type ultrasonic type motor is presented. Implementation highlights like the design of the filters and the concept of an universal digital modulator are outlined and measured results are presented. Finally the concept is compared to resonant converters under consideration of weight, volume and efficiency

Development of Power Converter for High Power Piezoelectric Motors.

Several types of piezoelectric motors are known to deliver few watts of mechanical output power.This paper deals with the design and development of a LLCC-resonant converter for a novel type ofhigh power piezoelectric motor of up to 4kW mechanical power being used in avionics. The devel-opment of a laboratory power supply became necessary, since suitable power supplies for testingthe novel piezoelectric motor during its breadboard stage are not available on the market. The gen-eral function of the LLCC-resonant converter which also provides a DC-offset voltage for avoidingdepolarisation problems is described, implementation highlights are outlined and the weight distri-bution is discussed with respect to future development of power converters for avionics

Improved setpoint adjustment for ultrasonic motors

Speed control strategies for piezoelectric drives have been presented by several authors. Beside various control strategies based on adaptive structures like MIAS, MRAS, neural nets or fuzzy control, a completely model based control system using an inner bending wave control and an outer speed control including a torque calculator for linearization has been presented. The paper deals with investigations and improvements of this torque calculator. The setpoint adjustment is focused to utilize the degrees of freedom for the bending wave values, which represents an additional potential for optimization of the performance of the drive system. Theoretical and experimental results confirm the advances

Resonant Power Converter for Ultrasonic Piezoelectric Converter.

Ultrasonic piezoelectric converters (UPC) require adequate power supplies providing high frequency output voltage of several hundred volts and a total output power up to several kilowatts. Several concepts are conceivable but the potential of optimisation adopting a certain concept depends on the electrical terminal behaviour of the UPC. In this contribution the operating behaviour ofUPC is discussed with respect to their transfer function, the necessary excitation and their terminal behaviour. The latter definies the demands for the power supply, while considering different parameter combinations for bandwidth, quality and piezoelectric capacitance. The main part of this contribution is concerned with the development and realisation of a laboratory power supply for UPC, which is of resonant type

Model-based control for ultrasonic motors

A complete model-based control for traveling-wave-type ultrasonic motors is presented. The control scheme consists of inner control loops with respect to the oscillation systems, offering all meaningful degrees of freedom for adjusting the traveling bending wave, and outer control loops for torque and speed. After a brief review on modeling the actuator and presentation of a parameter identification method, the control scheme is developed and verified by measurements on a prototype drive system, several measures for the compensation of nonlinearities and temperature effects are developed, and achieved improvements are discussed with respect to the special properties of this novel actuator. Finally, the developed drive is applied to an "active control stick

Development of Power Converter for High Power Piezoelectric Motors.

Several types of piezoelectric motors are known to deliver few watts of mechanical output power.This paper deals with the design and development of a LLCC-resonant converter for a novel type ofhigh power piezoelectric motor of up to 4kW mechanical power being used in avionics. The devel-opment of a laboratory power supply became necessary, since suitable power supplies for testingthe novel piezoelectric motor during its breadboard stage are not available on the market. The gen-eral function of the LLCC-resonant converter which also provides a DC-offset voltage for avoidingdepolarisation problems is described, implementation highlights are outlined and the weight distri-bution is discussed with respect to future development of power converters for avionics

Model-based control for ultrasonic motors

A complete model-based control for traveling-wave-type ultrasonic motors is presented. The control scheme consists of inner control loops with respect to the oscillation systems, offering all meaningful degrees of freedom for adjusting the traveling bending wave, and outer control loops for torque and speed. After a brief review on modeling the actuator and presentation of a parameter identification method, the control scheme is developed and verified by measurements on a prototype drive system, several measures for the compensation of nonlinearities and temperature effects are developed, and achieved improvements are discussed with respect to the special properties of this novel actuator. Finally, the developed drive is applied to an "active control stick