Dusan Graovac

A Transfer Function Approach to a Common Mode Filter (CMMF) Optimization in the PWM Inverter Supplied Motor Drives

The negative effects of pulse width modulated switch-mode inverters on electrical motors, such as failures in the motor windings isolation and electrical discharge machinery leading to motor bearing failures, are well known. Long cables between inverter and motor, very often found in, for example, railway applications, further increase these effects due to the cable reflections. The aim of this paper is to present an easy-to-use tool for practicing engineers, providing mathematical analysis, design, and optimization of the load ratio control common-mode filtering network at the inverter output. This topology has been chosen after a literature research and considering the practical experiences with different common mode filter (CMMF) topologies. First, a CMMF operation is explained. After that the filter is mathematically analyzed using Laplace domain, leading to the definition of the filter optimization criteria, and in the end the simulation and experimental results are presented. This procedure was used on converters on different trains and has confirmed its value in operation.

Optimal PWM method for electric and electro-hydraulic power steering applications

This paper presents a methodology for choosing the optimal PWM method for the 3-phase automotive drives applications for electric and electro-hydraulic power steering. It shows how some of the automotive specific requirements transpose to PWM requirements. A system overview with motor and control principles has been presented, followed by the method of power loss calculations based on datasheet parameters and, after that, an overview of the PWM Methods is given. These Methods are compared based on: power loss minimisation, usage of the battery voltage, quality of output current and noise emission minimisation.

Power stage for permanent magnet synchronous motors in high current automotive applications

This paper focuses on the Driver-IC and the MOSFETs in inverter used in automotive applications to control a permanent magnet AC-motor with the focus on high current handling capability and high reliability for safety critical applications. The features of the Driver IC together with latest MOSFET technologies will be discussed.

A method for common mode filter (CMMF) optimisation in the PWM inverter supplied motor drives

The negative effects of PWM switch-mode inverters on the electrical motors, such as failures in the motor windings isolation and electrical discharge machinery (EDM) leading to motor bearing failures are well known. Long cables between inverter and motor, very often found in, for example, railway applications, further increase these effects due to the cable reflections. The aim of this paper is to present an easy to use tool for practicing engineers providing mathematical analysis, design and optimisation of the LRC common-mode filtering network at the inverter output. This topology has been chosen after a literature research and considering the practical experiences with different CMMF topologies Firstly, a CMMF operation is explained, after that the filter is mathematically analysed using Laplace domain, leading to the definition of the filter optimisation criteria and in the end the simulation and experimental results are presented. This procedure was used on converters on different trains and has confirmed its value in operation.