Olaf Simon

Modern solutions for industrial matrix-converter applications

Thus far, matrix converter topology has not reached industrial use. Reasons for this have been complex control schemes, inefficient solutions for overvoltage protection, questionable robustness of the bi-directional switch commutation at disturbed supply voltages, and missing power semiconductor modules. Recent research results concerning these problems have led to innovative solutions and, from a technical point of view, industrial use seems to be reasonable now.

Matrix converter commutation strategies with and without explicit input voltage sign measurement

This paper gives an overview to voltage-controlled matrix converter commutation. Conventional converter systems with explicit sign measurement circuits that were necessary for the commutation in the past are discussed. New operation methods eliminating these extra measuring circuits are presented. The paper explains the new methods. Advantages and disadvantages of different approaches are discussed. The robustness of the new methods against disturbance is proved and measurements on a 5.5-kW matrix converter system are shown.

New concepts for matrix converter design

In this paper the design and testing of new concepts in matrix converter construction and control are presented. The matrix converter has a more complex commutation behaviour and over-voltage protection in emergency switch-off compared to the voltage-link converter. New investigations have overcome this problems. The new revolutionary concepts in protection, commutation, switch design and modulation strategy are simple and cheap. A further milestone towards an easy design for a matrix converter has been achieved. The practical operation of the new concepts are verified on a 5.5 kW matrix converter drive system with an induction motor.

Design of Pulse Patterns for Matrix Converters

Abstract For the matrix converter (Fig. 1) two basic methods are known to calculate the switching states and turn-on times necessary to generate the average output voltage and input current desired. One modulation technique is the direct method of Venturini and Alesina which controls each output phase separately and the other one is the space vector modulation or indirect method proposed by Huber, Borojevic and Burany which treats the complete converter as a whole. The paper presents a new pattern optimisation principle for the space vector modulation which reduces the switching losses of the matrix converter significantly. Already published optimisation techniques try to minimise the number of commutations within a switching period by different choice of the switching states for the zero voltage and by different arrangements of the switching states. These principles lead to pulse patterns which are quite similar to the Flat-Top Modulation or to the symmetrical use of zero switching states known from voltage source converters. The new optimisation method also takes into account the commutation voltage which is different for each individual switching operation and which has a strong influence on the switching losses. To minimize the commutation voltage it is necessary to follow a certain phase sequence, i.e. the input voltages must be connected to each output phase in a certain order. This order depends on the actual values of the input voltages. For the direct modulation technique this loss optimised sequence can be realized quite easily but for the space vector modulation no arrangement of switching states follows the loss optimised sequence. The paper proposes a technique to obtain the Loss Optimised Pulse Pattern out of the result of the space vector modulation by a subsequent phase oriented rearrangement of the switching states. The influence on switching losses and on harmonic distortion both on the input and on the output side will be discussed.

Field test results of interoperable electric vehicle wireless power transfer

To provide a public infrastructure for wireless power transfer (WPT) to electrical vehicles, the ability of interoperable use between infrastructure and vehicle parts of different manufacturers is necessary. Based on the interoperability definition given in IEC 61980-3 (draft) Annex AA several different primary and secondary devices (pickups) have been realized by four manufacturers and have been applied to full electric cars. Experimental results of the interoperability check and field test results of cross manufacturer vehicle operation are presented, proving the usability of the interoperability definition.

Flexible secondary pad design for wireless power transfer providing public interoperability

To provide a public infrastructure for wireless power transfer (WPT) of electrical vehicles, the ability of interoperable use between infrastructure and vehicles of different manufacturers is necessary. For that reason a Wireless interoperable Power Transfer (WiPT) definition has been conceived and developed for pilot field operation. Due to its ability of interoperable use and being inherently safe, the IEC 61980-3 (TS) Annex AA [3] uses this concept for public under floor installations. One of the main features of WiPT is the wide ranging flexibility for the design of vehicle pads. The concept of reaching this feature and corresponding secondary device design procedures are described.

Implementation of a Matrix Converter Space Vector Control in Programmable Logic

Abstract To control a matrix converter different modulations are possible. To benefit from the new topology the rectifying and inverting vector modulation (RIVM) can be used. It is a complex theory but this article presents a realization in one single programmable logic device. Additionally pulse pattern execution (PWM, commutation strategies and input voltage/current filtering) are situated in the same device. This was possible after the optimization and the reduction of the necessary calculation steps. This new solution works without an extra micro-controller or a digital signal processor (DSP). It allows great reduction in costs of matrix converter controls implementation and increases the performance.