A method for controlling an electrical converter 12 comprises the steps of: receiving an actual switching state u k-1 of the electrical converter 12; determining a scenario tree 50 for possible future switching states of the electrical converter 12 based on the actual switching state u k-1 , the scenario tree 50 defining a plurality of possible future switching sequences, a switching sequence U being defined by a path from a root node 52 of the scenario tree 50 to a leave node 58 of the scenario tree 50; calculating a weight w for a switching sequence by evaluating nodes 60 of the scenario tree 50; and determining the next switching state u k to be applied to the electrical converter 12 from a switching sequence with a best weight. The evaluation of the nodes 60 is performed by at least two processor cores 30a, 30b, 30c, 30d.

Multicore implemented weight - function based predictive control of an electric converter

The method involves detecting the mains current (29) with a transducer (2) between a single-phase ac voltage network (1) and a primary winding (5) of a mains transformer and feeding it to a Fourier function generator (28). A real and an imaginary part of the mains current are formed by a Fourier transformation so that a non-harmonic component of the mains current is essentially filtered in amplitude and its phase angle is essentially null. An Independent claim is also included for an arrangement for implementing the method.

Method for the control of a non-harmonic network current portion of a converter, and device for carrying out the method

Es wird ein Verfahren zum Betrieb eines elektrischen Bahnfahrzeugs beschrieben, welches die Stabilitat des Bahnnetzes erhoht. A method is described for operating an electric railway vehicle, which increases the stability of the railway network. In diesem Verfahren wird vom Bahnfahrzeug auf mindestens einer Frequenz oberhalb der Grundfrequenz die Impedanz (Z N ) des Bahnnetzes gemessen. In this method, the impedance (Z N) of the railway network is measured by the railway vehicle at at least one frequency above the fundamental frequency. Abhangig von der Netzimpedanz wird die Impedanz (Z L ) des Bahnfahrzeugs derart gewahlt, dass Instabilitaten bei der entsprechenden Frequenz vermieden werden. Depending on the network impedance, the impedance (Z L) is selected in the railway vehicle such that at the corresponding frequency instabilities are avoided.

Process for operating an electric railway car

In a first stage, the current frequency spectrum of the entire frictional adhesion control system is measured in closed circuit, or calculated using a suitable model. In a second stage the result is compared with a spectrum including maximum permissible values. Finally the traction control system is designed such that the current frequency content exceeding the maximum valve is shifted into adjacent frequency bands, where the frequency content still lies under the maximum permissible value.

Optimizing frictional adhesion of electrically-driven rail vehicles

The invention concerns the avoidance of resonance effects in a power supply of unknown impedance when a power converter connected to the power supply is in operation. In order that, in the case of a locomotive powered by a power converter for instance, standing waves which change uncontrollably as the locomotive travels do not form in the power supply, a characteristic transfer function (e.g. the power-supply input impedance) is first continuously identified by electrical measurement and the use of Fourier transforms and this function simulated at least in the region of the maxima of the function by means of a virtual power supply made up of discrete resonant circuits. The variables of the power-supply model, e.g. the currents flowing in each of the resonant circuits, can be calculated from the identified power-supply parameters as a function of the power-converter switching times. By virtual variation of the switching times, the optimum pulse pattern for power-converter operation can be calculated, this pattern causing no resonance in the true power supply.

Holtz Joachim

Papers

Device and process for optimum operation of a power converter connected to a power supply.