| 摘要 |
When using rotating-field machines in highly dynamic drives, the principle of "field-oriented control" has been proven. In this method, it is necessary to transform time-variable parameters between reference co-ordinate systems which rotate with respect to one another. While these transformations were originally implemented using purely analog circuit technology, microcomputers are now generally used, because of the drift and accuracy problems. However, their computation speed is frequently not adequate in the case of fast-running machines. The device according to the invention, which is shown by way of example in Fig. 4, avoids these disadvantages. The orthogonal components xd and xq of the parameter to be transformed are applied to the reference signal inputs (11) of multiplying digital/analog converters (12), (13), (15) and (16). The sine and the cosine of the instantaneous angle phi between the co-ordinate systems are applied to their digital inputs (14). The output parameters (10) of the co-ordinate transformation device (5), which are likewise orthogonal, are formed by means of summation (18), using the correct mathematical sign, of in each case two of the output parameters (19) of the multiplying digital/analog converters (12), (13), (15) and (16). Using this device, it is possible at a low cost to transform parameters between co-ordinate systems which rotate very quickly with respect to one another, virtually without any delay. <IMAGE>
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