Three‐phase distributed constants model of induction machines for EMC and surge propagation studies

Abstract

Purpose -This paper aims to provide a complete three-phase distributed constants model of cable-induction machine systems useful for EMC and overvoltages propagation studies. Design/methodology/approach -The paper considers a three-phase distributed constants model for the supply cable and a model of the same type for the induction machine. All the magneto-electric links between phases are considered. The Clarke transform is applied in order to reduce the analytical complexity of the obtained model. A new numerical method is also proposed for the integration of the resulting whole three-phase model, very similar, in terms of methodology, to the well-known finite differences models. Findings -The whole model for the three-phase drives is used for EMC and overvoltages propagation studies. The proposed examples highlight how, thanks to the Clarke model, the dynamic analysis of the three-phase drives in case of application of a standard fault source or an equivalent pulse width modulation (PWM) impulse, become easy to implement on a standard PC and with standard software (i.e. Matlab). The obtained results, compared with those that are presented in the literature, confirm the validity of the proposed model and numerical approach. Originality/value -The developed model is of a three-phase type because it is not possible to consider a single-phase equivalent model in case of asymmetric voltage sources (i.e. asymmetric faults or PWM inverter voltage supply). The model also includes all the magneto-electric couplings between phases that play a fundamental role in the considered applications.

Induction machine behavioral modeling for prediction of EMI propagation

“…Due to differences in values of winding inductance for common-and differential-mode operation for frequencies below 100kHz , the model has to be parameterized every time, depending on the type of analysis. An exemplary solution of this problem is shown in [13,14], where the additional mutual inductances between machine windings were considered. Despite the fact that the models' accuracy is reported high for frequencies up to 100 MHz, their topology is complex and the procedures of parameter extraction may be problematic.…”

Study of propagation phenomena in three-phase form wound machines operating at medium and high frequency

“…It is fundamental to observe that an analytical form of this inverse transformation can lead to a strong difficulty in formalising the obtained expressions. A new numerical method that is easy to implement on a standard PC and with standard software based on finite differences method is proposed in [18] for the integration of the induction machines model developed. This numerical method together with an FEM method to calculate the parameters of the machine will allow for analysis of differ- ent types of asynchronous machines.…”

“…The integration of the whole three-phase distributed-constants model is performed in the time domain with a numerical method based on the two-port classic theory [18] and on a combination of Laplace and Clarke transformations. The Clarke transformation gives numerical results that can be easily used to directly derive the common-and differential-mode contributions of the conducted emissions, as demonstrated in [16].…”

“…It is important to underline that the distributed-constant Clarke model of an induction machine presented in this paper constitutes the first step in research that aims to develop a distributed-constant model of asynchronous drives (composed of an induction machine, cable [17] and AC/DC drive [18]). The analytical solution is mandatory to develop numerical methods that allow us to implement on a standard PC-using standard software (i.e., Matlab, EMTP) [18] that can be very useful in the analysis of certain industrial problems, like the analysis of the correct installation of the inductive loads, such as transformers and asynchronous machines, subjected to frequent transient events such as repeated energising or power converter switching [3], or to design a drive that matches the EMC normative [18].…”

“…The analytical solution is mandatory to develop numerical methods that allow us to implement on a standard PC-using standard software (i.e., Matlab, EMTP) [18] that can be very useful in the analysis of certain industrial problems, like the analysis of the correct installation of the inductive loads, such as transformers and asynchronous machines, subjected to frequent transient events such as repeated energising or power converter switching [3], or to design a drive that matches the EMC normative [18]. Finally, the model presented here was applied to study typical cases with the aim of verifying the validity of the proposed model, underlining some its particular peculiarities, and studying the conducted emissions in all sections of a three-phase drive including the distributed mutual magneto-electric couplings between the phases.…”