Identification and compensation of inverter dead-time effect on zero speed sensorless control of AC machines based on voltage pulse injection

In this paper the influence of the non-ideal behavior of power electronics, sensors, and signal processing on pulse signal injection based speed sensorless control is addressed and investigated. The speed sensorless control signals are obtained from the transient current response resulting from an excitation of the machine with voltage pulses. The investigation is focused on sensorless control of induction machines however, the results are applicable also for other types of ac machines. By using pulse width modulation in combination with voltage source inverters the inverter interlock dead-time is essential necessary to prevent the short circuit of the dc link. A new approach to identify the interlook dead-time by utilizing the transient voltage pulses and the current response is presented. The disturbing influences and effects of the inverter interlock dead-time on the resulting signal include the deviation of the operating point during the pulse injection, as well as additional resulting harmonics in the control signal. For the specific problem of compensating these effects on the signal injection measurement a new approach is applied in this paper. After identifying the effective dead time the switching commands are adapted in order to clearly reduce the disturbing effects. Further simulation results and additionally measurement results are presented to show the influence on the resulting control signals.

[1]  M. Schroedl,et al.  Sensorless control of AC machines at low speed and standstill based on the "INFORM" method , 1996, IAS '96. Conference Record of the 1996 IEEE Industry Applications Conference Thirty-First IAS Annual Meeting.

[2]  Thomas M. Wolbank,et al.  Current sensors for shaft-sensorless control of inverter fed induction machines industrially used sensors vs. new current derivative sensors , 2003, Proceedings of the 20th IEEE Instrumentation Technology Conference (Cat. No.03CH37412).

[3]  T.M. Wolbank,et al.  Influence of inverter-nonlinearity and measurement setup on zero speed sensorless control of AC machines based on voltage pulse injection , 2005, 31st Annual Conference of IEEE Industrial Electronics Society, 2005. IECON 2005..

[4]  R. Lorenz,et al.  Using multiple saliencies for the estimation of flux, position, and velocity in AC machines , 1997, IAS '97. Conference Record of the 1997 IEEE Industry Applications Conference Thirty-Second IAS Annual Meeting.

[5]  Joachim Holtz.  Sensorless position control of induction motors-an emerging technology , 1998, IEEE Trans. Ind. Electron..

[6]  H. Hauser,et al.  Interaction of induction machines fundamental wave design and asymmetries in the transient electrical behavior caused by saturation , 2003, IECON'03. 29th Annual Conference of the IEEE Industrial Electronics Society (IEEE Cat. No.03CH37468).

[7]  Jon Clare,et al.  Sensorless vector control at low and zero frequency considering zero-sequence current in delta connected cage induction motors , 2003, IECON'03. 29th Annual Conference of the IEEE Industrial Electronics Society (IEEE Cat. No.03CH37468).

[8]  Jung-Ik Ha,et al.  Sensorless field orientation control of an induction machine by high frequency signal injection , 1997, IAS '97. Conference Record of the 1997 IEEE Industry Applications Conference Thirty-Second IAS Annual Meeting.

[9]  T.M. Wolbank,et al.  Sensorless control of induction machines by combining fundamental wave models with transient excitation technique , 2005, IEEE International Conference on Electric Machines and Drives, 2005..

[10]  Robert D. Lorenz,et al.  Using multiple saliencies for the estimation of flux, position, and velocity in AC machines , 1997 .