Voltage controller synthesis for an induction electric drives autonomous inverter using non-normalized polynomials

Currently, the development of new control approaches for asynchronous electric drives with stringent requirements for vibration-acoustic performance and spectral composition of autonomous inverter output currents represents a highly relevant research challenge. The key challenges in designing this class of electric drives stem from the relatively low effectiveness of existing technical solutions. This limitation arises either from constraints in current controller synthesis methods or from rigorous demands regarding power-to-weight and dimensional parameters. This paper presents an original method for generating control signals in an alternating current electric drive autonomous inverter. The proposed approach utilizes regulation based on the deviation of the generalized output voltage vector amplitude in the autonomous inverter. The synthesis procedure for such a controller begins with defining the desired closed-loop system transfer function. The system dynamic processes are determined by a characteristic polynomial that can be of arbitrary type. For comparative analysis, two controller types are examined: one based on a Butterworth filter and another utilizing a Newton polynomial. The study proposes employing bilinear transformation to implement the derived continuous functions in discrete form, enabling software implementation in Simulink and subsequent microprocessor-based execution. The developed model, which accounts for discrete control signal generation, has yielded the spectral composition of the drive converter output currents and voltage-frequency characteristics under parametric disturbances introduced by the control object. Results demonstrate that the Butterworth filter-based controller shows superior efficiency compared to both open-loop systems and closed-loop systems with Newton polynomial-based controllers. The obtained results can be effectively applied in the development of low-noise electric drives for specialized applications.