A squirrel cage induction generator (SCIG) system experiences the change of parameters due to variation in temperature, change of load demand, or minute variations in mechanical fabrication. Therefore, a conventional PI controller for DC-bus voltage with active front-end rectifier (AFE) is subjected to controller’s parameter tuning with system aging and load change. In this paper, a DC bus voltage control technique is realized utilizing root-locus based pole-zero placement technique. This DC-bus controller places poles and zeros at a desired location of the system root-locus, which gives the benefit of parameter invariant response. This mathematical analysis of voltage control technique and its implementation is explained in detail for SCIG. The voltage controller follows the conventional current controller design for an indirect field-oriented power control (FoPC) for a fixed speed SCIG. The overall control is investigated and tested in PLECs simulation platform, and the results are presented for various load dynamics operations.

The development of DC microgrids has accelerated due to their excellent compatibility with DC sources and loads. In these systems, the Triple Active Bridge (TAB) converters have emerged as key components, establishing a versatile three-port network that integrates distributed energy resources (DERs), battery energy storage systems (BESS), and loads. Given the susceptibility of these systems to disturbances and failures, ensuring fault-tolerant operation is essential. This paper proposes an enhanced TAB converter design with enhanced fault-tolerant capabilities, achieved through the addition of only two IGBTs and one diode to the conventional topology. Furthermore, a novel control strategy is presented for the proposed TAB, enabling seamless transition to Buck/Boost mode during short-circuit faults and rapid mitigation of open-circuit faults in switches, thereby ensuring continuous operation. The effectiveness of the proposed topology and control strategy is validated through simulation.

A conventional inverter-based induction motor drive has a maximum peak fundamental phase voltage of 0.577V dc, corresponding to a peak voltage space vector radius of 0.866V dc in its linear modulation range. The magnitude 0.866V dc here correlates to the radius of the largest circle that can be inscribed in the hexagonal space vector structure created by the inverter. Beyond 0.866V dc lies the overmodulation region where the inverter operates in a six-step mode. Here the voltage space vector traces a hexagonal locus causing a lower order harmonic rich phase voltage. In the proposed inverter scheme, the linear modulation range can be extended till a maximum peak phase fundamental voltage of 0.637V dc while achieving a circular trajectory of radius 0.955V dc for the voltage space vector, thus eliminating all lower-order harmonics. This extends the linear modulation range to the full base speed of the induction motor.

In this paper, DC-link capacitors voltage deviation control is achieved using a symmetrical six-phase induction machine (IM) load driven by a nine-level inverter. The motor phase currents are utilised intelligently to control the common coupling points (CCPs: terminal connections series-connected capacitors across a DC-link). Each phase of this inverter consists of a five-level stacked inverter and two cascaded H-bridge (CHB) inverters, which can be built using low voltage switching devices. Simultaneous control of DC-link capacitors and CHB capacitors balancing is achieved by using the pole voltage redundancies. This concept is validated using a standard simulation tool with a six-phase load under the 'V/f' control operation. The simulation results for steady-state and transient conditions are provided at low speed and high speed of operation with low and high power factors conditions. © 2022 IEEE.