General Current Control of Six-Phase-Based Non-Isolated Integrated On-Board Charger with Low Order Harmonic Compensation

Abstract

Electric vehicle charging technology has recently witnessed massive developments due to its significant role in the ever-growing number of electric vehicles on the market. The integrated on-board charger technology (IOBC) represents an effective and attractive solution to reduce EV size, cost, and weight. IOBC technology employs propulsion components, such as the motor and its converter, in the charging process. The main objective of IOBC is to achieve the maximum charging current with zero average/pulsating torque so that mechanical interlocking can be dispensed. Recently, some of the IOBC topologies have adopted machines with six-phase stators to exploit the many advantages of multiphase-based systems. This paper investigates the effect of the winding design, namely, chorded or un-chorded designs, as well as the winding configuration, namely, dual three-phase, asymmetrical, or symmetrical winding configurations, on the current quality of a six-phase-based non-isolated IOBC. The relation between the winding design and the induced low order harmonics in the charging current is first clarified. The required current controller structure is then proposed, which ensures balanced grid line currents with high quality, under either healthy or one-phase fault conditions. Finally, a comparative study between all available designs with the proposed current controller is carried out to validate the theoretical findings.

Effect of Winding Design on the Performance of Predictive Current Control of Six-Phase Induction Machine-Based Propulsion Systems

“…For the employed sampling time of 25𝜇𝜇sec, the average switching frequency and the computational burden are listed in Table III. The average switching frequency is calculated using (15) based on the switching frequency of each phase given by (16).…”

“…The A6P have been favored in most of industrial application, especially in marine propulsion applications [2,11,12]. Nevertheless, other six-phase configurations have also shown potentials in the recent literature [13][14][15]. A comparative study between these different configurations has been introduced in [6], which investigated the air gap flux distribution and the effect of winding configuration on the equivalent machine parameters.…”

“…A comparative study between these different configurations has been introduced in [6], which investigated the air gap flux distribution and the effect of winding configuration on the equivalent machine parameters. Moreover, the performance of each configuration under model predictive control has been studied in [13][14][15]. Also, a unified analysis has been done to investigate the fault tolerance capability of different configurations under several fault scenarios [10].…”

Online Control Strategy for Tolerating Resistance Asymmetry With Minimum Copper Loss in the Full Torque Range for Symmetrical Six-Phase AC Drives

“…For instance, they allow lower phase current for a given total power [1] and better fault tolerance [2]- [4]. Their extra degrees of freedom may also be exploited for special purposes including increased torque density [5], [6], integrated battery chargers [7], [8], bearingless machines [9], multimotor drives [10], or sensorless estimation of parameters such as temperature [11], [12] or speed [13]- [15]. Six-phase machines are especially convenient, because they can be fed by readily available threephase converters [2], [3], [16].…”

“…Among them, the symmetrical configuration yields superior performance under open/short-circuit faults [3], [4], [17]- [19]. Furthermore, provided the coils are not chorded [8], the low-order current harmonics tend to be smaller than for asymmetrical windings and it can be controlled in a simpler manner [20]. It is also worth noting that, for integrated battery chargers, the symmetrical layout allows fully exploiting the machine and converter power rating in charging mode [8].…”