Decoupled Floating Capacitor Voltage Control of a Dual Inverter Drive for an Open-Ended Winding Induction Motor

Abstract

A control scheme is presented for a dual inverter drive with a floating capacitor bridge, with decoupled motor and capacitor dynamics. A stator current reference frame is used that decouples the real and reactive power components of the motor and enables the decoupling of the motor and capacitor dynamics. Apart from the high frequency voltage ripple due to the inverter switching pattern, the capacitor voltage can be kept constant even during large step changes in motor speed reference and load torque. This allows for the use of a significantly smaller floating bridge capacitor whose size depends only on the steady-state high frequency voltage ripple. Additionally, the number of PI regulators used compared to previous works and the dc-link voltage requirements are both reduced. Index Terms-Dual inverter drive, field oriented control, floating capacitor bridge, open-ended winding induction machine.

Technical Review of Dual Inverter Topologies for More Electric Aircraft Applications

“…Reference [42] has studied using the ratio 1:2, but its approach is perceived as a very complex control scheme with several non-linear regulators tuning [90]. Besides, the utilization improvement of 35% and 100% can be achieved using a voltage ratio of 1:1 [94] and [41], respectively. A varied voltage ratio was investigated in [16], which can enhance the DC-link voltage utilization by up to 60%.…”

Voltage Harmonic Analysis of Typical PWM Strategies in a Dual Inverter with Floating Capacitor in the Partial-Load Condition

“…In this experiment, a DC power supply regulates the INV. 1 DC voltage at 300 V. The selection of the capacitance of the floating capacitor in various dual inverter drive methods is reported in (4) . It is known that in the operation method in which the sinusoidal voltage is output from both inverters, the sixth-order fluctuation of the DC voltage occurs due to the harmonic current caused by dead-time and spatial harmonics.…”

“…A circuit topology using a dual inverter has some advantages compared with a single inverter topology such as, expanded speed range (3), (4) , multilevel operation (5), (6) , and fault tolerant functions (7), (8) . In recent years, input current harmonic suppression methods have also been investigated in the dual inverter with floating capacitor topology, in order to satisfy harmonic regulation or suppress the stress of capacitors; it can be achieved by using active and reactive power compensation (9), (10) .…”

“…In recent years, input current harmonic suppression methods have also been investigated in the dual inverter with floating capacitor topology, in order to satisfy harmonic regulation or suppress the stress of capacitors; it can be achieved by using active and reactive power compensation (9), (10) . Conventionally, methods of reducing voltage harmonics by making the floating capacitor voltage the same as or half of the primary side DC voltage has been studied (4), (6) . On the other hand, a method of controlling the floating capacitor voltage variable, in order to improving the performance, depending on the load condition has been studied (11) .…”

Reduction of Voltage Harmonics in an Open-End Winding Induction Motor Driven by a Dual-Inverter with a Floating Capacitor in a Partial-Load Condition

“…In this experiment, a DC power supply regulates the INV. 1 DC voltage at 300 V. The selection of the capacitance of the floating capacitor in various dual-inverter drive methods is reported in (20) . It is known that in the operation method in which the sinusoidal voltage is output from both inverters, the sixth-order fluctuation of the DC voltage occurs due to the harmonic current caused by deadtime and spatial harmonics.…”