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 Title
 Advanced Electric Vehicle Drives Topology and Control
 Creator
 Janabi, Ameer
 Date
 2021
 Collection
 Electronic Theses & Dissertations
 Description

In the thesis, the author focuses on solving three problems related to voltage source inverter(VSI) in general and VSI used in an electric and hybrid electric vehicle in particular. The first problem is related to the fact that using pulse width modulated (PWM) voltage to supply the motor causes a commonmode voltage (CMV) at the motor bearings. To solve this problem, a hybrid space vector PWM is proposed that reduces the CMV amplitude and frequency to the maximally allowable extent. This can...
Show moreIn the thesis, the author focuses on solving three problems related to voltage source inverter(VSI) in general and VSI used in an electric and hybrid electric vehicle in particular. The first problem is related to the fact that using pulse width modulated (PWM) voltage to supply the motor causes a commonmode voltage (CMV) at the motor bearings. To solve this problem, a hybrid space vector PWM is proposed that reduces the CMV amplitude and frequency to the maximally allowable extent. This can be done by utilizing a special switching sequence that takes into consideration the phase angle between the load voltage and current. The second problem is related to the optimal PWM sequence that allows the elimination of selected low order odd harmonics. Previously, this optimization problem used to be solved using an offline approach. There have been several attempts to implement the control algorithm in realtime. All of the proposed methods in the literature, at some points, use initial guessing or iteration. This leads to an online approach with nondeterministic execution time and with the possibility to fail to reach convergence. The author shows that the optimal PWM can be implemented in realtime with deterministic execution time and without compromise. Furthermore, a significantly more generalized algorithm is proposed that allows the modulation of selected harmonics rather than merely eliminating them. The opportunities opened up by the generalized algorithm are limitless and currently being explored. The potential applications include wireless charging and digital wave generation. Modulation of several harmonics to arbitrarily prescribed values is impossible to implement using an offline approach. The third problem is to address the limitations associated with the fact that VSI is a buck converter. For applications where the available dc voltage is limited, an additional dcdc boost converter is needed to obtain the desirable ac voltage. Commercial hybrid vehicles typically use an inductor based dcdc converter to boost the voltage. At higher power, the dcdc converter becomes inefficient. Therefore, the application of the boost stage is seen only in hybrid vehicles with a battery of a few kWh. The author proposes a new family of bidirectional dcac boost converters that utilizes a switchedcapacitor network to boost the voltage. The switchedcapacitor and the inverter are modulated as one unit, which allows the removal of the large output filtering capacitor and the reverse blocking diode required by a typical switchedcapacitor converter. This effort results in extending the power level of switchedcapacitor based converters from existing sub kW range to tens kW and beyond with much mitigated penalty on device utilization.
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 Title
 Shunt and series conditioning of hybrid matrix converter
 Creator
 Janabi, Ameer
 Date
 2016
 Collection
 Electronic Theses & Dissertations
 Description

"Hybrid matrix converters can potentially enable matrix converters in high power applications that conventional matrix converters will not be able to attain. It uses a conventional nineswitch matrix converter in conjunction with an auxiliary backtoback acdcac converter that conditions the current and voltage waveforms on the input and output side of the matrix converter. The matrix converter processes the main power at low switching frequency to enable significant reduction of switching...
Show more"Hybrid matrix converters can potentially enable matrix converters in high power applications that conventional matrix converters will not be able to attain. It uses a conventional nineswitch matrix converter in conjunction with an auxiliary backtoback acdcac converter that conditions the current and voltage waveforms on the input and output side of the matrix converter. The matrix converter processes the main power at low switching frequency to enable significant reduction of switching losses and to allow for adoption of highpower semiconductor devices such as integrated gate commutated thyristors (IGCTs). The auxiliary acdcac converter is dedicated to improving the power quality at the input and output terminals of the matrix converter by minimizing harmonic currents drawn from the source and harmonic voltages applied to the load. Essentially, the auxiliary backtoback converter functions as a shuntandseries active filter (AF). Several AF control techniques have been presented in the literature. Based on the operating principle, these techniques can be categorized into two groups. The first group of methods are based on instantaneous reactive power theory (IRPT) and extract the reactive component of the power and the oscillatory component of the real power. The other methods are based on filtering techniques and extract the fundamental component of the current or voltage such as notch filter and fast Fourier transform (FFT) methods. The main limitation for IRPT based method lies in its ineffectiveness when the harmonics are concurrently present in voltage and current while the limitation for FFT based method is its inability to compensate the fundamental component. To address these limitations of the aforementioned methods, a new control strategy based on power averaging has been proposed. This proposed control method is able to effectively obtain the correct active component of current or voltage in cases where both the current and the voltage are nonsinusoidal and provide full control over the power factor."Pages iiiii.
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