|dc.description.abstract||Constant power loads (CPLs) have negative impedance characteristic. This characteristic can degrade the stability margin of the whole system when the CPL operates with other circuits, typically, an LC input filter. The stability of the CPL and the LC input filter can be determined by the impedance stability criterion.
Many active methods have been proposed to stabilize the interaction between LC input filters and CPLs. Compared with the mature study of active methods for stabilization of inverter based CPLs and LC input filters, there are few active methods proposed for stabilization of DC/DC converter based CPLs and LC input filters. Due to the difference between inverter based CPLs and DC/DC converter based CPLs in power stage dynamics and feedback controllers, applying the active methods for inverter based CPLs directly to DC/DC converter based CPLs may not achieve an optimal performance or may not even work. To address this problem, in the thesis, an optimal active method is proposed for DC/DC converters under voltage mode control. The proposed methods can increase a larger stability margin and simultaneously have smaller audio susceptibility than the existing methods. The thesis also proposed another active method for DC/DC converters under current mode control. The proposed method results in a larger stability margin than the existing method.
This thesis also contributes to the stabilization of LC input filters and CPLs from source side converters. The main advantage of this method is that it eliminates the drawback of the active stabilization method via adding a feedforward loop which enlarges the system audio susceptibility. The limitation of this method is that the upstream converter requires a wide bandwidth output voltage regulation.||en_AU|
|dc.publisher||University of Sydney||en_AU|
|dc.publisher||Faculty of Engineering and Information Technologies||en_AU|
|dc.publisher||School of Electrical and Information Engineering||en_AU|
|dc.rights||The author retains copyright of this thesis. It may only be used for the purposes of research and study. It must not be used for any other purposes and may not be transmitted or shared with others without prior permission.||en_AU|
|dc.subject||constant power loads||en_AU|
|dc.subject||LC input filters||en_AU|
|dc.subject||active stabilization methods||en_AU|
|dc.title||Active Methods for Addressing the Instability Problem between Constant Power Loads and their LC Input Filters in DC Power Systems||en_AU|
|dc.type.pubtype||Doctor of Philosophy Ph.D.||en_AU|
|dc.description.disclaimer||Access is restricted to staff and students of the University of Sydney . UniKey credentials are required. Non university access may be obtained by visiting the University of Sydney Library.||en_AU|
|Appears in Collections:||Sydney Digital Theses (University of Sydney Access only)|