IEEE 1662:2008 pdf free download – IEEE Guide for the Design and Application of Power Electronics in Electrical Power Systems on Ships
The purpose of distinguishing these functions is to segregate specific PE equipment applications, converterfunctions, and converter topologies as discussed in 8.2 from their respective system-level functions.
The reason for defining the two basic functions“sourcing” and“loading”for power conversion is toacknowledge the importance of voltage control in converter fed systems. Although a converter that assumesthe function of “*sourcing” performs primary voltage control, the one that is “loading” behaves passivelywith respect to voltage control. Many converters can assume either function solely by applying differentcontrol algorithms. These two basic functions have nothing to do with the actual flow of power. In manyapplications，only one converter will assume the function of “sourcing” in order to maintain systemstability.However, it is conceivable that in special cases, more than one converter can assume “sourcing”simultaneously. Three examples that shall illustrate the different combinations of power flow and functionare as follows:
– The active front end of a variable speed motor drive may regenerate power into the system it isconnected to without participating in system voltage control. Therefore，even during theregeneration phase, this front end converter still assumes the function of “loading.””
– The machine inverter of a flywheel energy storage system connected to a dc distribution system.During the charging of the flywheel, the inverter assumes the function of “loading” with respectto the dc system. However, if the upstream converter feeding the dc system shuts down and thedc system shall be powered from the flywheel energy storage system, its machine inverter willchange its function to “sourcing” because it then controls the voltage in the dc system.
– Bidirectional rectifier connected to an ac distribution system and powering a de system assumesthe function”sourcing”” on the dc side regardless of the actual power flow. Therefore, even ifpower flows from the dc system into the ac system, the rectifier is “sourcing” the dc system.
Whereas PE equipment that converts power between different frequencies or voltages may also participatein system-level protection functions,certain PE equipment only assumes the function of “protecting.”Itspecifically does NOT convert power between different frequencies or voltages and behaves passive withrespect to voltage control. Therefore, this function is specifically called out in this guide.Examples arestatic transfer switches, solid-state fault current limiters, solid-state crowbar switches, and so on.
Finally, a fourth system level function exists called “active filtering.”This function only affects the qualityof the voltage or current waveforms, although it does not actively control the magnitude of the fundamentalwaveform component. Only a static VAR compensator,which is also considered to assume the function of“active filtering,”affects the fundamental current waveform component in voltage-controlled systems.However, while performing the function of “active filtering,” it does not provide primary voltage control,and hence, it does not assume the function of “”sourcing.”
Note that any specific PE equipment or subsystem normally assumes different functions at its variouselectrical terminals. In addition, it may assume different functions at any specific electrical port at differenttimes (i.e., front end of an energy storage system). Therefore, because different functions result in differentrequirements, it is cssential to specify clearly the functions that each of the electrical terminals assume atany given time.