IEEE Std 1409:2012 pdf download

IEEE Std 1409:2012 pdf download.IEEE Guide for Application of Power Electronics for Power Quality lmprovement on Distribution Systems Rated 1 kV Through 38 kV.
5.2 Components of custom power technology
Custom power devices should be able to react in real time to the state of the distribution system and rapidly adjust to maintain the required level of powcr quality. Thc key technology that has made custom power devices possible is the wrn-on.turn-ofl’ solid-state switch. I)evclopments in power electronic technologies including the gate turn-off thyristor (GTO). the insulated gate bipolar transistor fIGHT), and the integrated gate commutated thytistor (IGCT) mcan that devices with operational capabilities suitable for high power applications arc now as ailabk at a cost that makes them economically possible for distribution power levels. Also important to realizing this technology have been the advances made in microcontrollers, signal processors, fiber optic communications, and techniques to series-connect solid-state switches.
At the heart of many custom power devices is a three-phase voltage source inverter, The inverier is controlled by a system that constantly monitors the distribunon line and compares the data with a reference signal. Connection of the inverter to the distnbuon line is via a transfonner To reduce unwanted harmonics generated by the inserter, filters are used to smooth the output waveform. The inserter itself consists of individual circuit blocks that incorporate the switching semiconductors, firing circuits, snubber network, anti-parallel diodes, and heat sinks. Modules arc commonly connected at the dc side of an invcrter to facilitate energy transfer between phases.
To fully implement some of the functions of custom power controllers, some form of energy storage module may he necessary. A number of technologies are now at sufficient stages of maturity to be considered as viable alternatives for custom power applications. These include the following devices:
a) capacitors
b) batteries
e) flywheel energy storage
dt superconducting magnetic energy storage SM ES)
5.3 Voltage sag and interruption protection devices
5.3.1 DynamIc voltage restorer (DVR)
The purpose of a dynamic voltage restorer (DVRI ts to mitigate the effects that voltage sags and interruptions have on a scnsitive customer’s load. A DVR is a waveform synthesis device based on power electronics that is series-connected directly into the primary distribution circuit by means of a set of single- phase injection transfutmers.
The DVR can be configured to use line energy supply to provide the energy that is to he injected into the disinbution circuit from the utility fccdcr For csamplc, LES systems can draw the energy from the incoming affected line, as in Figure 12. In this system configuration, when the voltage of one or more phases of the incoming supply drops below a preset threshold, the DVR injects a controlled amount of soltage into the affected phase or phases to boost the load voltage back to a more suitable level, The load therefore is buffered from the disturbance.