A new and intelligent operation assessment system in simulation training of substation
Most nation-wide substation simulation systems only provide the function of generating dispatch operation sheet and the new personnel always fail to cope well with the operation for the vital network and the complex dispatch task due to their lacking of practice and shortage of intensive memorization. It's necessary to enhance the training intensity while the new function should be implemented for optimizing in order to promote the training effectiveness. For above problems, the envisage design for the assessment system in this paper is presented based on self-invented substation simulation system of generating dispatch operation sheet.
Reason analysis and precautions of blackout in 220 kV substation
One 220kV substation blackout for the reason of bus relay protection equipment’s misoperation. According to the status of related equipments, monitor messages and the fault wave graphics and data, error action of bus relay protection equipment is caused by the fault of switcher’s location. After investigating the manual of voltage switcher and the map of bus relay protection equipment, one fault is found that the "switch relays relay on at the same time" alarm can’t be send out when I bus and II bus secondary voltage is paralleled non-normally. The monitor circuit for "switch relays relay on at the same time" signal has been improved, and the security of power grid has been enhanced.
Simplified impedance design and control for low-cost high-speed channels
Impedance design is the fundamentals of signal integrity at the very beginning, but controlled impedance is always costly or time-consuming for the high-speed channels. In this paper, many simulations of channel parasitics were taken and calculated that met with the specified impedances and correlated to the measurements very well. Selection of the different substrate stack-up without any layout modification in the BGA package reversed from the failed verification to pass the differential return loss. Adjustment of lead widths and spaces in the limited room of leadframe package improved 6 Ω of differential-mode impedance compared to the conventional leadframe packages. The differential pairs with wider traces routed on the 2-layer PCB are more robust for over-etching effects whose impedance errors are less than 5% without special impedance control. Moreover, those pairs inserted with a thin ground trace achieved 90 Ω differential-mode impedance and 28.2 Ω common-mode impedance simultaneously with 35% less routing area for MHL application and reserved a 10 Ω series resistor for ESD protection. With those diligent designs, the leadframe package and the 2-layer PCB can be still adopting in the consumer electronics for high-speed applications.