IMG_ 20200522_ 153325 communication module

IMG_ 20200522_ 153325 communication module

Technical data of product parameters

As can be seen from Fig. 3.5.10.2, IMG_ 20200522_ 153325 the relay setting for a zone of
protection of 95 % is 5 % of Umax. The scheme detects E/F’s on
the generator stator winding, the cables to the step-up transformer and the delta-connected windings of the step-up transformer.The capacitances between primary and secondary of the step-up
transformer conduct currents emanating from E/F’s on the HV
side to the LV side and can cause false tripping of the stator E/F
protection. The capacitive coupling of E/F currents on the HV
side takes place regardless of whether the HV star-point is
grounded or not. The capacitance C12 between HV and LV
windings of the step-up transformer and the capacitance C of the
generator circuit form a potential divider, which determines the
potential of the generator star-point (see Fig. 3.5.10.3a). The
value of the capacitance C is usually too low to definitely hold IMG_ 20200522_ 153325
the star-point below the pick-up setting of the protection. For this
reason, the generator star-point is grounded via a resistor RE
(see Fig. 3.5.10.4), which ensures that the potential of the starpoint remains below the setting of the protection for an E/F on the HV power system. Correspondingly, the value of the resistor
RE is chosen such that for a given C12 and an E/F at the HV
terminals of the step-up transformer, the off-set of the generator
star-point does not reach the pick-up setting of the 95 % E/F
protection.The value of the grounding resistor RE determines the E/F current. In view of the damage, which can be caused by an E/F current, especially to the laminations of the stator core, the maximum E/F current should be limited to 20 A for 10 s, i.e. the IMG_ 20200522_ 153325
grounding resistor RE must not be too small.The star-point v.t. is designed in relation to the maximum continuous voltage, which can be produced by an E/F, i.e. the
phase-to-neutral voltage of the generator. Arcing faults can
cause higher transient voltages and consequentially saturation of
the v.t. The specification of a relatively high overvoltage factor
such as 1.9 is therefore recommended.

Product picture display

bout us service idea

We are able to supply equipment and spare parts from different countries and manufacturers. We can solve the trouble you find in many places or worry about the quality of our products. We have great advantage on the price, E-mail the detailed information of our products. We sincerely welcome you to inquire by phone or use!

With the business philosophy of “professionalism, integrity, innovation, cooperation and win-win”, we continue to develop new products, provide high-quality services to customers, pursue customer satisfaction to the maximum extent, and continue to develop new areas of business.

Email: onewwww@foxmail.com

Introduction to main products

Focus on DCS, PLC, robot control system and large servo system.

Main products: various modules/cards, controllers, touch screens, servo drives.

Advantages: supply imported original products, professional discontinued parts, fast delivery, accurate delivery time,

Main brands include ABB Bailey, GE/FANC, FOXBORO, Invensys TRICONEX, Bentley BENTLY, A-B Rockwell, Emerson EMERSON, OVATION, MOTOROLA, XYVOM, Honeywell HONEYWELL, Rexroth, KUKA, NI, DEIF, Yokogawa, Woodward WOODWARD, Ryan, Schneider SCHNEIDER, Yaskawa, Moog MOOG, PROSOFT and other brands

reminder

For more products, please contact the email for inquiry onewwww@foxmail.com

This article from the temporal Ming sheng automation equipment co., LTD.,

link: http:www.onewwww.com