The main products

Spare parts spare parts, the DCS control system of PLC system and the robot system spare parts,

Brand advantage: Allen Bradley, BentlyNevada, ABB, Emerson Ovation, Honeywell DCS, Rockwell ICS Triplex, FOXBORO, Schneider PLC, GE Fanuc, Motorola, HIMA, TRICONEX, Prosoft etc. Various kinds of imported industrial parts

MB510 3BSE002540R1 Industrial control module

evaluation of the voltage/frequency ratio
single-phase measurement
definite time delay
determination of frequency from the complex voltage vector
insensitive to DC components
insensitive to harmonics
over or underexcitation mode Explanation of parameters: RunOnCPU defines the processing unit which runs the function. ParSet 4..1 Parameter for determining in which set of parameters a particular function is active (see Section 5.11.). Trip 01-08 defines the tripping channel activated by the tripping O/P of the function (matrix tripping logic). Trip 09-16 corresponds to Trip 01-08 (providing tripping unit fitted). Trip 17-24 corresponds to Trip 01-08 (providing tripping unit fitted). Trip 25-32 corresponds to Trip 01-08 (providing tripping unit fitted).

The overfluxing function is primarily intended to protect the iron cores of power transformers. Tripping by the function is delayed to avoid false operation during system transients such as load shedding. The magnetic flux is not measured directly. Instead the voltage/frequency ratio, which is proportional to the flux and easier to measure, is monitored. Overfluxing can result from either an increase of system voltage or a reduction of system frequency. For example, 10 % overfluxing at constant frequency is equivalent to increasing the value of the U/f ratio to 1.1 UN/fN

Inverse time overfluxing (U/f-Inv) 

A. Application Protection of generators and power transformers against excessive flux. B. Features
evaluation of the voltage/frequency ratio
single-phase measurement
inverse time delay according to U/f ratio
determination of frequency from the complex voltage vector
insensitive to DC components
insensitive to harmonics
determination of delay by integration
input of delay table facilitates matching the operating characteristic to a specific machine according to IEEE Guide C 37.91-1985.
adjustable rate of counting backwards when the overfluxing disappears.

Magnetic flux for enabling char. V/f-Setting Reference value VB-Setting Minimum operating time t-min Maximum operating time t-max 10 values defining the inverse t [V/f = 1.05] ... t [V/f = 1.50] time operating characteristic Reset time t-Reset The overfluxing function protects the iron cores of generators and power transformers against excessive flux. The magnetic flux is not measured directly. Instead the voltage/frequency ratio, which is proportional to the flux and easier to measure, is monitored. Overfluxing can result from either an increase of system voltage or a reduction of system frequency. For example, 10 % overfluxing at constant frequency is equivalent to increasing the value of the V/f ratio to 1.1 UN/fN. The limit curve for the maximum magnetic flux (V/f) permissible for electrical machines is defined in
standards
data supplied by manufacturers. The limit curve for Westinghouse machines is given in Fig. 3.5.23.1