GE RPV311 Technical Manual page 200

RPV311
2.3.1 Description
2.3.2 TW Fault Location Methods
RPV311-TM-EN-7
After the fault location calculations are performed, the distance to fault is displayed
on the software interface and it is made available via MODBUS communication
according to the MODBUS IDs configured on the Transmission Line configuration
menu and the IP address configured in the windows Ethernet properties of the RPV
Manager computer.
Whenever a TW fault location is performed the RPV Manager will provide three
separate 16-bit MODBUS registers. The registers are described below:
Description MODBUS
Register_1
Register_2
Register_3
In order to achieve the actual fault location it is necessary to combine the 2 fault
location registers (30002 and 30003) into a single 32-bit value. The register 30003 is a
decimal representation of the 16 most significant bits of the complete 32-bit register
which contains the fault location and the register 30002 is a decimal representation
of the 16 least significant bits of the 32-bit register. The combination of them will
result in the actual fault location in meters.
Below is the necessary operation to combine both fault location registers:
Actual fault location in meters = ((Register_2 & 0XFFFF) | (Register_3 << 16))
The RPV Manager uses two calculation methods for TW fault location. They are called
"Basic" and "Advanced". The method used for each calculation is identified on the
RPV Manager interface, as shown in Figure 97. The two methods are described
below:

Basic Method
Uses a threshold configured on the Transmission Line menu, which is a percentage
value of the full scale of the register, to identify the beginning of the traveling wave
created by the fault and, consequently, to find its timestamp in order to use in TWFL
calculations. This method uses only the high frequency COMTRADE files acquired by
the RA333 units locate the fault.

Advanced Method
This method uses both the fault register (waveform at 50/60Hz) and the TW register
(high frequency register) to identify the fault location. The fault register is analyzed
using a high-pass filter filter in order to find the time window that contains the fault
begging, then that time window is used in the TW register to enhance the location of
MODBUS identifier configured on the Transmission Line
30001 menu used to identify which transmission line the current
fault location refers to.
As the fault location is split into 2x16-bit register. This
30002 register carries the LSBs (least significant bits) of the 32-bit
register.
Second part of the fault location. This register carries the
30003
MSBs (most significant bits) of the 32-bit register.
Chapter 13 – RPV Manager
Observation
200