ABB Relion 620 Series - Power Quality Measurement Functions; Current Total Demand Distortion CMHAI; Identification; Function Block

10 Power quality measurement functions
10.1 Current total demand distortion CMHAI
10.1.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE
C37.2 device
number
Current total demand distortion CMHAI PQM3I PQM3I
10.1.2 Function block
Figure 570: Function block
10.1.3 Functionality
The current total demand distortion function CMHAI is used for monitoring the
current total demand distortion TDD.
10.1.4 Operation principle
The function can be enabled and disabled with the Operation setting. The
corresponding parameter values are "On" and "Off".
The operation of CMHAI can be described with a module diagram. All the modules in
the diagram are explained in the next sections.
BLOCK
ALARM
Distortion
measure-
ment
I_A
I_B
I_C
Demand
calculation
Figure 571: Functional module diagram
Power quality measurement functions
1MRS757644 H
1082 620 series
Technical Manual