Setting Guidelines; Current Harmonic Monitoring Chmmhai(Ithd); Function Revision History; Identification - Hitachi Relion 670 Series Applications Manual

Section 16
Monitoring
16.9.3

Setting guidelines

The settings tAlarm and tWarning are user settable limits defined in hours. The achievable resolution of
the settings is 0.1 hours (6 minutes).
The limit for the overflow supervision is fixed at 99999.9 hours.
The setting tAddToTime is a user settable time parameter in hours.
16.10

Current harmonic monitoring CHMMHAI(ITHD)

16.10.1

Function revision history

Document
revision
D
E
F
G
H
J
K
M
N
16.10.2

Identification

Function description
Current harmonic monitoring
16.10.3

Application

In order to maintain the power quality for better supply, harmonics in the system must be monitored. Due
to the nonlinear loads connected to the system, harmonics (apart from fundamental frequency
component) are generated and thereby the system voltage is distorted. Voltage distortion appears to
have a little effect on operation of nonlinear loads connected, either phase-to-phase or phase-to-neutral.
Current distortion is limited at the point of common coupling PCC to control the harmonic current from the
utility to the consumer. Thereby, the voltage distortion must be limited in order to prevent it from
spreading to other facilities.
256
tAlarm and tWarning are independent settings, that is, there is no check if tAlarm > tWarning.
Product History
revision
2.2.3 -
2.2.3 -
2.2.3 -
2.2.4 -
2.2.4 -
2.2.4 -
2.2.5
Updated monitoring till 9
th
monitoring till 5
2.2.6 -
2.2.6 -
IEC 61850
identification
CHMMHAI
© 2017 - 2023 Hitachi Energy. All rights reserved
th
order current harmonics. Refer to document revision J for
order current harmonics.
IEC 60617
identification
ITHD
1MRK511407-UUS Rev. N
GUID-D3BED56A-BA80-486F-B2A8-E47F7AC63468 v1
GUID-692151F8-812B-4B32-AE86-E7A4E4B0101B v1
GUID-5883ADA7-549A-464B-AC60-082A50165A2B v2
GUID-C7863D78-34DB-42E5-90FE-6483EDAAF319 v1
ANSI/IEEE C37.2
device number
ITHD
GUID-987BCB6C-C559-42EE-9AAB-5F71189A58C6 v3
Phasor measurement unit RES670
Application manual