Hitachi Relion 670 Series Applications Manual page 264

Section 16
Monitoring
standard IEEE 519-2014, harmonic current distortions on a power system with short circuit strength less
than 20 is limited to 5% total demand distortion (TDD).
tDelayAlmTDD: It defines the alarm time limit for the calculated total demand distortion which is applied
after the warning signal pickup and depends on its sustainability.
WrnLimitTHD: It defines the warning limit for the calculated total harmonic distortion.
tDelayAlmTHD: It defines the alarm time limit for the calculated total harmonic distortion which is applied
after the warning signal pickup and depends on its sustainability. This intimates the operator to take
corrective operations immediately, otherwise the system will go under thermal stress.
WrnLimit2ndHD: It defines the warning limit for the calculated second harmonic distortion.
tDelayAlm2ndHD: It defines the alarm time limit for the calculated second harmonic distortion which is
applied after the warning signal pickup and depends on its sustainability.
WrnLimit3rdHD: It defines the warning limit for the calculated third harmonic distortion.
tDelayAlm3rdHD: It defines the alarm time limit for the calculated third harmonic distortion which is
applied after the warning signal pickup and depends on its sustainability.
WrnLimit4thHD: It defines the warning limit for the calculated fourth harmonic distortion.
tDelayAlm4thHD: It defines the alarm time limit for the calculated fourth harmonic distortion which is
applied after the warning signal pickup and depends on its sustainability.
WrnLimit5thHD: It defines the warning limit for the calculated fifth harmonic distortion.
tDelayAlm5thHD: It defines the alarm time limit for the calculated fifth harmonic distortion which is applied
after the warning signal pickup and depends on its sustainability.
WrnLimit6thHD: It defines the warning limit for the calculated sixth harmonic distortion.
tDelayAlm6thHD: It defines the alarm time limit for the calculated sixth harmonic distortion which is
applied after the warning signal pickup and depends on its sustainability.
WrnLimit7thHD: It defines the warning limit for the calculated seventh harmonic distortion.
tDelayAlm7thHD: It defines the alarm time limit for the calculated seventh harmonic distortion which is
applied after the warning signal pickup and depends on its sustainability.
WrnLimit8thHD: It defines the warning limit for the calculated eighth harmonic distortion.
tDelayAlm8thHD: It defines the alarm time limit for the calculated eighth harmonic distortion which is
applied after the warning signal pickup and depends on its sustainability.
WrnLimit9thHD: It defines the warning limit for the calculated ninth harmonic distortion.
tDelayAlm9thHD: It defines the alarm time limit for the calculated ninth harmonic distortion which is
applied after the warning signal pickup and depends on its sustainability.
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1MRK511407-UUS Rev. N
Phasor measurement unit RES670
Application manual