Atec Power-NH300 User Manual
Harmonic Neutralizer
Magna-Power Electronics Harmonic Neutralizers eliminate
families of harmonic components by multiplying the number
of input phases with specially wound magnetic components.
These transformers, in combination with equally loaded,
high-power DC power supplies, o er a cost-e ective solution
to maintaining power quality at acceptable levels. Harmonic
Neutralizers are packaged in cabinetry designed to be integrated with multiple MT Series VI installations.
Why Neutralize Harmonics?
Input current harmonics are a by-product of nearly all
power supplies. Power can only be delivered to the load if the
frequency and phase of the voltage and current match. For a
three phase power supply using a three phase input rectifi er, the input current has a theoretical spectrum of 6n±1
where n is an integer incrementing from 1; this is known as
a 6-pulse waveform. This means that a power supply with
a three phase input rectifi er will produce input currents at
1, 5, 7, 11, 13, 17, 19 ... times the fundamental frequency.
The theoretical magnitude decays as the reciprocal of the
harmonic component. The 5th and 7th harmonic components have magnitudes of 20% and 14% of the fundamental
component, respectively.
Harmonics currents in power systems can fi nd unusual
paths and can cause problems if the magnitude is signifi cant
and there are loads sensitive to harmonic frequencies. For
example, lighting ballasts have series connected capacitors
and inductors which can be excited by harmonic currents.
IEEE has introduced standard, IEEE 519, which defi nes
recommended limits. Implementing this standard requires
a knowledge of the power system and other loads producing
harmonics. Unfortunately, the standard can allow the same
power supply to possibly exceed limits in one application
and not in another. In the same respect, a power supply may
or may not can cause a harmonic related problem with or
without meeting IEEE 519. The best solution to minimize
the risk of a harmonic problem is to eliminate the harmonic
current at the source.
AC Harmonic Waveforms
The following fi gures are representative of expected AC
current waveforms for the various pulses available from
Magna-Power Electronics power supplies. As standard, models 2 kW through 150 kW produce 6-pulse waveforms, while
250 kW models produce 12-pulse waveforms. Magna-Power
Electronics Harmonic Neutralizers suppress families of
harmonics by increasing the number of power phases. It can
be used when multiple power supplies are used in series or
parallel and are equally loaded. Harmonic Neutralizers can
produce 12-pulse, 18-pulse, 24-pulse, or 48-pulse waveforms
which have harmonic current components on the order of
12n±1, 18n±1, 24n±1, or 48n±1, respectively. The following
fi gures show the theoretical difference for waveforms with a
different number of pulses. Harmonic Neutralizers are protected with appropriate sized primary-side circuit breakers.
1
0.8
0.6
0.4
0.2
0
−0.2
−0.4
−0.6
−0.8
−1
0 0.005 0.01 0.015 0.02 0.025 0.03
1
0.8
0.6
0.4
0.2
0
−0.2
−0.4
−0.6
−0.8
−1
0 0.005 0.01 0.015 0.02 0.025 0.03
6-Pulse Waveform
Time (s)
18-Pulse Waveform
Time (s)
1
0.8
0.6
0.4
0.2
0
−0.2
−0.4
−0.6
−0.8
−1
0 0.005 0.01 0.015 0.02 0.025 0.03
1
0.8
0.6
0.4
0.2
0
−0.2
−0.4
−0.6
−0.8
−1
0 0.005 0.01 0.015 0.02 0.025 0.03
12-Pulse Waveform
Time (s)
24-Pulse Waveform
Time (s)
Size Diagrams
1
24.000
Models and Ratings
Model
Power
Modules
HN200-12 2 x 100 kW 200 12 935 62.5 x 24 x 31.5
HN300-12 2 x 150 kW 300 12 1602 62.5 x 24 x 31.5
HN400-12 4 x 100 kW 400 12 1670 62.5 x 24 x 31.5
HN450-18 3 x 150 kW 450 18 1982 62.5 x 24 x 31.5
HN500-24 2 x 250 kW 500 24 3003 62.5 x 24 x 31.5
HN600-12 4 x 150 kW 600 12 3003 62.5 x 24 x 31.5
HN1000-48 4 x 250 kW 1000 48 9012 62.5 x 72 x 31.5
www.magna-power.com 29
Power
(kW)
Pulse
No.
Weight
(lbs)
Size
(H” x W” x D”)
62.500
4.250
2
4
3
1
Air Exhaust Fans
2
Input Circuit Breakers
(Some Models Have
One Circuit Breaker)
3
Air Intake
4
AC Input Entry
Loading...