PARALLELING
HONDA
EU6500s & EU7000s
for
100A/120A OUTPUT
in our
HD P&P Pkg
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feature electrical packages
for
100A or 120A Output
We have developed a new HD Plug-n-Play Pkg. that enables the
paralleling of either two Honda EU6500 or EU 7000 inverter generators to generate an
unprecedented 100 or 120 Amps of power from portable generators. A complete
system consists of two generators, a Paralleling Control
Box, and one of our Transformer/Distros (either 60-, 84-, or 100 Amps.)
(Parallel operation of two unmodified Honda EU6500 generators made
possible by our 100A Paralleling Control Box)
The Paralleling Control Box syncs the frequency and equalizes the load
between the generators. Our proprietary paralleling control circuitry
(pictured below) uses the Pulse Width Modulation (PWM) of the generator's inverters to synchronize the phase angles of the two generators
using an open-loop architecture. In order to optimize the combined output of two machines, the load must be split evenly amongst them otherwise
one generator will reach its' maximum output while the other can still take more load. For this reason, our Paralleling Control Box enables you to adjust
load sharing between the generators by turning a knob. The final function of our control box is to switch the outputs of the inverters to a common
load bus after their frequencies are locked in step (same phase angle and time base.)
(Paralleling Control Box load sharing equalization knob (left),
100A/240V Bates & 50A/240V Hollywood Twist-lock receptacles (right)
To provide power that is readily accessible, our 100A Paralleling Control
Box is outfitted with a "Hollywood Style" 240V Twist-lock receptacle. The "Hollywood Style" Twist-lock
receptacle is there to supply power to either our 60-, 84-, or 100 Amp
Transformer/Distro. The addition of a Paralleling Siamese with a 240V Bates pocket will enable you to power large
HMIs that operate at 240V (4k - 9k ARRIMAXs) as well as 120V loads on the Transformer/Distro. To power 12kw HMIs
requires modification to the generators (both EU6500s and EU7000s) and our 120A Paralleling Control Box (see picture below.)
(Our 120A Paralleling Control Box combining the output of two modified Honda EU6500s
to
power a Mole 12/18K Par head with 12kw globe)
The Transformer/Distro serves several important
functions in this system that enables two generators to be paralleled (see
below for details), but its' primary function is to step-down the
combined 240V output of the two generators into a single large 120V
circuit (either 60-, 84-, or 100 Amps) that is capable of powering more small
lights or larger 120V lights (up to 10k Quartz) than has ever been
possible before on the super quiet Honda EU generators.
(A peek under the hood of our Paralleling Control Box)
Each of our
Transformer/Distros is likewise outfitted with an industry standard 120V
Bates receptacle so that you can use standard distro equipment, like
Bates Siameses, Extensions, and Break-Out boxes to distribute power
around your set, breaking out to U-Ground Edison Outlets where ever
needed.
An added feature of our Transformer/Distros is that, no matter where
you plug into the distro on its' secondary side, it automatically
balances the load on the generator's two legs (which is critical for
successful paralleling of two machines - see below for details.)
(As demonstrated
here, our new HD Plug-n-Play Paralleling System can power
a 6K HMI as
well as 6000W of additional lights)
This
feature also makes electrical distribution on set incredibly simple:
you just plug in lights until one of the generator's load indicators
reads 6000 Watts and the Transformer/Distro does the rest. But, the
most important benefit to be gained by using our Transformer/Distro,
the one that makes it possible to parallel two EU6500s and EU7000s in the first
place, is that it isolates the generators from high neutral return
currents that can lead to dangerous neutral “cross-current”
between the two generators (see below for more details.) For sales or rental information contact rentals@screenlightandgrip.com
__________________________________________________________________
Each component of our
"HD Plug & Play Package"
is available for
Rental or
Sale
Mole Richardson, K5600, Power to Light, Kino Flo, and Honda.
-More efficient and compact HMI, Quartz, and now Fluorescent Par Lights.
-Brighter and more efficient "short arc" HMI bulb designs.
-120/240V Electronic HMI ballasts with Power Factor Correction.
-Cool burning, energy efficient Fluorescent Lighting Fixtures.
-Innovative new rigging hardware.
These technological advances in lighting design now enable the use of bigger lights, or more smaller lights, off of standard wall outlets or off a new generation of quieter and more powerfull Honda Inverter Generators. Click here for detailed information on our HD P&P Pkg.
__________________________________________________________________
Time to put our Geek Hats on:
The following is a brief explanation of the importance of our
Transformer/Distro in the successful paralleling of two Honda EU6500s and EU7000s.
If some of these concepts are foreign to you, we suggest you first read
our technical “White Paper” on the use of "Portable Generators in Motion Picture Production"
that is cited in the 4th
Edition of Harry Box's "Set Lighting Technician's Handbook" and then read an
informative article by Gary Olson, Technical Support for Cummins Power,
on “Paralleling Dissimilar Generators.”
on portable generators than has ever been possible before."- Harry Box
The voltage waveform shape created by a generator is affected by its'
load. The resulting waveform may be described in terms of its
fundamental frequency and voltage magnitude and the magnitude of the
harmonic voltages and their frequencies that make it up. This harmonic
voltage distortion, while small in the case of inverter generators, may
still be significant, particularly in paralleling applications.
(Harmonic Content of a Generator's Voltage
Waveform)
The illustration above shows the relationship of first-order
(fundamental frequency waveform) to third- and fifth-order harmonic
waveforms of the resulting waveform. The harmonic voltages are
effectively added to the fundamental waveform, resulting in the pure
sinusoidal shape of the fundamental being somewhat distorted. For
example, the resultant voltage at time A in the illustration above will be
the sum of the blue (fifth-order), green (third-order), and red voltage
magnitudes. So, the instantaneous voltage at that instant in time would
be somewhat higher than the voltage of the fundamental.
Even though the voltage of the two
machines is forced to the exact same RMS magnitude when generators are paralleled, each voltage
waveform can have different harmonic components. Differences in the
harmonic make up of the resulting voltage waveforms results in current
circulating continuously between the two machines because their neutral
conductors are tied together in paralleling operation. This is referred
to as a “cross current” situation. The source of this
circulating neutral current is illustrated below.
(How 3rd Harmonics are
generated)
In this illustration, two voltage waveforms of the same RMS value (the red and blue lines) are superimposed upon each
other. Note that even though these voltage waveforms have the exact same RMS magnitude (they would read the same on a true RMS meter),
at different points in time the blue voltage is higher than the red, and vice versa. Since there exists potential (voltage) between the two
machines at these points, when the machines are connected together on a common bus, current will flow between the machines
(cross current.) Note that because the blue and red voltage lines cross each
other three times in each half cycle, the cross current includes a 3rd harmonic component (this current is represented by the green line.)
And, because the neutral systems of the two machines are tied together into a common neutral bus, this cross current will circulate (as illustrated below)
between the two generators continuously.
Cross current can become a problem if we add to it the triplen harmonics dumped into the neutral by non-linear loads such as non-power factor corrected HMIs, Kinos, & LEDs. Because these harmonic currents (the triplens and the 3rd harmonic of the cross current) are in phase with one another they do not cancel in the neutral as fundamentals do, but instead build one on the other to create elevated cross current with a large 3rd harmonic that circulates continuously on the neutral conductors. And, because the elevated 3rd harmonic cross-current is at a higher frequency (180Hz) it generates heat exponentially (use this link for details.), resulting in the overheating of the conductors and the generator's inverters. Since the harmonic content of a generator waveform varies with the load, the negative effects of operating with dissimilar voltage waveforms will be most apparent at rated load because that is the point at which the rise in internal temperature created by elevated cross currents will typically be highest and the generator's inverters most susceptible to failure.
Our 100A Paralleling Control Box for unmodified Honda EU7000s provides 100A output
and load sharing control to optimize the output.
One way to avoid the problems associated with 3rd harmonic currents continuously circulating on the neutral
is to simply drop the neutral connection between the load and the generators. For this reason, we have designed the electrical distribution
of our paralleling set-up to include a 240V-to-120V step-down Transformer/Distro to serve 120V loads (rather than a "Splitter Box.") Since
there is no electrical connection between the primary and secondary of a transformer, our Transformer/Distro
interrupts the path on which the most disruptive current can flow in a paralleling set up (the load 3rd harmonic.) Again, load 3rd harmonics
(those generated by non-power factor corrected loads like HMIs, Kinos, & LEDs) are problematic because they will not cancel with the cross current 3rd
harmonic generated by paralleling two generators. The net result can be severely elevated cross current circulating between the two generators leading to
their inverters over-heating.
(As demonstrated here, our new HD
Plug-n-Play Paralleling System can power
a 6K HMI as well as 6000W of additional lights)
In our system, large HMIs operate single-phase at 240V on the 250V Bates
receptacle on the control box and hence return no harmonic currents to
circulate as cross current. But, what about smaller HMIs, Kinos, and
Quartz lights that operate at 120V and require a neutral? That's where
our Transformer/Distros play an important role. Their Single Phase step-down
configuration both creates the required neutral connection for smaller
120V loads, and at the same time (as illustrated below) isolate the generators from the 3rd
harmonics created by these loads that would otherwise lead to elevated
cross current.
(Our Transformer/Distros isolate triplen harmonics from the generators so that they can not elevate cross current to a hazardous level.)
The harmonic currents generated by small HMIs, Kinos,
& LEDs will cause heating in the primary of our Transformer/Distro
(it can take it - it's built for it), but the disruptive effect of
their flow in the system neutral of the paralleled generators is
eliminated so the generator inverters remain cool. By eliminating a neutral
connection between the gen-set bus and the loads, a Transformer/Distro eliminates
the reason (harmonic problems) that prevented the successful parallel operation
of EU6500s before - making it now possible to operate more
lights, or larger lights, on portable Hondas than has ever been
possible before (use this link for a more detailed explanation.). Given the high sensitivity of HD camera systems these
days, just about all the light you will need to obtain good production
values can now be operated on our new HD Plug-n-Play Pkg. Use this link for
sales information on our HD Plug-n-Play Pkg. or contact rentals@screenlightandgrip.com.