Warpverter

A Serious Electronic Project For The Expert DIYer

The Wiseguy (WG) Inverter

This guide is based on many of Wiseguy’s posts on the Back Shed forum … along with more from KeepIS and Poida, other key contributors to the project.

Wiseguy has been on the scene in the back shed for many years and as an Electronic Engineer had been involved in trying to determine why some Ozinverters would work perfectly and yet others would randomly blow up for no obvious reason.

His analysis of the design and experimenting led to a number of changes that improved the reliability considerably … and eventually led to a complete new layout altogether … now called a Wiseguy or WG Inverter.

KeepIS has built several versions of the Wiseguy inverter, all documented over on the Back Shed … effectively proving Wiseguy’s work and providing constant feedback on real life use (and abuse :)).

See here and here

He also has massive electronics and project building skills … and is a prolific experimenter … constantly exploring the limits to test every new segment of the design and method of building.

Read why KeepIS decided to go down the “Wiseguy” track …

“Way back, I actually purchased two other boards for an inverter build.

Once I got hold of the Wiseguy board and design, there was just no contest in it for the size, quality, stability and relative simplicity of building Wiseguys design and power board.

IMHO, in combination with the New Nano R6 controller, it's simply unbeatable.”

Here's one of his prototypes

Poida has also been on the Back Shed for many years and has been instrumental in adding microprocessor control for inverters and solar charge controllers being designed in the group.

His Arduino Nano programs have been used on many of the inverters built … and his 150V 45A MPPT has many, many examples built all around the world.

I have four of them and have clocked over 20MWh of power production in the last 20 months

Poida: 02/06/24

“It's one thing to see amateur people do a few things (think: me) and deliver a result that sort of works, if you hold your tongue right and have a coupl'a beers and accept fireworks and stuff.

It's an entirely other thing to have an E.E. of many decades offering a solution. This is Wiseguy. His inverter design is going to kick ass and it will not blow up.

It has most excellent FET Gate drive and there is NO shoot through at all. Not even a tiny bit. This is the best I have ever seen. I am lucky to be involved in a professional project.

If you want a good inverter, I would go for this project. It's just going to run and run and ran for years.”

Wiseguy is currently in the process of making available all the gerber files for his boards from one or two locations.

Then anyone can order whatever they want individually … or organise a group buy to get the price way down.

Wiseguy 02/12/25:

FYI I got quotes for 5, 10, 15 & 20 of the Power PCBs including shipping the results are below

WG30R2 PCB (Main Power board)

5 = $100 total (inc ship $48)  per ea $20.00  w/o shipping $10ea

10 = $121 total (inc ship $60)  per ea $12.00  w/o shipping $6ea

15 = $132 total (inc ship $71)  per ea $ 8.80  w/o shipping $4ea

20 = $198 total (inc ship $83)  per ea $ 9.90  w/o shipping $5.75ea !!

If the other various PCBs are purchased in prototype quantities (5) each type is under $7 (manufactured and delivered worldwide I believe), but if you were to add them to the Power PCBs order, freight can increase the overall freight cost rapidly.

My advice, a few Aussies? get together and order the power PCBs to share the more expensive 2oz PCBs and the cost.

Else if someone lives overseas just buy min. quantity of 5 & get over it, they now have 5 power PCBs for ~ $100!

All the rest are best ordered by each person separately local or overseas, the cost of the remaining boards is then ~$35 total for the 5 types & 5 of each (a few spares).

For anyone wondering what the "2oz" refers to ... it is simply the thickness/weight of the copper cladding on the pcb.

PCBs are normally 1oz ... but because of the massive currents involved in an inverter like this ... it is helpful to have thicker copper to help reduce voltage drop and heating effects.

It also saves having to run extra wires or copper bars across the surface to reduce resistance.

Sooo …. If you’d like to join the homemade inverter builder’s club, this is what you’ll need.

Power pcb (WG30-Rev2) 260mm x 108mm (2oz Copper)

Controller pcb (WG39-Rev7) 100mm square

Bulk Capacitor pcb x 2 (WG06-R1) 100 x 100mm (2oz Copper)

Toroid

Choke x 2

Display 20 character x 4 line

Arduino Nano x2 Microcontroller

Fan/s For Toroid and Heatsink

FETS HY5608 Mosfets

Capacitors 4,700uF or 10,000uF x 63V

It is recommended to buy a spare pair of Bulk Capacitor boards (WG06-R1) and fit some low value caps to use while setting up or during any fault finding. A lot more forgiving if there are any faults.

The Controller board has an Arduino Nano microcontroller that takes care of the control and monitoring of the inverter.

And the Controller connects to a Display driven by a second Arduino Nano … via 3 wires

The display can show

Vin … DC Voltage In … battery voltage

Vcap … Voltage across Capacitor bank

VAC … Voltage AC … AC voltage out

AAC … Amps AC … AC amps out

Temperature … of the toroid and the heatsink

Indicates if either fans are running

% of PWM power drive 0.0 - 99.9%

Error/fault codes

HY5608 Mosfets are recommended for the power board.

Wiseguy

“I do advocate the use of HY5608s for the Power PCB’s, they have proven to be extremely robust, each FET is roughly equivalent to two HY4008’s in parallel.”

Toroids:

We have the same requirements for a toroid with a Wiseguy inverter as for an OzInverter.

So anyone who can find an old 3kW Aerosharp will be set … or maybe three 2kW Aerosharps.

KeepIS has built a couple of inverters using three 2kW Aerosharp toroids stacked together. In his case, he removed the outer winding on each toroid … and then hooked the remaining windings in series. Followed by winding the heavy primary winding around them all.

Of course AEM Cores in Adelaide can provide what ever size toroid core you might want depending on your required output … though freight costs may be substantial.

Chokes:

Two chokes are required … one on each end of the primary winding.

Six toroidal ceramic cores are stacked together and have four or five turns wound through them.

KeepIS favours using a slightly lighter gauge wire for the chokes than the primary winding … to add some resistance … which helps reduces the load/shock on the mosfets.

WG Inverter Bare Boards

WG Inverter Capacitor Boards in Place

Power Board 260 x 108mm and Control Board 100 x 100mm

Wiseguy Inverter with Capacitor Boards in Position

Wanna run 24V or 36V instead of 48V …

With this controller you can run a 24V or 36V or 48V inverter with essentially no changes to the electronics.

The Toroid and the choke are the only parts that need to be changed to suit the DC input voltage and Power output requirement.

And for something really wild …

With the right toroid and chokes, a WG Inverter should happily run up to 6kW loads … BUT add a second power board, toroid and chokes … you can turn it into a 12kW inverter … all running off the one controller.

Trendsetter that he is ... KeepIS has built one of these as well ... using a total of six 2kW Aerosharp toroids ... three on each side.

Some Random Photos

To see more detail right click and "Open image in new tab"

How Split Phase works on a Warpverter

Stripping the enamel off the ends of the individual copper wires using a DF-8 electric wire stripper ... available from Amazon or aliexpress

Starting the final assembly

Bit heavy to lift at 57kg, so just rolled into place

Lor

Stripping the wire enamel off the "Small" toroid winding ends

Warpverter Full Bridge board layout

Warpverter Half Bridge board layout

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➤ Who designed the Warpverter?

Tony Le Grip, a retired professional power electronics design engineer from Melbourne, Australia

Tony is also known as "Warpspeed" on the forums he frequents

➤ What can you power with a Warpverter?

A Warpverter is a normal inverter and so can power anything a normal inverter can power ... as long as it is within the power capability of the inverter.

One huge advantage is that Warpverters have a massive surge capability so can start motors and loads with heavy startup current easily.

➤ What DC input voltage limits are there?

There's no major restrictions, it's a matter of designing the Warpverter for the batteries you plan to run. Anything from 24V to as high as you feel comfortable using.

Bear in mind, the higher the voltage the lighter gauge cables and windings you may be able to use.

Tony's Warpverter uses 100V Lithium cells and others have used 48V in either FLA or Lithium. A 3-phase version has also been built to operate on a 200V Toyota Prius battery.

➤ What batteries are best suited?

There's no real issue using whatever battery chemistry you desire ... as long as it has the capability of running the sorts of loads you plan to use ... and you have sufficient charging available to keep them healthy

➤ Can they be built for split phase operation?

The basic Warpverter builds up a stepped single phase 240v sine wave voltage, by combining in series, the secondaries of four independent transformers driven by the appropriate digital waveforms.

Its really a form of direct digital to analog conversion at very high power.

Two separate isolated 120v outputs can be generated from the same four transformers by arranging each transformer to have a pair of separate secondary windings, each of half the nominal voltage of the basic Warpverter.

That then will produce two 120v isolated outputs which could either be used in parallel for full inverter output power at 120v, or if connected in series, 240v split phase.

➤ Can a Warpverter be used as a grid tie inverter?

➤ Can you AC-Couple a Grid Tie Inverter to a Warpverter?

Yes ... there are examples out in the field.

➤ What sort of idle power does a Warpverter consume?

Tony's 5kW Warpverter has an idle power of 32 Watts and Roger's 15kW is at 35 Watts.

I believe the best to date is one that is 20Watts for a 7kW inverter

There is a bit of luck involved that concerns the quality of the core material used in the transformers. Some material is excellent, and some less so....

➤ Could a Warpverter provide 3 phase power?

Yes, a three phase Warpverter can be built ... and obviously will require three sets of four transformers.

As mentioned above, a three phase Warpverter has already been built.

➤ Could you rewind a three phase transformer to replace the individual transformers in a Warpverter?

No.

➤ If the design is so robust and uses easily available parts, why are they not in production?

It's really boils down to a matter of cost for all the copper wire and transformers. HF inverters are so much cheaper due to not needing large, heavy and expensive transformers.

It is probably really only viable for the DIY market where builders can source suitable second hand material and wind their own transformers.

➤ What are the main advantages of the Warpverter design?

The biggest advantage is all the switching is done at a very low frequency, so the circuit layout is far less critical than high frequency pwm, where it becomes increasingly difficult to successfully parallel multiple devices for very high power.

There are no data screens or firmware. It's a basic bare bones inverter, dc in, ac out.

The simplicity of the system means that it is much more easily repaired and less skill is required if any faults occur.

Its also fully bi directional. Really nasty highly reactive loads can bounce out of phase current right back onto the dc bus.

It also has massive surge capability, fully protected on the ac side with just a normal C curve thermal/magnetic circuit breaker.

If someone needed a 10Kw, 20Kw, or 30Kw inverter, this would scale up really easily, especially compared to a pwm type inverter where anything over about 5kW becomes problematic. Though bear in mind the transformers would obviously need to be suitably large.

➤ What are the main disadvantages of a Warpverter?

Winding four transformers is a huge undertaking, and not to be taken lightly. But if serious power is your goal, a Warpverter is likely to cause you much less long term grief. Its a lot of work, but you only have to do it once !

Of course the expense involved for copper wire and toroid or transformer cores is much higher than for a pwm transformer inverter build.

And then the finished weight is also much more than a pwm inverter.

Below about 4kW-5kW a conventional pwm transformer inverter would be cheaper to build.

➤ What surge capability does a Warpverter have?

Warpverters have a massive surge capability

➤ Is there any software to set up or be updated regularly?

No, not if using Tony's control board. That has no software at all.

A couple of others have been built using an Arduino for control, so they could potentially be updated or modified depending on who built them.

➤ How does the feed forward voltage control work?

Most inverters use voltage feedback to maintain a constant output voltage with changes of dc input voltage and load.

The main problem with that is its slow to correct.

The correction must be introduced slowly, or it can over correct and become unstable. Sudden large step changes in load (up or down) can cause annoying sags and surges in voltage resulting in light flicker.

The inverter output voltage will eventually settle, and then remain fairly constant.

Feed forward works in an entirely different manner.

The dc input voltage is measured, and the inverter can then very quickly adjust the waveforms driving the output transformers to compensate for any change in dc input voltage. The result is that the reaction time of the inverter to sudden dramatic load change can be made much faster acting.

It can compensate pretty much perfectly for input voltage variation over a very wide 2:1 dc input voltage range.

The down side is that although the transformer primary waveforms are well corrected, the transformer secondary voltages do fall slightly with increasing inverter load.

Voltage droop in my own 5Kw Warpverter is about ten volts (at 240v) from zero load to the full 5Kw rated output. That should be pretty typical, all mainly due to unavoidable voltage drop under load in the transformers.

The grid supply here varies more than ten volts anyway from day to day, and hour by hour, and none of my household appliances seem to mind. So I don't think its necessary to have a precise inverter set output voltage.

What is much more important is to have very fast voltage corrections for sudden step load change, and feed forward correction provides that.

Its especially good at reducing light flicker during the starting of large motors.

Its much easier and faster and more accurate to measure a dc voltage than an ac voltage, which is a constantly changing sine wave at 50/60Hz anyway.

The incoming dc is measured in a dual slope integrating a/d converter (to average out impulse noise) on the dc, and the measured voltage used to address one of 256 different lookup tables in ROM.

These lookup tables cover a 2:1 input voltage range, and allow for a very fine adjustment of inverter output voltage. Large very sudden jumps in voltage correction are possible, and always occur right at a zero crossing, so there are never any waveform discontinuities created from large applied corrections.

This can all be achieved with some simple robust and reliable hardware. The lookup

tables contain direct simple gate drive data to the four power switching bridges, there is no software or data manipulation involved.

➤ Where can you buy transformers to suit a Warpverter?

That is the $64,000 question. Unless you are very lucky and can find the odd transformer that can be used ... you either have to wind them yourself ... or have them wound professionally.

Considering the potential of a well built Warpverter, that is still quite viable ... but it seems to be the biggest deterrent for most home builders.

Click Circuits to Open High Resolution Versions

Tony's Warpverter showing the four transformers

Contact: Visit this thread on diysolarforum and message Warpspeed or rogerdw