DC-AC Inverters - Insights

I like IGBT transistors and this time when I worked with water plasma ... I read about new conception power HV transistors 10kV cca 100kHz.

SiC switching transistors, operations at very high frequencies, 5-Transistors H-Bridge transformer-less topology, switching at high voltages, all-digital IT-enabled designs, remote-diagnostics

Transformerless, re-programmable, reduction of component cost, improvement of component quality, fault management (diagnostics, reporting, error correction)

I cannot say at this time, but I found a Chinese company that was responsive to helping engineer a product to whatever specifications I might have.

Most of the Chinese companies are producing reliable inverters because now a days China is the biggest user of solar and wind power energy.

Schneider Electric, ABB, Siemens,Power one, Emerson, Delta Samsung Delta, AU optronic.......................

In the year 1992 I repaired a frequency inverter which was built on CMOS logic, Operation amplifiers and bipolar transistors In Samsung we had 100kVA UPS and frequency changer, but I didn't design their equipment.

Railway Rolling Stock- Onboard power supply in the United Kingdom is generally DC. Application to provide power to Mobile phones and radio equipment has required investigation at Design and procurement stages.

Solar PV connection to AC building networks. Supporting UPS sections (Essential/Nonessential) of building supplies. Supporting building supplies in areas of uncertain power supply.

Many! 1. Use of a soft-start inverter (5KVA) to power a motor-driven 'sluice gate' which was using a diesel genset of 25-KVA earlier. The gate opening increased from 5 minutes to 12 minutes. 2-KWp of PV and battery bank of approx. 30-KWhr did the job. DG was replaced by this. 2. Power a 'floor mill' in few remote villages using a huge and bulky DC motors by a robust induction motor and driven by soft start inverters.

Using them for solar panel power modification to convert the dc produced by the panels to usable AC is not really a non-standard application, but this is my next project for them. I have plans to build a solar powered car that will utilize an inverter too.

At a former employer I had a need for 400 Hz, 117 VAC, 1 amp. Had to borrow 'boat anchor' inverter from another lab several buildings away. A low cost 400/117/1 inverter would have been ideal for this application.

Inefficient inverter, undersized battery bank cables, bad battery charges and a wrong choice of location - all or any of above factors can cause major failure, fire!!

Some years back at a boat show, one of the vendors had a dual output inverter, 120/240 and had it set to 240 volts, blew out the tv/vcr. Bad day.

Wanted to use the inverter standalone but it needed to power on with main supply. This was a bad experience.

Mass produced low cost grid-tied macro-inverters (300W to 600W) that can work in remote regions (without conventional grids) with a captive smart-grid. The modular design should permit both consumer and the micro-grid to expand as the energy-needs of such first-timer users grow.

Close to true sinusoidal wave production. Consistent performance throughout heat and life cycle. Tolerance for input variations or a compatible external component that will be tunable to specific needs. This would increase the useability of a single DCACi.

500W out put power 60Hz true sine wave Operating ambient temperature range -10 degree C to 45 degree C No-fan cooling less than 1kg in weight

1. It should be a very low loss, inverter that can work safely at your ambient temperatures. Even if it costs a little extra. 2. It must have a healthy and smart battery management algorithm - the battery replacement costs are very large and a ordinary inverter can cause a premature death to the battery bank. 3. Make sure that it does not create a bad power factor on your grid . Ask for an inverter that uses a unity power factor of battery charging. 4. Make sure that the inverter batteries are placed at location with free flow air.

Starting with one solar cell (and one inverter), trying it before spending so much money... this application is for low voltages so you don't need to ask special permission, or use special experts for installation. also, check the lifetime of the inverter because it is not a trivial thing, short lifetime of one of the components will cause replacing the inverter which costs a lot of money... you might need a lot of inverters for reaching enough power to the house needs, there are topologies and technics in order to save...

Know exactly what you need in terms of input, output, safety and reliability. There are very few inverters that are appropriate for a wide range of applications; find the one suitable for your application.

1. Insist for the sinewave output. 2. Insist of highest efficiency at loads of 60% of the rated capacity (typically 95% low voltage DC e.g 48VDC). 3. Insist for the value of the 'tare loss' (self consumption) it must be very small. Typically 5Watts for small to medium power inverters. 4. Ideal unit should be ' load seeking' type i.e of the load goes below the lowest limit set.the inverter should go on the scanning mode, as soon as the load is switched on it shall switch on in few seconds. (This is for non-UPS application).

Products vary widely and too many players play in only the low power range. There is a host of uses for high power/high efficiency units and a company that can deliver a reliable product in this realm will have tremendous growth potential.

Checking life time, way of connecting the solar cells and inverters, efficiency, how much money does the government return for each watt and for how long.