For effective power management, companies today are providing their customers with end to end integrated solutions
By Richa Chakravarty
Saturday, September 15, 2012: Industrial inverters are designed to handle heavy loads on a daily basis. These inverters have a wider operating range, which means they can handle colder temperatures and greater heat. They are used in all sectors in which power backup is required, like telecommunications, manufacturing, commercial buildings, hospitals, malls, etc. Basically, they are being used in scenarios in which there is a non-critical load, yet where power backup is a must.
The latest in the market
Effective power management solutions are the need of the day. To meet these requirements, many companies with good product lines now provide their customers with end to end integrated solutions. Digital signal processing (DSP) is the reigning technology that companies are cashing in on. Delta has introduced the 160 to 1600 kVA Delta Ultron DSP range. This is a double conversion, insulated gate bipolar transistor (IGBT) rectifier three phase UPS system, incorporating state of the art triple level inverter (TLI ) topology. This offers better efficiency at full load than a two level inverter, which in turn translates to a smaller heat sink and better reliability. With this advanced technology, Delta claims to have set a new benchmark for backup power solutions with a high efficiency of up to 96 per cent.
The Colossal series by Su-Kam, another new product, is a heavy duty inverter that produces pure sine wave power. Ranging from 5 kVA up to 100 kVA, it incorporates DSP in conjunction with sine wave technology and delivers an output that is completely stable and distortion free. This technology offers high speed data processing and is absolutely safe to run even the most sensitive equipment. It is also equipped with the advanced communication mode. It has an LCD display that provides information regarding the overall status of the inverter, charge of the battery, load level, etc. Also, it is preloaded with a power manager to audit power quality, and is capable of initiating SMS or email alerts and managing scheduled shutdowns. It comes with ‘Powerdoc’, which is Web based software that helps in remote monitoring of the inverter. This series comes with special features like inbuilt galvanic isolation transformers and auto self-tests, which make it different from other inverters in the industry.
Uniline’s latest offer is a high frequency, high efficiency DSP based industrial inverter. Ranging from 1 kVA to 300 kVA, in single or three phase, it is a pure sine wave inverter with unlimited backup. Uniline also offers DSP based industrial inverters based on IGBT pulse width modulation (PWM) technology. It has zero changeover time, as well as automatic boost and trickle charging, which comes with deep discharge battery protection. These inverters are mainly for telecom, railways and applications where reliability of system is most important.
Measuring the pulse of the market, most of the inverter companies are moving ahead towards greener products and practices, harnessing solar power for energy storage. Emerson Network Power’s latest offering is the Liebert ESU off-grid inverter with a battery to store solar power. It
uses the maximum power point tracking (MPPT) system to maximise power production. It is built on bi-directional solar inverter topology with DSP/microcontroller-based controls and an IGBT/MOSFET based power design with an output isolation transformer. It features three different modes of operations—stand alone mode, grid import mode and grid export mode. Liebert ESU is a single and three phase inverter, which operates in parallel with the grid. Solar photovoltaic panels convert solar energy into electrical energy as DC power. With 20 years of design life, it offers high efficiency and reliability. It comes with an inbuilt LCD display and sophisticated local and remote monitoring system.
The latest offering from Volta Powerlink Pvt Ltd is the lift inverter, which ranges from a capacity of 6 to 200 kVA. These industrial inverters have a high inrush/peak current handling capability, pure sine wave output, high frequency PWM inverter, crystal controlled output frequency, compact and well engineered architecture, with smooth and silent operation and superior performance.
Manufacturing various inverters of rating 500 VA to 20 kVA, RS Power Systems offer pure sine wave inverters with microcontroller based PWM technology using MOSFETs. With Soft start capability for initiating heavy loads, it comes with auto reset features for overload, short circuit, low battery on inverter mode. It also offers high and low input voltage protection for connected appliances and battery deep discharge protection against overload.
Customised solutions
Manufacturers today have not only increased the capacities of inverters but are also meeting the demands of reliability, minimised time to repair (MTTR), high efficiency, etc. Companies are offering a low cost of ownership both in terms of capital expenses and operational costs. The reliability of inverter designs is currently constrained by technology, quality of components and manufacturing processes. So, to further improve uptime, efforts are being made to reduce the MTTR.
Today, inverter systems are being designed with heavy duty chargers capable of working 24 hours even in
extreme environments. These inverters are being customised in the areas of battery backup, rating of inverters and even voltage. Companies are designing solutions for industrial applications in order to handle high inrush current. Su-Kam has introduced its range of Kisan inverters designed for farmers wherein the tractor battery is used to provide power for lighting. Fuzzy logic technology introduced by the company offers better battery charging to increase the life of batteries and enhance the backup. It also provides inbuilt galvanic isolation.
Most players like Emerson work closely with their customers to achieve the kind of customisation required. Liebert ESU features three different modes of operations standalone, grid import and grid export. Customisation allows customers to discharge battery once solar is not available or transfer the load to grid without discharging the battery while keeping it for emergency purpose.
How to choose the right inverter
Before buying industrial inverters, buyers should look for the latest technology, for example, IGBT. The input range of the inverters should be wide enough to cater to the voltage fluctuation at the user’s location. 
The output waveform should be pure sinusoidal output with very low harmonic distortions and the capability to handle non-linear loads.
The systems should be highly efficient, allowing the user to reduce the energy bill and improve the overall heat handling requirements. Also, manufacturers should help buyers identify their load requirement, the applications required and even gauge the criticality of the application. Equally, the buyer should consider reliability, efficiency, size and cost of the inverter.
Here are a few more aspects to be considered before deciding on the right inverter for any particular application:
- Inverter technology used and whether it is built on the MPPT design
- Isolation, exact load and backup time in order to arrive at the optimum battery size
- Service response time
- Featured operational modes and the option of a solar inverter
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