Special solar inverters with the new features

Following the release of the Freesun HEC and HEC+ in Q1 2014, the Freesun HE Gen II is available ranging from 450kW to 1700kW. Engineered for serviceability and ease of maintenance, Freesun HE offers up to ten withdrawable conversion modules with an easy front access and direct rear cooling. It can be integrated in concrete stations HESr or 40” ISO container HET, allowing worldwide integrators and EPCs to play with different solutions but all with the same core.

The Freesun HE Gen II integrates substantial advances in control and construction: three output voltage levels 360Vac, 380Vac and 400Vac with wide MPPt windows by using motor control techniques, hyper range of power factor, reactive control during the night, added utility interactive functionalities, zonal VSD fan control without dust filters and automatic derating above 50 ° C or 820Vcc.

“The Freesun HE Gen II is based on intense and close work with the key players of the PV solar sector. Our product has been tested under the harshest environments in Mauritania and the United Kingdom, and now we are boosting its capacity to provide more cost competitive solutions to a price oriented PV market.

The omnik new energy has also rolled out the second generation single phase inverter, it use world class technologies, the maximum convert efficiency could reach 97.5%, and the MPPT adaptation efficiency is high up to 99.9% . 

The second generation single phase inverter has longer life cycle. It becomes more stable and reliable, faster CPU speed. It has higher inverter control accuracy and more convenient monitoring solution without any charge. The second generation series of Omnik PV Inverter are smaller and more compact than the first generation. They have longer lifetime and higher efficiency.

The two kinds inverters above are new styles, there are so many solar pv inverters on the markets,you can also compare their solar inverter prices and quality, wish you to a best solar pv inverter!

Structure and working principle of photovoltaic inverters

The inverter is mainly composed of switching elements such as transistors, so that by regularly repeated switching elements - off, the DC input to AC output. Of course, this is simply a solar inverter wholesale output waveform generated by the circuit on and off is not practical. Generally require the use of high-frequency pulse width modulation, so close to the sine wave voltage across the width becomes narrow, the center of the sine wave voltage of wider width, and in a half-cycle so that the switching element is always in one direction at a certain frequency operation, so that the formation of a pulse wave columns. Then let the pulse forming a simple sine wave filters.

The inverter is a power adjustment device consisting of a semiconductor device, is mainly used to convert the DC power into AC power. Generally consists of a boost circuit and an inverter bridge circuit. Boosting circuit boosting the DC voltage of the solar cell to the inverter output control required DC voltage; DC voltage of the inverter bridge circuit put boosted equivalently converted into a common frequency AC voltage.

AC inverter only has direct conversion function, it also has to maximize the performance of the solar cell functions and system fault protection. Summed up automatically run and stop function, the maximum power tracking control, anti-run single function, automatic voltage adjustment, DC detection, DC ground detection. Here a brief self-running and stop function and maximum power tracking control.

Omnik has launched new single phase inverters,Omniksol-2k-TL series inverters use world class technologies, the maximum convert efficiency could reach 97.5%, MPPT adaptation efficiency is high up to 99.9%, and Omniksol-2k-TL Photon Efficiency No.1 up to 3k in the world.

The morning after sunrise, solar radiation intensity gradually increased, the output of solar cells also increased, when the work required to achieve the output power of the inverter, the inverter automatically starts running. After entering operation, the inverter output will always monitors the solar cell module, as long as the required output power of the solar cell module is greater than the output power of inverter operation, the Hybrid Inverter will continue to run until sunset shutdown, even rainy days The inverter can also run. When the output of solar modules become smaller, the inverter output close to 0:00, the inverter will form a standby state.

The output of the solar cell module is vary with the intensity of solar radiation and temperature of the solar cell module itself. In addition, as the solar cell module having a voltage drop with the increase of the current characteristics, so there can be obtain the optimum operating point of maximum power. Solar radiation intensity is changing, apparently optimal operating point is changing. In contrast to these changes, and always let the operating point of solar modules at maximum power point, the system always get the maximum power output from the solar module, this control is the maximum power tracking control. Most important feature of solar power inverter system is included with the maximum power point tracking this feature.

Industrial grid-tied solar inverters

Grid Tie Inverters that are available on the market today use a number of different technologies. The inverters may use the newer high-frequency transformers, conventional low-frequency transformers, or no transformer. Instead of converting direct current directly to 120 or 240 volts AC, high-frequency transformers employ a computerized multi-step process that involves converting the power to high-frequency AC and then back to DC and then to the final AC output voltage.

Solar grid-tie inverters are designed to quickly disconnect from the grid if the utility grid goes down. This is an NEC requirement that ensures that in the event of a blackout, the grid tie inverter will shut down to prevent the energy it produces from harming any line workers who are sent to fix the power grid.

Many solar inverters are designed to be connected to a utility grid, and will not operate when they do not detect the presence of the grid. They contain special circuitry to precisely match the voltage and frequency of the grid.

Historically, there have been concerns about having transformerless electrical systems feed into the public utility grid. The concerns stem from the fact that there is a lack of galvanic isolation between the DC and AC circuits, which could allow the passage of dangerous DC faults to be transmitted to the AC side. Since 2005, the NFPA's NEC allows transformerless inverters. The VDE 0126-1-1 and IEC 6210 also have been amended to allow and define the safety mechanisms needed for such systems.