Now the application of inverter is mainly divided into four, one is a desert plant, there are some hills, ponds and so some of the additional land use, third is a commercial roofing, finally is the family of power station. The plant scale gradually decreases, the largest family of desert plant, mainly below 40000000. Reflected from four applications, technology development of photovoltaic inverter now of these a few years is very fast, the emergence of the four forms in its classification of the above, the first is the so-called centralized inverter, for it is defined as the photovoltaic component massive series parallel after the centralized inverter fed into the grid. String inverter is for each string photovoltaic inverter fed into the grid group, micro is for each block components of photovoltaic inverter independently after the fed into the grid, power optimization is each formed by DC summary.
Technical present situation, five aspects of specific performance, the development of photovoltaic inverter is highly dependent on the power electronics and microelectronics technology, if no new power device, no semiconductor device model, if there is no microprocessor speed of superior performance, the inverter is no method to achieve higher performance, mainly focuses on how to improve the photovoltaic component, the operating efficiency of photovoltaic arrays, reduce loss, improve reliability, and the whole photovoltaic other PID and so on, and keep the dust and so on, on the inverter itself, focusing on how to reduce their loss and increase the reliability of the equipment. Control technology of complex commonly used algorithm, and some modern control inside. Now is the basic focus on how to improve the safety of power grid, friendliness, and provide some intelligent service and technology. Now the technology around the five block has also done a lot of innovation, has done a lot of work, photovoltaic inverter is like a bridge, between our renewable energy and power grid, build this bridge work.
The current level of technology, the conversion efficiency to achieve 97% to 99%, MPPT efficiency do 98% to 99.9%, the largest single power now has 2.5 megawatts, main circuit structure is currently taking two level mainly small amounts for three level, wind cooling way edge, a few self cooling, cooling, power device based on IGBT, a small amount of silicon carbide devices, in support of the Ministry of industry, the recent domestic some breakthrough of silicon carbide devices. Now the present voltage level at 1000 Volts or less.
Industry conditions, it is still SMA is the global inverter big boss, ABB bought Power-One, is currently the second. Sunshine inverters shipped last year is second in the world, but shipments, but the sales amount in a row before five can not be reached, because we sell too cheap.
Application of inverter, which change with the change of the inverter, string inverter, or micro inverter, inverter or large, in the global market basically is still has certain general character, is more than a certain power in general is equipped with a large inversion equipment, in China market due to the large number of are large power plant, mainly to the centralized inverter, string inverter development is relatively fast.
Application of the inverter, with the expansion of the scale, the scale of it has not declined, still its power level rising, at present the main model in around 1 MW, with individual also has parallel. String of inverter, the current situation is that string inverter is developing very fast, especially suitable for use in small projects, especially the roof slopes, family, cables and so on, the biggest advantage in cloudy weather, we photovoltaic power station access network standard which provides a rising power of rate of change of the rate, rate of rise can control, through the inverter regulation, can put the power limitation, so the rate of rise can be restricted.
Photovoltaic inverter is also provided with a safety performance, first security is PID, all components manufacturers say that PID got the certification, to get the certification does not mean that there is no PID, but PID do better than others. Department of animal here to give you an example, in a winery, wine, with 10 MW of solar power, after burning, the wine steam inside, wine is acidic substances, so that the top of the solar power plant, must penetrate it, finally the plant failure, failure to what extent do, half of the power is gone, so who is going to bear the loss. There is leakage leakage, how to do. The last one is on fire, the DC is not easy to catch fire, a large number of distributed in the future with the family on the roof, or precious room on top of the fire, has now happened, several things, how to do, just like our electric automobile fire the same, I will go back to five years, all parties to condemn us, we start to put these work well, detect arc, arc start when we can detect, turn it off, and let it not fire.
The rapid development of inverter technology, centralized inverter to the greater development direction, string inverter to more portable, more secure, more intelligent direction, the future of our equipment inverter equipment will be more gathered in their own benefits and to improve the reliability, while providing such as, smooth, reactive, crossing, support, emergency and other friendly service power grid. Types of PV power station become more and more complex, diverse, so the actual situation according to the different types of power suit one's measures to local conditions, scientific design, reasonable choice of inverter device.
