The high cost of photovoltaic power generation has always been one of the obstacles to the rapid development of the industry. It has always been held in the hat of relying on policy support and government subsidies to develop. With the rapid progress of marketization, the cost has dropped sharply in recent years, and the installed capacity has increased nearly geometrically
However, the price of solar power generation is basically equal to that of traditional fossil energy, and the real implementation of grid-connected photovoltaic power generation at a fair price has become an urgent problem to be solved in the process of photovoltaic commercialization. Effectively reducing the cost of photovoltaic system and improving the efficiency of photovoltaic power generation will still be the core issue of the development of photovoltaic industry in the future.
At present, some manufacturers have proposed to develop 1500V photovoltaic system to reduce the cost of photovoltaic power generation and improve the efficiency of the system.
So here comes the question...!
Someone @Photovoltaic asked a lot of questions!!!
1. Why do manufacturers actively introduce the concept of 1500V system?
2. How can 1500V system improve system efficiency and reduce cost?
3. How about the matching of relevant parts and technical standards for 1500V system?
4. What are the problems and challenges of 1500V system?
Driving factors for the launch of 1500V system
Every manufacturer will publicize the advantages of 1500V system everywhere in conferences, forums and lectures. To be frank, of course, it is to seize the commanding heights of technical standards, set technical threshold, support the public opinion in the manufacturing market and strive to be the industry leader. But for power plant owners, whether they can enjoy the "benefits" is the key to push the whole market forward.
So let's talk about how the 1500V system improves efficiency and reduces costs. Are all systems suitable for 1500V?
How can 1500V system improve efficiency and reduce cost?
In theory, 1500V high-voltage components and supporting electrical equipment mean lower system costs and higher power generation efficiency. Take the 1MW system as an example
With the increase of input voltage on DC side, more components can be connected in each series. Compared with the traditional 1000V system, the length of series can be increased by 50%, the number of substrings can be reduced by 58, the number of shunt boxes can be reduced by 3, the usage of DC (DC) side cables can be reduced, and the unit power density of electrical equipment (shunt box, DC cabinet, inverters) can be increased, and the workload of installation and maintenance can be reduced. It also reduces the cost of photovoltaic system to a certain extent.
From the system point of view, higher input and output voltage levels can reduce current, AC and DC side line losses and transformer low-voltage side winding losses. According to relevant calculations, the system efficiency of the power plant is expected to increase by 1.5-2%.fined Solar pv connectors MC4 wire harness 1000V 30A professional xime connectors can do it .
German SMA, as the leader of the inverters industry, and First Solar, the film giant, are actively verifying the 1500V photovoltaic system.
How about the matching of related parts and technical standards?
1. Photovoltaic modules:
Material Upgrading: Thickening of Backplane PET Intermediate Layer
(2) Connection box upgrade: Cable, connector, electrical gap and creepage distance all need to meet 1500V certification requirements.
(3) Component structure:
Conventional backplane structure: glass + 1500V backplane + EVA (POE) + aluminium frame + 1500V box
Double glass structure: glass + EVA (POE) + glass + 1500V box (no frame)
Some component manufacturers have also introduced 1500V certified products.
2. Inverters and related components:
From the electrical point of view, it is relatively simple to break through 1500V technology for 1500V components. In view of the 1500VDC metro, traction vehicle inverters and power devices will not become the problem of selection, including Mitsubishi, Infineon and other power devices with more than 2000V, capacitors can be increased by series connection. As an important protection device in photovoltaic system, photovoltaic DC switches have been used. Enterprises such as IMO, OP and PROJOY have participated, but this application has not yet become popular. Although there are no technical problems, it will take time to achieve market popularization through customer identification.
Inverter manufacturer: SMA, Sungrow Power etc. have already introduced inverter products suitable for 1500V photovoltaic system. Other manufacturers are also doing related supporting research and development.
3. Relevant technical standards:
Because the existing IEC standards are for the design and safety of 1000V systems, in many places, the lack of existing standards for 1500V systems in the market often makes it difficult to obtain construction permits from local governments. However, just like the early transition to 1000V design, these problems can be solved, and the industry does not anticipate long-term obstacles to the application of this design.
Authoritative bodies such as the International Electrotechnical Commission (IEC) and the German Technical Supervision Association (TUV) are gradually improving the corresponding inspection standards and certification services. It is believed that they will soon become mandatory standards. Need a lot of wire harness Customized MC4|EVO2|1000V|1500V cables, PV connector,solar connectors can cost down for system.
Problems and challenges of 1500V system?
1. System security and reliability:
1500V system requires higher safety performance. There is no zero-crossing point between DC and AC. Once leakage occurs, it will cause serious accidents. Reliable 1500V DC circuit breaker is very important. In addition, 1500V system voltage will reduce electrical reliability, while increasing the risk of photovoltaic module PID.
2. Inverter topology:
The voltage of 1500V system requires higher inverters, mainly considering the insulation, electrical gap and voltage rise may lead to breakdown discharge, so the inverters need to adopt more complex topology and higher voltage level power devices and DC switchgear.
3. Applicability of 1500V system:
For the smaller capacity of civil distributed generation, most of the 230V output is connected to the grid. The converted DC side voltage is more than 300 volts. The cost of converting 1500V photovoltaic system into phase increases. Moreover, the roof area of household type is limited, the installed capacity is limited, and there is no confluence problem on DC side. So 1500V has little market for residential roof. For the household type, the safety of micro-inversion, power generation, and the economic type of group series, these two types of inverters will be the mainstream products of household power plants.Summary: 1500V photovoltaic system is still in the initial stage of common promotion. The existing problems need to be overcome by all sectors of the whole photovoltaic industry chain. Whenever 1500V can be popularized, at least it is a good idea. The main trend is that the goal of reducing cost and improving efficiency of photovoltaic system will not change.