Compared with 1000V system, the advantages of 1500V system are self-evident. First, economies of scale save costs, such as cables, junction boxes and inverters. Secondly, the installation and maintenance costs are reduced, because so many inverters are not needed to convert DC into AC. Take 1MW system as an example. After the input voltage of DC side is increased, more components can be connected to each string, which can increase the string length by 50%, reduce 58 substrings, reduce 3 bus boxes and use DC side cables compared with the traditional 1000V system. The unit power density of electrical equipment (junction box, DC cabinet, inverter) is improved, and the workload of installation and maintenance is also reduced, which promotes the cost reduction of photovoltaic system to some extent.
Second, the challenges faced by 1500V photovoltaic system
1500V system has obvious advantages, but the challenges it brings cannot be ignored. First, improve the safety requirements of all aspects of the system. 1500V system voltage components should choose junction box, backplane, connectors, etc. Better quality and stricter requirements. At the same time, the inverter is required to adopt more complex topology, higher voltage power devices and DC switching devices. From 1000V to 1500V, it needs the cooperation of the whole industry, including power station owners, EPC enterprises, components, inverters, junction boxes and cables.
Most importantly, how to find a suitable measuring tool is particularly important for the field test of power station. It is understood that at present, there seems to be similar products of Mao Feng Lingjiao, an instrument manufacturer for the operation and maintenance of 1500V power stations in Germany, including:
1) 1500V voltmeter
Voltage range: 1000 volt AC/1500 volt DC.
When the voltage is greater than 24v, the measurement will be started automatically.
Resistance range: 1- 1999 kω.
Polarity display
IP65 protection level
Weight 270 grams
2) Insulation resistance tester
Insulation test voltage: 0-5000V adjustable.
Insulation resistance range: 0-100gΩ
Polarization index/absorption rate
Optional temperature and humidity sensors
Luggage design
3) Power analyzer
1-7 channels are optional, and both centralized and series inverters have solutions.
Using high-precision voltage divider, the voltage can be measured at 3KV (6/ 12Kv is optional).
There are three different precision modules to choose from.
Double A/D sampling technology, the power under different filtering can be displayed at the same time.
Touch screen operation, custom display interface
4G mass storage is standard and 320G is optional.
The unique large-aperture sensor meets the harsh test environment.
4) Power Quality Analyzer
Chinese touch screen operation interface
Sampling at 5 12 points every cycle.
30/300/3000A Three-gear Adjustable Flexible Probe
VNC remote control, no need to be exposed to dangerous environment.
One-click generation of the latest national standard report
5) 1500V power station comprehensIVe safety table and iv curve tester.
Specially developed for 1500V power station system.
Test voltage 2000V current 30A
IP67 protection level
You can view the IV curve without connecting a computer.
6) daytime EL tester
Patented technology realizes daytime EL test, improving efficiency and safety.
Support photovoltaic module types: monocrystalline silicon, CIS and amorphous silicon.
Effectively detect PID attenuation and other problems that are easy to occur in 1500V system.
320 camera and 640 camera are optional.
IP54 protection level
Power can also be supplied by other power generation components without power supply.
Three. abstract
Increasing DC voltage to 1500V is an important change to reduce costs and increase efficiency. More components can be connected in each string, the number of DC cables and junction box inverters used by inverters can be reduced, and the output power can be fully improved under the condition of reducing line loss. Overall, the system PR can be increased by 1%-2%. At present, several 1500V system power stations are under construction. In the future, with the continuous improvement of standards and technologies and the maturity of components and other related supporting equipment, 1500V photovoltaic system will surely become the mainstream. Germany GMC-I, as the leader of European instrument industry, will pay close attention to the industry trends and continuously develop measuring instruments suitable for photovoltaic power station field use.