China's first 1500V inverter step-up integrated photovoltaic power station was successfully connected to the grid

Recently, the first integrated solution for applying 1500V inverter boost in China-Huaneng Shaanxi Jingbian Phase II 15MW photovoltaic power station was officially put into operation, marking that the 1500V integrated transformer solution has entered the application stage
.
Shangneng Electric provided a complete photovoltaic inverter solution
for the project.
It is understood that the power station is currently a benchmark project of Huaneng Group and even China, creating a number of industry leaders
.

1.
For the first time, the design of 2MW distributed amorphous alloy dry transformation integrated unit is adopted

2.
For the first time, the 2MW 1500V inverter step-up integration scheme is adopted

3.
For the first time, the domestic 1500V inverter + monocrystalline 275W module is overallocated to 1.
2

4.
For the first time, domestic 1500V inverter + 1500V monocrystalline module is adopted

1500V inverter boost integrated system

The core value of 1500V photovoltaic system is to reduce system cost and improve system power generation efficiency
.
By increasing the input and output voltage, the inverter power density and stand-alone power will be greatly improved, and the workload of transportation and maintenance will also be reduced
.
The increase in input and output voltage greatly reduces the loss of AC and DC cables and transformers, and the power generation efficiency of photovoltaic systems is improved and the cost is considerably reduced
.

According to reports, the 1500V inverter step-up integrated inverter scheme integrates a 2MW unit of 1500V inverter, DC lightning protection distribution cabinet, 2MW box-type transformer, communication management machine, etc.
in a standard 20-foot container, customers only need to prepare a container foundation, hoist the 1500V inverter step-up integrated device to the foundation, connect the AC and DC input and output cables and communication cables, you can connect to the grid for power generation, simple construction, fast station construction speed; Save wires and cables, reduce system costs
.
Experts said that in the context of lower electricity prices and lower subsidies, the scheme represents the future development trend
.

Type I three-level technology

It is understood that the 1500V system puts forward higher requirements for the inverter topology, and in the 1000V photovoltaic system, the inverter adopts 1200V IGBT and two-level topology in terms of cost and efficiency
.
The voltage level rises to 1500V, and if the two-level topology continues, a voltage level of 1700V or above IGBT is required, and as the voltage rises, the problem of IGBT failure caused by cosmic rays is highlighted
.
At the same time, in a two-level topology, the switching losses of IGBTs in operation of 1500V voltage systems will also increase
significantly.

The 1500V inverter in Huaneng Shaanxi Jingbian Phase II project adopts I-type three-level technology, which structurally reduces the voltage stress of semiconductor devices and the switching loss of inverters, and can achieve higher inverter conversion efficiency and reliability
under high-voltage systems.

At the same time, in this project, Shangneng also applied the "I" type three-level technology with active clamping to the 1500 V MW-class high-power inverter for the first time, and the inverter efficiency and reliability were further improved.

The power generation and cost advantages are more obvious

According to reports, the total capacity of the project is 45MW, and the first phase of 30MW all adopts the Shangneng distributed inverter scheme, which has been fully connected to the grid in December 2015, with obvious power generation and cost advantages; Then, the second phase of 15MW also adopts a distributed inverter boost integrated solution and a 2MW unit 1500V system
.

"The distributed inverter system has all the advantages of the centralized inverter system, and also overcomes the technical problems of AC multi-machine parallel connection, the system scheme is clear and the implementation is simple", the on-site staff said, the 2MW unit distributed inverter scheme adopted by the project has 96 MPPTs, which can maintain the independent MPPT optimization function of each string to the greatest extent, and the power generation is significantly
improved.

In addition, the integrated solution has greatly reduced the cost of AC and DC cables, transformers, and civil construction costs, shortened the construction period, and become the primary method for owners to cope with the decline in subsidies in the wave of electricity price reduction and bidding for the Internet, and is the backbone of the parity Internet
.