Whether centralized power generation and distributed generation needs a stable power supply, and reliable. Distributed use of solar photovoltaic power generation is an important means for people to use clean energy. However, the night of the replacement, weather impermanence, distributed photovoltaic power output does not have regularity, and access to the public grid, the public power grid as a backup. Access to distributed power grid includes several aspects
First, the impact on the grid planning. Load forecasting is the basis for the design of grid planning, the ability to accurately predict the load of grid planning prerequisite. Distributed PV solar inverter grid, increase the load forecasting difficulty in their region, and change the existing load growth mode. Access to a large number of distributed power, transformation and management of the distribution network has become more complex.
Second, different grid effects vary. Off the network running distributed PV on the grid; grid but not distributed power to the power grid photovoltaic power generation will cause voltage fluctuations; grid and the power grid to the power grid, will cause voltage fluctuations and affect the relay protection of the configuration.
Third, the impact of power quality. The influence of a distributed photovoltaic access important is caused by the change in the voltage distribution on the feeder, the impact of the size and access capacity, access location closely related. The photovoltaic power generation is generally connected to the grid through an inverter, frequent turn-on and turn-off of the type of power electronic devices, prone to harmonic pollution.
Fourth on protection. Most of our distribution network for single supply radial structure to use more off-speed, limited forms of protection quick break, and do not have directionality. This type of protection in the conventional radiation distribution networks, it is possible to effectively protect all the lines. However, the distribution network access for distributed power injected power causes the relay range narrow, can not be reliably protect the whole line, even in the other parallel branch failure, caused by the installation of distributed photovoltaic relay mistakenly action.
Take economic levers to ensure the photovoltaic power generation capacity continued to grow steadily. German Renewable Energy Act subsidies for photovoltaic power generation, application for rooftop PV PV inverter and other types of terrestrial photovoltaic photovoltaic power generation mode, the subsidy intensity scale.
The law of the country in 2012, the latest modified grid tariff for photovoltaic power generation from 17.94 euro cents per kWh to 24.43 cents per kilowatt-hour. The country also provides that, within the next 12 months if the installed capacity of more than 3.5 million kilowatts, Internet price dropped 3%;, Internet price decreased by 15% if more than 7.5 million kilowatts.
is eager to save the domestic photovoltaic enterprises, ready to quickly start
the PV market, but should also consider how to take reasonable strategy in the
future to ensure its steady development. China
The development of rational distributed photovoltaic power management methods to ensure the safe operation of the power grid.
requires an area to install a distributed power capacity of less than 50% for
the region of the peak load, try to avoid the the distributed power anti power
requires more than 100 kilowatts of distributed power remote communication and
control devices must be installed, in order to understand its output in
real-time scheduling and scheduling. Germany
Spanish grid scheduling does not have the remote monitoring and control of large-scale photovoltaic power generation capacity, transmission operators only require more than 10,000 kilowatts of solar grid tie inverter photovoltaic power generation projects installed telemetry device, while no such large-scale photovoltaic projects in Spain. With the increase of megawatt-class projects, these projects is the lack of the telemetry equipment grid operation will have a significant impact.
Development of large-scale distributed power, you need to invest a lot of money to upgrade the power grid. At present, Germany has begun to take some indirect measures to meet the requirements of distributed power access distribution network, as superiors transformer upgrade transforming the access point, reconfigure the feeder voltage conditions and control equipment. German research institutions that need an additional 195,000 to 38 million meters of new high-voltage and medium-voltage distribution network line to meet the German PV development goals, and appropriate investment of 13 billion euros to 27 billion euros.
The whole society to allocate the cost of power grids of distributed photovoltaic power generation access. Additional foreign government through the imposition of tariffs to support the necessary power grids and distributed power access.