Photovoltaic energy storage DC power supply system DC power supply can be expected in the future
Alternating current is more convenient than direct current in high-voltage power transmission, and its practical application scenarios are more diverse. However, in some cases, applying the DC power supply directly to the DC load can make the circuit design simpler and more efficient.
In the new energy power system, some DC load applications, such as solar street lights, DC air conditioners, 5G communication base stations, etc., can directly provide DC power through photovoltaics or batteries in the photovoltaic + energy storage system.
There are usually two ways to achieve DC power supply in an energy storage system. The first is achieved by solar modules through MPP trackers or batteries through a DC converter; the second is achieved through the power grid through an AC-DC converter.
The DC power supply system usually coexists with the AC power supply system.
The DC power supply system has great potential in the household field, such as:
Electric vehicle charging system
Electric vehicles are expected to become mainstream in the near future. Electric vehicle charging systems usually use solar energy or batteries to reduce the peak power consumption of household electricity. At present, household electric vehicles generally use AC charging. But in fact, because DC charging does not require DC-AC conversion, the charging speed of DC charging is faster and more efficient. The battery of an electric vehicle can be used as an emergency power source in the event of a power failure.
One of the important application scenarios of the energy storage system is that the battery is only used as an emergency power source when the grid is out of power. If the battery of an electric car can power the house, no additional battery pack is needed.
In this application, two solar inverters are required to operate independently when the power grid fails, have special charge and discharge control functions, and have off-grid output capabilities. In addition, the battery of an electric vehicle must be able to discharge the external load.
The above example illustrates the application scenario of DC power supply in a single energy storage system. What if we integrate multiple systems? Look at the following example, we call it “DC bus sharing system”. The grid system or virtual power plant system usually shares multiple power sources on the AC side. But in some cases, shared DC power may be more suitable for balancing power demand. In some countries, households are not allowed to sell power to the grid (backflow prevention), which makes it impossible to share power among multiple households. The DC bus power supply system can solve this problem.
In the DC bus power sharing system, multiple household solar energy storage systems are connected in parallel on the DC side, and excess solar or battery energy can be traded between different users. The DC bus power supply sharing is controlled by the central management system and controlled by communication commands.
In addition, the excess solar energy or battery energy on the DC bus can also supply power to community public DC loads, such as DC-powered street lights or community electric vehicle charging piles. Such a power sharing system can easily maximize the efficiency of new energy utilization. Solar energy is shared between different users, which can balance the power load among users, and is also an effective way to relieve the pressure on the power system under the time-of-use price strategy. If artificial intelligence algorithms are added to the system, through self-learning to understand and analyze the power demand of each household, the control between power supply and demand can be completed more efficiently and intelligently.
At present, most household electric vehicle charging piles draw power from the AC side and cannot support V2H applications. Most daily household loads also draw power from the AC side. Whether some of the applications in this article can be realized in the future, let us look forward to it together.
Popular ic chip you may need:
ATIC39-B4
A3120V
AM29F200BB-70SE
CA3086
