Huawei introduces the next generation solutions with unique energy design for photovoltaic installations, which include not only one but three new devices designed to work together in a unique and intelligent way. The above solutions ensure significant savings in BoS (Balance of System) and significantly increased system performance.
With the new FusionSolar 8.0 solution, which incorporates the Gemini architecture, Huawei lays the foundations for solar energy to become the main source of energy in the future.
The system consists of three new elements designed to reduce “BoS” costs as well as to take full advantage of the advantages of centralised and decentralised plant design. First, instead of a traditional string converter, Huawei offers the “smart” string controller, Venus 2000-32-U0, which is a DC-DC converter with 8 MPPTs. Second, the smart PV Controller, SUN 2000-345KTL-H0, is a DC to AC converter installed around the substation or storage battery. We also present the much-anticipated, 2 MWh Luna 2000-1/2-S0, the fully prefabricated containerized energy storage solution.
Instead of using traditional string converters on each support base, this solution uses DC-DC converters, the smart string controller, near the frames. This type of system architecture allows for a significant reduction in BoS costs, by 0.01 € per watt. In addition, by performing only DC-to-DC conversion and MPP monitoring at the support base level, this bipolar design allows power transmission via DC cables, thus reducing total wiring costs as well as losses. This feature improves overall performance and is the desired way to add storage – something that until now could not be implemented in conjunction with strings converters
Also, as far as the battery energy storage part is concerned, Huawei presents a number of innovations, such as the battery container with a capacity of 2 MWh. Lithium-phosphate iron batteries are installed within a 20′ container and delivered pre-installed and connected to the corresponding power electronics. This LFP battery solution competes with nickel-manganese-cobalt-based systems and is known to exhibit high levels of thermal stability.
The storage system has a comprehensive range of electronic power that improves the cost and availability of the entire system. In addition, racks can be controlled separately, offering a modular approach for optimal use of the system. Through separate rack management rather than whole packs together, Huawei argues that it can increase charging and discharge capacity by about 15% compared to a solution based on a central battery management system. In addition, it can manage the mismatch between battery packs much better and level the charging/discharge state with high accuracy. This improves battery life.
In an array of, for example, 100 MW, Huawei claims to have the significant advantage of organizing inverters, substations and storage containers in 8.8 MW blocks each. “If you were to install it around a 100 MW block, for example, you would need a lot of low-voltage wiring,” Mr Subramanian says. In addition, it explains that even with Huawei’s bipolar DC transmission system, it is best to use medium voltage wiring for long-distance transmission to save transmission losses as well as wiring costs. So instead of there being a substation and all the converters and storage in one place, Huawei suggests that it is better to have 12 substations and accumulators in a 100 MW field.
Read also : The Pros and Cons about Renewable Energy Sources
Another important feature of the new solution is the ability to provide virtual inactivity. Inertia in an electrical system is the ability of a power system to compensate for sudden voltage drops and subsequent frequency deviations. If the load on a network is not fully aligned with the power supply, the voltage of the system decreases, reducing the frequency.
When the rate of change in frequency deviation becomes too high – less than half hertz is sufficient – the network security system is activated and entire parts of a power grid are isolated, causing widespread power outages. In a traditional power system, large rotors inside thermal generators can compensate for the effect to some extent, as they are subject to physical inertia and do not change their rotational speed suddenly.
When a power system has more than 30% of the production methods of interconnected electronic power, there is a potential risk that very little inertia will remain on the network to compensate for sudden load changes. Therefore, in the context of highlighting PV as its main power source, Huawei strengthens its converters with the ability to provide virtual inertia.
Although actual inertia is instantaneously induced, it is enough to supply the voltage and, therefore, the frequency, in the space of a second. “We are already identifying a market for this network stability application in many countries such as Ireland and the United Kingdom, Finland, the Nordic countries and Australia”, stresses Mr Subramanian.
source : pv-magazine