Smart energy storage container
(Lithium Ion) for micro grids
Smart energy storage container (Lithium Ion) for micro grids
August 2015 – Due to the increase in local power generation, there is a growing demand for smart storage systems.
This is the reason Ymif Engineering has started a new project: developing the electronics within a smart Lithium Ion battery container.
The user gets immediate insight into the status of the battery container via an app, and through the internet connection, the current energy prices will be traded at the right moment (both buying and selling). This container becomes really interesting when local power generation is above 100 kWh. Ymif Engineering has developed the battery management electronics and the communication within the entire system.
The first systems have already been successfully implemented; read (in Dutch only) about the case of arable farming company De Jong.
According to Esger Schouten (Esger Energy Management) there are four different business models available when using this system. By stacking and combining these models with a good IT-platform (in this case, Jules Energy), cost recovery is quick. In the first place, the client can supply his own company with energy by buffering energy. Secondly, by trading on the energy market, extra income will be generated. The system purchases energy automatically when prices are low. The energy will be returned only when prices are high. Thirdly, there is the possibility of receiving compensation for peak shaving on the energy grid. And in the fourth place, it is also possible to connect the generated electricity to a number of private users who choose to buy the electricity from this specific installation (or, if the battery is empty, from a Dutch wind farm or solar power unit).
Jules Energy states that in this manner, businesses can earn up to twice as much when production exceeds consumption, and it is therefore realistic to count on 7 to 8 years for cost recovery.
Safety and quality
This container is the first battery storage system in the world to comply with the regulations as drawn up by DNV GL. These so-called “GRIDSTOR” regulations give a detailed description of what is necessary in a system to be given approval. The DNV GL approval covers safety, operation and performance of the energy storage system connection to the power grid. See also: DNVGL.
The container has a modular structure, so that the modules can be configured to accommodate systems with voltages from 50V up to 1200V.
Each module is supplied including its own backplane segment; these can be connected in series or parallel depending on the system specifications.
The external Battery Management Unit (BMU) has communication ports for connecting battery modules and for communicating with other components such as motor controllers, computers, PLCs and other intelligent components.
There is a Master Controller (MC) available for larger systems. This Master Controller can communicate with more than 100 BMUs and can be implemented for self developed control algorithms that, when compiled, communicate immediately and therefore ultra-fast with the batteries and other system components. Several communication ports can be used next to each other on the MC, that provides digital I/O, analogue I/O and pulse input and output, making a very broad implementation possible.
The 19” battery modules are also available as separate units and can be used for example, in: Supplying energy for UPS systems and telecommunication applications, stabilizing voltage (whether or not in combination with DC/DC or DC/AC converters), or in providing on-board voltage for boats, yachts and recreational vehicles.
Ymif Engineering’s intelligence
In the various modules (BC, BMU, MC), added intelligence in production and installation of a complete battery container is used, including fine-tuning of the module-IDs, to keep it as simple and faultless as possible. The end product of all units is exactly the same. When the modules are being installed, they will then be provided with a unique identification code. This is achieved by an automatic process using a smart algorithm. This eliminates the risk of potential errors during installation (as for example by an incorrect manual set up of BC or BMS-IDs).
Specific knowledge of Lithium Ion was necessary in developing the Battery Controller and the Battery Management Unit. To ensure getting the maximum from the battery, but also for safety’s sake, management of the battery is crucial. The software in the Battery Controllers, BMU’s and Master Controller is continuously monitoring each battery for the “state of charge” and the “state of health”. In this way, total discharge is prevented, and the temperature in each Battery Controller is also continuously monitored
Ymif Engineering made sure that all modular parts in the container communicate (energy measure, ICT platform (Jules Energy), Master Controller, Battery Management Unit and Battery Controller). Besides that, this communication is monitored on many levels and should a problem arise causing lack of communication between crucial parts in the system, then the entire system will be immediately deactivated.
The entire system will also be monitored by remote access using one or more secure internet connections.