Power Conversion Systems
AC/DC and DC/AC conversion is done in the power conversion system (PCS). Energy is flowing into the batteries to charge them or being converted from the battery storage into AC power and fed into the grid. In the PCS, solutions lying under 30 kW are typically best served with discrete solutions OptiMOS™, CoolMOS™, and CoolSiC™ MOSFETs, whereas above 100 kW the module approach IGBTs modules as well as highly integrated 3-level Easy 1B/2B modules, makes most economic sense.
The area in between is best reviewed on a case-by-case basis to determine the use of discrete or module solutions. Since every switch needs a driver, and every driver needs to be controlled, we offer the right EiceDRIVER™ gate driver ICs as well as XMC™ and current sensor solutions. OPTIGA™ products round out the offer, ensuring data protection and security.
Energy storage systems with power below 10 kW are usually used in residential areas and homes. The systems are commonly applying two stages that need to operate in bi-directional mode: DCDC and ACDC stage.
Infineon enables full system solutions with the highest efficiency and power density by applying market-leading Silicon Carbide (SiC) and Silicon (Si) MOSFETS as well as IGBT technologies paired with best-fit gate drivers.
10 kW to 125 kW power range in energy storage systems comes under the category of residential or commercial ESS in combination with photovoltaic systems. In many cases, multiple 125 kW systems are used for substation storage systems. The main topology in this power class is 3-level ANPC or 3-level active natural clamping converter. Apart from this topology, sometimes standard two-level topologies are used depending on the battery and grid connection voltage.
The main purpose of such systems, installed in offices, factories, and supermarkets, is mostly for self-consumption. The excessive non-self-consumed generated energy is stored in batteries for later consumption or fed back to the grid to earn additional revenue.
One of the key requirements of such systems is to reduce losses, thereby maximizing the round trip efficiency. Nowadays, these systems can handle up to 1500 V DC bus voltage.
125 kW to 2 MW power range in the energy storage systems comes under category utility to bulk energy storage systems. They are standalone usage systems or combined with Utility-scale photovoltaic and wind systems.
The main topology in this power class is 3-level ANPC or standard 2-level converter depending on the battery and grid connection voltage. In general, as ESS power level increases, 2-level topologies are preferred.
The main purpose of such large power level ESS is to stabilize unstable grids, thereby avoiding full-blown blackouts. Such energy storage systems can improve grid reliability and power system stability. Furthermore, growing demand for electricity, especially during peak periods, can be met without additional generation through a concept called peak shaving or energy time-shift.
1200 V Module with CoolSiC™ MOSFET: CoolSiC™
PrimePACK™ Module with IGBT4: PrimePACK™
EconoDUAL™ Module: EconoDUAL™ 3
Gate Driver IC: EiceDRIVER™
Having battery packs with a different state of charge (SOC) connected in series, this system is only able to operate until one pack reaches the minimum allowable charge level. At this point, the whole system is shutting down, even though other packs may still be sufficiently charged. In short, battery utilization is limited to the weakest battery pack.
To overcome this limitation, modularly cascaded, multilevel architectures have been developed that utilize the benefit of highly efficient, low-voltage MOSFETs such as Infineon's market-leading OPTIMOS™ family. Each battery pack is connected to its own directional power converter and the outputs of these converters are then connected in series to create the high voltage DC-bus.
By doing so, an equal current can be supplied from the outputs of each of these stages. With this added flexibility it is now possible for advance control schemes to balance the SOC of different batteries among all the packs by placing a heavier load on those packs with higher SOC, i.e. BMS functionality is a feature that additionally comes along with this solution.
Low Voltage MOSFET (<300V): OPTIMOS™
Gate Driver IC: EiceDriver™
From Solar and Wind to Energy Storage: Trends and Solutions
Learn about the application and power semiconductor requirements for solar, wind and energy storage systems. Understand how Infineon responds to the trends in the market of renewable energies and storage systems, e.g. inverter integration with CoolSiC™ MOSFETs. Get an overview of different solution offerings for solar, wind and energy storage systems.
On-demand webinar: From solar and wind to energy storage
In the webinar, you will gain insight into renewables and the emerging applications of energy storage. Learn more about application trends and requirements, and understand Infineon's solution offerings for these applications.