Power Transmission and Distribution Solutions 56 Siemens Energy Sector t Power Engineering Guide t Edition 7.0 2 2.8 SIESTORAGE 2.8.1 The Modular Energy Storage System for a Sustainable Energy Supply The challenge: reliable energy supply! Distributed, renewable energy sources, such as wind turbines and photovoltaic plants, are making a bigger and bigger contribution to the energy mix of the public power supply (fig . 2.8-1). However , as the amount of electrical power they generate cannot be predicted, their increasing use is creating new challenges in terms of system stability, integration into the power supply system, operating reserves, quality of voltage and supply, as well as peak load management. The answer: SIESTORAGE – Siemens Energy Storage – the sustainable and eco-friendly solution! Energy storage systems are the right solution in all these cases. SIESTORAGE ensures a sufficient amount of available reserve power for balancing and regulation purposes, especially of renewable energy sources, and creates higher system stability for industr y, buildings and infrastructure. Energy that is stored by the system can be regained in case of demand. Generation outages can be com- pensated for minutes and even for hours on end. SIESTORA GE combines cutting-edge power electronics for power system applications with high-performance lithium-ion-batteries. With a compact battery and converter cabinet as the smallest unit, the capacity of the SIESTORAGE system can be expanded to up to 2 megawatt hours, and its output up to 8 megawatts (fig. 2.8-2). The advantages at a glance The SIESTORAGE energy storage system from Siemens is ideally suited to various applications. Compared to other energy storage solutions, it has a number of additional advantages, such as: tȋ High degree of availability and reliability thanks to modular design tȋ Suitable for all requirements due to highest flexibility tȋ Easy handling of battery modules (safe low voltage) ensures the highest degree of safety for system an persons tȋ Completely integrated turnkey solution thoughout the entire life cycle tȋ Parallel connection of energy storage cabinets on AC side ensures the highest flexibility tȋ Prowen expertence in power electronics for power system applications tȋ Black start capability for microgrid application tȋ Emissions-free solution and improvement of CO 2 footprint Always the right storage solution Modular design (fig. 2.8-3) SIESTORAGE is a modular energy storage solution. Batteries and control electronics are inserted in cabinets as plug-in units. One energy storage cabinet contains up to 16 ba ttery modules, each Fig. 2.8-1: SIESTORAGE offers solutions for distribution systems with a high share of distributed re newable energy sources Powerful combination: Cutting-edge power electronics and high-power Li-ion batteries Variable through modularity: In power and capacity with parallel connection of combined energy storage cabinets on the AC side Adequate capacity: Up to about 2 MWh Top performance: Modular up to about 8 MW Power system AC/DC inverter Filter Transformer Medium-voltage switchgear Li-ion battery system n c e l l s i n s e r i e s S I P L I N K Smart Network Control Inverter control Data logging Battery management System control Fig. 2.8-2: A modular energy storage solution based on proven components with a maximum voltage of 60 V DC. The individual battery mod- ules can be pull ed out, inserted and moved safely . The required power and capacity are achieved through a parallel connection of several cabinets on their AC side. Both parameters can be adapted to fit the par ticular requirements of a project. The intelligent Battery Management System (BMS) monitors state of charge, voltage and temperature of the individual battery modules, among others. SIESTORAGE’s core is the SIP- LINK converter product platform. The batteries are charged and discharged at the AC system using SIPLINK active front ends. The SIPLINK power electronics were developed especially for sophis- ticated system applications such as MVDC system couplings, and are the basis of the various SIESTORAGE applications. The control components for the entire storage unit are accom- modated in a separate cabinet. A combined control and system connection cabinet is used for up to four energy storage cabi- nets. The system is controlled with SIMATIC S7, either on site or over the Internet. Informatio n on the system’s operating state, for instance on batteries, auxiliary systems, medium-voltage switchgear and error messages, are displayed on the human machine interface (HMI).