Surge Protection for Battery Energy Storage Systems.



Available from Specialist distributor Switchtec is the new DDC50S-21Y Surge Protection Device from Citel.

Battery storage systems store excess energy produced by Renewable Energy systems such as PV or Wind and store it for use when needed. This counterbalances the fluctuation between energy production and demand for electricity. The importance of such equipment makes interruption of their service unacceptable, so measures must be taken to limit damage due to external influences. One of the risks to be taken into account is possible damage due to transient overvoltage’s generated by lightning or by switching operations.

Specialist manufacturers of Battery Storage Equipment have noted a reduced robustness in impulse overvoltage of this type of equipment’s – particularly in battery systems - and due to the imperative need for continuity of service they recommend the use of surge protectors at their terminals. Due to the maximum DC operating voltage often being very high (1000 Vdc and more), an SPD correctly specified for the application is necessary and for it to be compatible with these voltages and in conformity with the forth coming IEC61643-41. Due to the unique characteristics of Battery Energy Storage systems, standard DC or PV SPD’s are not suitable for use with this type application due to the potentially extremely high short circuit current (up to 100kA or more).

Citel have designed from the ground up the DDC50S-21Y specifically for Battery Energy Storage Systems. The DDC50S-21Y is a Type 2 SPD available with either 500, 800, 1200 or 1500VDC Max operating Voltage (Uc), an In (Nominal Discharge current) of 20kA, an Imax of 50kA and importantly an Admissible short-circuit current (Isccr) of 100,00A. It is DIN rail mounted and as such easy to install in any standardized distribution panel or control cabinets.

The DDC50S-21Y is part of Citel’s new DAC & DDC range of SPD’s and is born from Citel’s 80 years’ experience in the manufacture of high-quality Surge Protection Devices. The range includes AC and DC Surge Protection Devices, available in Type 1, Type 2 & Type 3, for use with AC, DC and PV applications. The SPDs are suitable for use on all earthing system including TN, TT/TN, TNS and TN-C-S. The SPD’s are available in Single Pole, Single Phase, 3 Phase and 3 Phase & Neutral.

As leaders in Surge Protection, Citel have designed the DDC50S-21Y to meet the most extreme constraints, beyond that asked by the IEC/EN standards. In order to ensure total safety, the DDC50S-21Y is designed to provide a safe disconnection, high resistance to fire and short circuit and built with a high mechanical robustness.

The DDC50S-21Y utilises technology uniquely available to Citel, who are specialists in the manufacture of Gas Discharge Tubes (Gas Spark Gap), along with their own design of varistors to obtain the best performance and reliability.

Further features include, improved plastic materials used to increase the products strength and rigidity, whilst also taking into account environmental concerns with the use of Halogen free plastics. A large disconnection indicator allows the operator to easily and quickly identify if the SPD has come End of Life. A green indicator displays a fully functioning SPD whilst a red indicator indicates immediate replacement required. This indicator is in conjunction with the built-in remote signal output, a volt free contact, suitable for connection to an external signalling device.

The DDC50S-21Y has been tested in Citel’s own internal laboratories, where they can test up to 240kA, and also recognised by external laboratory including EAC, IEC, VDE and cULus.