Switching & Protection Solutions for Power Conversion Systems in Battery Systems

Are you searching for Switching and Protection solutions to protect and your Power Conversion System (PCS) and keep it running in your Utility Scale Battery Energy Storage System (BESS)? For switching and to protect your BESS installation from faults, over current events and other hazards, the best product for your PCS can be easily found thanks to concrete examples.

What is a Power Conversion System (PCS)?

If you want your Utility scale BESS (battery energy storage system) installation to function efficiently, you need a Power Conversion System to convert the power from AC to DC and vice versa. The PCS, is a bi-directional inverter that enables the batteries to charge and discharge with precision control.

Why you need a Switching and Protection (S&P) solution

The PCS requires adequate protection and switching capability on the AC and DC side in order to switch the system - also in the load condition - and protect the entire electrical circuit from faults and overcurrent events.

Our switching and protection devices will also provide your PCS with communication connectivity to the BESS control system.

Main benefits

• Smarter protection: Increases power in your installation and reduces CAPEX by using the full range of 1500 VDC LV components.
• Safety: Avoids the risk of fire in your facility and loss of valuable assets by using a complete range of SPD to protect the whole electrical system from lightning and surges.
• Speeds up your projects: Reduces CAPEX and speeds up your projects by using a range of products in compact sizes able to provide excellent performance at different temperatures and humidity ratings.
• Smarter metering & monitoring: Maximizes power yield and cash generation by correct measurement of your BESS parameters.

Utility Scale Battery Systems

Utility scale stationary battery storage systems, also known as grid-scale front-of-the-meter storage systems, play a key role in integrating variable energy resources while providing the required flexibility. Battery storage increases flexibility in power systems, enabling an optimal use of variable electricity sources like photovoltaic and wind energy. Batteries can provide services for system operation, defer investments in peak generation and grid reinforcement.

Key characteristics of BESS in a Front-of-the-meter configuration:

• Direct connection to the AC Utility without the User's plant in parallel
• Grid support (ancillary services, fast power injection for peak requirements)
• Storage capacity typically ranging from just a few, to hundreds of MWh.

Diagram of a Utility Scale Battery System

The system includes an MV Utility connection, MV Switchboard, MV/LV Transformer, PCS (Power Conversion System), DC Recombiner, DC Combiners, and Battery racks. Protection and switching devices like Air Circuit Breakers, Fuses, Air Switch Disconnectors, Molded Case Circuit Breakers, and Molded Case Switch Disconnectors are utilized throughout the system.

Power Conversion System: Fundamentals, main components & functionalities

Power is converted by an AC & DC Power Conversion System. This is a bi-directional inverter that enables the batteries to be charged/discharged with precision control.

The PCS requires appropriate protection and switching on the AC and DC side. In addition, the protection devices must provide communication connectivity with the BESS control system.

AC and DC Power Flow

A simplified diagram shows AC power entering a PCS, which converts it to DC. The DC power then flows to battery systems. The reverse process occurs when batteries discharge.

Main subsystem functionalities

• AC Incoming or primary switching and protection: A disconnect function, overcurrent protection, and interfaced protection are required since the PCS is connected to a utility line. The PCS can be supplied with either a fused manual disconnect switch or circuit breaker suitably rated for the incoming line voltage. Primary current and voltage transformers are connected to a protective relay and metering equipment.
• Auxiliary power: An auxiliary power circuit provides control and auxiliary power to the PCS. This includes a fused disconnect switch, auxiliary power transformer, an uninterruptible power supply (UPS), and a power source for external battery heaters, if required.
• Converter Modules: These are the heart of the power conversion unit, converting DC to three-phase AC and vice versa. Twelve to sixteen identical modules are used for each 1 MW battery input to achieve the total output rating. The converter modules are specifically designed for custom applications where enhanced system flexibility is needed.
• DC switching and protection: The DC section of the PCS enclosure can contain either fused DC disconnect switches or DC circuit breakers, depending on the requirements of the battery supplier.
• Local control.

Additional subsystem functionality

• ARC flash mitigation: Active, Passive & Preventive solutions. Surge protection device for AC and DC side, against direct lightning.

Application Bundle 1#: 4MWh, 4MW Utility Scale Application

Discover our switching & protection solutions for easy PCS configuration considering 4MWh BESS architecture with four 1MWh main system modules in parallel.

Single-line diagram of a 4 MWh, 4 MW Utility scale application

The diagram illustrates a system with MVAC Utility connected via MV/LV Transformers to four PCS units. Each PCS is connected to a DC combiner, which then connects to multiple Battery racks. Protection and switching devices are shown at various points.

Specifications of electrical quantities with a 1500 V DC PCS (Single inverter per module)

ABB offering (IEC) - PCS with single inverter per module

Based on the configuration, the diagram illustrates the ABB S&P devices best suited to the AC and DC side, as required by the IEC specifications.

AC side components:

• AF 750 (1050A – AC1) contactor for switching
• Tmax XT7L: Tmax XT7LM 1000 3p In=1000A Ekip Dip LS/I for protection and isolation, equipped with Ekip com Modbus TCP communication module and with SOR* and motor operator to open/close remotely
• Tmax XT7L M 1000 3p In=1000A Ekip Touch Measuring LSI for protection and isolation, equipped with Ekip com Modbus TCP communication module and with SOR* and motor operator to open/close remotely
• Tmax XT7L M 1000 3p In=1000A Ekip Hi-Touch LSI for protection and isolation, equipped with Ekip com Modbus TCP communication module and with SOR* and motor operator to open/close remotely
• OVR T2 3L 40-600 P TS QS to protect against overvoltages from the AC Utility
• TVOC-2 + RELT Module for Arc Flash Mitigation

* Shunt Opening Release (SOR)

DC side components:

• Tmax T7D/PV-E 1250 4p switch disconnector combined with fuses. The switch disconnector is equipped with YU* and motor operator to open/close remotely
• OVR PV T1-T2 10-1500P TS QS to protect against overvoltages

* Undervoltage Release (YU)

ABB offering (UL) - PCS with single inverter per module

Based on the configuration, the diagram illustrates the ABB S&P devices best suited to the AC and DC side, as required by the UL specifications.

AC side components:

• AF 1250 contactor for switching
• Tmax XT7H: Tmax XT7H M 1200 3p In=1200A Ekip Dip LS/I for protection and isolation, equipped with Ekip com Modbus TCP communication module and with SOR* and motor operator to open/close remotely
• Tmax XT7H M 1200 3p In=1200A Ekip Touch Measuring LSI for protection and isolation, equipped with Ekip com Modbus TCP communication module and with SOR* and motor operator to open/close remotely
• Tmax XT7H M 1200 3p In=1200A Ekip Hi-Touch LSI for protection and isolation, equipped with Ekip com Modbus TCP communication module and with SOR* and motor operator to open/close remotely
• OVR T2 3L 40-600 P TS QS to protect against overvoltages from the AC Utility
• TVOC-2 + RELT Module for Arc Flash Mitigation

* Shunt Opening Release (SOR)

DC side components:

• Tmax T7N-D/PV-E 1200 4p switch disconnector combined with fuses. The switch disconnector is equipped with the YU* and the motor operator to open/close remotely
• OVR PV T1-T2 10-1500P TS QS to protect against overvoltages

* Undervoltage Release (YU)

Application Bundle 2#: 4MWh, 4MW Utility Scale Application

Discover our switching & protection solutions for easy PCS configuration considering 4MWh BESS architecture with a single 4MWh main system module.

Single-line diagram of a 4MWh, 4MW Utility scale application

The diagram shows a system with MVAC Utility connected via MV/LV Transformer to a PCS. The PCS connects to a DC combiner, which then connects to multiple Battery racks.

Specifications of electrical quantities with a 1500 V DC PCS (Four inverters per module)

ABB's offering (IEC) - PCS with 4 inverters per 4MWh module

The diagram illustrates ABB S&P devices suited to the AC and DC side for a PCS with 4 inverters per 4MWh module.

AC side components:

• AF 750 (1050A – AC1) contactor for switching on each inverter branch
• Emax E4.2N: Emax E4.2N 4000 3p Ekip Dip LSI main circuit breaker for protection and isolation, equipped with Ekip com Modbus TCP communication module and with YO/YC* and motor to open/close remotely
• Emax E4.2N 4000 3p Ekip Touch LSI main circuit breaker for protection and isolation, equipped with Ekip com Modbus TCP communication module and with YO/YC* and motor to open/close remotely
• Emax E4.2N 4000 3p Ekip Hi-Touch LSI main circuit breaker for protection and isolation, equipped with Ekip com Modbus TCP communication module and with YO/YC* and motor to open/close remotely
• OVR T2 3L 40-600 P TS QS to protect against overvoltages from the AC Utility
• TVOC-2 + RELT Module for Arc Flash Mitigation

* Opening Release (YO); Closing Release (YC)

DC side components:

• Fuses installed on each inverter branch to protect the converter combined with a main Emax E4.2S MS-DC/E 4000 4p switch disconnector equipped with YO/YC* and motor to open/close remotely
• OVR PV T1-T2 10-1500P TS QS surge protection device to protect against overvoltages

Application Bundle 3#: 4MWh, 4MW Utility Scale Application

Discover our switching & protection solutions for easy PCS configuration considering 4MWh BESS architecture with two 2MWh main system modules in parallel.

Single-line diagram of 4MWh, 4MW Utility Scale application

The diagram shows a system with MVAC Utility connected via MV/LV Transformer to two PCS units. Each PCS connects to a DC combiner, which then connects to multiple Battery racks.

Specifications of electrical quantities with a 1500 V DC PCS (Two inverters per module)

ABB's offering (UL) - PCS with 2 inverters per 2MWh module

The diagram illustrates ABB S&P devices suited to the AC and DC side for a PCS with 2 inverters per 2MWh module.

AC side components:

• AF 1250 contactor for switching on each inverter branch
• Emax E4.2S-A: Emax E4.2S-A 2500 3p Ekip Dip LSI main circuit breaker for protection and isolation, equipped with Ekip com Modbus TCP communication module and with YO/YC* and motor to open/close remotely
• Emax E4.2S-A 2500 3p Ekip Touch LSI main circuit breaker for protection and isolation, equipped with Ekip com Modbus TCP communication module and with YO/YC* and motor to open/close remotely
• Emax E4.2S-A 2500 3p Ekip Hi-Touch LSI main circuit breaker for protection and isolation, equipped with Ekip com Modbus TCP communication module and with YO/YC* and motor to open/close remotely
• OVR T2 3L 40-600 P TS QS to protect against overvoltages from the AC Utility
• TVOC-2 + RELT Module for Arc Flash Mitigation

* Opening Release (YO); Closing Release (YC)

DC side components:

• Fuses installed on each module to protect the converter combined with a main Emax E4.2S-A MS-DC/E 2000 4p switch disconnector equipped with YO/YC* and motor to open/close remotely
• OVR PV T1-T2 10-1500P TS QS surge protection device to protect against overvoltages

Application Bundle 3#: 4MWh, 4MW Utility Scale Application

Discover our switching & protection solutions for easy PCS configuration considering 4MWh BESS architecture with four 1MWh main system modules in parallel.

Single-line diagram of a 4MWh, 4MW Utility scale application

The diagram shows a system with MVAC Utility connected via MV/LV Transformers to four PCS units. Each PCS connects to a DC combiner, which then connects to multiple Battery racks.

Specifications of electrical quantities with a 1500 V DC PCS (Three inverters per module)

ABB's offering (IEC) - PCS with 3 inverters per 1MWh module

The diagram illustrates ABB S&P devices suited to the AC and DC side for a PCS with 3 inverters per 1MWh module.

AC side components:

• AF 205 (350A – AC1) contactors for switching on each inverter branch
• Tmax XT7L: Tmax XT7L M1000 3p In=1000A Ekip Dip LS/I main circuit breaker for protection and isolation, equipped with Ekip com Modbus TCP communication module and with SOR* and motor operator to open/close remotely
• Tmax XT7L M 1000 3p In=1000A Ekip Touch Measuring LSI main circuit breaker for protection and isolation, equipped with Ekip com Modbus TCP communication module and with SOR* and motor operator to open/close remotely
• Tmax XT7L M 1000 3p In=1000A Ekip Hi-Touch LSI main circuit breaker for protection and isolation, equipped with Ekip com Modbus TCP communication module and with SOR* and motor operator to open/close remotely
• OVR T2 3L 40-600 P TS QS to protect against overvoltages from the AC Utility
• TVOC-2 + RELT Module for Arc Flash Mitigation

* Shunt Opening Release (SOR)

DC side components:

• GF 875 contactors for switching combined with fuses on each inverter branch. The 2 poles are fitted with special arcing contacts enabling bi-directional breaking of currents up to 750VDC per pole
• OT1600E02-135 main disconnector for DC20 application
• OVR PV T1-T2 10-1500P TS QS surge protection device to protect against overvoltages

Product offering

ABB offers a comprehensive range of products for switching and protection solutions in Battery Energy Storage Systems. The product categories include:

• Contactors: Available via Web Page, Catalog, and Interactive Catalog.
• Tmax XT: Available via Web Page, Catalog IEC, and Catalog UL.
• Emax 2: Available via Web Page, Catalog IEC, and Catalog UL.
• GF Contactor: Available via Web Page and Catalog.
• ODTC: Available via Web Page and Catalog.
• OT: Available via Web Page and Catalog.
• TVOC: Available via Web Page and Catalog.