ACS880 energy storage system

DC/DC converter

DC/DC converter transfers energy from a common DC bus of a multidrive into an external energy storage. From there it can transfer the energy back to the DC bus when needed. Energy storages can be batteries, fuel cells or super capacitors. Applications for energy storage and reuse are found in a range of industries, such as marine (zero emission operation, peak shaving and hybridization), process industry (electrical braking or DC bus voltage stabilization) and automotive (charging systems).

Customer benefits include reduced energy consumption, emissions,  costs (reduced fuel consumption, reduced maintenance), improved ship performance and safety in critical situations. The converter unit consists of ACS880 frames R7i or R8i and DCL filter modules.

Typical applications are energy storages in hybrid and full electric systems, where the energy storage can supply all or a part of the needed power. The converter can assist in power peak shaving and strategic loading. The energy storage is charged from shore or from onboard power sources when the energy demand is low and discharged during power peaks. The converter keeps the drive’s DC voltage constant during peaks. The converter can be used for electrical braking, where motors are decelerated, and transfers the excess energy to an energy storage to be re-used later. This is a much more economical solution compared to resistor braking where the energy is simply wasted. The converter can also provide back-up power for critical applications during disturbances in the supply network, e.g. during voltage dips or power outages.

It is also possible to use DC/DC converter with fuel cell power plant.



  • Optimization of energy consumption
  • Stability and back-up power in critical applications
  • Full support for hybrid and fully electrical systems 
  • Fast and accurate current control providing rapid response in dynamic situations
  • Output current range: 94 A to 1800 A per unit. 
  • Units can be connected in parallel if higher powers are needed. In parallel connection, both the inputs and outputs must be connected together. The inputs are connected together through the common DC bus in the drive and the outputs (ES+ to ES+, ES- to ES-) must be connected together at the energy storage side.
  • Modular design, compact units, and easy installation
  • Converter modules are hardware compatible with ACS880-104LC inverter modules


Direct connected energy storage

If you connect energy storage directly to the drive it is simple, compact and cost-effective solution, but it does not include the features build-in to DC/DC-converter (e.g. voltage boosting or support for wider voltage range). Extra attention needs to be paid to battery minimum and maximum voltage levels and those are needed to be selected according to drive DC bus and motor AC voltage levels. It also requires you to size the other equipment on the DC bus such as motor inverters to work across the voltage range of the batteries since the DC bus will be floating with the battery voltage (state of charge). It can also make control and protection design a bit more challenging. 

Voltage and power ranges


R7iLC modules

400 V

  • 48 - 560 kW
  • 94 - 1100 ADC

500 V

  • 60 - 700 kW
  • 94 - 1100 ADC

690 V

  • 82 - 703 kW
  • 94 - 800 ADC

R8iLC modules

690 V

  • 219 - 1581 kW
  • 250 - 1800 ADC

ACS880-1604, DC/DC converter, IP00

Frame size
R7i installation frame424250541


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