Concepts for efficient battery charging management

From ship propulsion to storage and retrieval machine

For applications such as power supply, battery charging and grid support, sustainability and productivity are important factors. Requirements are for example charging technology for a high power range, the possibility of regenerating and buffering energy. KEB’s portfolio offers scalable solutions for charging and storage technologies from 11 kVA to 1,000 kVA from a single source.

Proven products from the industrial environment, which are developed and manufactured by KEB, are used in the systems. This enables the availability of high quantities and cost-optimised packages. In addition to the required hardware, the appropriate COMBIVIS application software is integrated on KEB controls (CODESYS-based control applications according to IEC 61131-3). Advantages include:

  • Use on various mains types and mains voltages/frequencies TN-C-S, (IT, TT both in consultation with KEB)
  • Low mains feedback THDi < 5 % Typ. 3 %

Function principle of the battery charge management

  • For non-rotating applications or static/resting electrical machines
  • Common mode filter: Second-order filter against the mains and attenuation of the common-mode component on the DC side
  • Energy intake from the mains via the AIC (Active Infeed Converter, also called AFE – Active Front End) → the battery is charged
  • Energy output to the grid → Energy flows from the battery via the AIC to the grid
  • Application examples:
    • Photovoltaic system with storage
    • Central storage at the grid connection point


The concept 1 outlined here is important for fields of application such as drive technology and the energy supply of highly dynamic systems, for example storage and retrieval machines and lift systems.

The following concept can be used in the field of marine propulsion. It offers the advantage that no external charging devices are necessary. The system is earthed via the hull or also operated on an IT mains.

The third concept is an artificial grid or stand-alone systems for power supply.

The fourth concept shown expands the Artificial Mains Network to a UPS system with mains support and secure power supply.

A mains-independent, continuous power supply at frequencies from 50 Hz/60 Hz/200 Hz to 400 Hz is shown in the following concept.


AIC/AFEActive Infeed Converter/Active Front End
AMNArtificial Mains Network
BMSBattery Management System
CMSCapacitor Management System
EMCElectromagnetic compatibility
ITFrench for Isolé Terre. Type of implementation of a low-voltage grid in electrical power supply. Most important feature: type of earth connection at the power source and the electrical equipment.
THDTotal Harmonic Distortion
TN-C-SFrench for terre neutre combiné séparé. Translates roughly as separate combined neutral earth. Consists of a TN-C system primarily for the distribution network of the energy supplier and a TN-S system in the customer installation.
TTFrench for terre terre. Type of implementation of a low-voltage grid in electrical power supply. Most important feature: type of earth connection at the power source and the electrical equipment within the building installation.
UPSUninterruptible Power Supply