Day 22 - Hybrid Energy Storage Systems (HESS)

Super Capacitors + Li-Ion Battery - Best from Both Worlds
HESS Topology at a Glance – Novel Unique Patented Technology by RUTRONIK

VUCA problem

Volatile: Charging and discharging of the supercaps takes place rapidly and changes constantly during operation

Uncertainty: Unwanted and parasitic effects in the electronics of DC/DC converters Oscillations in the system which have to be controlled (analogue or digital)

Oscillations have a positive and negative sign (voltage and current). In a bidirectional DC/DC converter there are also positive and negative signs (voltage and current).

System must distinguish between actual function (bidirectionality /current direction reversal) and current direction of parasitic/unintended effects)

Detection by parallel monitoring of multiple control loops and parameters

Complexity: requires optimized control behavior, digital control loop monitoring currents and voltages and a superimposed analog control loop compensating the latency (digital control loop is slower) of the digital control loop

Ambiguity: special circuit technique that unambiguously resolves ambiguity (parasitic or function)

Solution: analog foresight (predictive, in ns) what is coming to the digital control loop switch off, switch over, switch on (signal processing and detection of the control signals takes place in the ns range and controls (overrides) all switching operations from the digital control loop (mathematically, the first derivative of the rate of current rise/ The second derivative of current

Analog computing technology in combination with digital computing technology

If the wrong sign is detected, the parasitic diode in the transistor is prevented from conducting -> Control of the DC/DC converter into a safe operating state DC/DC converter is therefore ALWAYS in a safe operating state, regardless of the current direction

Key Features:

  • Combined novel Buck OR MOS Boost Topology
  • Digital power control loop with superimposed ultra-high speed di/dt sensor (ns)
  • Configurable control parameters / current limiter for each energy storage device
  • Gives a high impedance battery system a low impedance performance
  • Ultra high speed superimposed special control loop topology to avoid oscillation and cross conduction
  • Avoid conduction of the internal body diode of the MOSFETS
  • New technology compensate latency of the digital power control loop
  • di/dt controlled MOSFET Switches
  • Predictive new OR-MOSFET control


  • Improved battery lifetime
  • Adjustable battery current limiter
  • Extremely high peak current performance
  • Improved Temperature Behavior
  • Predicted battery lifetime and state-of-health (SoH)
  • Patented technology usable for all uni-directional and bi-directional DC/DC Converter Topologies

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