Brushless Hybrid Solution Generating Precise, Quiet Efficiency

Wind Turbine

WIND TURBINE

Direct drive brushless
DC generator

Wind_Hydropower_Nameplate_1a
Wind_Hydropower_Nameplate_2b
Wind_Hydropower_Nameplate_3c
Hydropower

HYDROPOWER

Direct drive brushless
DC generator

Wind_Hydropower_Nameplate_1a
Wind_Hydropower_Nameplate_2b
Wind_Hydropower_Nameplate_3c

Business Case for Replacing Brushed Motors with Brushless Asymmetrically Commutated Motor/Generator​

BLDC NEMA-56 ISO_Trns

Our Disruptive Technology

DDU Magnetics’ Brushless DC Asymmetric Commutation Technology disposes a means for creating a rotating magnetic field using ‘prime numbered’-phase stepped sequence coils combining the low form factor of ‘brushed’ DC motors with the increased reliability, efficiency and performance of brushless. This technology does not require a higher voltage battery incentivizing OEM’s of brushed DC motors to upgrade to Brushless DC without replacing the original battery and ancillary components.

Brushless motor replacements for brushed DC motors have been in development for many years and promise to dramatically improve drivetrain performance.

A brushless retrofit has many challenges including the increased cost of the electronic commutator and the need to upgrade the battery. The brushless motor takes DC power from a battery pack and inverts into 3-phase Vrms power generating a rotating magnetic field (RMF). By comparison, the brushed motor mechanically inverts DC power into Vrms RMF using copper segmented commutator bars and graphite brushes with increased mechanical wear and electrical arcing.

Brushless motors operate with a better rate of acceleration, efficiency, reliability, top speed and regen characteristics all of which are programmable. The performance characteristics of brushless motors are a leap above its brushed counterpart. Brushless motors have been slow to come to market because of the engineering & programming complexity of the inverter/speed controller and the increased cost as well as the need to increase the battery voltage due to the difference in form factor.

When upgrading a 12Vrms brushed motor to brushless, the battery voltage must be increased by a form factor of 1.35 x DC voltage e.g., 12Vrms x 1.35 = 16 VDC Batt. By comparison, a brushed DC motor’s mechanical commutator converts DC power into ‘multi-phase’ square waves having a form factor of nearly 1.0 x 12Vrms = 12V Batt.

Brushless motors do not require mechanical commutation and are more efficient than its brushed DC counterpart by a factor of 20 to 40%, depending on the load. It creates significantly more torque, faster acceleration and since it has no mechanical connections, other than the ball bearings at each end of the rotor, maintenance is minimal. Available DC ‘brushed’ systems cannot deliver all these features.

Brushed DC:

  • Baseline cost
  • Mature infrastructure
  • Limited regeneration
  • Relatively low operating efficiency
  • Relatively high MRO cost

Conventional Brushless Motor:

  • Baseline cost
  • Mature infrastructure
  • Limited regeneration
  • Relatively low operating efficiency
  • Relatively high MRO cost

Brushless DC Asymmetrically Commutator Motor:

  • Nearly cost neutral compared to brushed motor
  • Drop-in replacement: battery system upgrades not required
  • Integrated electronics save space
  • Precision speed torque control
  • 1.0 form factor
  • Higher operating efficiency
  • Lower MRO costs compared to brushed motor carts

DDU Brushless Commutation Topology Advantage

  • Simple step sequenced Prime Numbered Commutation ‘PNC’ algorithm.
  • Distributed electronic switching layout utilizing close to 50% of all available solid state switches per cycle versus 33% for conventional trapezoidal/sinusoidal commutation.
  • High power density via our unique prime numbered coil layout utilizing greater than 90% of the total number of coils at up to 100% duty cycle vs 66% trapezoidal mode coil utilization @ 100% duty cycle and 100% sinusoidal mode coil utilization at 66% duty cycle.
  • Smooth quiet operation via our single coil transitioning method switching or ‘transitioning’ the current in only one of the energized coils per step.
  • Low cost open loop control mode with stall detection.
  • Sensored closed loop control mode with a common or ‘single channel’ PWM.
  • Sensor-less closed loop control mode using back emf.
  • Smooth power generation with minimal harmonic distortion or torque/voltage ripple.
  • Low speed direct drive power generation using high pole count Reluctance, PM or hybrid configurations.
  • Electronically simulated constantly variable speed/torque operation via our unique multiplexing switching sequence.

About

DDU Magnetics is an existing veteran-owned motor/generator design test firm located in Lynwood, Illinois. We have designed a lower-cost alternative to high maintenance brushed DC motors and generators. Our integral controller brushless machine design significantly lowers both the initial, and ongoing, operational costs of DC brushed motors versus trapezoidal and/or sinusoidal electronically commutated brushless motors. With 25 years of control and design experience in generation, transmission and distribution protection, we provide generator solutions to your most challenging projects.