Control Algorithm for Protection Circuit for DC Power Distribution Systems


Reference #:  01052

The University of South Carolina is offering licensing opportunities for this novel technology that is useful in the rapidly proliferating field of dc power distribution systems. It protects circuits against short circuits while ensuring high power quality and power continuity to protected loads. 

Invention Description:

This invention is an algorithm for controlling a specific (previously disclosed) electronic circuit “the hardware”. Together, the algorithm and the hardware assure delivery of high-quality power to loads in dc systems by protecting against common disturbances such as short circuits, over-currents, under-voltage supply, momentary power outages, and dynamic instabilities. The system thus increases the safety, reliability and continuity of service of the power distribution system. .

This control algorithm allows the hardware to protect against multiple types of failures that would otherwise require several different devices and procedures (e.g. UPS, fuses, circuit breakers, auxiliary power feeds) to achieve similar protection. If one succeeded in stringing together these different devices, they could interfere with each other and would normally require communication and coordination among them to work effectively.

All forms of protection are automatically actuated by the controller based on local measurements and without requiring any communication with or among other protection devices, thereby reducing interferences with other protections and guaranteeing protection during multiple simultaneous events.

Advantages and Benefits:

•    Hardware controlled with this algorithm eliminates the need for a mechanical circuit breaker, while offering several advantages: it can distinguish temporary faults from permanent faults; it doesn’t require manual resetting after a fault is cleared; it limits energy input to the fault, it reduces any arc flash hazard, and it simplifies the process of de-energizing and disconnecting the faulted distribution line.

•    The appropriate protection mode is automatically actuated by the local controller based on local measurements, without any need for communication with the rest of the system.

•    The operation is independent of the structure of the system, and it doesn’t require any modification to the structure of the system or to the control strategies of the converters in the system. 

•    The control algorithm operates switching devices in the protection circuit at a significantly higher frequency than is typical of regular switching power converters. This provides a significantly faster response time, which allows fault and transient detection and implementation of the appropriate protection configuration before such events affect the behavior of power converters in the system, and avoids propagation of adverse effects throughout the whole system.

•    Instability compensation during transient events does not require a dedicated approach for each load topology. Transient events within design limits are compensated; in case of transient events beyond the design limits, the high bandwidth of the protection system disconnects loads before disturbances can propagate to supply-side power converters, which could causes complete system failure.

•    The control algorithm provides a load ride through time 3 to 4 times longer than would be provided a comparable passive solution.

Potential Applications:

The control algorithm is suitable for use in dc distribution systems at any power level, but is intended for systems above the kW level including industrial power systems, electric vehicles (ships, trains, planes, cars, etc.), or local-area dc micro-grids – anywhere that one or more power sources are distributed to loads on two or more branch circuits. The physical hardware replaces a circuit breaker while the control algorithm (software) operates the hardware to provide all of the listed benefits.


Patent Information:
Title App Type Country Serial No. Patent No. File Date Issued Date Expire Date Patent Status
Methods And Systems For Protecting DC Circuits Utility United States 14/461,347 9,502,884 8/15/2014 11/22/2016    
For Information, Contact:
Technology Commercialization
University of South Carolina
Ugo Ghisla
Roger Dougal
Igor Kondratiev
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