High-Resistance Grounding (HRG) of Industrial and Commercial Power System


Presented by: Dev Paul

Lunch will be provided between 12pm and 1pm.

The tutorial will provide handouts consisting of technical material on the design and application of HRG system applied to the Industrial and Commercial Power Systems.

This tutorial is intended for both the experienced engineers much familiar with the HRG design as well as for the younger engineers starting their career in the power system design. How such an HRG design enhances safety of maintenance personnel and minimizes equipment hazard will be the main focus once the instructor provides clarifications on the fundamentals of HRG design.

One of the most confusing and challenging technical information of using HRG design is the flow of system charging current directions during phase-ground fault condition. This tutorial will go in details of this system charging current and related capacitive component of the ground fault current during fault condition.

Ground fault current has both the magnitude and the phase angle with respect to the voltage responsible for the ground fault current flow. This appears to be overlooked which caused published literature showing inconsistent power factor of the ground fault current for the HRG design. Also the word charging current appears to be causing confusion to application engineers who argued with the presenter that the charged capacitance between the power system components to ground becomes generators to provide capacitive component of fault current during phase-ground fault conditions. Presenter will provide brief and concise clear understanding of this “system charging current” and its flow during normal operation and during phase to ground fault condition.

For clarification purposes, the tutorial will include three-line presentation of a MV power system requiring HRG design to explain how system charging current flows in the reverse direction in the two un-faulted phase conductors before this current returns to the faulted phase to ground location. Clearly; this capacitive current flow towards the power system neutral in the two un-faulted phases in the reverse direction to the system charging current flow under normal power system operations. Upon reaching the system neutral this current traverses by the faulted phase conductor to the phase to ground fault location. At the power system neutral, the currents in the two un-faulted phases are added together by phasor diagram such that it becomes equal to total system charging current. By Kirkoff current law, current entering into the neutral (-3ICO) becomes 3ICO. This is how in the fault current phasor diagram, system charging current is presented as 3ICO, whereas capacitive component of the fault current are presented as -3ICO such that the two currents has 180° phase angle difference.

Tutorial will cover the following topics:

  1. History of HRG grounding method
  2. Development of automatic monitoring devices to identify phase-ground fault for faster isolation of faulted section of power system for power system reliability.
  3. Application of HRG grounding to low-voltage (LV) power systems
  4. Application of HRG grounding to medium-voltage (MV) power systems
  5. Clarification of HRG limitations “voltage not to exceed 4.16 kV and phase-ground fault current not to exceed 10A (system charging current 7.2A)” included in the IEEE/IAS Std. 142-2007.
  6. Damage at the fault location due to resistive component of fault current only.
  7. Arcing fault, impact of arc-fault resistance on fault damage. Condition of maximum damage at the fault location.
  8. Application of voltage polarized directional current relays suitable for HRG application identifying which phase has fault, which feeder parallel feeder has fault, and which parallel feeders are un-faulted by virtue of forward fault direction and reverse fault direction sensed by the protection relay.
  9. Review of system charging current and capacitive component of fault current
  10. Explanation of “how system charging current direction reverses during phase-ground fault condition”.
  11. Phasor diagram must present leading power factor of phase-ground fault current and its correct voltage and current phasor diagrams
  12. Why do we need to use HRG grounding and not use solidly grounded or low-resistance grounding methods?
  13. Practical examples of power systems isolation of phase-ground faults to minimize possibility of ground fault hazard if the fault is not isolated in the minimum practical time interval and possibility of phase fault involving other phases bypassing the HRG causing higher fault current and possible damage.
  14. Difference between HRG grounding for the mining power systems and the general industrial power systems
  15. Complete list of IEEE standards and Text books as reference material covering HRG
  16. Recent technical papers on HRG grounding by the author
  17. Open discussion

Registration consists of two parts - vTools and PayPal. Follow the "Register Now" link below, and complete the information. The system will then take you to a PayPal page to enter your payment information. When you have successfully registered and paid, you will receive 2 confirmation emails, 1 from IEEE and 1 from PayPal. Your registration is not complete until your payment has been received, and you have received both confirmation emails.

  Date and Time




  • 133 9th Avenue SW
  • Calgary, Alberta
  • Canada T2P 2M3
  • Building: Fairmont Palliser Hotel
  • Starts 11 April 2019 12:00 PM
  • Ends 08 May 2019 12:00 PM
  • All times are Canada/Mountain
  • Admission fee ?
  • Register


Dev Paul


Dev Paul, Senior Life Member IEEE (M’73-SLM’10) received a master’s degree in electrical engineering, and has more than 46 years of design, construction, and startup experience on various projects. This includes power plants; substations; transmission and distribution; cement plants; steel mills; alumina and aluminum smelters; water and wastewater; naval shipyards; airports; ports and port facilities; Department of Defense (DOD) and Department of Energy (DOE) facilities; and commercial and electrified rapid transit projects. Dev is the author of 48 technical papers published in American Public Transportation Association (APTA) and IEEE conferences. In 2002, he received the Ralph H. Lee Award from IEEE for his paper on DC Power Systems Grounding. He is the IEEE Vice-Chair of the 3 international standards on “Cold Ironing” also called shore to ship power supplies. These standards are IEC/ISO/IEEE P80005‑1, P80005‑2 and P8005‑3 and Dev’s technical input to these standards contributed to HRG grounding for both LV and MV installations as well as continuously monitored grounding/bonding conductor between the ship and shore. Chair of IEEE-SA P1627 Std. on application of DC surge arrester to electrified rail transit system.