Harmonic Load Issues, Impact, and Mitigation
DSTAR Project 12-6 was initiated to investigate the changing nature of loads on electric distribution systems. The project confirmed that the utility load is becoming more active and non-linear, and as a result the loading due to harmonics created by these loads is increasing and changing. With more phase-to-neutral connected electronic loads, distribution utilities are finding that in many cases the dominant harmonic is the 3rd, which causes high neutral currents and neutral-to-ground voltages in addition to substantial increase in voltage distortion. This project will study and report on 3rd harmonic producing loads, (as well as other harmonics) and
- Analyze their impact on distribution systems, with regard to thermal loading, distortion and neutral voltage elevation
- Identify what mitigating measures are currently available or in development, including system design, equipment application, filters, etc.
- Assess (as far as possible) their effectiveness in mitigating impacts