Concept 2
PV Integration Challenges
Once solar generation exceeds local demand, the feeder stops behaving like a one-way delivery system. That is the root of the voltage problem.
What Changes When Solar Penetration Rises
1
Reverse Power Flow
Excess PV generation pushes power backward through the feeder instead of only outward from the substation.
2
Voltage Rise
That reversed flow increases voltage at the end of the feeder, especially near clustered PV.
3
Operational Limits
Protection settings, equipment ratings, and ANSI compliance start to bind long before all solar demand is met.
Quick Formula View
Voltage Rise Approximation
ΔV ≈ (R × P + X × Q) / V
When active power export P climbs during high solar periods, voltage rises at the point of interconnection unless DERMS actively counteracts it.
- RLine resistance turns real power flow into measurable voltage change.
- QReactive power is the main DERMS lever for soft voltage correction.
Cause & Effect
PV Generation and Voltage Violations
The red area grows at the same time the PV curve peaks. This is the visual link between solar export and feeder non-compliance.
Grid Impacts
Voltage Regulation
Conventional devices react too slowly for rapid solar ramps.
Protection
Reverse flow complicates relay coordination and feeder protection assumptions.
Equipment Stress
Sustained high voltage shortens the life of transformers, capacitors, and customer devices.
What DERMS Adds
- QVolt-VAR absorbs reactive power to soften voltage rise before energy is curtailed.
- PCurtailment trims active power output when compliance cannot be maintained any other way.
- OPTOptimization coordinates all devices to reduce waste while meeting constraints.
- BBattery storage shifts energy in time instead of simply throwing it away.