Power producer, PV plant
Harmonic study on an industrial MV ring
Distortion levels across several scenarios, resonance risk and transformer derating.
Market
Renewable energy
PV plants and wind farms. We carry out grid connection studies and compliance evidence, from the point-of-connection substation to the grid connection point.
Network operator requirements
The network operator checks reactive power at the point of delivery. Between the inverter terminals and that point, the internal network absorbs or generates reactive power depending on the transformers, the MV cables and their lengths. A plant can therefore be compliant according to the inverter datasheet without being compliant at the point of delivery.
Behaviour during faults (voltage dip ride-through, reactive current injection, active power recovery) is demonstrated by simulation, with verified inverter models.
Voltage quality is also examined, in particular inverter harmonics, resonances with cables and capacitors, and flicker.
Specific features of PV plants and wind farms
Internal MV networks are long, often in rings or radial over several kilometres. Cable capacitance shifts the resonances and raises the voltage at low output. On the DC side, PV plants present an arc risk and require specific protection.
MV connection to Enedis or HV connection to RTE
Depending on its power, the plant is connected to the distribution network (Enedis, at MV) or to the transmission network (RTE, at HV). At MV, the point-of-connection substation follows NF C 13-100, with an interface protection (protection de découplage) whose type and settings are imposed by the network operator. At HV, RTE's requirements apply at the connection point.
We carry out the calculations and prepare the evidence expected by the network operator. The submission remains the generator's responsibility. We also work for integrators in West Africa.
01What we do
Studies
- Load flow, P/Q and U/Q diagrams
- Harmonics and resonances
- Inverter EMT
- Stability and fault ride-through
- Protection plan, earthing, DC arc flash
Services
- Support to the project owner
- Testing of the power plant controller and control loops
- Review of the integrator's documents
02Examples
03Our offer
Usual content of an offer for this type of assignment. The exact scope, deliverables and price are set in the quotation.
- Package 1Check of data and models
Internal network, cables, transformers, inverter models.
- Package 2Steady-state studies
Load flow, P/Q and U/Q diagrams at the point of delivery, short-circuit.
- Package 3Dynamic studies
Fault ride-through, inverter EMT, harmonics, according to the applicable requirements.
- Package 4Compliance evidence
Compliance notes in the format expected by the network operator, answers to its questions.
04How we work
- 01Data and models
Check of the internal network data and of the manufacturer models.
- 02Steady-state studies
Load flow, P/Q and U/Q diagrams at the point of delivery, short-circuit.
- 03Dynamic studies
Voltage dips, inverter EMT, harmonics.
- 04Compliance evidence
Notes and compliance conclusions in the format expected by the network operator.
05References
Integrator, West Africa
Four PV plants
Load flow, short-circuit, neutral earthing, earthing, stability and protection plan for each plant.
Integrator, West Africa
9 MWp, 30 kV PV plant
LV, MV and DC arc flash: incident energies and PPE per work location.
Wind farm owner
Dispute over an MV cable network
Technical notes on cable joint failures and switching overvoltages, responses to the opposing party's submissions (dires).
06Frequently asked questions
Do you submit the compliance file?
We produce the calculations and the evidence. Submission remains the responsibility of the generator.
The inverter model is supplied by the manufacturer. Do you use it as is?
No. We first check it on simple cases (setpoint step, voltage dip) before using it.