Power quality is one of the most technically scrutinised aspects of renewable energy grid connection. Network service providers require detailed analysis of harmonic distortion, flicker, voltage unbalance and audio frequency interference before approving connection of solar or BESS systems.
ElectraGlobe provides comprehensive power quality analysis and design solutions that satisfy NSP requirements and protect your project's connection timeline.
Power quality analysis assesses the extent to which a generator or load disturbs the quality of the voltage waveform at its connection point. Inverter-based generators such as solar PV and BESS are inherently capable of injecting harmonic currents into the network, and network service providers set allocation limits at the connection point to keep that injection within what the network can absorb. Demonstrating compliance with those limits is a prerequisite for connection approval.
| Parameter | What it describes | Why the NSP cares |
|---|---|---|
| Harmonic distortion | Current and voltage components at multiples of 50 Hz, injected by inverters and non-linear loads | Distorts the voltage waveform for other customers and stresses network plant |
| Flicker (Pst and Plt) | Rapid, repetitive voltage variations caused by fluctuating output or switching | Visible light flicker and a direct customer complaint pathway |
| Voltage unbalance and rapid voltage change | Differences between phase voltages, and step changes at switching or trip events | Affects rotating plant and can trip sensitive equipment nearby |
| Audio frequency injection | Interference with the DNSP's ripple control signal band | Can disable load control and hot water switching across the feeder |
| Workstream | What we deliver |
|---|---|
| Harmonic studies |
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| Flicker and voltage quality |
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| Audio frequency injection |
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| Compliance reporting |
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We take on the full power quality scope or step in at a single point, whether that is a filter design, an AF injection assessment, or a response to a power quality condition an NSP has raised in a connection offer.
Harmonic performance is usually the parameter that decides whether mitigation equipment is needed at all, and it is sensitive to assumptions about network impedance that are easy to get wrong. We model the network harmonic impedance across the relevant frequency range, assess injection against the allocation the NSP has given the connection, and where mitigation is required, design and specify the filter and document it to a standard the NSP and the contractor can both work from.
Power quality is often left until late in a connection programme, on the assumption that inverter datasheets will settle it. They rarely do. The assessment depends on the network the plant is connecting into, the harmonic allocation the NSP has issued, and how the plant behaves across its full operating range, and a result that does not hold up comes back as a request for further information or a condition on the connection offer.
If you have a power quality assessment in progress, under review by an NSP, or a result you do not trust, we can tell you quickly where the real risks sit.