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Case study of Copenhagen International School:

Electrical noise generated by PV system

Presented by Boris Lund Havmøller

PV systems and electrical disturbance

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DC/AC

InverterDC AC Main circuit

board

Meter

POC: Point of connection

10 kV/ 0,4 kV

Transformer

0,4 kV

10 kV

AC

AC

ACConsumption

Inverters modulation of a sine waveform

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Pulse Width Modulation

Types of AC signal in inverter systems

Harmonic disturbances

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-1.5

-1

-0.5

0

0.5

1

1.5

Fundamental

3. harmonic

5. Harmonic

7. Harmonic

11. Harmonic

Resulting Waveform

-1.5

-1

-0.5

0

0.5

1

1.5

Fundamental

3. harmonic

Resulting Waveform

Example of disturbance

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Measured U, I and P for an LED lamp

THD,i

Technical regulations for connecting PV

systems to the distribution grid

Technical regulation 3.2.2 for PV power plants above 11 kW

The electricity supply undertaking

• is responsible for setting emission limits in the Point of Connection.

• must agree on a schedule for determining emission limits with grid connection applicants.

Plant owner

• must ensure that the PV power plant is designed, constructed and configured in observance of the specified emission limits without grid reinforcements being required.

• may, according to agreement, purchase supplementary services from the electricity supply undertaking to ensure compliance with the specified limit values.

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PV plants categorized based onrated power

The technical requirements of the regulation are divided into the following categories based on the total rated power in the Point of Connection:

• A2. Plants above 11 kW up to and including 50 kW

• B. Plants above 50 kW up to and including 1. 5 MW

• C. Plants above 1.5 MW up to and including 25 MW

• D. Plants above 25 kW or connected to over 100 kV

The requirements concern: DC-content, asymmetry, fast voltage changes, flicker, harmonic disturbances, interharmonic disturbances, disturbances 2 - 9 kHz.

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Copenhagen International School

• Vis skolen

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Copenhagen International School –EnergyLab Nordhavn

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• Flexible energy demand and production

• Cognitive buildings

• Storage

• BESS as a grid investment

• EV fleet

• Aggregators in the energy market

Thank you for your attention

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