Test Case 01

01

OCT

2

ERIGrid 2.0

03/05/2021

Control of voltage with an on-load tap change controller

The aim of this test case is to prove that an on-load tap changer controller “OLTC” is able to regulate the voltage level of the distribution network to the required value as stipulated both by international standards and by the network operator. This regulation would happen when the components connected to its low voltage side or when external anomalies such as the weather disturbing the normal behavior of the grid voltage. Depending on the control strategy, the measured value could come from locally measured values, remotely measured values, or even from end-user (smart meter) measurements.

The function under test is the voltage level control

• OLTC controller
• The communication infrastructure between the controller and the RTU.
• Flexible loads and sources on the demand side

Electric Power System, Communication, Control

Verify if the performance of OLTC controller is adequate to maintain the voltage level within the required limits

Characterize the OLTC operating performance in terms of loss reduction and hosting capacity enhancement.

The SuT is composed real experimental grid with the follow-ing components:

• Generator.
• OLTC
• Transformers.
• automated switchgear with RTUs.
• Controllable loads
• Communication facilities

• OLTC controller regulating the voltage.
• Communication of ICT with the RTU.
• Interaction of the OLTC with the SuT configuration and conditions.
• Loads and generation control.

The OLTC shall be able to control voltage with the pre-established limits in a predefined time-frame.

• Voltage (V) on low-voltage side of transformer.
• Operation time (s).
• Number of TAP position changes.

• Voltage variation.
• Control of loads and generation
• Errors in measurement
• Errors in Communication
• Loss of a line/generator

• Complies with the quality standards,
• Maintain voltages within the ±10% specified limit.