Nov 2015
Electricity Transmission
Development of a Standard 33kV Damped Harmonic Filter Design
Nov 2015
May 2017
SP Energy Networks and SP Transmission
James Yu (Future Networks Manager)
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Network Innovation Allowance
Electricity Transmission Networks
The scope of project involves two stages:

Stage I:

Investigate the feasibility of a standard harmonic filter “building block” that can be deployed at 33kV to mitigate increased harmonic voltages that are primarily due to amplification of background harmonics.

  1. Carry out a review of where problems have arisen, within SPEN and the UK if possible.

  2. Recommend a filter “block size”, i.e. filter MVAr rating that would be suitable for most SPT (or SPD/SPM) sites.

  3. Develop a cost effective design for the filter – Although “C-type” damped filter design is envisaged, other designs can be proposed if these are deemed more cost effective or offer improved performance.

  4. Optimise design by considering cost, performance, footprint, losses, visual impact and other environmental factors.

  5. Broadly define the application range, i.e. network designs or characteristics of networks for which the filter is suitable, reasonably efficient and cost effective.

Stage II

If Stage I shows that a standard harmonic filter is feasible, the second project stage will aim to develop a detailed filter design and a component-level specification which can be used when tendering for filters.

  1. Develop Insulation coordination and surge arrestor requirements.

  2. Develop Protection and harmonic monitoring requirements.

  3. Develop Switching requirements. Can a standard 33kV circuit breaker be used?

  4. Develop detailed component specification.

  5. Spares recommendation.

  6. Develop building and ventilation requirements for indoor installation, specify footprint requirements including exclusion zone for electromagnetic fields, and requirements for possible future relocation of a filter.

  7. Produce an application guide for design engineers

Reduce costs by deploying a standardised design

Improve the management of harmonic voltage levels on transmission networks

Substantially reduce the risk of harmonic non-compliance

Provide an increased level of certainty regarding harmonic mitigation requirements to developers

Production of Stage I final report

Production of Stage II final report – If Stage I suggests that a standard harmonic filter is feasible