Table 3 Summary of protection schemes for distribution systems with DER Penetration
Technique | Main feature | Merits | Demerits |
|---|---|---|---|
Fault current limiter based [68] | Suitable for wind mill based DER penetration | Block the fault current during faults | Costly |
Harmonic restrained Protection [93] | The DER power is penetrated in the power utility until the allowed harmonic limit and protection is maintained | This approach is highly suitable for inverter based DER. | Not applicable for non-invertor based DER. |
Optimal sizing of DER. [90] | DER power is penetrated at safe location where existing protection is least effected. | Existing protection may hold good. | Applicable for small penetration |
Adaptive Relaying [25] | The relay setting are adopted based on the changing network topologies/configurations. | This method is applicable for large scale penetration from wind farms. | Communication and numerical relays are essential for design of protection schemes. |
Local adaptive overcurrent based Protection scheme [88]. | It monitors local information (current & voltage) continuously and re-calculate the relay setting based on network topology. | This technique is applicable for both grid connected and islanded mode systems. | Fails during network dynamic conditions, |
A Novel adaptive over-current Protection [96] | DERs are considering as current injection sources. Steady state fault currents are calculated from steady state equivalent reduction of the system for design of protection | Capable to handle the network dynamic changes. | The algorithm run time increase with system size. |
Adaptive–relay-recloser-fuse coordination. | In this scheme, the relay/recloser and fuse current are determined. Based on the ratio relay and fuse current | This method is applicable for both synchronous based DG and Inverter based DG | Sometimes it is not desirable change the complete fast curve of recloser [33]. |
Online-Adaptive Over current Protection | Based on the network condition, it will calculate the fault levels & relay setting will be updated by using HIL IEC 61850 communication. | This protection scheme is applicable for both grid connected mode and Islanded mode. | Performance fails during network changes. |
Expert/Fuzzy based protection scheme [104] | Monitor the status of the DER source, voltage phasor based DFT technique and update the pickup & TDS settings based on the network changes. | This approach is suitable for limited network topologies | The identification of all potential network topologies is difficult. |
Group setting based protection scheme [106] | The multiple relay group setting are identified based on the fault level in network | This approach is suitable for multiple DER and series compensated lines | The identification of all potential network topologies is difficult and communication protocol are essential. |
Multi-agent based protection [103] | Coordinated decentralized protection | Distributed protection control | Requites the communicable agents like relay, breaker etc. |