1. DISPERSED GENERATION INFLUENCE ON FAULT PASSAGE INDICATOR RESPONSE
Context of research
Performed studies presentation
Simulation of Fault Passage Indicator (FPI)
Application Network
Results and discussion
Conclusions
Good afternoon,
Let’s me present my subject to you. It’s called “Dispersed Generation influence on fault passage indicator response”.
My presentation include three parts:
Context of research
Performed studies presentation
Results and discussion
Conclusions and Perspectives
This research is carried out in the GIE-IDEA (Groupement d’Intérêt Economique - Inventer la Distribution Electrique de l’Avenir ). It is a Economic grouping of Interest created by National Polytechnic Institut of Grenoble (INPG), Electrotechnic Laboratory of Grenoble (LEG), Electricity of France (EDF) and Schneider Electric Industries.

2. Context of research Distribution network
Link between transport network and consumers
Development of Dispersed Generation (DG)
Fault detection and localisation
Importance in network management
Evolution due to DG insertion
Fault passage indicator (FPI)
For the first part, The context of this research is the fault detection and location on distribution network by Fault passage indicator with consideration of the development of Dispersed Generation (DG).
Distribution networks perform the connexion from transport network to final customers and have to fulfil services and a good power quality. Nowadays, We consider an evolution of distribution network with the direct connexion of Dispersed Generation on this network.
Faults detection and localisation is therefore of first importance in this network management. It is in fact often a grant given to a distributor who has to ensure safety and security. The evolution due to DG insertion maybe throws back fault location methods into question. Actually, the power flows are modified and the signal magnitudes are transformed too.
To perform the fault detection and location , Fault Passage Indicators (FPI) can be used. As a permanent fault occurs, they make it possible to locate the faulty part of the network and isolate it from the sane parts. A FPI may give the Local visual signs or Remote information to SCADA.
Our study deals with the influence of DG insertion on the fault location by FPI. These devices are simulated and tested on a distribution network under different conditions: without or with DG sources.

3. Performed studies presentation
Simulation of Fault Passage Indicator (FPI)
Principe of operation
Crossing of the thresholds (on amplitude or derivative (di/dt))
FPI considered : directional and non directional
To study the operation of FPI in distribution networks and influence of DG source integration on these operations, a simulation of FPI is carried out with ARENE software, developed by EDF (modelling of the considered networks and creation of the faults) and MATLAB (coding developed for the description of the operation of FPI in the network).
The Principe of operation of FPI is the crossing of the thresholds on amplitude or derivative (di/dt).
Two types of FPI is considered : Non directional FPI and Directional FPI. See the picture.
Non directional: Only the FPI between the main source and the point of fault provide an indication of fault presence
Directional: all FPI provide directional indication and we determine the point of fault.
Non directional detection
Directional detection

4. Performed studies presentation
Simulation of Fault Passage Indicator (FPI)
Algorithm
Sleep No
Fault passage
Yes
Indication & Start timer T
Here are the algorithm of each FPI. The first important block is fault passage. It’s the fault detection.
Yes
Line energized T > 8 sec No
Yes No
T > 3h

5. Performed studies presentation
Network application
Note:
: LV Networks connected to MV network studied,
: MV Customers.
: Main source (bond towards HV).
We used the urban distribution network called C0505 set up within GIE-IDEA. It has an impedance neutral system (as for the underground power networks in France). A DG source is also introduced into this network.
We chose 6 different positions for FPI installation. They are located at the intersections of secondary branches with the main branch and along the main branch of the network.
We also set the points of fault (three-phase, single-phase...). The fault detection is tested for each FPI type. To simulate influence of the circuit breakers on the operation of FPI, a circuit breaker is placed at the beginning of this network.
Urban network C0505 with the loads, the switchgear,the DG, the positions of FPI and fault considered

6. Results and discussion
Example : Indication of FPI_ND1 with phase-to-earth fault in network without DG
Fault localisation is correct
Use of non directional FPI_ND1 on C0505 network without DG source
Here are an example on indication of Non directional FPI, who is very often used in distribution network, with phase to earth fault on network without DG.
The point of fault is determined between two FPI with indication and no indication.
The tests for various fault types allows us to conclude that on network without DG source, all the results of FPI_ND1’ simulation for the various faults are correct; it is possible to determine the fault section.

7. Results and discussion
Example : Indication of FPI_ND1 with phase-to-earth fault in network with DG
Fault localisation is uncorrect
Use of non directional FPI_ND1 on C0505 network with DG source
Now, We insert a DG source (a 10MVA alternator -this value close to the acceptable limit fixed by the French regulations- and a transformer) in this network. The thresholds of FPI are identical to the preceding case.
It is noted that, FPI5 located between the DG and the point of fault provide an indication of fault presence. This phenomenon causes bad fault location: FPI indicates a fault after FPI5.
If we replace this DG source by another one with a 1.2MW power, the results of simulation are identical to the case without DG. The fault current starting from the DG source is too weak compared to the threshold selected. This means that we can locate the fault whilst this DG source functions (small power).

8. Results and discussion
Example : Indication of FPI_D1 and FPI_D0 with phase-to-earth fault in network with DG
Fault localisation is correct
Use of Directional FPI_D1 and FPI_D0 on C0505 network with DG source
When a huge power DG source is connected to the network, false indications can be produced with non directional FPI FPI_ND1. To avoid this problem, directional FPI can be used. We propose to use FPI based on phase current and phase voltage (FPI_D1) or FPI based on residual current and voltage (FPI_D0).
The simulation results are correct: the fault can be located between two FPI with opposite signal outputs.

9. Results and discussion
Remarks on the use of FPI
Fault detection
Fault localisation
Type of FPI
Directional
Three phase
Two phase
Single phase
Without DG
With DG
FPI_ND1 No
Yes
Yes
Yes
Yes
No(1)
FPI_D1
Yes
Yes
Yes
Yes
Yes
Yes
Here are some remarks on the use of FPI. The FPI_D0 is only detected the earth fault. And FPI_ND1 is not used in the case of huge DG connecting in to network
FPI_D0
Yes No
Yes(2)
Yes
Yes
Yes
In the case of huge DG
In the case of two-phase to earth fault

10. Conclusions and Perspectives
Fault passage indicators (FPI)
Network application
Perspectives
Neutral point treatment influence on FPI behaviours
FPI and DG position influence on produced indications
Optimal position of FPI
In this paper, models of fault passage indicators have been presented (non directional and directional FPI models) and tested with simulation signals from a MV distribution network without or with dispersed generation sources.
Our goal is to establish “rules” in FPI use with DG insertion in the distribution network: what are the conditions to fulfil in order to ensure that a non directional FPI will give correct indications or the fault location will always be possible? 
When a huge power DG source is connected to the network, false indications can be produced with non directional FPI. Using directional FPI can be for the moment a solution.
This work will pursue following different directions:
- Neutral point treatment influence on FPI behaviours.
- FPI and DG position influence on produced indications.
- Optimal location of FPI