New Methodology to Estimate Hosting

Capacity of Photovoltaic Generators in

Electric Power Distribution Systems

Code: 07.001

Leandro C. Brolin, Fernanda C. T. Arioli

FEEC – University of Campinas

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• To discuss the impact of photovoltaic generation on voltage

rise;

• To present a sensitivity study of hosting capacity with respect

to local network parameters;

• To propose a graphic approach to check if a rooftop PV can

be connected to the low voltage distribution system without

any steady-state overvoltage problem.

Objectives

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Renewable sources represent an important alternative to supply

the natural growth of demand and to diversify the energy matrix.

Depending on the penetration level of distributed generators, the

distribution systems can benefit from:

• Loss reduction;

• Voltage support;

• Reinforcement deferment;

• Increased reliability;

• Etc.

Introduction

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Massive connections of PV generators can cause undesirable effects. The

voltage rise is one of the most restrictive technical issues related to the

massive connection of distributed generation.

Introduction

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PVPV

SUBPVV

QR

XP

jRV

R

XQP

RVV ˆ VjVVSUB ˆ

• Hosting capacity:

• Definition;

• How to calculate?

• Request for access to the photovoltaic generation

connection;

• How to reduce the time spend in the analysis?

Introduction

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Network parameters:

1) Ratio between the resistance and the nominal voltage at the PV

connection point

2) Ratio R/X at the PV connection point

Sensitivity Study

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PVV

R

P

V

X

R

Network parameters:

3) Impedance at the PV connection point

3) Sensitivity based on Jacobian matrix

3) Sensitivity based on Jacobian matrix

Sensitivity Study

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Z

10

kkRPVJ

k

RPV

k

GF V

J

P

kk

k

11

Sensitivity Study

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Procedure to determine the hosting capacity in

function of network parameters.

Typic result

Characteristics of the Test Systems

Sensitivity Study

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*Network 3 is a secondary network. ** The peak load refers to LV customers only because the PV generators are installed at the LV network.

Name Network 1 Network 2

Length (km) 3.50 4.71

Short-circuit level at the substation (MVA) 207 525

Phase-to-phase voltage at the medium voltage level (kV) 12.47 13.80

Phase-to-Phase voltage at the low voltage level (kV) 0.415 0.22

Peak load of low voltage customers (MW)** 5.50 4.10

Maximum accumulated impedance magnitude (Ohms) 2.50 2.03

Name Network 3*

Length (km) 0.12

Short-circuit level at the transformer connection point (MVA) 160

Phase-to-phase voltage at the medium voltage level of the transformer (kV) 11.40

Phase-to-Phase voltage at the low voltage level of the transformer (kV) 0.22

Peak load of low voltage customers (MW)** 0.03

Maximum accumulated impedance magnitude (Ohms) 0.85

Results

Parameter:

Sensitivity Study

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Network 1

Network 2 Network 3

PVV

R

P

V

How to apply the procedure?

The Fast Screening Approach

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Example 01

The Fast Screening Approach

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Network 2

The new PV can be installed

Example 02

The Fast Screening Approach

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Network 2

Further Investigation

This work presented a sensitivity study of the hosting capacity in function

of network parameters for three real electric power distribution systems.

In general, the maximum allowed PV penetration is inversely proportional

to the parameter values at the PV connection points.

From the results of the sensitivity study was proposed a fast screening

approach to support the utilities in the analyses of requests to connect new

rooftop PV generators on distribution systems.

The fast screening approach refers to a simple graphic check allowing the

utility engineers to evaluate quickly the access requests reducing the

number of man-hours and processing time.

The graphic need to be updated when there is a change in the network or

the point to be checked belongs to the Further Investigation Region.

Conclusions

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Acknowledgments

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Acknowledgments

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THANK YOU!