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GRID CODE

MEDIUM SCALE DISTRIBUTED

GENERATION (MSDG)

Greater than 50kW but less than 200kW

CENTRAL ELECTRICITY BOARD Royal Road Curepipe

Mauritius Tel No.: (230) 601 1100 Fax No.: (230) 601 1180

Foreword

The purpose of this document is to assist the public to better understand the

procedure for application, the requirements for interconnection, the Feed-in-Tariffs

and other related issues regarding Medium Scale Distributed Generation (MSDG).

Any prospective applicant willing to take advantage of the Medium Scale

Distributed Generation (MSDG) Scheme is informed that:

I. Compliance to this Grid Code is mandatory

II. The provisions of the Electricity Act shall be adhered to.

III. This Grid Code will be reviewed and updated when the need arises.

Table of Contents

CHAPTER 1 - Purpose of the Grid Code........................................................................ 1

CHAPTER 2 - Connecting MSDG to the Grid .............................................................. 2

CHAPTER 3 - MSDG Interconnection Requirements and Safety Aspects ............... 4

3.1 Interconnection Facility Characteristics ............................................................. 4

3.2 Interconnection Facility Design Parameters ...................................................... 4

3.3 Protection Requirements ..................................................................................... 4

3.3.1 Availability of protection ............................................................................. 4

3.3.2 DC Functions of Protection Apparatus ....................................................... 6

3.3.3 Protection Flagging, Indications and Alarms ............................................. 6

3.3.4 Trip settings ................................................................................................... 6

3.3.5 Network Islanding ........................................................................................ 7

3.3.6 Re-connection ................................................................................................ 7

3.3.7 Synchronising AC generators ...................................................................... 7

3.3.8 Earthing requirements .................................................................................. 7

3.4 Power Quality....................................................................................................... 8

3.4.1 Limitation of DC injection ............................................................................ 8

3.4.2 Limitation of voltage flicker induced by the MSDG .................................. 8

3.4.3 Harmonics ..................................................................................................... 8

3.4.4 Surge Withstand Capability ......................................................................... 9

3.4.5 Voltage and Current Unbalance .................................................................. 9

3.4.6 Voltage Step Change ..................................................................................... 9

3.5 Power Factor ....................................................................................................... 10

3.6 Safety, Isolation and Switching ......................................................................... 10

3.6.1 Rules for working on low voltage grid (LV) ............................................. 10

3.6.2 Safety Concerns ........................................................................................... 11

3.6.3 Electromagnetic emission/Immunity ........................................................ 11

3.6.4 Labels ........................................................................................................... 12

3.6.5 Documentation ............................................................................................ 12

3.6.6 Information plate ........................................................................................ 13

3.6.7 Electrical contractor / Installer ................................................................... 14

3.7 Metering .............................................................................................................. 14

3.8 Testing, Commissioning and Maintenance...................................................... 15

3.9 Standards and Regulations ............................................................................... 15

ANNEX 1 - Abbreviations and Definition .................................................................. 16

ANNEX 2 - Feed-In-Tariff ............................................................................................. 18

ANNEX 3 - CEB Fees ...................................................................................................... 19

ANNEX 4 - Application Form ........................................................................................ 20

ANNEX 5 - Certificate of Installation .......................................................................... 26

ANNEX 6 - Certificate of Compliance ......................................................................... 27

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CHAPTER 1 - Purpose of the Grid Code

The Medium Scale Distributed Generation (MSDG) set of Grid Codes describe the

technical criteria and requirements for the connection of distributed generation plant

of capacity greater than 50kW and not exceeding 2MW to the CEB’s 22kV

distribution network.

This Grid Code only addresses the connection of MSDGs of capacity greater than 50

kW and not exceeding 200 kW1 to the CEB’s 22 kV distribution network.

The aggregate capacity of all MSDGs that can be interconnected to a 22kV

distribution feeder is termed as the hosting capacity of the feeder and is taken as

100% of the minimum load demand on that feeder.

For MSDG facilities falling under this Grid Code; the maximum aggregate installed

plant capacity that can be connected to a 22 kV feeder is limited to 50% of the hosting

capacity that feeder.

The application for the interconnection of any MSDG facility to a 22kV distribution

feeder shall be considered provided that with the proposed MSDG facility, the

aggregate installed capacity of the MSDG facilities connected to the 22kV

distribution feeder does not exceed the hosting capacity of that feeder.

Notwithstanding the above limits, the feasibility of connecting any MSDG to a 22 kV

feeder will be confirmed by a System Impact Study which will be conducted by CEB

on a case to case basis. In addition, the possibility of interconnecting any MSDG

facility using variable renewable energy technology (VRET) shall be subject to the

maximum amount of VRET-based power generation that can be accommodated in

the CEB’s power system while maintaining the system stability and security.

The Grid Code caters for the production of electricity from the following renewable

technologies:

1. Photovoltaic (PV)

2. Wind Turbine

3. Hydro

4. Biomass

1 For the technical criteria and requirements for the connection of MSDG of capacity greater than 200 kW,

please consult the relevant grid code available on ceb.intnet.mu

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CHAPTER 2 - Connecting MSDG to the Grid

START

Analysis of MSDG Proposal with respect to MSDG Grid Code

requirements and standards

CEB provides Applicant with a Public Notice, to be published

in Government gazette and 2 newspapers

Copy of published notices forwarded to CEB

Is there any objection

within 14 days?

Applicant takes

remedial action

NO

YES

Duly filled MSDG Application Form, requested technical

specifications and processing fees (see Annex A) to be

deposited at CEB Head Office, Curepipe

Cost estimate for any required network construction & System

Impact Study Fees sent to applicant

Applicant agrees to

proceed with the

MSDG project?

NO MSDG

Project

terminated

YES END

1.

2.

3.

4.

5.

6.

7.

8.

9.

Applicant to settle related Engineering Review Fee upon CEB

request (see ANNEX 3 - )

A

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CEB request the Ministry of Energy and Public Utilities (MEPU)

for the Granting of Permit by the President to the Applicant

Applicant shall complete the MSDG installation within the 12

months from date of Grant of Permit

CEB shall inspect and test the installation for compliance with the

requirements and standards. CEB will then issue a certificate of

commissioning to the Applicant

CEB request the MEPU for the Proclamation by the President to the

applicant

Upon proclamation, Applicant reaches Commercial Operation

END

Applicant shall effect payment for any network construction or

upgrade for safe interconnection of MSDG

The applicant shall be given a non-transferable permit as per the

terms and conditions that will be laid down in a Connection

Agreement* to be signed by the CEB and the Applicant after

successful testing of the latter’s installation

Upon completion of installation, applicant/installer shall submit a

duly signed Certificate of Installation as per Annex C to the CEB

Signature of Connection Agreement

11.

12.

13.

14.

15.

16.

17.

18.

10.

A

19.

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CHAPTER 3 - MSDG Interconnection Requirements and Safety Aspects

3.1 Interconnection Facility Characteristics

The facility shall have the following characteristics:

The MSDG facility is connected to the CEB’s 22 kV network through a

22/0.415 kV transformer.

Metering is to be performed at Low Voltage (LV).

3.2 Interconnection Facility Design Parameters

The MSDG shall have the following design parameters. The MSDG has to functions

and protects itself within the following range of the voltages, currents and

frequencies existing in the CEB grid.

Table 3-1: Normal operating parameters of the CEB’s Low Voltage

Description Range

Statutory Voltage range 230/400 V ± 6 %

Short circuit Characteristics (excluding

contribution of the MSDG installation) (1 sec) 18 kA, (50 Hz)

Nominal frequency 50 Hz

Statutory frequency deviation 50 Hz ±1.5 %

Operating frequency range 47 Hz – 52 Hz

3.3 Protection Requirements

3.3.1 Availability of protection

The applicant shall ensure that all equipment is protected and that all elements of the

protection, including associated inter-tripping, are operational at all times.

Unavailability of the protection will require the MSDG plant to be taken out of

service.

The MSDG shall be protected against

a) Overload.

b) Short circuit within the MSDG.

c) Earth faults in the close vicinity of the MSDG.

d) Over Current.

e) Abnormal voltages(Table 2 below)

f) Abnormal frequencies (Table 2 below)

g) Lightning.

h) Loss of mains

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CEB

HT Distribution

network

ConsumerCEB

HT pole-

mounted

switch fuse

Distribution

Transformer

CEB circuit

breaker /

fuse

Customer main

circuit breaker

LV loads

MSDGkWh

Production

meter

Import/

Export meter

Net Power Connection of MSDG of capacity greater than 50kW Up to 200 kW:Excess of power is exported to CEB network

Note: (a) New Busbar System shall be accessible to CEB on a 24hrs basis (b) Visible Lockable Isolator No. 1 is required only when there is a requirement for isolated generation (c) Visible Lockable Isolator switches 2 and 3 shall be replaced by a Lockable Circuit Breaker if the Client Facilities is located far from the Joint Use Facility. (d) Point of Common Coupling (PCC) refers to the terminals of CEB’s circuit breaker/fuse (e) The Visible Lockable Isolator Switch shall ensure absolute cut.

Visible Lockable

Isolator

No. 3

kWh

Lockable Local

Isolator

No. 4

Busbar System

Drawing No: CPR/SP/MSDG/01-rev01

Visible Lockable

Isolator

No. 1

Joint Use Facility

5

5

54

3

21

1

2

3

4

5

HT Pole on which the switch fuses are installed

Transformer Cabin Door and Fence

Meter Cabin and Box

CEB Breaker(4) or Fuse (1)

Visible Lockable Isolator 1, 2,3 & 5, Earth switch and on Cabin Door

Location of Warning Sign and Stickers

Visible Lockable

Isolator

No. 2

Lockable

Earth

switch

5

Interconnection

circuit breaker

PCC

Figure 3-1: Typical layout for any MSDG of capacity greater than 50 kW and not exceeding 200 kW

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3.3.2 DC Functions of Protection Apparatus

All protection apparatus functions shall operate down to a level of 50% of the nominal

DC supply voltage of the DC system, or the system must be able to safely disconnect

and shutdown when operation conditions are outside the nominal operating DC

voltage specified in the DC system specifications.

3.3.3 Protection Flagging, Indications and Alarms

All protective devices supplied to satisfy the CEB’s requirements shall be equipped

with operation indicators. Such indicators shall be sufficient to enable the determination

of which devices caused a particular trip.

Any failure of the applicant’s tripping supplies, protection apparatus and circuit

breaker trip coils shall be alarmed within the applicant’s installation, and the applicant

shall be responsible for prompt action to be taken to remedy such failure.

3.3.4 Trip settings

The trip settings must comply with the values stated in Table 3-2.

Table 3-2: Default interface protection settings

Parameter Symbol Trip setting Clearance time

Over voltage (a) U>> 230 V + 10 % 0,2 s

Over voltage U> 230 V + 6 % 1,5 s

Under voltage U< 230 V – 6 % 1,5 s

Over frequency (b) f> 50 Hz + 2 % 0,5 s

Under frequency f< 50 Hz - 6 % 0,5 s

Loss of mains df/dt 2.5 Hz / s

0,5 s Vector shift 10 degrees

NOTE: Voltage and frequency is referenced to the Supply Terminals.

(a) If the MSDG can generate higher voltage than the trip setting, the step 2 over

voltage is required.

(b) The trip setting for over frequency is set lower than the maximum operating

frequency defined in Table 3-2 in order to avoid contribution of the MSDG to rising

frequency.

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3.3.5 Network Islanding

The applicant shall not supply power to the CEB’s network during any outages of the

system. The MSDG may only be operated during such outages to supply the applicant’s

own load (isolated generation) with a visibly open tie to the CEB’s network. The MSDG

shall cease to energise the CEB’s network within 0.5 seconds of the formation of an

island as shown in Table 3-2.

3.3.6 Re-connection

Following a protection initiated disconnection, the MSDG is to remain disconnected

from the network until the voltage and frequency at the supply terminals has been

restored within the nominal limits for at least 3 minutes. Automatic reconnection is only

allowed when disconnection was due to operating parameters being outside the normal

operating range stated in Table 3-2, not if disconnection was caused by malfunctioning

of any devices within the MSDG installation.

3.3.7 Synchronising AC generators

The MSDG shall provide and install automatic synchronizing. Check Synchronizing

shall be provided on all generator circuit breakers and any other circuit breakers, unless

interlocked, that are capable of connecting the MSDG plant to the CEB’s network.

Check Synchronising Interlocks shall include a feature such that circuit breaker closure

via the Check Synchronising Interlock is not possible if the permissive closing contact is

closed prior to the circuit breaker close signal being generated.

3.3.8 Earthing requirements

Earthing shall be according to IEC 60364-5-55.

For systems capable of operating in isolated generation, the neutral point of the a.c.

generator must not be earthed when operating in parallel with CEB’s network. When

the MSDG operates in isolation, the generator neutral-to-earth connection must be

closed. The operation of the neutral-to-earth connection shall be carried out by an inter-

locking system.

When a MSDG is operating in parallel with the CEB’s network, there shall be no direct

connection between the co-generator winding (or pole of the primary energy source in

the case of a PV array or Fuel Cells) and the CEB’s earth terminal.

The winding of an a.c. generator must not be earthed. Note that a DC source or DC

generator could be earthed provided the inverter separates the AC and DC sides by at

least the equivalent of a safety isolating transformer. However, consideration would

then need to be given to the avoidance of corrosion on the DC side.

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At the CEB’s grid TT earthing system is adopted. The neutral and earth conductors

must be kept separate throughout the installation, with the final earth terminal

connected to a local earth electrode.

The Busbar System, referred to as the Joint Use Facility in Figure 3-1, shall be equipped

with lockable earthing facility.

Warning Notice that: “CONDUCTORS MAY REMAIN LIVE WHEN ISOLATOR IS

OPEN” shall be conspicuously displayed at the installation.

3.4 Power Quality

3.4.1 Limitation of DC injection

The MSDG should not inject a DC current greater than the largest value of 0.25 % of the

rated AC output current per phase.

3.4.2 Limitation of voltage flicker induced by the MSDG

The MSDG installation shall not cause abnormal flicker beyond the limits defined by

the “Maximum Borderline of Irritation Curve” specified in the IEEE 519-1992.

3.4.3 Harmonics

Based on IEEE 519, the total harmonic distortion (THD) voltage shall not exceed 5.0% of

the fundamental on 400 V when measured at the point of common coupling (PCC).

The total harmonic distortion will depend on the injected harmonic current and the

system impedance seen from the PCC. However, in order to facilitate the fulfilment of

the requirements by e.g. inverter manufacturers, the voltage distortion limits have been

translated into a similar requirement on current distortion.

The MSDG system output should have low current-distortion levels to ensure that no

adverse effects are caused to other equipment connected to the utility system. The

MSDG system electrical output at the PCC should comply with Clause 10 of IEEE Std.

519-1992 and should be used to define the acceptable distortion levels for PV systems

connected to a utility. The key requirements of this clause are summarized in the

following:

(a) Total harmonic current distortion (Total demand distortion, TDD) shall be less

than 5% of the fundamental frequency current at rated current output.

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(b) Each individual harmonic shall be limited to the percentages listed in Table 3.

The limits in Table 3 are a percentage of the fundamental frequency current at

rated current output.

(c) Even harmonics in these ranges shall be <25% of the odd harmonic limits listed.

Table 3-3: Distortion limits as recommended in

IEEE Std. 519-1992 for six-pulse converters

Odd Harmonics Maximum Harmonic

Current Distortion

3rd -9th 4.0%

11th -15th 2.0%

17th -21st 1.5%

23rd -33rd 0.6%

Above the 33rd 0.3%

3.4.4 Surge Withstand Capability

The interconnection system shall have a surge withstand capability, both oscillatory and

fast transient, in accordance with IEC 62305-3, the test levels of 1.5 kV. The design of

control systems shall meet or exceed the surge withstand capability requirements of

IEEE C37.90.

3.4.5 Voltage and Current Unbalance

The total voltage unbalance in the grid should be smaller than 2%, where the unbalance,

Uunbalance, is defined as the maximum deviation from the average of the three-phase

voltages, Ua, Ub and Uc, divided by average of the three-phase voltages.

The contribution from the MSDG installation may not cause an increase of the voltage

unbalance of more than 1.3%.

3.4.6 Voltage Step Change

The process of starting a medium scale distributed generation (MSDG) can sometimes

cause step changes in voltage levels in the distribution network. These step changes are

caused by inrush currents, which may occur when transformers or induction generators

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are energised from the network. Step voltage changes will also occur whenever a

loaded generator is suddenly disconnected from the network due to faults or other

occurrences.

Step voltage changes caused by the connection and disconnection of generating plants

at the distribution level should not exceed ± 3% for infrequent planned switching events

or outages and ± 6% for unplanned outages such as faults.

3.5 Power Factor

The power factor of the MSDG at normal operating conditions across the statutory

range of nominal voltage shall be between 0.95 leading and 0.95 lagging.

3.6 Safety, Isolation and Switching

3.6.1 Rules for working on low voltage grid (LV)

According to the CEB safety rules based on Occupational Safety and Health Act 2005,

the following rules must be respected before working on a LV grid:

(a) The system must be isolated from all possible sources of supply, all switches

must be locked in visibly open positions, the system must be tested on the site

of work, and the system must be short-circuited.

(b) The MSDG shall have a local means of isolation that disconnects all live

conductors including the neutral. The producer shall not energize a de-

energized CEB’s Power circuit.

(c) Switches shall be installed to disable the automatic or manual closing of the

interconnecting switches or breakers. These switches shall be accessible to the

CEB’s personnel to obtain the necessary safety requirements when the CEB’s

personnel is working on associated equipment or lines. While the CEB’s

personnel is working on the grid the operation of switches shall not be possible

for others than the CEB, which can be assured by keeping the keys to lockable

switches. Alternatively the CEB’s personnel will remove and keep fuses while

working on lines.

(d) In all instances the switches, which must be manual, must be capable of being

secured in the ‘off’ isolating position. The switches must be located in an

accessible position in the producer’s installation.

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(e) The Busbar system, referred to as the Joint Use Facility, shall be accessible to the

CEB on a 24 Hours basis.

(f) The visible switches shall be visibly marked. Also all transformers that carry

MSDG installations on the LV side shall be visibly marked. Additionally the

CEB will maintain an updated register of all MSDGs with precise addresses,

connecting points and relevant transformers.

3.6.2 Safety Concerns

The applicant shall observe the following safety concerns which include:

(a) Persons must be warned that the installation includes any MSDG so that

precautions can be taken to avoid the risk of electric shock. Both the mains

supply and the electric generator must be securely isolated before electrical work

is performed on any part of the installation. Adequate labelling must be available

to warn that the installation includes another source of energy.

(b) Photovoltaic (PV) cells will produce an output whenever they are exposed to

light, and wind turbines are likely to produce an output whenever they are

turning. Additional precautions such as covering the PV cells or restraining the

turbine from turning will be necessary when working on those parts of the

circuit close to the source of energy and upstream of the means of isolation.

(c) The manufacturer or supplier of the MSDG is required to certify compliance with

the Electrical Equipment Safety Regulations and the Electromagnetic

Compatibility Regulations. The MSDG will be CE marked or tested by equivalent

accredited testing agencies to confirm this. This should ensure that the MSDG is

satisfactory in a domestic installation in terms of the power factor, generation of

harmonics and voltage disturbances arising from starting current and

synchronisation.

(d) CEB personnel must be warned of the safety procedures pertaining to switching

operation applicable to the MSDG. These procedures must clearly be displayed

and visible at the MSDG site.

3.6.3 Electromagnetic emission/Immunity

The MSDG shall comply with the requirements of the EMC Directive and in particular

the product family emission standards.

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3.6.4 Labels

To indicate the presence of the MSDG within the premises, a label as per Figure 3-2will

be fixed by the CEB at:

i. the 22 kV pole on which the switch fuses are installed (or the Ring Main Unit in

case of underground networks)

ii. the transformer cabin door and fence

iii. the metering cabin and box

iv. the low voltage CEB circuit breaker or fuse

v. the visible lockable isolators 1 and 2, lockable earth switch and the cabin door

vi. Any other locations that are found necessary by the CEB.

Figure 3-2: MSDG label

The installation operating instructions must contain the manufacturer’s contact details

e.g. name, telephone number and web address.

3.6.5 Documentation

Up-to-date information must be displayed at the MSDG as follows:

(a) A circuit diagram showing the relationship between the MSDG and the CEB’s

circuit breaker/ fused cut-out. This diagram is also required to show by whom

the generator is owned and maintained.

(b) A summary of the protection’s separate settings incorporated within the

equipment. The Figure 3-3 below is an example of the type of circuit diagram

that needs to be displayed.

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Figure 3-3 is for illustrative purposes and not intended to be fully descriptive.

Customer

Installation

CEB

Network

CEB

circuit

breaker /

fuse

Customer main

circuit breaker

LV loads

MSDG PLANT

Visible

Lockable

Isolator

No. 3

Lockable Local

Isolator

No. 4

Visible

Lockable

Isolator

No. 1

Visible

Lockable

Isolator

No. 2

Lockable

Earth

SwitchGenerator

Circuit Breaker

Figure 3-3: Example of a circuit diagram for any MSDG installation

(c) Isolation procedures of both CEB and the applicant

(d) In addition the maintenance requirements and maintenance services available

shall be documented.

(e) The applicant shall keep a certificate signed by the maintenance contractor

containing at least the following:

A statement confirming that the solar PV system/wind turbine/hydro meets

the requirements of this standard.

Client’s name and address.

Site address (if different).

Contractors name, address etc.

List of key components installed.

Estimation of system performance

3.6.6 Information plate

The following information shall appear on the information plate:

(a) manufacturer’s name or trade mark;

(b) type designation or identification number, or any other means of identification

making it possible to obtain relevant information from the manufacturer;

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(c) rated power;

(d) nominal voltage;

(e) nominal frequency,

(f) phases;

(g) power factor

3.6.7 Electrical contractor / Installer

The MSDG shall be installed in accordance with the instructions issued by the

manufacturer.

In designing a connection for any MSDG, the electrical contractor /installer must

consider all the issues that would need to be covered for a conventional final circuit,

including:

the maximum demand (and the generator output);

the type of earthing arrangement;

the nature of the supply;

external influences;

compatibility, maintainability and accessibility;

protection against electric shock;

protection against thermal effects;

protection against overcurrent;

isolation and switching;

selection and installation issues.

The installer must affix a label clearly indicating the next scheduled maintenance of the

installations and inform the CEB, who will add the information to the MSDG-register.

The installer must be skilled in the field of MSDG installations and possess an

approved certificate.

3.7 Metering

In order to enable correct billing of the applicant, a bidirectional meter measuring both

the import and export energy shall be in place. Billing will not be based on the gross

production of the MSDG, but on the imported and exported energy separately. For

information and data purposes, a second meter measuring the gross production of the

MSDG may be installed by the applicant as shown in Figure 3-1.

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3.8 Testing, Commissioning and Maintenance

Testing of MSDGs will be done in the presence of the CEB. The applicant shall notify

the CEB in advance with a testing and commissioning plan. The applicant shall keep

written records of test results and protection settings. The applicant shall regularly

maintain their protection systems in accordance with good electrical industry practice

and any revision brought to this Grid Code.

3.9 Standards and Regulations

All electrical apparatus, materials and wiring supplied shall comply with the Electricity

Act, the Central Electricity Board Act, Electricity Regulations, this code and the

following standards:

Table 3-4 List of Standards

EN 50438 Requirements for the connection of micro-generators in parallel

with public low-voltage distribution networks

IEC 60364-5-55 Electrical installations of buildings

IEC 60664-1

Insulation coordination for equipment within low-voltage

systems –

Part 1: Principles, requirements and tests

IEC 60909-1 Short circuit calculation in three-phase ac systems.

IEC 61000-6-1 Generic standard -EMC - Susceptibility - Residential,

Commercial and Light industry

IEC 61000-6-3 Generic standard - EMC - Emissions - Residential, Commercial

and Light industry

IEC 62305-3 Protection against lightning, part 3 physical damage and life

hazards in structures

IEC 60364-1 Electrical installations of buildings - Part 1: Scope, object and

fundamental principles

IEC 60364-5-54

Electrical installations of buildings. Part 5: Selection and erection

of electrical equipment. Chapter 54: Earthing arrangements and

protective conductors

IEEE P1547 Series of Standards for Interconnection, May, 2003, NREL/CP-

560-34003

IEEE 519-1992

IEEE Recommended practice and requirements for harmonic

control of electric power systems, Institute of Electrical and

Electronic Engineers, Piscataway, NJ. April 1992

IEEE C37.90 IEEE Standard for Relays and Relay Systems Associated with

Electric Power Apparatus

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ANNEX 1 - Abbreviations and Definition

“AC” means Alternating Current;

“Applicant” means a producer of electricity through any MSDG installation;

“CEB” means the Central Electricity Board;

“Circuit breaker” means a switching device capable of making, carrying, and breaking

currents under normal circuit conditions and also making, carrying for a specified time,

and breaking currents under specified abnormal conditions such as those of short

circuit;

“DC” means Direct Current;

“DG” means Distributed Generation;

“Distributed generation” means electric generation facilities connected to the Utility

network at the PCC;

“Flicker” means a variation of input voltage sufficient in duration to allow visual

observation of a change in electric light source intensity;

“Fault” means a physical condition that causes a device, a component, or an element to

fail to perform in a required manner, for example a short-circuit, a broken wire, an

intermittent connection;

“Frequency” means the number of complete cycles of sinusoidal variations per unit

time;

“Grid” means CEB’s network that brings electricity from power stations to consumers”

“THD” means Total Harmonic Distortion

“Harmonic distortion” means continuous distortion of the normal sine wave; typically

caused by nonlinear loads or by inverters, measured in Total Harmonic Distortion

(THD);

“Islanding” means a condition in which a portion of the CEB’s network is energised by

one or more MSDGs through their PCC(s) while electrically separated from the rest of

the system;

“Isolated Generation” means a condition where the electrical path at the PCC is open

and the MSDG continues to energise local loads;

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“kV” means kilovolt;

“kVA” means Kilovolt Ampere

“kW” means Kilo Watt (1,000 W = 1,000 J/s);

“kWh” means Kilowatt hour (1,000 watt hours);

“LV” means Low Voltage (refers to systems normally operating at a voltage not

exceeding 1000 volts A.C. or 1500 volt D.C.);

“HT” means High Tension (refers to systems normally operating at a voltage exceeding

1000 volts A.C. or 1500 volt D.C.)

“HV” means High Voltage (see “HT”)

“MW” means megawatt (1,000,000 W = 1,000,000 J/s);

“Parallel operation” means a condition where the MSDG is operating while connected

to CEB’s network;

“PCC” means point of common coupling;

“Point of Common Coupling (PCC)” means the point at which a MSDG is connected to

the CEB’s network

“Power factor” means ratio of real to total apparent power (kW/kVA) expressed as a

decimal or percentage;

“Producer” means a producer of electricity through a MSDG installation or the owner

thereof;

“PV” means photovoltaic;

“RE” means renewable energy;

“MSDG” means Medium Scale Distributed Generation greater than 50 kW but less than

200 kW as categorised in this document

“SWC” means Surge Withstand Capability, the immunity of this equipment to fast and

repetitive electrical transients;

“TT system” means in a TT earthing system, the protective earth connection of the

consumer is provided by a local connection to earth;

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ANNEX 2 - Feed-In-Tariff

Tariff, if applicable, will be determined subject to discussion with the CEB. However for

MSDG projects designed to meet their own local consumption, a charge may be

applicable.

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ANNEX 3 - CEB Fees

Interconnection facility and cost

The MSDG will be connected to CEB 22kV network through a 22/0.415 kV distribution

transformer and metered on the low-voltage side as per schematics shown in Figure 3-1.

In addition, the applicant shall bear fees for processing applications and preparation of

cost estimate for network construction or modification as shown below.

Fees for processing of application:

Processing of the Application Rs 375

Connection Fees:

Connection for Three Phase Rs 3,000

Engineering Review/ Distribution Study

Preparation of estimate for network modification:

a) Domestic customers Rs 1,500

b) Non-domestic customers

i) For Low Voltage network only Rs 8,500

ii) For High Tension Lines + substation + Low Voltage network Rs 13,000

Revision of Estimate

a) Domestic customer Rs 1,500

b) Non-domestic customers

i) For Low voltage network (more than 3 spans) Rs 1,500

ii) For High Tension Lines + substation + Low Voltage network Rs 3,000

System Impact Study Fee Rs **

Network construction / modification

The cost for network construction or modification will be determined after carrying out

the engineering review.

** A system impact study will be performed for all MSDG projects to ensure safe

interconnection to the network. The applicable fee will be determined on a case-to-case

basis.

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ANNEX 4 - Application Form

Medium Scale Distributed Generation (above 50 kW and up to 200 kW) Application Form

1.0 Applicant Information For office

use only

1.1 Name of Applicant /

Company

1.2 Name & Title of Contact Person

(if applicable)

1.3 Postal address

1.4 Contact telephone number

Office: …………………………….

Mobile: ……………………………

1.5 Fax number

1.6 Tax Account Number

1.7 VAT Registration Number

(if applicable)

1.8 Business Registration

Number (if applicable)

1.9 Email address

Serial No….…………… (For office use only)

CENTRAL ELECTRICITY BOARD

Application Form to be filled and forwarded together with processing fee to the MSDG Unit, Corporate

Planning & Research Department, CEB Head Office, Royal Road, Curepipe before 15.15Hrs, the closing

time of CEB’s cash offices. Tel: 601 1100 Fax: 601 1180

Note: Incomplete submission of information will entail delays in processing your application

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2.0 Installer details 1 For office

use only

2.1 Installer

2.2 Accreditation/qualification

2.3 Postal address

2.4 Contact person

2.5 Telephone number

2.6 Fax number

1 At the start of this project until further notice, the CEB shall accept a ‘Certificate’ from the

supplier of the equipment certifying that the installer is well-versed with the installation of

the equipment. Furthermore, the topics covered and the duration of the training shall be

mentioned on the ‘Certificate’.

3.0 Project details For office

use only

3.1 Site/project address

3.2 Telephone number

(project site)

3.3

Business Partner Number (please refer to your electricity

bill or alternatively attach a

recent electricity bill) 2

3.4

Contract Account

Number (please refer to your electricity

bill or alternatively attach a

recent electricity bill) 2

3.5 Expected installation

commencement date

3.6 Expected commissioning

date

2 If not available, to submit the following together with the application form

a) Copy of the Business Registration Card

b) Copy of Certificate of incorporation

c) Copy of Identification Card

d) A letter of Power Attorney (if applicable)

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4.0 MSDG details For office

use only

4.1 MSDG location within the

installation To submit site and location plan

4.2

Type of RE technology

(photovoltaic/ hydro/

wind/biomass)

To submit manufacturer data sheet

4.3

Type of generator

(synchronous/induction/

inverter-based)

To submit manufacturer data sheet

4.4

Total number of MSDG units to

be installed under this project,

to include MSDG installation

capacity in kW and kVA

No. of Units: ……….of ………kW each

Total kWac : ……………

Total kVA : ………….

4.5 Expected annual generation

(kWh)

4.6

Any other existing SSDG/MSDG

operating on installation site

(Yes/No)

If yes, to specify

Total kW : …… Total kVA : ……………

5.0 Other information to be submitted For office

use only

5.1

Type test certificate of RE technology (photovoltaic/ hydro/ wind/biomass)

thereon including the following information:

Manufacturer and model type

Country of origin

Standard of compliance 3

Contact details of Certifying Laboratory– telephone number, web

address etc

5.2

Type test certificate of generator (synchronous/induction/ inverter-based)

thereon including the following information:

Manufacturer and model type

Country of origin

MSDG current rating (A), voltage rating (V), rated power factor and

frequency (Hz)

Maximum peak short circuit current (A)

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Other information to be submitted (cont.) For office use only

Standard of compliance 3

Contact details of Certifying Laboratory – telephone number, web

address etc

5.3 Copy of system circuit diagram (single line diagram) within the installation including the proposed grid connection and the associated metering points/ supply points

5.4 Single Line Diagram illustrating the protection schemes of the MSDG (including relay positioning, protection functions and related circuit breaker)

5.5 Earthing arrangements (Single Line Diagram)

5.6 Site layout plan showing location of MSDGs and other major electrical equipment installed including the Joint Use Facility –

5.7 Procedures for the isolation of MSDG installation

5.8

Complete sequence of operations: (a) In normal mode (b) Upon loss of mains (operation of MSDG protections; changeover

sequence; starting of standby sets; interlocking between changeover & MSDG; where is decoupling performed)

(c) On restoration of grid power

5.9 Complete set of specifications of the equipment to be used in the Joint Use Facility (busbar, isolators, circuit breakers, enclosure, etc…)

3All MSDGs to submit certificate of compliance with the Electrical Equipment Safety Regulations

and the Electromagnetic Compatibility Regulations (CE Marked). PV installations to submit certificates that the panels are to IEC 61215 for crystalline silicon and IEC 61646 for thin film silicon. Wind installations to submit certificates that the wind turbine is as per IEC 61400-2.

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MSDG Guaranteed Particulars

(All information given hereunder should be substantiated by documents from the Manufacturer)

6.0 MSDG Guaranteed Particulars

Item.

No. Protection Parameters Settings

Required settings To specify System settings

Trip

Setting

Clearance

Time

Trip

Setting

Clearance

Time

Trip

Indication

Provided

6.1 Over Voltage (a) (400 V + 10 %) 4 440 V 0,2 s

6.2 Over Voltage (400 V + 6 %) 424 V 1,5 s

6.3 Under Voltage (400 V – 6 %) 376 V 1,5 s

6.4 Over Frequency (b) (50 Hz + 2 %) 51 Hz 0,5 s

6.5 Under Frequency (50 Hz - 6 %) 4 47 Hz 0,5 s

6.6 Loss of Mains(df/dt - Vector shift) 2.5 Hz / s

10 degrees 0,5 s

6.7 Islanding Detection Yes

6.8 Isolated Generation possible Yes / No

6.9 Reconnection Time 3 minutes

6.10 Max. DC Current injection to grid

(in case of inverter-based) To specify

6.11 Rated AC output Current per

phase (A) To specify

6.12 Total Harmonics Distortion

(Voltage) To specify

6.13 Total Harmonics Distortion

(Current) To specify

6.14 Surge Withstand Capability (kV) To specify

6.15 Power Factor (leading & lagging) 0.95

6.16 Will local Switch after production

meter have visible contacts? Yes

6.17

Will local Switches after

production meter have lock

facilities in open position?

Yes

6.18 Will Production Meter be installed? Yes / No

6.19 Will Earthing System be TT? Yes

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Item.

No. Protection Parameters Settings

Required

settings

To specify System

settings

6.20 Will Batteries be Installed? Yes / No

6.21 Fault-ride through capability

(in case of inverter-based) Yes / No

6.22 Documentation on relays to be used

on low-voltage side To submit

6.23 Likely load profile and generation

profile To submit

6.24

Is inverter equipped with Maximum

Power Point Tracking (MPPT)

(in case of inverter)

Yes / No

4 For No. 6.1 and No.6.4 see section 0 of the MSDG Grid Code (50 kW to 200 kW).

7.0 Declaration – to be completed by applicant

Comments (use separate

sheet if necessary)

(a) I declare that this installation will be designed to comply with the requirements of CEB as

detailed in MSDG Grid Code (50 kW to 200 kW).

(b) I declare that I shall adhere to the Grant of Permit and Proclamation procedures for MSDG

installation as detailed in CHAPTER 2 - of the MSDG Grid Code (50 kW to 200 kW).

(c) I declare that I have been informed by the CEB that

(1) The tariff, if applicable, for the energy sold to the CEB by the proposed MSDG

installation will be determined subject to discussion with the CEB.

(2) A charge may be applicable if the MSDG project has been designed to meet my

own local consumption.

Name (BLOCK

LETTERS):

Signature:

Date:

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ANNEX 5 - Certificate of Installation

Applicant/installer to submit duly signed certificate (as shown below) to the CEB.

CERTIFICATE OF INSTALLATION

I hereby certify that the installation of the MSDG of capacity …………….kW, situated at (address) for

(name of Applicant/ Company) has been done as per the requirements of the MSDG Grid Code (50

kW to 200 kW) and as per attached detailed schematic diagram.

Name (BLOCK LETTERS) of Qualified Installer:

……………………..……………………….…………………………………………………………………………………………….….

Signature of Installer:…………………………………………………..…….. Date:……………..…………….…….

Name (BLOCK LETTERS) of Applicant/Representative:

……………………..……………………….…………………………………………………………………………………………….….

Signature of Applicant:……………………………………………..…………. Date:……………………………….

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ANNEX 6 - Certificate of Compliance

Prior to commissioning, the CEB will issue a Certificate of Compliance to the applicant.

Certificate of Compliance

This is to certify that on [date] the MSDG installation with an installed capacity of …………….kW,

situated at [address] in the name of [Applicant/Company name]bearing Serial No. [……], has

been found compliant with the requirements of the MSDG Grid Code (50 kW to 200 kW) by the

Representatives of the CEB Sections found hereunder and it has been found to be fit for the

connection to the Grid. The installation shall be commissioned after the signature of the Connection

Agreement and the Publication of the Proclamation.

Representative of Distribution Network Name (Block Letters): ……………………………………………………………. Signature: ………………………….…. Representative of Meter Installation Name (Block Letters):: ……………………………………………………………. Signature: ……………………………. Representative of MSDG Unit Name (Block Letters):: …………………………………………………..………. Signature: …………………….………. Representative of Health and Safety Officer Name(Block Letters):: ………………………………………………………….. Signature: ………………………….….

Date: …………………….………..