Alstom SHPM 101 User manual

Service Manual
Quadramho
Distance Protection Type SHPM 101

Quadramho
Distance Protection Type SHPM 101
Service Manual
R5888C
The following publications form part of this manual:
Publication R5580 Quadramho descriptive leaflet
Publication R5234 Electronic module housing

Service Manual
Quadramho
Distance Protection Type SHPM 101
HANDLING OF ELECTRONIC EQUIPMENT
A person's normal movements can easily generate electrostatic potentials of several thousand volts.
Discharge of these voltages into semiconductor devices when handling electronic circuits can cause
serious damage, which often may not be immediately apparent but the reliability of the circuit will have
been reduced.
The electronic circuits of ALSTOM T&D Protection & Control Ltd products are completely safe from
electrostatic discharge when housed in the case. Do not expose them to the risk of damage by
withdrawing modules unnecessarily.
Each module incorporates the highest practicable protection for its semiconductor devices. However, if it
becomes necessary to withdraw a module, the following precautions should be taken to preserve the high
reliability and long life for which the equipment has been designed and manufactured.
1. Before removing a module, ensure that you are at the same electrostatic potential as the equipment
by touching the case.
2. Handle the module by its front-plate, frame, or edges of the printed circuit board.
Avoid touching the electronic components, printed circuit track or connectors.
3. Do not pass the module to any person without first ensuring that you are both at the same
electrostatic potential. Shaking hands achieves equipotential.
4. Place the module on an antistatic surface, or on a conducting surface which is at the same
potential as yourself.
5. Store or transport the module in a conductive bag.
More information on safe working procedures for all electronic equipment can be found in BS5783 and
IEC 60147-0F.
If you are making measurements on the internal electronic circuitry of an equipment in service, it is
preferable that you are earthed to the case with a conductive wrist strap.
Wrist straps should have a resistance to ground between 500k – 10M ohms. If a wrist strap is not
available, you should maintain regular contact with the case to prevent the build up of static.
Instrumentation which may be used for making measurements should be earthed to the case whenever
possible.
ALSTOM T&D Protection & Control Ltd strongly recommends that detailed investigations on the electronic
circuitry, or modification work, should be carried out in a Special Handling Area such as described in
BS5783 or IEC 60147-0F.

SERVICE MANUAL R5888C
QUADRAMHO Contents
DISTANCE PROTECTION
SAFETY SECTION
THIS MUST BE READ BEFORE ANY WORK IS CARRIED OUT ON THE RELAY
CHAPTER 1 APPLICATION NOTES (R5580 included)
CHAPTER 2 DESCRIPTION, TECHNICAL DATA
CHAPTER 3 ELECTRONIC MODULE HOUSING (R5234 included)
CHAPTER 4 INSTALLATION AND HANDLING
CHAPTER 5 COMMISSIONING
CHAPTER 6 PROBLEM ANALYSIS
CHAPTER 7 MODULE IDENTIFICATION
CHAPTER 8 SPECIAL VARIATIONS

SAFETY SECTION
This Safety Section should be read before commencing any work on the equipment.
Health and safety
The information in the Safety Section of the product documentation is intended to
ensure that products are properly installed and handled in order to maintain them
in a safe condition. It is assumed that everyone who will be associated with the
equipment will be familiar with the contents of the Safety Section.
Explanation of symbols and labels
The meaning of symbols and labels which may be used on the equipment or in the
product documentation, is given below.
Caution: refer to product documentation Caution: risk of electric shock
Protective/safety *earth terminal
Functional *earth terminal.
Note: this symbol may also be used for a protective/
safety earth terminal if that terminal is part of a
terminal block or sub-assembly eg. power supply.
*Note:The term earth used throughout the product documentation is the direct
equivalent of the North American term ground.
Installing, Commissioning and Servicing
Equipment connections
Personnel undertaking installation, commissioning or servicing work on this
equipment should be aware of the correct working procedures to ensure safety.
The product documentation should be consulted before installing, commissioning or
servicing the equipment.
Terminals exposed during installation, commissioning and maintenance may
present a hazardous voltage unless the equipment is electrically isolated.
If there is unlocked access to the rear of the equipment, care should be taken by all
personnel to avoid electric shock or energy hazards.
Voltage and current connections should be made using insulated crimp
terminations to ensure that terminal block insulation requirements are maintained
for safety. To ensure that wires are correctly terminated, the correct crimp terminal
and tool for the wire size should be used.

Before energising the equipment it must be earthed using the protective earth
terminal, or the appropriate termination of the supply plug in the case of plug
connected equipment. Omitting or disconnecting the equipment earth may cause a
safety hazard.
The recommended minimum earth wire size is 2.5 mm2, unless otherwise stated in
the technical data section of the product documentation.
Before energising the equipment, the following should be checked:
Voltage rating and polarity;
CT circuit rating and integrity of connections;
Protective fuse rating;
Integrity of earth connection (
where applicable )
Equipment operating conditions
The equipment should be operated within the specified electrical and
environmental limits.
Current transformer circuits
Do not open the secondary circuit of a live CT since the high voltage produced
may be lethal to personnel and could damage insulation.
External resistors
Where external resistors are fitted to relays, these may present a risk of electric
shock or burns, if touched.
Battery replacement
Where internal batteries are fitted they should be replaced with the recommended
type and be installed with the correct polarity, to avoid possible damage to the
equipment.
Insulation and dielectric strength testing
Insulation testing may leave capacitors charged up to a hazardous voltage. At the
end of each part of the test, the voltage should be gradually reduced to zero, to
discharge capacitors, before the test leads are disconnected.
Insertion of modules and pcb cards
These must not be inserted into or withdrawn from equipment whilst it is energised,
since this may result in damage.
Fibre optic communication
Where fibre optic communication devices are fitted, these should not be viewed
directly. Optical power meters should be used to determine the operation or signal
level of the device.

Older Products
Electrical adjustments
Equipments which require direct physical adjustments to their operating mechanism
to change current or voltage settings, should have the electrical power removed
before making the change, to avoid any risk of electric shock.
Mechanical adjustments
The electrical power to the relay contacts should be removed before checking any
mechanical settings, to avoid any risk of electric shock.
Draw out case relays
Removal of the cover on equipment incorporating electromechanical operating
elements, may expose hazardous live parts such as relay contacts.
Insertion and withdrawal of extender cards
When using an extender card, this should not be inserted or withdrawn from the
equipment whilst it is energised. This is to avoid possible shock or damage
hazards. Hazardous live voltages may be accessible on the extender card.
Insertion and withdrawal of heavy current test plugs
When using a heavy current test plug, CT shorting links must be in place before
insertion or removal, to avoid potentially lethal voltages.
Decommissioning and Disposal
Decommissioning: The auxiliary supply circuit in the relay may include capacitors
across the supply or to earth. To avoid electric shock or energy
hazards, after completely isolating the supplies to the relay
(both poles of any dc supply), the capacitors should be safely
discharged via the external terminals prior to
decommissioning.
Disposal: It is recommended that incineration and disposal to water
courses is avoided. The product should be disposed of in a
safe manner. Any products containing batteries should have
them removed before disposal, taking precautions to avoid
short circuits. Particular regulations within the country of
operation, may apply to the disposal of lithium batteries.

Technical Specifications
Protective fuse rating
The recommended maximum rating of the external protective fuse for this
equipment is 16A, Red Spot type or equivalent, unless otherwise stated in the
technical data section of the product documentation.
Insulation class: IEC 61010-1: 1990/A2: 1995 This equipment requires a
Class I protective (safety) earth
EN 61010-1: 1993/A2: 1995 connection to ensure user
Class I safety.
Installation IEC 61010-1: 1990/A2: 1995 Distribution level, fixed
Category Category III installation. Equipment in
(Overvoltage): EN 61010-1: 1993/A2: 1995 this category is qualification
Category III tested at 5kV peak,
1.2/50µs, 500Ω, 0.5J,
between all supply circuits
and earth and also between
independent circuits.
Environment: IEC 61010-1: 1990/A2: 1995 Compliance is demonstrated
Pollution degree 2 by reference to generic safety
EN 61010-1: 1993/A2: 1995 standards.
Pollution degree 2
Product safety: 73/23/EEC Compliance with the
European Commission Low
Voltage Directive.
EN 61010-1: 1993/A2: 1995 Compliance is demonstrated
EN 60950: 1992/A11: 1997 by reference to generic safety
standards.

Quadramho Distance Protection
Type SHPM 101
Service Manual
Chapter 1
Application

SERVICE MANUAL R5888B
QUADRAMHO Chapter 1
Contents
1. GENERAL 1
2. RELAY CHARACTERISTICS 1
3. SCHEMES AVAILABLE ON RELAY 1
4. CHOICE OF CHARACTERISTIC 2
5. CHOICE OF ZONE 1 IMPEDANCE REACH 2
6. CHOICE OF ZONE 2 IMPEDANCE REACH 2
7. CHOICE OF ZONE 3 IMPEDANCE REACH 3
8. POWER SWING BLOCKING FEATURE (PSB) 4
9. CHOICE OF RESISTIVE REACH OF QUADRILATERAL CHARACTERISTIC 4
10. AUTOMATIC COMPENSATION OF QUADRILATERAL REACH
LINE ANGLE 4
11. CHOICE OF ASPECT RATIO (LENTICULAR ZONE 3 CHARACTERISTIC) 5
12. CHOICE OF RELAY CHARACTERISTIC ANGLES 5
13. ZONE TIME DELAY SETTINGS 5
14. SWITCH-ON-TO-FAULT TRIPPING FEATURE (SOTF) 5
14.1 Performance of relay for earth faults 6
15. SELECTION OF SCHEME LOGIC PROGRAMS 7
16. SETTING OF SCHEME OPTION SWITCHES 7
17. DISCUSSION ON APPLICATION OF VARIOUS DISTANCE SCHEME
OPTIONS 7
17.1 Basic (see Figure 3) 7
17.2 Zone 1 extension (see Figure 4) 8
17.3 Permissive underreach transfer tripping (PUR – see Figure 5) 8
17.4 Permissive overreach transfer tripping (POR – see Figures 6 and 7) 8
17.5 Blocking (see Figure 8) 9
18. TIMER SETTINGS FOR DISTANCE SCHEME LOGIC OF QUADRAMHO 9
18.1 Permissive underreach scheme 9
18.2 Permissive overreach scheme 10
18.3 Blocking scheme 11
19. CURRENT TRANSFORMER REQUIREMENTS 12
19.1 Worked example No. 1 12
19.2 Data 13
19.3 Calculation of maximum and minimum source impedance at MAY 60kV 13
19.4 Selecting Zone 1 reach 14
19.5 Selecting Zone 2 reach 15
19.6 Selecting Zone 3 reach 15
19.7 Ground fault compensation settings 16
19.8 Setting restrictive reach of ground fault comparators 17
19.9 Checking minimum relay voltage for a fault at the Zone 1 reach point 17
19.10 Checking relay current sensitivity for faults at the Zone 3 reach point 18
19.11 Sketching relay characteristics 19

SERVICE MANUAL R5888B
QUADRAMHO Chapter 1
Contents
19.12 Circuit transformer requirements 19
19.13 Worked example No. 2 21
19.14 Data 21
19.15 Selecting Zone 1 reach 21
19.16 Selecting Zone 2 reach 22
19.17 Selecting Zone 3 Reach 23
19.18 Ground fault compensation settings 23
19.19 Checking minimum relay voltage for a fault at the Zone 1 reach point 24
19.20 Sketching relay characteristics 26
19.21 Circuit transformer requirements 26
APPENDIX A 1
Figure 1: Basic relay characteristics 1
Figure 2: Principle of zone-1 reach line angular compensation 2
Figure 3: Basic-simplified distance scheme logic 3
Figure 4: Z1 EXT-simplified distance scheme logic 4
Figure 5: PUR-simplified scheme logic 5
Figure 6: POR-simplified distance scheme logic (with ‘open terminal’ signal
echo feature) 6
Figure 7: POR-simplified distance scheme logic (with ‘open terminal’ signal
echo feature and week infeed signal echo and trip feature) 7
Figure 8: PUR-simplified distance scheme logic 8
APPENDIX B 1
SKETCHING RELAY CHARACTERISTICS 1

SERVICE MANUAL R5888B
QUADRAMHO Chapter 1
Page 1 of 27
Section 1. GENERAL
The Quadramho has been developed for use on medium to high voltage
transmission and distribution lines where traditionally switched distance schemes
have been used.
The relay is a full 3 zone distance scheme which eliminates the need for starting
and switching circuits, but which remains as compact as a switched relay because
it employs modern components and circuit techniques. A full distance scheme
allows better reliability and faster operating times than a switched distance
scheme.
Section 2. RELAY CHARACTERISTICS
There are two versions of the Quadramho to choose from, with the following
impedance characteristics:
Type A (mho) Zone 1, Zone 2 phase and ground fault : shaped partially
cross-polarised mho.
Zone 3, phase and ground fault : offset lenticular shape.
Type B (quad) Zone 1, Zone 2 ground fault : quadrilateral, with partially
cross-polarised directional line and load flow compensated
reach line.
Zone 3 ground fault : offset quadrilateral with load flow
compensated reach line.
Zone 1, Zone 2 phase fault : shaped partially cross-polarised
mho.
Zone 3 phase fault : offset circular mho.
See Figure 1 Appendix A, for examples of impedance
characteristics.
Note: Voltage transformer supervision and power swing blocking feature are
included with both models.
Section 3. SCHEMES AVAILABLE ON RELAY
There are 5 schemes available and each scheme can be selected as a three phase
tripping scheme or a single and three phase tripping scheme:
Basic three zone distance protection
Zone 1 extension scheme
Permissive underreach transfer tripping scheme
Permissive overreach transfer tripping scheme
Blocking scheme

SERVICE MANUAL R5888B
QUADRAMHO Chapter 1
Page 2 of 27
Section 4. CHOICE OF CHARACTERISTIC
The Type A (mho) relay is suitable for protecting most lines, where their length and
source impedances are such that the resulting shaped Zone 1 characteristics
provide the required resistive coverage. The longer the line is, the higher the
Zone 1 and Zone 2 reach settings, hence the greater the resistive coverage will be
for ground faults. Also the higher the source impedance behind the relay, the
greater the Zone 1 and Zone 2 resistive expansion will be.
For the case of a long heavily loaded line, it may be that with the Zone 3 reach
settings required, the load impedance could “encroach” upon the Zone 3
characteristics if they were purely of the offset mho type or, if being used, the load
could encroach upon the power swing blocking starter characteristic. For such a
case the Type A (mho) allows the resistive reach of the Zone 3 and power swing
blocking starter characteristics, to be reduced with respect to their forward reach
(lenticular facility). This means that desired forward reaches can be attained
without problems of load encroachment.
For very short lines, where distance relay reach settings would be low, particularly
when there is a low source impedance behind the relay, the shaped Zone 1 and
Zone 2 impedance characteristics may not provide the required ground fault
resistive coverage. In such a case, the Type B (quad) relay could be used which
has a quadrilateral ground fault characteristic. This would allow the ground fault
resistive reach to be increased or decreased independently of the forward reach,
and source impedance behind the relay so that the required ground fault resistive
coverage can be achieved.
Section 5. CHOICE OF ZONE 1 IMPEDANCE REACH
Although in most applications the reach accuracy of the relay distance
comparators is ±5%, greater errors can occur as a result of voltage and current
transformer errors and inaccuracies in line data from which the relay settings are
calculated. To prevent the possibility of relays tripping instantaneously for faults in
the next line, it is usual practice to set the Zone 1 reach of the relay to 80% of the
protected line section and rely on Zone 2 to cover the remaining 20% of the line.
With a signal aided distance protection scheme arrangement, the Zone 2 distance
comparators could provide fast triping at both ends of the line for end-zone faults.
If the Zone 1 extension scheme is used, it is usual practice to set the Zone 1
extension to 150% of the normal Zone 1 reach.
Section 6. CHOICE OF ZONE 2 IMPEDANCE REACH
As a general rule, the Zone 2 impedance reach is set to cover the protected line
plus 50% of the shortest adjacent line. The reasoning behind the value of 50% is
that Zone 2 should cover at least 20% of the adjacent line, even in the presence of
typical additional infeed at the remote terminal of the protected line.
One case of additional infeed at the remote line terminal occurs when the
protected line is paralleled by another line. When a fault occurs in the adjacent
line, approximately equal currents will flow in each of the parallel lines. The relay
on the protected line, looking towards the fault, will see an impedance which will

SERVICE MANUAL R5888B
QUADRAMHO Chapter 1
Page 3 of 27
be the sum of the protected line impedance, plus, twice the impedance of the
adjacent line to the fault. If the Zone 2 reach is set to cover 50% of the adjacent
line impedance, then in this parallel infeed case, Zone 2 will effectively cover 25%
of the adjacent line.
In most situations, if the relay reaches at least 20% into the adjacent line, then
faults at the remote terminal of the protected line will be well within Zone 2 reach
and so fast operation of the Zone 2 comparators will be achieved. This is
important if signal aided tripping schemes are used.
In some situations where the protected line is long and the adjacent line is short,
then a 50% reach into the adjacent line will only be a very small overreach of the
protected line. If the protected line is paralleled by another line, then it may be that
the zero sequence mutual coupling, between the two lines, will be sufficient to
prevent the Zone 2 comparators from seeing a ground fault at the remote terminal
of the line until the remote circuit breaker trips, preventing ground fault current
flowing in the healthy parallel circuit. In such a case the Zone 2 setting may need
to be increased slightly, to avoid sequential or time delayed clearance of the fault
at the terminal remote from the fault.
In a parallel line situation, a fault on one line which is cleared sequentially can
cause a fault current reversal in the healthy line. If the Zone 2 settings are greater
than 150% of the protected line impedance and the permissive overreach or
blocking scheme is being used, then a fault current reversal in the healthy circuit
could cause that circuit to be incorrectly tripped, unless special steps are taken.
The permissive overreach and blocking schemes both have current reversal guards
incorporated to prevent such maloperations. The operation of these current reversal
guards is explained in detail later, when considering some logic timer settings.
Section 7. CHOICE OF ZONE 3 IMPEDANCE REACH
The Zone 3 forward reach should normally be set to cover the protected line
section, plus the longest adjacent section and 25% of a third section, to provide an
overall time delayed back-up protection. The reverse Zone 3 offset provides back-
up protection for the busbars behind the relay and would typically be set to 25%
of the Zone 1 setting.
When the blocking scheme or permissive overreach with weak infeed scheme is
being used, Zone 3 is required to provide a blocking function when it operates
without Zone 2, to prevent the protection scheme operating for reverse faults.
The reverse Zone 3 reach in this case must be set to reach further than Zone 2 of
the relay at the other end of the line. It must also be ensured that any resistive faults
behind the relay that are seen by Zone 2 of the remote end relay, are also seen by
Zone 3 of the local relay, to prevent tripping of healthy line for external faults.
As a general guide for most applications, it is recommended that the reverse Zone
3 reach is set to the same value as the Zone 2 setting of the remote end relay.
The forward Zone 3 reach should be set to minimum unless the power swing
blocking facility is also being used.
If the power swing blocking feature is to be used with the permissive overreach
scheme with weak infeed feature, or the blocking scheme, then the forward Zone 3
reach should be set to ≥120% of the Zone 2 reach. This could mean that the
overall diameter of the Zone 3 characteristic will be large, which could lead to
encroachment problems on the power swing blocking starter characteristic, which

SERVICE MANUAL R5888B
QUADRAMHO Chapter 1
Page 4 of 27
is ganged to the Zone 3 setting. This situation is only likely to arise on long lines
where the type A (mho) relay will be in use. Full advantage will need to be taken
of the Zone 3 and power swing blocking lenticular facility in order to avoid load
encroachment problems.
Section 8. POWER SWING BLOCKING FEATURE (PSB)
The power swing blocking feature can be enabled or disabled by an option switch
and the individual distance zones to be blocked are also selectable via switches.
The inner power swing blocking impedance characteristic is formed by the A – B
Zone 3 phase fault characteristic. The additional PSB starter characteristic has its
settings automatically ganged to the relay Zone 3 settings, so that the PSB
characteristic is concentric with the Zone 3 characteristic, but its dimensions are
such that its forward reach is 30% greater than the Zone 3 forward reach.
If the power system A – B phase impedance locus enters the operating area of the
starter characteristic, but takes longer than 50ms to pass through into the Zone 3
operating area, then the PSB unit will block the selected zones if the A – B phase
impedance does eventually pass into the Zone 3 operating area.
If the PSB feature is to be used, then when setting the Zone 3 impedance
characteristic, it must be ensured that the resulting PSB starter characteristic will not
be encroached upon by the minimum phase to phase load impedance (a 10%
impedance safety margin should be observed).
Section 9. CHOICE OF RESISTIVE REACH OF QUADRILATERAL CHARACTERISTIC
The resistive reach should be set to cover the desired level of ground fault
resistance, which would comprise arc resistance and tower footing resistance.
A 10% impedance margin should be observed between the resistive reach and the
minimum load impedance.
In addition to ensure Zone 1 reach accuracy, the resistive reach should not be set
greater than 15 times the Zone 1 ground loop reach.
Section 10. AUTOMATIC COMPENSATION OF QUADRILATERAL REACH
LINE ANGLE
For the quadrilateral ground fault characteristics, the phase current is in phase with
the resistive axis of the R/X diagram. The reach line for the Zone 1 characteristic is
in phase with the residual or neutral current measured (with a –3°droop). Thus if
there is a difference in angle between the measured phase current and neutral
current, then the Zone 1 reach line will be at a corresponding angle to the resistive
axis. This feature ensures that resistive ground faults on a double end fed loaded
system will not result in underreach or overreach of the relay.
The Zone 2 and Zone 3 reach lines and the Zone 3 offset lines are in phase with
the resultant angle of the measured neutral current, plus the relevant phase current.
A qualitative analysis of the purpose of reach line compensation for Zone 1 is
given in Figure 2.