Power Protection Relays

Digital Line Protection

BPL002 Series

Digital Line Protection

1 Chapter 1: General

1.1 Basic types and main functions

BPL002A series digital HV line protective equipment (BPL002A) takes the pilot protection as the main protection of rapid action for whole line and the distance protection and zero-sequence current protection as the backup protection. The protective functions are implemented by two CPU modules, one of which (CPU1) is used for the pilot protective function and the other (CPU2) for the functions of distance protection and zero-sequence current protection. The hardware of CPU modules in BPL002A is same while the output circuits are independent.

The Equipment has split-phase outputs, mainly suitable for the power transmission lines of 220kV and above.

For the single breaker line-connection, one CPU module (CPU3) is added in BPL002B to implement the reclosing functions: the single phase Reclosing, three phases reclosing or integrated reclosing.

Table 1-1 The main types and functions of BPL002B


Main functions




Pilot protection

Distance  protection  and

Zero-sequence current protection







Energy-integral directional pilot protection


Fast distance protection

3-zone phase-to-phase distance protection

3-zone grounding distance protection

4-zone zero-sequence current protection






 Suitable for single breaker line-connection




 Energy-integral directional pilot protection


 Fast distance protection

3-zone phase-to-phase distance protection

3-zone  grounding distance protection

4-zone zero-sequence current  protection  or zero-sequence

inverse-time limit





Suitable for 3/2 line-connection



1.2 Main features

1.2.1 Application of new principles and techniques

BPL002B applies a series of new principles and techniques, which enhances the overall performance of protection. Such as:

(1) The energy-integral directional relay is applied, which uses total fault information. It does not need filtering and has fast action speed. It keeps the correct direction for a longer period and the sensitivities of the directional elements at both sides of line match up to each other.

(2) The waveform identification method is applied in the fast distance protection, the zone-I action time of which reaches 12ms.

(3) The track radius of oscillation is used to quickly distinguish fault from system oscillation, which improves the performance of protection during the oscillation-blocking period.

(4) The composite phase-selection method with superimpose current and voltage is used to correctly select the fault phase during complex fault and weak feeder system fault.

1.2.2 Open design concepts

The open design concepts of BPL002B increase the interoperability between BPL002B and other devices.

BPL002B adopts Ethernet communication interface, which allows the substation automation system to construct its communication network with Ethernet. Because Ethernet is widely applied in various domains, the Ethernet interface resource is abundant and cheap. Furthermore, it is easy to link with WAN with the open TCP/IP. At present, IEC is establishing the internal communication protocol system for substation automation system, which will make the products from different manufacturers interoperable. The relevant materials show that the backbone network is Ethernet.

BPL002B provides the compatibility design for current communication modes (RS-232C, EIA422/485 or field bus), which makes the design or retrofitting of the substation automation system more selective and more flexible

1.2.3 Humanized design concepts

BPL002B takes the lead in adopting the design concepts of “adjustment-free” and “plug-and-play”, the general SW and HW platform, the English supervisory interface and the graphic and tabular output interface. The technique of complete process information review is applied. With the supplied debug and analysis software, User can access easily the information stored in the unit devices, and display clearly the device data and logic processing procedures.

1.2.4 Reliable general platform with high performance

BPL002B has the same general platform as the other protection and control devices of BS6000 Substation Automation System. It adopts 32-bit microprocessor, large capacity of RAM and Flash Memory, and overall reliability design, and the Equipment has higher reliability and stronger ability of data processing, logic calculation and information storage. All this not only raises the product performance, but also generalizes thoroughly the product design in both hardware and software.

Since the Equipment applies the reliable platform with high performance, its

operation and maintenance become easier and simpler, and the complete process information can be recorded and used as the incident review for system operation and analysis.

1.2.5 High standard EMC

As for the other protections and control products of BS6000 Substation Automation System, much attention is paid to the integral EMC of BPL002B. The product design is no longer to meet only some anti-interference standards, EMC design is made in each section of the unit devices, such as AC input, DC power-supply, binary input, binary output, communication, etc.

BPL002B has passed ten national EMC laboratory tests, such as the electromagnetic radiation test, the fast-transient pulse group disturbance test, etc. All test results verify that its EMC index is much higher than the national standard, which ensures the thorough transfer of the unit device to lower level.

Chapter 2: Technical Parameters

2.1 Rated data

2.1.1 Rated DC voltage 220V or 110V(specified on order)

2.1.2 Rated AC data

a) Phase voltage 100 / 3V

b) Line sampling voltage 100V or 100 / 3V

c) Current 5A or 1A (specified on order)

d) Rated frequency 50Hz

2.1.3 Power consumption

a) DC circuit <= 40W (normal)

<= 50W (protection trip)

b) AC voltage circuit <= 0.5VA/Φ

c) AC current circuit In=1A,<= 0.5VA/Φ

In=5A,<= 1VA/Φ

2.1.4 Binary

a) Input voltage of CPU & communication interface modules


b) Input voltage of GPS sync pulse


c) CPU output voltage allowed (optically coupled)


d) Driving capability of CPU outputs (optically coupled)


2.1.5 Contact capacity

a) Carrying capacity of signal circuit

1100VA (Arc-no-breaking)

b) Carrying capacity of signal circuit


2.2 Main technical performance

2.2.1 Accurate working range of sampling circuits a) Phase voltage 0.2 V ~ 70V b) Line voltage 0.3 V ~ 120V c) Current 0.04In ~ 40In

2.2.2 Analog measuring precision

Current, voltage <=+5%, minimum setting of current is up to


2.2.3 Action minimum time of directional element

Energy integral directional element: Release mode 2ms Blocking mode 5ms

Impedance directional element


Zero-sequence directional element

10ms,zero-sequence voltage uses float threshold,

minimum action voltage is 0.5V

2.2.4 Action time of whole group

a) Zone-I (0.7 * setting value) of phase-to-phase and grounding distance protection

<20ms, typical value <12ms b) Zone-I (1.2 * setting value) of zero-sequence protection <20ms

c) High-frequency protection

Whole line rapid action < 25ms

d) Split-phase current differential protection

Whole line rapid action < 25ms

2.2.5 Transient overrun

The transient overrun of distance protection zone-I or zero-sequence protection zone-I< 5%.

2.2.6 The minimum setting impedance (not including the error induced by the external factors)

When the transient overrun is not greater than 5%, the minimum setting impedance at secondary side is 0.01Ω (short-circuit remained voltage > 0.5V).

2.2.7 Distance measurement error (not including the error induced by the external factors)

For metal-type fault, the error is between ±2%.

2.3 Insulation

2.3.1 Insulation resistance

Under normal test environment, the insulation resistance between any energized or non-energized part and the case, or between any circuits, which are not electrically

connected to each other, is not less than 50MΩ when tested by megger with 500V

open-circuit voltage.

2.3.2 Dielectric intensity

Under normal test environment, BPL002B can undergo the withstand-voltage test (frequency: 50Hz; voltage: 2000V, signal terminals 500V; duration: 1min) without breakdown or flashover. During the test, when the test voltage is exerted on a circuit, all other circuits are connected together to earth.

2.3.3 Impulsive voltage

Under normal test environment, BPL002B can undergo the standard lightning-surge test of 1.2/50µs between the power-supply input circuit or AC input circuit or output contact circuit and the ground, or between the circuits. The open circuit test voltage is 5kV.

2.3.4 Humid heat endurance

BPL002B has passed the humid heat endurance test stipulated in chapter 21 of GB7261. The highest test temperature is +40℃, the highest humidity is 95%, and the test duration is 48 hours. The period of cycling humid heat test is 24 hours. Within 2 hours before the end of test, the measurements required in section 2.3.1 and section

2.3.2 are acquired. The insulation resistance between any circuit and the revealed non-energized metal part or case, or between any circuits, which are not electrically connected to each other, should not be less than 1.5M Ω . The dielectric voltage-withstand intensity should not be less than 75% of the test voltage stipulated in section 2.3.2.

2.4 EMC capability

2.4.1 Electrostatic discharge interference

BPL002B has passed the electrostatic discharge interference test of GB/T 17626.2-1998 standard, level 4.

2.4.2 Radio frequency interference

BPL002B has passed the radio frequency interference test of GB/T 17626.3-1998 standard, level 3.

2.4.3 Fast-transient pulse group disturbance

BPL002B has passed the fast-transient pulse group disturbance test of GB/T 17626.4-1998 standard, level 4.

2.4.4 Surge (impulsive) interference

BPL002B has passed the surge (impulsive) interference test of GB/T 17626.5-1998 standard, level 3.

2.4.5 Radio field transmission annoyance

BPL002B has passed the radio field transmission annoyance test of GB/T 17626.6-1998 standard, level 3.

2.4.6 Power-frequency magnetic field interference

BPL002B has passed the power-frequency magnetic field interference test of GB/T17626.8-1998 standard, level 5.

2.4.7 Pulse magnetic field interference

BPL002B has passed the pulse magnetic field interference test of GB/T 17626.9-1998 standard, level 5.

2.4.8 Damping oscillation magnetic field interference

BPL002B has passed the damping oscillation magnetic field interference test of GB/T17626.10-1998 standard, level 5.

2.4.9 Oscillating wave field interference

BPL002B has passed the oscillating wave field interference test of GB/T 17626.12-1998 standard, level 4.

2.4.10 Radiation emission limit test

BPL002B has passed the radiation emission limit test of GB 9254-1998 standard, type A.

2.5 Mechanical performance

2.5.1 Vibration

BPL002B can undergo the vibration durability test stipulated in section 16.3 of GB7261 standard, severity class-I.

2.5.2 Impact

BPL002B can undergo the impact durability test stipulated in section 17.5 of GB 7261 standard, severity class-I.

2.5.3 Collision

BPL002B can undergo the collision durability test stipulated in chapter 18 of GB 7261 standard, severity class-I.

2.6 Environment conditions

2.6.1 Ambient temperature


2.6.2 Relative humidity


2.6.3 Atmosphere pressure



* You can also contact us for a quote by E-mail: sales@buenoptic.net

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