Distance protection#
Block appearance in REPEAT VISION#
Distance protection is a complex protection consisting of a number of elements (organs), each of which performs its own specific function, including: starting and remote organs, directional and time-delay organs, as well as blocking for disabling the protection in the event of damage to the voltage circuits supplying the protection.
Distance protections are used in networks with complex configurations, in which simpler maximum current and directional current protections cannot be used to ensure the required speed and sensitivity.
Distance protection determines the impedance (or distance) to the SC location and, depending on this, operates with a shorter or longer time delay. The time delay for distance protection is determined by the distance, in other words, the impedance to the SC location.
Distance protection devices with stepped time characteristics do not measure the resistance values at the terminals of the measuring element every time a SC occurs and do not set a longer or shorter time delay depending on this, but only monitor the damaged zone. The protection response time for a SC at any point in the zone is constant.
Each protection is carried out in multiple stages, and in the first zone, covering approximately 85% of the length of the protected line, the time delay is one stage higher and is no more than 0.15 s. For the second zone, located outside the protected line, the time delay is one step higher and is approximately 0.4–0.6 s. For SC in the third zone, the time delay is even longer and is selected in the same way as for directional current protection.
The bypass switch status is responsible for switching the voltage and current from the switch (0) to the bypass switch (1).
Ban is a blocking of remote protection:
0 - in progress;
1 - blocked.
Acceleration is an operational acceleration of protection, performed with the aim of reducing the response time.
The signal on the bypass switch is transmitted in the event of the current switch being switched on (the BD is turned on).
Protection activation - a command to turn off the circuit breaker and turn on the circuit breaker alarm.
1. Properties#
Property |
Default Value |
Description |
Units of measurement |
|---|---|---|---|
Operation resistance |
0.2955 |
– |
Ohm |
Response time |
0.35 |
– |
s |
2. Inputs and outputs#
Parameters |
Input/Output |
Description |
Units of measurement |
Port type |
|---|---|---|---|---|
Bypass Status(0/1) |
Input |
– |
– |
Automation |
Voltage |
Input |
– |
V |
Automation |
Bypass switch voltage |
Input |
– |
V |
Automation |
Current |
Input |
– |
А |
Automation |
Bypass switch current |
Input |
– |
А |
Automation |
Blocking(0/1) |
Input |
– |
– |
Automation |
Active current of the switch |
Input |
– |
А |
Automation |
Acceleration(0/1) |
Input |
– |
– |
Automation |
Switch status(0/1) |
Input |
– |
– |
Automation |
Alarm on bypass switch(0/1) |
Output |
– |
– |
Automation |
Protection triggered(0/1) |
Output |
– |
– |
Automation |
In order to see the connection capabilities of the block, you need to go to page Description of block ports