Overhead transient wave recording type remote transmission fault indicator
Functions:
Meet the overhead line applied signal model and transient characteristics of the fault indicator detection requirements, at the same time have a better fault wave record this device mainly realize the following functions:
1. Remote signalling：
Line short circuit fault: can automatically determine the fault current alarm action value according to the change of line load.
Line grounding fault: Both passive method and signal injection method have two grounding detection principles.
When the ground fault occurs, the three-phase synchronous wave recording can be realized and sent to the collecting unit to synthesize zero sequence current waveform, which is used to judge the ground fault. (This function is optional).
Low battery alarm: When the backup battery of the collection unit is lower than the set value, a remote message is sent to the collection unit, and the low battery indicator is on.
Power switch: When the external power supply is lost, the backup power supply can be automatically and seamlessly input and send action information.
Collect unit self-test information.
2. Remote Measuring:
Load current: Periodically collect the load current of the line sent to the installation point. Load current 0A-100A, measurement error is not more than ±3A; Load current 100A-600A, measurement error is not more than ±1%.
Electric field strength: periodically collect the electric field strength of the line at the installation point to the ground.
Battery power: Periodically report the battery power information of the backup battery.
Electric field to Earth: Periodically report the electric field strength at the indicator location.
Cable temperature: Periodically report the temperature at the location of the indicator.
Ultracapacitor voltage: The voltage of the indicator ultracapacitor is sent on time.
3. Parameter setting
The main station sets various parameters of the collection unit through the collection unit. Commonly used parameter Settings are as follows:
Sudden change value of short-circuit fault current
Fault reset time
Telemetry active upload interval
Heartbeat interval with the collector unit
Battery low voltage alarm threshold
Abrupt value of fault triggered recording current
4.Local debugging function
The debugging software can be used for local debugging and parameter setting of the acquisition unit. Using the provided wireless debugging tool, you can debug online without disassembling the acquisition unit.
5.Fault recording function
When the ground fault occurs, the acquisition unit realizes the three-phase synchronous wave recording and sends it to the collecting unit to synthesize the zero sequence current waveform, which is used to judge the ground fault.
The starting condition of recording wave: current mutation, phase electric field intensity mutation, etc. Can realize the same group trigger, the threshold can be set.
6.Self-fetching power function
When the line load current is greater than or equal to 5A, the TA can meet the full function of the device within 5s. When the line load current is lower than 5A and the supercapacitor loses its power supply ability, the device can determine the short circuit fault, collect the load current regularly, and upload it to the collection unit.
TA power is taken and supplemented by supercapacitors as the main power supply, and non-rechargeable lithium batteries as the backup power supply.
7.Remote upgrade function
The acquisition unit supports the remote program upgrade of the collection unit, and the acquisition unit can also be upgraded locally wirelessly. The remote wireless upgrade program uses a security protection mechanism to ensure the safe upgrade of the program. If the program upgrade fails, it automatically restores to the previous version of the program.
8.With broadcasting timing function
Receive time commands from the master station or other time synchronization devices to keep up with the system clock.
9.History and upload function
The device has a line fault record SOE, which can record the fault nature (short circuit fault, ground fault), the fault time, the current value at the time of the fault, and the setting value of the acquisition unit at that time.
Historical data, such as load current and fault data, can be stored for 31 days and exported.
10.communication function
When the energy storage battery is not replaceable, the fault signal can be sent in real time, and the telemetry signal can be sent at a frequency not less than once every 2 hours, and the time can be set.
The collection unit communicates with the acquisition unit through wireless two-way communication, and the visual unobstructed communication distance is not less than 50 meters.
11. Others
Automatic reset: The indicator automatically resets after the set time or the line returns to normal power supply.
Remote reset: Remote reset of the indicator.
It can distinguish between permanent short circuit and transient short circuit fault.
Prevent false alarm function.
Line short circuit fault protection includes the following five cases:
Anti-misoperation of load current fluctuation, anti-misoperation of transformer no-load closing surge current, anti-misoperation of line sudden closing load surge current, anti-misoperation of manual switching large load, anti-misoperation of non-fault phase re-closing surge current.
The minimum recognition time of reclosing is 0.2s
The indicator recognizes transient faults with a reclosing interval of 0.2s and acts correctly