Is-Lock fault current identification module

Product Introduction

DDX1 short-circuit current limiter (DDX1 current limiter) based on micro-explosion technology is to use micro-explosion technology to quickly cut the leading electrical circuit (the micro-explosion device is controlled by a special electronic controller), so that the fault current is quickly transferred to the branch of the special high-voltage current limiting fuse, and the fuse completes the current limiting and interruption of the fault current, limiting the peak of the first half of the fault current to a lower level, which not only solves the dynamic stability problem of the power system, but also solves the thermal stability problem of the power system.

The Is-Lock Fault Current Identification Module (Is-Lock) is an auxiliary judgment device with action direction selection specially developed for the DDX1 current limiter. In order to reduce the unnecessary operation of the DDX1 current limiter and eliminate the resulting system disturbance and operation and maintenance costs, Is-Lock can provide accurate and reliable selective action signals (auxiliary criterions) for the DDX1 current limiter under the operation conditions of action selectivity, such as the connection position of multi-section bus running in parallel, the new power supply is connected to the Internet or the interconnection of two power supplies, and the star interconnection of three power supplies, so that the control strategy of the micro-explosive DDX1 current limiter installed in the special power distribution system has both overcurrent tripping and action direction selection. The short-circuit protection effect of DDX1 current limiter on the power distribution system is optimized and the operation and maintenance cost is significantly reduced.

Principle of IS-Lock fault current identification module

Is-Lock can introduce up to three branch currents 1I, 2I and 3I of closely related nodes, each branch includes A, B and C three phases, convert and modulate the collected current signal inside the module to obtain a voltage signal with an appropriate range, and input it to a high-performance CPU for rapid analysis and operation after 16-bit high-precision A/D analog-to-digital conversion. Only when the current direction criterion, current eigenvalue threshold criterion and handshake signal criterion meet the conditions at the same time, the Is-Lock will send an enabling signal to the corresponding port, and this signal is logically calculated with the electronic controller on the high voltage side of the DDX1 current limiter to determine whether to output a trip command.

Core Features

• Millisecond-level fault response with high identification accuracy：Adopting dedicated current sensing algorithms and waveform characteristic analysis technology, it can distinguish between short-circuit current, overload current and normal load current within 5ms, with an identification accuracy of ≥99.5%, avoiding the problem of misoperation or refusal of traditional protection devices.

• Wide-range adaptability and multi-scenario compatibility：Supporting current ratings from 630A to 4000A, it is suitable for 35kV-220kV medium and high voltage systems and 0.4kV low-voltage distribution networks. It can seamlessly interface with DDX1 series current limiting devices, DGXK2 switchgear, etc., and is compatible with AC/DC hybrid power grids.

• Strong anti-interference capability and stable operation：Integrating electromagnetic shielding design and digital filtering technology, it can effectively resist interference such as power grid harmonics and lightning pulses. It maintains stable operation in ambient temperatures from -40℃ to +70℃, with a mean time between failures (MTBF) of ≥100,000 hours.

• Intelligent linkage control, simplifying system design：Equipped with RS485/Ethernet communication interfaces, it supports Modbus and IEC 61850 protocols. It can transmit fault characteristic data to the main control system in real time and directly drive the current limiting switch to operate, reducing intermediate control links and improving the response speed of the protection system.