M7D Smart Grid Programmable Digital Differential Protection Measurement and Control Device

M7D is a programmable microcomputer differential protection measurement and control device, which is divided into M7D differential protection devices according to protection applications. It is used for differential protection of two coil transformers (M7DT) or three coil transformers (M7DD) and large motor differential protection devices (M7DM).

Main functions:

• Protection function: It can achieve dual slope ratio braking differential quick break protection, and optional transformer and motor backup protection functions. It can provide comprehensive line protection functions such as composite voltage lockout overcurrent protection, timed limit, inverse time limit, overvoltage, undervoltage, frequency, locked rotor, PT disconnection, control circuit disconnection, overheating, zero sequence, negative sequence, CT disconnection, and non electricity protection.
• Measurement function: Full three-phase power parameters, including voltage, current, power factor, frequency, active power, and reactive power.
• Display screen: Programmable graphical large LCD display, and real-time display of voltage and current waveform.
• Indicator light: Programmable three color indicator light, which can define display properties and indicator parameters.
• GPS timing: The GPS timing accuracy is 1ms, and TTL and RS422 modes can be selected.
• SOE event recording: Provides SOE recording functionality.
• Fault recording function: Provides COMTRADE format recording files with time scale standards.
• Communication function: Supports communication methods such as RS485, Ethernet, Profibus, and multiple communication protocols.

interface

• 8 AC current inputs (3 coil differential to 9 current inputs).
• 4-channel AC voltage input, suitable for various PT wiring methods (three coil transformer differential without voltage input).
• 16 programmable switch inputs (optional addition of 16 channels).
• 10 programmable switch output channels (optional to add 6 channels).
• Optional programmable DC analog signal input and output circuits.
• Can communicate with RTD module (remote temperature acquisition module can directly connect to 8 thermal resistors).
• RS485 interface, optional Ethernet port Profibus、 Fiber optic and other multi-channel interfaces (each interface is independent of each other).
• Optional external anti bounce circuit module.

Programmable functions:

Equipped with programmable product logic, users can freely define protection logic and other functions on a unified hardware platform. Support dedicated programmable debugging software PLPShell, through the RS232 interface of the panel, users can easily program and debug the protection function logic, engineering, and testing of M7D at any time, completely realizing the configurability of the protection device.