Devices for data collection and processing: NPT RTU and NPT microRTU controllers

NPT RTU

NPT RTU controllers are used to structural component centralized Automatic Process Control System and Information Acquisition & Transmission System: receiving analog and digital signals, generation of commands for regulation, and activation of operational blocking of disconnectors. The devices are also designed to collect and pre-process information from MP of Relay Protection and Automatic Equipment, multifunction measuring devices, and other microprocessor-based devices. Key features of this device include its ability to handle large amounts of digital data and possibility of redundancy of input-output channels.

Amount of controlled data:

• up to 256 digital signals;

• up to 128 control commands;

• 96 normalized analog signals (-10-10 V, 4-20 mA etc.);

• up to 4 units of direct input of current and voltage transformers (each unit of up to 5 channels of voltage and up to 8 channels of current).

NPT RTU advantages

NPT RTU can be usedas a substation controller (10-110 kV substation);

• large amounts of information can be received and processed by a single NPT RTU device, which reduces the number of components at a power plant;

• configuration flexibility;

• reliability of the scan of digital inputs (small input impedance of less than 120 ohms; injection pulse of 20 mA for 10 ms);

• compatibility with modern insulation monitoring devices (Bender etc.);

• relay control circuit with activation control and rigid logic for activation.

NPT microRTU

 NPT microRTU controllers are designed for implementation into digital substations, as well as for the purposes of data collection and power equipment control at power facilities located in regions with unfavorable climatic conditions.

NPT microRTU advantages

• NPT microRTU controller is mounted into the outdoor rack with a sealing protection class of IP54;

• units designed to work in the NPT microRTU controller have a special moisture-resistant cover;

• due to the fact that NPT microRTU controllers serve as field-level controllers for devices of relay protection and automatic equipment and emergency control automatics at digital substations, they come in the dubbed version. 

Data are transmitted from NPT microRTU by means of fiber-optic communication, which is a part of the process bus according to the protocol IEC 61850-8-1 (GOOSE). Control commands from switching devices to NPT microRTU controllers are also transferred with the use of the protocol IEC 61850-8-1 (GOOSE).

NPT microRTU controllers is also recommended for data collection and power equipment control when creating traditional remote control systems and automatic process control systems in the regions with unfavorable climatic conditions. It can be mounted both in outdoor switchboards and in unheated rooms. In this case, information can be transmitted to the top level both by means of modern protocols 61850 (MMS and GOOSE) and traditional remote control protocols IEC 60870-5-101(104). Small-sized version of the device allows flexible mounting of the controller and, if necessary, allows installing equipment into existing distribution device panels or cells.

Functions of NPT RTU and NPT microRTU controllers 

• input of data on the single-connection switchgear status at 110 kV and above; their transfer to KP Automatic Process Control System, Relay Protection and Automatic Equipment, and emergency control automatics with the use of GOOSE messages (IEC 61850-8-1);

• introduction of additional control signals for switching devices and other primary equipment and transmission of such signals to controllers APCS with the use of GOOSE messages (IEC 61850-8-1);

• broadcast of commands to switching devices from the bay controller via GOOSE messages (IEC 61850-8-1);

• broadcast of switch control commands from KP, Relay Protection and Automatic Equipment, and emergency control automatics transmitted via GOOSE messages (IEC 61850-8-1);

• self-test of the devices up to one unit, and data transmission to SCADA with the use of the MMS protocol (IEC 61850-8-1).

Time synchronization in the controllers is performed via an information channel and is based on the PPS signal from the GPS receiver. Accuracy of event binding to astronomical time is 1 ms.

Specification of I/O boards of NPT RTU and NPTmicroRTU:
I/O units support the “hot” replacement mode. When installing a double set of units into the rack, doubling of input-output channels is possible.

Digital signal input unit:

• 32 inputs (4 groups of 8 signals each);

• event recording with an accuracy of 1 ms;

Digital control unit:

• 16 control channels with a relay output;

• false alarm protection designed on the basis of rigid logic;

• diagnosis of output relay contacts.

“Dry contact” signal input unit:

• 32 inputs (4 groups of 8 signals each);

• event recording with an accuracy of 1 ms;

• 24 V power supply from units.

Normalized analog signal input unit:

• 16 channels: 5...5 mA, 0...5 mA, 4...20 mA, 0...20 mA, 0...1 V, 0...5 V, 0...10 V and -10...10 mA.

Digital signal input unit for switch control (in accordance with RD 34.35.153.310) for NPT microRTU:

• 16 inputs (2 groups of 8 signals each);

• 8 relay outputs with control of the state of output contacts;

• event recording with an accuracy of 1 ms;

• input voltage = 220 V;

• input impedance of less than 60 Ohms.

Design of NPT RTU and NPT microRTU controllers

NPT RTU is a Euromechanics-format rack that can house up to 14 unit cards.

NPT microRTU is a Euromechanics-format rack that can house up to 7 unit cards.

NPT MU and NPT microRTU controllers are mounted onto the mounting plate with the use of standard mounting flanges located on the rear panel of the products.

Specification of the units includes input/output devices for digital and analog data. All units are designed under existing rules and regulations and provide electrical isolation for circuits and noise immunity.