M-2001D DIGITAL TAPCHANGER CONTROL
SUGGESTED SPECIFICATIONS
Pole-Top/Pad Mount Digital Tapchanger Control, for metering, monitoring, and operational control of step-voltage load tapchangers shall be provided by a microprocessor-based package. The microprocessor-based package shall be suitable for Pole Top Mounted or Pad Mounted single-phase or three-phase line regulators, substation regulators, and substation LTC transformers. The control shall have the following minimum functional and behavioral attributes:
CONTROL FUNCTIONS
The control shall include the following features and can be used for pole-mounted or pad-mounted single-phase or three-phase line regulators, substation regulators, and substation LTC transformer installations where SCADA communications are desired.
Automatic/Manual Control: The Control shall have user-selectable control on the front panel for Automatic or Manual operation. In addition, it shall have an option for SCADA command to change the Auto/Manual control state remotely.
Automatic/Manual Switch Status: The control shall provide indication of the Automatic/Manual Switch status via the communication ports.
Voltage Limits, Tap Position Limits, and Runback: The control shall have Overvoltage and Undervoltage limits that are independently adjustable from 95 V to 135 V in 0.1 V increments. It shall have user-settable Upper and Lower tap position limits, with tap position knowledge active. There shall be an option for an adjustable deadband (above the overvoltage limit) of 1 V to 4 V to set the runback limit.
Voltage Reduction: The control shall have three independent steps, each adjustable from 0% to 10% in 0.1% increments of the bandcenter set point. The Voltage Reduction function shall be capable of operating from the front panel or through contact inputs and disabled locally or remotely.
LTC Contact Position Tracking: The control shall have a means of acquiring positive LTC transformer contact (tap) position information and tracking that can be integrated into an Integrated Volt VAr Management (IVVM) system.
LTC Contact Position Record: The control shall provide a record of the number of times each tap has been passed through. This function shall be user-resettable.
Operations Counter: The control shall have a pre-settable counter that records the number of raise and lower operations and increments based on the counter configuration, as set by the user. The counter shall be able to store up to 999.999 operation counts without being affected by a loss of power supply.
Resettable Operations Counter: The control shall have a second software counter, user-resettable, similar to the Operations Counter.
Neutral Counter: The control shall have a pre-settable neutral counter that records the number of times the Neutral Input is energized. The counter shall be able to store up to 999.999 operation counts without being affected by a loss of power supply.
Bandcenter and Bandwidth: The control shall have an adjustable bandcenter range from 100 V to135 V in 0.1 V increments. The bandwidth shall have an adjustable bandwidth range from 1 V to 10 V in 0.1 V increments.
Line Drop Compensation: The control shall have R and X compensation adjustable from –72 V to +72 V in 1 V increments. There shall also be an option for Z compensation with the voltage raise adjustment range from 0 V to +72 V, in increments of 1 V.
Time-Delay: The control shall have a Definite Time-Delay function adjustable from 1 second to 120 seconds, in 1-second increments and Inverse Time-Delay adjustable from 1 second to 120 seconds, in 1-second increments.
Inter-Tap Time-Delay: The control shall have an Inter-Tap Time-Delay to introduce time-delay between tap operations when control is in sequential mode; the time-delay range shall be adjustable from 0 to 60 seconds in 1 second increments and require input from an operation counter validating the tap change operation actually occurred before allowing tap change operation to the next step.
Selectable Outputs: The control shall provide user-selectable continuous or pulsed outputs. When the output selection is in continuous mode, an output (raise or lower) signal runs the tapchanger until the voltage moves within the band setting. When pulsed output is selected and initiated, the pulse will continue until it reaches the programmed pulse time-out or a counter contact or motor hold input operates. The pulse length is programmable from 0.2 to 12 seconds, in increments of 0.1 second.
Reverse Power Operation: The control shall be able to automatically detect a power flow reversal and determine the direction of power flow, the LTC tap position, and the magnitude of the reverse power voltage to the regulator. The operational choices shall include Ignore (does not use power direction to make control decisions), Block (remain in present tap position and stop operating as a controller), Regulate-in-Reverse (use power reversal as the new source side voltage and change LTC tap position accordingly), and Run-to-Neutral (change LTC taps to the neutral position).
CT to VT Phasing Correction: The control shall provide CT to VT phasing correction adjustable from 0° to +330° in 30° increments.
VT Ratio Correction: The control shall provide a means of VT correction from –15 V to +15 V in 0.1 V increments
Normalizing Voltage: The control shall offer an option for a Normalizing Voltage Multiplier with a range of 0.80 to 1.20 to applied to Meter Out Voltage. This shall be displayed in real-time as Normalizing Voltage for the purpose of allowing the user to overcome differences in the ratio of the PT that the Load Voltage input is using versus the PT the end user or other metering methods are using.
Inhibit of Auto Tapchange: The control shall provide an Inhibit of Auto Tapchange function that blocks automatic tapchanger operation in response to external contact closure or software setting.
Non-Sequential/SCADA Block Operation: The control shall provide a Non-Sequential/SCADA Block Operation function that blocks automatic tapchanger operation in response to external contact closure or software setting and also resets the time-delay upon momentary external contact closure at the non-sequential input.
Transformer Paralleling: The control must provide a means of connection to external transformer balancing equipment for the purpose of operating with two transformers in parallel.
A or B Regulator Type: The control shall allow the user to select the type of regulator being used to provide a more accurate source voltage calculation.
Self-Test Alarm Output Contacts: The control shall assert an alarm upon loss of power or malfunction of the control.
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User-Programmable Alarm Contacts: The control shall have alarm capability to alert operator personnel to one or more of the following system conditions:
● Communications Block Invoked / ● Block Raise Voltage Limit Exceeded● Block Lower Voltage Limit Exceeded / ● Voltage Reduction (any step) Invoked
● Reverse Power Flow Condition Detected / ● Load Current Limit Exceeded
● Tap Block Raise in Effect / ● Tap Block Lower in Effect
● VAr Bias Lead / ● VAr Bias Lag
● Abnormal Tap Position / ● LDC/LDZ
SCADA CONTROL MODES
SCADA Heartbeat: The control shall provide a means of monitoring SCADA heartbeat and change the control’s operating mode based on the presence or absence of SCADA communications (using DNP protocol) to the control.
SCADA Remote Manual Mode – SCADA Heartbeat: The control shall allow the SCADA system to place the unit in Remote Manual mode and perform RAISE and LOWER operations as directed by a central source as long as it detects the presence of the SCADA heartbeat.
SCADA Remote Manual Mode: The control shall be capable of operating from SCADA signals received through wired or wireless communications media to command LTC RAISE or LOWER operations.
SCADA Remote Management of Local Automatic Control Mode: The voltage regulator control shall have the capability to allow Remote SCADA Management of Local Automatic voltage regulator control. This mode shall employ a SCADA heartbeat feature as described in “SCADA Remote Manual Mode – SCADA Heartbeat” to ignore the SCADA control settings and return the unit to operation using its programmed settings.
COMMUNICATIONS
The communication ports shall provide access to all features, including metering, software updates, and programming of all functions. This shall be accomplished using a modem or direct serial connection from any PC-compatible personal computer running the control’s Communications Software package or via SCADA communications software.
Communications Ports: Communication ports shall be optionally available in the following forms:
· Ethernet 10/100 Mbps through a copper RJ-45 connection (100 Base-T)
· Ethernet 100Mbps Fiber Optic with ST connectors (100 Base-FX)
· Serial Ports with RS-485, ST or V-Pin Fiber Optics, or RS-232
Protocols: The control shall support the following standard protocols: DNP3.0 and MODBUS® and optional IEC 61850.
Ethernet Port: The control shall offer an optional 10/100 Mbps Ethernet port through an RJ-45 or Fiber Optic Connection.
Bluetooth®
The control shall have an option for Bluetooth® capability to enable wireless access to the control that allows the user to configure the control, read status and metering values, as well as change set points. A generic serial service shall be provided by the control’s Bluetooth® capability to facilitate establishing initial communications should the Bluetooth® not automatically recognize listed services. The Bluetooth feature shall include a secure mode with the Bluetooth module undiscoverable without a user knowing the Bluetooth hardware address in the unit to meet NERC requirements for Bluetooth communications.
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ADVANCED SCADA COMMUNICATIONS
True Ethernet
The control shall provide an integrated, true 10/100 Mbps Ethernet, auto negotiable, capable of supporting up to eight concurrent sessions and simultaneous multiple protocols with up to eight sockets (concurrent sessions) open at a time. The eight sockets shall be capable of supporting Modbus and DNP over TCP/IP and UDP with up to five of the eight sockets capable of supporting DNP 3.0. This requirement allows users simultaneous remote access to the control via the same physical Ethernet port to view/change settings or retrieve data, without affecting the SCADA communications.
Full DNP Implementation
The control shall provide full DNP implementation to support both report-by-exception and unsolicited reporting within DNP 3.0 to aid in the reduction of bandwidth requirements. The control shall also provide DNP File Transfer to permit the recovery of data logs and triggered events, oscillography, and device discovery to facilitate setting up the integrated system. The control shall support DNP security as defined in the DNP 3.0 standard.
The control shall have DNP addressing capability that allows networking of multiple controls. The DNP implementation shall support the pre-defined global addresses within DNP 3.0 and allow the user to define two additional global addresses. Each control shall be able to be assigned a Device Address, Feeder Address, and Substation Address ranging from 1 to 65519. The control shall support broadcast commands from the master to all controls on the network in order to allow some or all controls to act on one command at the same time. The control shall provide a configuration program that allows any point to be mapped into any DNP location and allows dummy filler points to be added to facilitate interoperability by replicating legacy vendor point-maps to SCADA. This program shall also allow for individual point dead-banding and individual point assignments into Class 1, 2, or 3.
Cyber Security
Within DNP, the control shall permit multiple master source-address authentications, source-address validation, and multilevel access codes logged with date and time. It shall support Secure DNP authentication using FIPS 180-2 Secure Hash Standard (SHA-1). The control shall be fully compliant and offer all settings and configuration as defined by the DNP3 user group and IEC 62351-5. The control shall have a 6-15 character password and an audit log that shows when someone is logged on the control and which password was used to gain access to the control, in compliance with NERC CIP standards. The control shall allow for storage of 30 unique passwords within each control and have an SD card slot to allow the use of a password-keyed SD card that the control automatically reads to allow user login.
The control’s design shall include the ability to disable ports and services not required for normal or emergency operations. In cases where disabling is not possible, the port or service shall be password and access level protected through a communication access security and timeout feature in the communication software.
MONITORING/METERING
Harmonic Analysis: The control shall measure, log, and display individual harmonics including THD (total harmonics distortion) and the harmonic content of the load voltage and load current up to the 31st harmonic.
Oscillograph Recorder: The control shall have an oscillograph recording function that provides comprehensive data recording (voltage, current, and status input/output signals) for all monitored waveforms (at 16, 32 or 64 samples per cycle). The control shall have a means of downloading oscillograph data via the communications ports to any PC compatible personal computer running the included communications software program. The downloaded data shall be in a format that can be examined and printed. The waveform data shall also be available in COMTRADE file format.
Real-Time Metering: The control shall meter the following single/three-phase measured and calculated values in real-time:
● Load Voltage / ● Primary Voltage / ● Tap Position● Source Voltage / ● Primary Current / ● Drag Hands
● Meter Out Voltage / ● Primary Watts / ● Raise/Lower Timer
● Power Factor / ● Primary VArs / ● Circulating Current
● Normalizing Voltage / ● Primary VA / ● Operation Control
● Load Current / ● Frequency / ● Resettable Counter
● Compensating Voltage / ● Primary Source Voltage / ● Neutral Counter
● Intertap Timer
Present Demand: The control shall provide a Present Demand feature that captures the maximum values during the specified time interval. The user-selectable time interval shall be 15, 30, or 60 minutes.
● Demand Load Voltage / ● Demand Primary Current● Primary Watts / ● Primary VArs
● Primary VA
Demand History (Drag Hands Operation): The control shall have the following “drag-hand” values stored with date and time stamping, averaged over 32 seconds:
● Min Load Voltage● Max Load Voltage
The control shall have capability to store the following “drag-hand” values with date and time stamping and calculated over the demand of the user-selectable time intervals of 15, 30, or 60 minutes:
● Max Primary Current (Amps) / ● Max Primary VArs (kVAr or MVAr)● Max Primary Watts (kW or MW) / ● Power Factor @ Max VA
● Max Primary VA (kVA or MVA)
Energy Metering: The control shall be capable of retaining the following measured values in nonvolatile memory and have a real-time clock to record the date/time stamp for each quantity indicating when the measurement period was initiated.