Beckwith M-2001B Digital Voltage Regulating Controller

Transformer LTC application: Users can choose to ignore reverse power, lockout voltage regulation, reverse regulation (using independent settings), or return to neutral point.

Single phase voltage regulator: supports "keep track" tap position or "reverse adjustment" function, the latter allows bidirectional voltage regulation using reverse power signals without PT on the power side.

When reverse power is applied, the REV PWR LED on the panel lights up and the programmable alarm contact outputs.

Parallel operation and circulation control

M-2001B supports multiple parallel modes:

4.1 Circulating Current Method

The standard method requires the use of M-0115A parallel balancing module. Each controller detects the circulating current between transformers through circulating current CT. M-0115A generates a correction signal and sends it to the circulating current input of M-2001B. The controller adjusts the tap according to this to balance the circulating current.

4.2 ΔVAR ™ method

Δ VAR1: It needs to be used in conjunction with M-0115A and adjusted in parallel based on reactive power deviation.

Δ VAR2: Without the need for M-0115A, the controller can directly achieve parallel connection by exchanging reactive power information through communication, simplifying hardware configuration.

4.3 External Master Follower

Implementing instruction following for a host controller through external circuits, suitable for simple parallel scenarios.

Important: Except for Δ VAR2, it is recommended to configure overcurrent protection (such as M-0127 overcurrent relay) for all other parallel connections to prevent damage to the transformer in case of abnormal circulating current.

Communication function and networking

5.1 Communication port

COM1 (top): Optional RS-232, RS-485, or fiber optic (ST interface), supporting BECO 2200, BECO 2179, Cooper 2179, GP2179, DNP3.0, MODBUS, UCA2.0 protocols.

COM2 (front panel): RS-232 port, used for local communication and firmware upgrades, using BECO 2200 protocol.

Only one communication port is activated at the same time.

5.2 Network Topology

M-2001B supports multiple networking methods:

Point to point direct connection: Connect directly to the PC via a null modem cable (M-0423).

Remote communication via modem: Supports Hayes compatible modems for remote access via telephone network.

Fiber optic Loop: Using ST interfaces to form a fiber optic loop network, it has strong anti-interference ability and is suitable for high-voltage substations.

RS-485 bus: 2-wire multi-point network, capable of mounting multiple controllers (addresses 1-200), with a 120 Ω terminal resistor required at the end.

5.3 TapTalk Software Features

The M-2029A TapTalk communication software provides the following remote operation capabilities:

Read and modify all set values

Broadcast commands (such as voltage regulation lockout, three-step voltage reduction)

Identify alarm conditions (voltage exceeding limit, overload, etc.)

Selective control of voltage rise/fall operation

Change configuration (such as required credit cycle)

Download data records and historical information

5.4 Load recording and dragging pointer

Drag Hands: Record the minimum/maximum local voltage within 32 seconds with a time stamp.

Demand measurement: Record the maximum current, maximum active/reactive/apparent power, and corresponding power factor with time stamps on a 15/30/60 minute cycle.

Tap position recording: Record the number of times each tap position has been passed (using BECO 2200 protocol).

Input/output specifications

6.1 Input

Control voltage: 90~140Vac, 50/60Hz optional, power consumption ≤ 8VA.

Motor power supply: 120~240Vac, maximum 6A, no need to change wiring.

Line current: 0.2A rated (CT input), requiring M-0121 or M-0169 auxiliary CT to adapt to 5A/8.66A CT.

Circulating current: 0.2A rated, used for parallel operation.

6.2 Output

Boost/buck output: switchable motor power supply of 120~240Vac, maximum 6A.

Output mode: Continuous (continuous output when voltage exceeds the limit) or Pulse (programmable for 0.2~12 seconds).

6.3 Alarm Contact Points

1 programmable normally open contact

1 normally closed self-test alarm contact (activated in case of power failure or malfunction)

Contact capacity: 3A@120Vac

On site debugging and maintenance

7.1 Basic setup process

Set electrical parameters: input VT/CT ratio, rated voltage, phase angle correction.

Set voltage regulation parameters: with center, bandwidth, delay mode and value.

Configure LDC: Calculate line impedance and set R/X or Z compensation values.

Set protection limits: overvoltage/undervoltage limits, tap position limits, and rollback dead zone.

Configure output mode: Select continuous or pulse output, set pulse width.

Set parallel mode (if applicable): Select circulating current/Δ VAR/master-slave and connect the corresponding hardware.

Configure communication: Set protocol, address, and baud rate.

7.2 Common troubleshooting

Possible causes and solutions for the phenomenon

Long term deviation of voltage from the center LDC setting deviation, CT polarity error check CT wiring and phase angle correction, recalculate compensation value

The voltage regulation action is too frequent, the bandwidth is too narrow, the delay is too short, and the sequential mode is not enabled to increase the bandwidth or delay. Enable the sequential mode