A winch control program is launched for use with ABB industrial drives ranging from 0.55 to 5600 kW.
The winch control program can be used in different control system configurations found within the marine environment. All the functions, commonly required for winch applications, are contained within the winch control program. It incorporates built-in programmable logic controller (PLC) features, enabling the drive to be used without any external PLC.
The winch application can be programmed within the PLC that communicates with the ABB industrial drive via fieldbus gateways.
The ABB industrial drive is certified for marine use and when combined with the winch control program it can replace traditional and costly hydraulic winch controllers typically used in anchoring and mooring. This eliminates high maintenance costs and performance inefficiencies, while improving operator safety and overall system reliability.
A key benefit of the ABB industrial drive is its motor control platform, Direct Torque Control (DTC). DTC enables the drive to achieve full torque at zero speed without the need for a feedback encoder. Using a feedback encoder can be a problem on board a vessel as the harsh climate on deck can often damage the encoder itself or interfere with the feedback signal to the motors.
Winch interface
Using the ABB industrial drive’s digital I/Os, along with the winch control program, means that the winch can be operated directly from three control stands located typically on the port, starboard and upper deck of a vessel. This lets the operator control the speed of the winch while in a harbor, for example, from anywhere on the vessel, regardless of whether the vessel is coming alongside on port or starboard.
Winch control enables a control stand to be operated with the other two stands disabled or with all three stands active at the same time.
From each stand an operator can start and stop, or by way of a joystick, raise or lower the winch. A complete set of protection functions is built into the program to safeguard the health and safety of everyone working in the location of the winch.
Anchor control
From each control stand, an anchor mode can be selected which lets the winch raise or lower an anchor. As this procedure requires careful speed control, the operator manually controls the joystick at his chosen stand.
Among the in-built protection functions are slip detection which detects any high load on the chain, should it become snagged when raising the anchor. Such a high load creates a speed difference between the winch drum and the motor shaft and activates a load switch. The speed/torque of the winch motor is immediately reduced, to a level set by the winch manufacturer. This prevents damage to the motor shaft, winch drum or clutch between the drum and motor.
A further protection feature is anchor-in protection. As the anchor is being raised and reaches the end of its limit, winch control detects the anchor winch speed and motor torque level, together with the relative length of the chain. It then slows down the winch automatically, allowing the operator to manually complete the task, controlling the joystick to the zero position.
Mooring control
When mooring a vessel to a harbour or pier, the tension within the mooring ropes can be controlled manually from any of the three control stands using winch control, while staying in full view of the rope movement. Without winch control, there is a risk that the force within the rope becomes too high, resulting in the rope breaking. As this is a speed control application, winch control detects the high force in the rope through changes in the torque and controls the speed accordingly.
The routine which prevents breakage in the rope is call peak torque protection. It detects severe tightening of the rope and immediately sends a signal to adjust the speed, thereby saving the rope and protecting the winch system from overload. The speed and torque is reduced to a level that the operator can control before the mechanical brake is applied and locked or change over to auto mooring mode.
Mechanical brake control logic and torque memory
The program features an integrated brake control logic which in turn uses torque memory and pre-magnetizing to open and close the mechanical brake safely and reliably.
Additional safety is achieved using brake feedback status from the brake hardware to the drive’s I/O board to monitor brake status compared to drive run/stop status.
Adaptive programming
The drive also features adaptive programming. This function block programming technique is included as standard and allows winch features to be changed or modified on-site without having to wait for further software upgrades from the manufacturer. For example, overspeed monitoring and speed match can easily be done with adaptive programming.