Advances in genset control
The PPM-3 protection and power management unit
Among the recent introductions by Deif for its range of engine and generator controllers is the Protection and Power Management (PPM-3) unit.
This is described as a flexible standard power management system suitable for a wide variety of marine applications. The microprocessor-based control unit contains all necessary functions for protection and control of diesel generators, shaft generators, shore connections and bus tie breakers.
The PPM-3 contains all necessary three-phase measuring circuits and shows values and alarms on an LCD display. Using a separate engine interface card as a backup shutdown unit, the PPM-3 can provide extra engine protection thanks to its use of a separate microprocessor and the separate power supply.
The system can be configured using the unit’s M-Logic PC configuration tool, which allows set up and monitoring of simple and complex systems.
One area where Deif has been aware of shortcomings in monitoring systems is in DP applications. The company says that classification societies have recently focused on problems such as cases of no alarm when analogue load share lines have been affected by wire breaks or short circuits. As a result, classification societies have sometimes been reluctant to grant approvals for DP systems, knowing that the consequences of faults such as these can be critical, leading to loss of load share ability and ultimately overload, tripping, and even blackouts.
To counter this problem and secure classification approvals, DEIF has developed a CANshare with supervision (option G9) as part of a software update for the Paralleling and Protection Unit PPU-3. With CANshare supervision active (default) each unit’s CANbus ID is set, just as each unit is told which CANshare section it is part of. The latter can be fixed or controlled from M-logic/serial communications, typically based on the BTB position.
For example, in a DP2 system, with BTB open, the system consists of two load share sections; DG1 and DG2 being set to LS section 1, with DG3 and DG4 set to LS section 2. With BTB closed, the system consists of one load share section; DG1, DG2, DG3 and DG4 all being set to LS section 1. In this case the BTB feedback is wired to ID 2. The BTB position is shared on the CANbus with the other units and can be used in M-logic to switch between LS sections. Alternatively the LS sections can be controlled with Modbus.
Implementation of CANshare has enabled Deif to fully integrate the Emulation Solution, previously introduced for the PPM-3. Traditionally, power management system (PMS) tests have been performed on mounted systems; which the company says is time-consuming and interrupts day-to-day operations. Using the Emulation Solution, PMS tests can be run offline, which offers benefits in design and test of power management systems for multiple diesel gensets. The controller can emulate both genset, breaker and other elements of a switchboard, simulating alternative setups in order to optimise the application. It is said to save time and money as controller configuration and testing can be performed prior to building switchboards or gensets.
In retrofit applications, the Emulation Solution allows existing applications to continue running while testing new setups in the office. It can also be used for demonstration and training purposes. The Emulation Solution is currently in development for other DEIF product lines.