Scalar multifactor evaluation of diagnostic characteristics of ships power systems

Vestnik of Astrakhan State Technical University. Series: Marine Engineering and Technologies

2021

The article considers the point sensor technology for onshore power systems, which has a significant potential in providing new and effective solutions for monitoring and protecting marine electrical systems. These technologies can reduce the risk levels associated with marine electrical systems by providing comprehensive monitoring and protection functions that benefit from the distributed nature of the metering system. There has been described a system that consists of a data collecting device with optical fiber to collect multiple readings from a distributed passive array of sensors connected along a fiber length up to 100 km (applicable for any marine systems). There have been illustrated the variants of distributed monitoring and protection system in marine electrical systems. It has been stated that in the advanced marine systems there are used all-electric propulsion systems that distribute electricity between the ship's propulsion plants and other consumers. The power distribution has been proved necessary to rise efficiency, controllability, flexibility and cost of the system. Application of the new DC systems with zoned architecture, the emergence of batteries and other forms of power storage, and studying the superconducting cables and machines add to the importance of having knowledge of system operability and timely and safe response to failures and damages of the system.

Application of distributed optical control technology in ship power systems

Vestnik of Astrakhan State Technical University. Series: Marine Engineering and Technologies

2021

Application of plate with optical sensors in ship information systems

Vestnik of Astrakhan State Technical University. Series: Marine Engineering and Technologies

2021

The article considers application of fiber optic devices in many devices due to their small size and high accuracy. The new fiber optic devices are equipped with a Slab Coupled Fiber (SCF) system. The SCF method uses resonant coupling between an optical fiber and a plate waveguide to create an intra-fiber device. Devices manufactured with this technology consist of polarizers, filters and sensors. Fiber optic systems have been used in torque measurement systems in the oil and gas industry and in aerospace industry. Using this system on ships is more expensive in comparison with the technologies based on strain gauges. There is offered using inexpensive optical measuring system with plate optical sensors. SCF devices use D-shaped fiber as a platform. Plate optical sensor (SCOS) devices are based on the use of an electro-optical sensor. Today, a D-fiber coupled magnetic field sensor has been developed. The device combines a magneto-optical plate waveguide with a D-fiber to measure magnetic fields. The plate coupled magneto-optical sensor (MO-SCOS) measures magnetic fields up to 2 A/m. Due to its short length the sensor can display fields with a spatial resolution of 1 mm.

Developing function diagram of digital-analogue control system of ship electric drive

Vestnik of Astrakhan State Technical University. Series: Marine Engineering and Technologies

2022

The article considers the direct digital control based on microprocessor technology, which has both the undoubted advantages in implementation and some difficulties, for example, work in real time. When developing the control system, two main problems were taken into account: a compromise in choosing possible equipment and signal processing devices. A function diagram of a digital-analogue control system for a ship electric drive is proposed, with can help to increase the reliability of an electric drive with a variable speed. When an electric drive is monitored and regulated, the current, voltage, drive rotation frequency, and the drive shaft rotation angle are under control. In addition, a functional diagram of an electric drive with frequency control has been developed, in which the signal is converted into analog form using a digital-to-analog converter. The application of a two-phase sinusoidal signal generator and a voltage shaper are proposed for obtaining sinusoidal signals of high stability both in phase displacement and in amplitude, which is important from the point of view of the energy characteristics of the electric drive. Further, the signal is converted to the analog form using a digital-to-analog converter and is used as a reference voltage that generates sinusoidal signals. After choosing the element base it can be concluded that the read-only memory device programming is carried out for each engine separately, in contrast to the rest circuit blocks, which are universal, which creates difficulties for creating a universal control system for a ship electric drive. There has been found the possibility of implementing the control system of the electric drive with frequency current control by using the rational distribution of functions between the microprocessor and digital and analog devices.