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

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.