The Research On The Control System Of Offshore Jack-up Platform

With the development of the society, the demand for energy is becoming more and more big, inland already cannot offer people enough oil and gas resources, the requirements of the development of ocean resources become the key. In the offshore oil drilling, jack-up platform is usually used, although our country have a lot of this type of platforms, but most of them come from Europe and the United States, we do not master its key technologies, and do not have the ability of independently building. Power upgrade system is the key technology of jack-up platform, if we master the technology,to build our own platforms is possible.This topic comes from the operation project between dalian maritime university and nantong company that jack-up platform control system development Marine ascension. This paper first introduce the principle and function of the whole system of jack-up platform, there are many monitoring points and alarm points overall the platform, according to the need we design the distributed control system including: main console, central control cabinet and field control box.In order to ensure the smooth running of platform we need to detect the running state of each motor, at the same time we need to ensure the motor synchronization and load balancing in the operation process. Inverters are generally used because frequency control is the main method in motor controlling, inverter not only can control the speed of motor, but also detect the state of motor. In this paper DC-AC inverter control scheme is used, the part of rectifier is taken out alone. In the process of platform lifting, motors need to keep synchronization, in this paper several different synchronous control schemes are compared, at last we put forward a method which is based on the fuzzy PI compensator. Experiment shows that the synchronicity is better when using the fuzzy PI compensation than the ordinary PI compensator.