The Middle Frequency Heating Power Design Of Heavy Oil Well And Study On Its Control Methods

The recovery technologies to heavy oil are usually adopting thermal fashion. At present, the heavy oil electrical heating power supply in use has a lot of disadvantages such as the low thermal efficiency and high electricity waste. It affects exploitation cost of the heavy oil badly. The development and application of new high efficiency middle frequency heating power supply will take on quite important meaning to the increasing of oil industry economy benefit and competition ability, also to the economizing the energy and the reduction of the waste. It is a research field with great developing potential and abroad application foreground.The paper finishes the deeply research and analysis to the fundamental and the developing actuality of middle frequency heating. Then carry through the theory analysis to the power distribution of wellbore by distributing parameter model of the load circuit, and get the rule of the wellbore output power changing along with the well deep at the different frequency. It will take on direction significance to the research and design of heating power supply of heavy oil well in different frequency.The middle frequency heating power supply adopts no controlled rectifier and AC-DC-AC frequency conversion technology. The voltage type IGBT series resonance inverter circuit is designed for the hollow center sucker rod load. The control circuit uses the SCM as the kernel. The power modulation of the inverter circuit is realized by PWM fashion to reduce the waste of the power and increase the heating efficiency.The math model of heating object is built to the heavy oil electrical heating system. It is a non-linearity, big lag and strong interferential complex controlled object. The improved PID control method with self-turning optimal parameter is designed to make the system have the accurate temperature closed loop control and increase the heating efficiency of the power supply. The simulation results and its analysis are given out to confirm the correctness and validity of the design.