Three-teiminal Power Router Mode Switching Control For Electric Workover Rig

The working environment of electric workover rigs is located in the gobi desert,deserts,etc.,the power distribution is limited.It is difficult to meet the different power supply requirements of electric workover rig.Therefore,the wellsite power grid is often overloaded,and its trans former is threatened.In this paper,a three-terminal electric energy router is constructed,which includes rectification,inverter and energy storage.The controller of energy storage side is the main controller of the three-terminal electric energy router.First of all,combined with the working characteristics of the electric workover rig,the capacity of supercapacitor is con figured.After comparing several common bidirectional DC/DC converters,the bidirectional half-bridge DC/DC converter is finally selected as the main circuit of the energy storage system.At the same time,the main circuit component parameters of the three-terminal electric energy router are designed.Secondly,a three-terminal power router control strategy suitable for electric workover rigs is proposed,which could coordinates the energy of the three ports by detecting and controlling the current and voltage signals on the rectifier side and the inverter side.In the lifting period of the electric workover rig,while the phase current of the transformer on the rectifier side is too large,the overcurrent protection control is activated to limit the effective value of the phase current on the rectifier side below the rated value;In the intermittent period,the supercapacitor on the energy storage side absorbs energy from the rectifier side to achieve capacity storage;In the lowering period,the bus voltage rises due to the feedback energy generated by the inverter side,and the energy storage side recovers and reuses this part of the energy to maintain the stability of the bus voltage.Based on the PSIM simulation platform,the simulation of the above-mentioned control strategy is completed,which finally verifies the feasibility of the control strategy in this article.Finally,a three-terminal electric power router experimental platform suitable for electric workover rigs is established with TMS320F28335DSP as the core controller,and related control programs are designed.Through experiments,using the control strategy proposed in this article,the energy storage side can realize different functions according to the voltage and current signals of the rectifier side and the inverter side,and when the system is running unsafely,an alarm could be given to stop the system.Finally,the correctness and effectiveness of the control strategy in this article are verified.