Research On Motor Drive And Energy Feedback System Of Mining Batter Electric Locomotive

As the main auxiliary transportation equipment of mine,the mine electric locomotive bears the transportation task of gangue,equipment and personnel,but the technology of mine electric locomotive lags behind.The electric motor of dc mine electric locomotive is easy to produce spark and has high explosion-proof requirement.Moreover,the direct current electric locomotive generally adopts the graded speed regulation and energy consumption braking mode,the energy cannot be recovered.The low power factor of the induction motor used by the ac electric locomotive leads to low energy utilization.And the permanent magnet synchronous motor adopts electric commutation,and has the advantage of high torque,high power factor and easy energy recovery.In order to improve the mine electric locomotive driving performance and battery energy utilization,this paper takes use of permanent magnet synchronous motor for mine electric locomotive as the research object,analyzes its speed regulation and energy feedback system and research.Firstly,the permanent magnet synchronous motor is used as traction motor according to the parameters and actual working conditions of mine electric locomotive.Compared with the DTC and FOC control strategies commonly used in PMSM,it is determined that the FOC control strategy is adopted to speed the electric locomotive.In the FOC control strategy,position sensor is an important part of speed regulation,but it is susceptible to wet and high pollution.In this paper,PLL rotor position detection method is used to replace the mechanical position sensor and improve the anti-interference ability of the system.Then,respectively from the mechanical braking process of mine electric locomotive,motor feedback process,feedback energy calculation theory,the structure of the electric locomotive feedback system circuit four Angle on the energy feedback system are analyzed.The feedback system finally adopts bidirectional semi-bridge dc-dc circuit structure to realize the recovery of braking energy.Finally,PWM wave generation module,coordinate conversion module and phase-locked loop position observer are designed in the speed control system,and the PI adjustment process is analyzed in detail.In the braking feedback system,the external loop voltage regulation and the inner ring current are adopted for the bidirectional dc-dc converter,and the voltage of the bus and the voltage current of the power supply end are stable.After each sub-module is verified,simulation is made on the non-inductive FOC speed control system of permanent magnet synchronous motor and the braking feedback system of bidirectional DC-DC converter.The results show that the stability of the sensor vector control system and the feasibility of the braking feedback system in the practical application parameters of the mine electric locomotive are verified.