Drive system of scraper conveyor and control method

A control method for a drive system of a scraper conveyor, comprising the following steps:

• step 1:
• switching, by a start-stop controller in a controller, to a start mode, and controlling, by the start-stop controller, actions of solenoid valves in a hydraulic valve group, to supply hydraulic oil in a hydraulic oil source and high-pressure oil stored in an accumulator to a hydraulic motor I and a hydraulic motor II at the same time, and gradually reduce swash plate inclination angles of the hydraulic motor I and the hydraulic motor II from the maximum until the scraper conveyor reaches a rated operating rotational speed;
• step 2:
• in a coal conveying process of the scraper conveyor, sending, by rotational speed torque sensors, real-time rotational speeds and average rotational speeds of the hydraulic motor I and the hydraulic motor II respectively to a speed synchronization controller, and controlling, by the synchronization controller, the swash plate inclination angles of the hydraulic motor I and the hydraulic motor II respectively according to a preset relative error value and an expected rotational speed value, to keep a tail sprocket and a nose sprocket synchronously rotating, to maintain a stable operating speed of the scraper conveyor;
• step 3:
• when a chain tension monitoring sensor detects that chain tension is lower than a preset minimum tension value, switching, by the controller, to a tension coordination controller in real time, controlling, by the tension coordination controller, the swash plate inclination angle of the hydraulic motor II at a tail to increase, to reduce a rotational speed of the tail sprocket and keep a rotational speed of the nose sprocket unchanged, thereby gradually increasing the chain tension until the chain tension falls within a preset value range, and switching, by the controller, to the synchronization controller in real time, to keep the tail sprocket and the nose sprocket synchronously rotating;
• step 4:
• when the chain tension monitoring sensor detects that the chain tension is higher than a preset maximum tension value, switching, by the controller, to the tension coordination controller in real time, controlling, by the tension coordination controller, the swash plate inclination angle of the hydraulic motor II at the tail to decrease, to increase the rotational speed of the tail sprocket and keep the rotational speed of the nose sprocket unchanged, thereby gradually reducing the chain tension until the chain tension falls within the preset value range, and switching, by the controller, to the synchronization controller in real time, to keep the tail sprocket and the nose sprocket synchronously rotating;
• and
• step 5:
• switching, by the start-stop controller in the controller, to a stop mode, and controlling, by the start-stop controller, actions of the solenoid valves in the hydraulic valve group, wherein the hydraulic motor I and the hydraulic motor II continuously rotate because of inertia, so that an oil inlet side of a motor is evacuated, the oil inlet side is supplemented with oil through an oil supplement valve group, at the same time, hydraulic oil on oil return port sides of the hydraulic motor I and the hydraulic motor II flows into the accumulator and an oil tank, and pressure of the accumulator increases as stored oil increases, to form specific back pressure, to prevent the hydraulic motor I and the hydraulic motor II from continuously rotating, and speed up the hydraulic motors to stop rotating.