(1) Basic information

In industrial production, motor drive systems are widely used, such as electric locomotives, pumps and fans, cranes, etc. A system that uses a motor as the prime mover to drive equipment to operate is called an electric traction system. The electric traction system generally includes four parts: the motor, traction equipment, control equipment and power supply.

(2) Product introduction

Specifically, motor driving includes many aspects, such as the motion equations of DC motors and motor systems, as well as the static and dynamic characteristics of DC motors, transformers, etc. From the perspective of control categories, the open-loop speed is the frequency conversion speed control system of the unloader pump motor, and the power supply frequency conversion speed control system is controlled by using a constant voltage to frequency ratio. In actual use, if you want to control the output DC voltage, the main basis is voltage.

By giving the speed, the control signal in the entire power system can be obtained. Even in the case of a jump change, the regular changes in the output voltage and current of the inverter can be coordinated and controlled by giving the speed. Therefore, we set the given integrator and replace the jump input with a ramp output signal, so that the forward and reverse rotation of the motor can be effectively controlled. It is known through practice that during the entire operation of the motor driving system, positive and negative voltages are used to effectively divide the given speed and the given integrator output. Because the positive signal voltage is the output voltage of the current controller and the output frequency of the inverter, there is no big difference in absolute value of the converter set. A large number of practical studies have shown that the frequency converter system has a wide speed regulation range and good speed regulation smoothness, which can effectively improve the performance of the motor when starting, so it can be effectively applied to motor dragging. In addition, it can also be widely used in ship electric dragging. The control signals used are the same. You only need to coordinate the output voltage and output frequency and more rationally understand the frequency conversion speed regulation technology, so that the frequency conversion speed regulation technology can be better applied in motor driving.

(3) Product application areas

In power systems such as industrial machines and automobiles,

(4) Application cases

Shanghai Huafeng Aluminum Co., Ltd.

b) Implementation content and cycle: Before the project transformation, the company's general equipment such as fans and water pumps adjusts the load of the equipment through valve control and adjustment methods. The uses of such equipment are: ① ventilation in the workshop, ② environmental protection fans in the workshop, ③ equipment cold cutting water circulation water pump, ④ part of the process dragging equipment, during this operation process, due to the inability of manual control in real time, the equipment energy consumption is high or low in some times. Now a frequency conversion control system is added to this kind of motor. By adjusting the speed of the motor, the flow of the water pump or fan, the operating efficiency of the process equipment, etc. The power of the motor driving equipment has a cubic relationship with the actual operating speed, and the energy-saving effect is obvious. The project started in March 2016 and was completed in April 2019.

c) Energy conservation and emission reduction effect and investment payback period: After the implementation of this project section, the company can reduce electricity by 19.4997 million kWh and diesel by 99.39 tons every year. Calculated based on Shanghai City's industrial electricity by 8,000 yuan/10,000 kWh and diesel by 7500 yuan/ton, the annual savings of this project are 16.3452 million yuan, the project investment amount is 11.4874 million yuan, and the investment return period of the project is 0.7 years.