Application of PFA rectifier feedback device in power dynamometer

Electric dynamometer is widely used in engine and motor performance and durability testing. The dynamometer is mainly used in testing to apply loads on the output shaft of the engine or the tested motor, in order to perform performance tests on the engine and motor. An electric dynamometer can achieve constant speed control and constant torque control to realize a load system that applies load to the tested engine or motor and absorbs its power. At the same time, it is equipped with a display control system to test the output torque, speed, power, and characteristic curves of various types of vehicle engines (automotive engines, motorcycle engines, general machinery engines, non road machinery engines, etc.), motors (such as single-phase and three-phase asynchronous motors, synchronous motors, DC motors, series excited motors, electric tools, wheel hub motors, starter motors, automotive motors, etc.). When conducting engine testing, the system configuration testing module can test parameters such as temperature, pressure, and flow rate of the engine. When conducting motor testing, the system configuration related testing module can test parameters such as voltage, current, power, and temperature of the motor. According to the working principle of the dynamometer, it is mainly divided into hysteresis dynamometer, magnetic powder dynamometer, electric turbine dynamometer, and electric dynamometer. Specifically for electric dynamometer systems, DC motors or AC variable frequency motors are used as the main components to convert electrical energy into braking mechanical energy of the motor rotor, which is then loaded onto the tested engine or motor in the form of torque. Real time control of the loading torque is achieved through a frequency converter to simulate the mechanical load carried by the engine or motor. This system mainly consists of the following parts: (1) Host: AC power dynamometer; (2) Dynamometer control: SIEMENS AC variable frequency speed regulation device, using manual knob to adjust the operating condition point; (3) Detection and data processing part: using industrial control computers to detect and display various detection parameters, manage data, print test reports, and draw engine characteristic curves; 2. Adopting SIEMENS fully digital control device, the AC electric dynamometer has two operating states: electric and dynamometer. When electric, it can drive the engine to automatically operate, and when dynamometer is used, it applies load to the engine, with fast and stable control characteristics; 3. During dynamometer operation, the mechanical energy of the engine is fed back to the power grid through a PFA rectifier feedback device. When the dynamometer operates below the rated speed of the variable frequency motor, it can reach the rated torque capacity of the dynamometer. When the dynamometer operates above the rated speed of the variable frequency motor, it can reach the rated power of the dynamometer; 4. The dynamometer adopts constant speed control or constant torque control mode; The system testing accuracy maintains the control accuracy of Siemens universal vector frequency converter (1) Speed: ± 0.2% ± 1r/min; (2) Torque: ± 1%;

IPC Elevator Energy Saving Feedback Enters Peking Union Medical College Hospital

In December 2022, IPC Elevator Energy Saving Feedback settled in Peking Union Medical College Hospital The hospital has a huge flow of people, and the frequency of elevator usage is very high, resulting in high electricity consumption. Energy conservation and consumption reduction have become the most pressing issues that need to be addressed at present. Installing energy-saving feedback for elevators can effectively return the electrical energy generated by the elevator to the power grid. The energy-saving rate reaches 25% -45%. In addition, due to the absence of resistance heating elements, the ambient temperature in the machine room is reduced, and the operating temperature of the elevator control system is also improved, preventing the control system from crashing and extending the service life of the elevator. The computer room can no longer use air conditioning and other cooling equipment, which can save the power consumption of the computer room air conditioning and cooling equipment, save energy and environmental protection, and make the elevator more energy-efficient.

Application of IPC Variable Frequency Feedback Electronic Control System in Mine Winch 380V/660V

Requirements for the Driver of Mine Winch Motor ① High starting torque and good speed regulation characteristics; ② Strong overload capacity; ③ At low frequencies, it can output a large torque and cannot slide when suspended; ④ When lowering, the motor generates a large amount of regenerative energy, and it is required to be able to handle the regenerative energy of the motor reasonably. 3. Disadvantages of traditional control systems for mine winches ① High energy consumption The traditional speed control method for mine winches is the winding motor rotor series resistance speed control. This control system consumes a large amount of slip power on the resistors connected in series with the rotor (usually accounting for more than 30% of the total energy consumption), resulting in a significant waste of electrical energy. From both energy-saving and economic perspectives, it is not advisable. ② Poor speed regulation performance The rotor series resistance speed regulation method belongs to graded speed regulation, and the decrease in speed is achieved through the energy consumption of the external resistance of the rotor. The most important thing is that the lower the speed, the softer the mechanical characteristics of the motor, and the smaller the output torque. Moreover, graded speed regulation has a significant impact on motors and mechanical equipment, resulting in unstable equipment operation, discontinuous speed regulation, easy derailment, and high failure rate. For the 24-hour continuous production mode of coal mines, there are significant economic losses. ③ Poor system reliability Frequent opening and closing of contactors (contactors frequently open and close under high current conditions) often causes sintering of contactor contacts and burning of coils. Inadequate protective measures can easily lead to motor burnout. The C brake is subjected to significant impact, and the brake pads are severely worn, making it easy for the brake to not hold tightly and requiring frequent maintenance and replacement. ④ High maintenance costs Contactors, wound motor rotor brushes, and slip rings often require maintenance and replacement, which is costly. The reducer and brake are greatly impacted and often require maintenance. The characteristics of the C rotor series resistance speed regulation method ultimately result in limited production efficiency (frequent failures in shutdown and maintenance states), heavy maintenance workload, and increased usage and maintenance costs. 4. Advantages of frequency conversion feedback electric control system for mine winch ① The frequency converter has good speed regulation performance, large starting torque, hard mechanical characteristics, and accurate positioning. ② The frequency converter runs smoothly, with minimal impact on the reducer and brake, reducing equipment maintenance and extending the service life of the hoist. ③ After using the frequency converter, there is no need to use contactors anymore, and the wound motor can also be changed to a squirrel cage motor without the need for maintenance of the brushes and slip rings ④ The frequency converter has high operating efficiency and has complete protection, monitoring, and self diagnostic functions for the motor and system. If combined with PLC control, it can greatly improve the reliability of the mine winch electrical control system. ⑤ The energy feedback function can feed back the regenerative energy of the motor to the power grid, greatly saving electricity The Application Effect and Customer Evaluation of IPC Frequency Conversion Feedback Electric Control System in Energy saving Renovation of Mine Winches The actual operation of the system has proven that the application of IPC variable frequency feedback electric control system in energy-saving renovation of mine winches does not change the original operation mode of the mine winches, and the original handbrake can be basically no longer used, simplifying the operation. The system runs stably and reliably, with excellent speed regulation performance and large starting torque and low-frequency torque output; When the mechanism is lowered, the excess electricity generated by the motor's regenerative power generation is fed back to the grid, greatly saving energy. The customer is very satisfied with the effectiveness of the IPC variable frequency feedback electronic control system in the energy-saving renovation of mine winches. After actual measurement, the IPC variable frequency feedback electronic control system can save more than 28% of electrical energy compared to the original mine winch winding motor rotor series resistance speed regulation method.