Research On Energy Saving Control System Based On Frequency Conversion Power Technology

Asynchronous motor works high-efficiently under the rated load.The traditional frequency converter power supply asynchronous motor speed regulating system with rated excitation control further improves the operational efficiency under a synchronous motor rated conditions.However,when asynchronous motor is in light running or working condition with wide load change range,both the common constant voltage frequency ratio control and the vector control mode have the problem of high motor iron core loss,with poor electric energy use efficiency.Taking frequency conversion speed control system with the minimum operation loss as target,the energy conservation control of asynchronous motor is realized in this paper when guaranteeing the system with high dynamic response characteristic.The main research contents include:Firstly,establishing asynchronous motor mathematical model with consideration to iron loss,realizing the model based on MATLAB/Simulink platform,the effectiveness of asynchronous motor iron loss with the consideration to iron loss is verified with the mode of simulation comparison analysis.Secondly,based on analyzing frequency conversion speed control system loss and its efficiency optimization control principle,the optimal stator flux linkage in minimum controllable loss of the corresponding motor system is derived,and this flux linkage is taken as the given flux linkage of direct torque control system,gaining direct torque control asynchronous motor efficiency optimization of energy conservation control strategy based on the loss model.Meanwhile,based on MATLAB/Simulink platform,direct torque control basic model is realized,and the direct torque control optimization model based on loss model is also realized;moreover,the simulation comparison analysis is also implemented.The simulation results verified the good effect of energy conservation strategy in the aspects of improving motor response speed and reducing frequency conversion speed control system loss.Thirdly,combining with the laden frequency conversion transformation energy conservation principle of draught fan and water pump,etc.,the frequency conversion energy conservation reconstruction engineering design scheme conforming to load mechanical properties is proposed based on analyzing thermal power plant frequency conversion transformation energy conservation potential.Exampled by second boiler fan of thermal power plant,the main circuit,external control circuit design,and software design including energy conservation system are realized.Lastly,exampled by boiler fan frequency conversion energy conservation transformation of thermal power plant,the energy conservation effects achieved of fan frequency conversion transformation are analyzed from two aspects including direct benefit and indirect benefit combining with the frequency conversion energy conservation principle of fluidity machinery such as draught fan.The conservable electric energy can be gained directly from the differencevalue of annual energy's total consumption before and after the transformation of single pressure fan frequency conversion;the advantages of frequency conversion transformation is analyzed from the aspects such as improving control precision and perfecting protection function.