Currently,the article analyzes the CAN bus's rule of priority's arbitration bit by bit without destroy. It elicits the conclusion that if static priority based on the aflirmatory system model is used,the lower priority's messages will be delayed considerably more,even some data will be lost when the bus's bandwidth is widely used. The scheduling cannot be modified neither during the system when static priority is used.The dynamic priority promoting method and the math model of SQSA and SQMA are presented;it analyzes the model's rate of taking in and sending out in large quantities,the largest delay,the problems and solutions when using SQMA.In the end, it is confirmed that the method of improving dynamic priority has good performances on the network rate of taking in and sending out in large quantities,the average delay,and the rate of network usage by emulational experiments.
电力系统电网电压总存在畸变和不平衡,有源电力滤波器(Active power filter,APF)对谐波和无功进行补偿时,采用传统的正弦电流合成(Sinusoidal Current Synthesis,SCS)方法,公共连接点处的电压畸变会导致谐波传输的问题。而采用阻性负载合成(resistive load synthesis,RLS)方法,补偿后的主电流与实际的电网电压具有相同的波形,系统特征表现为阻性,可以有效的阻尼系统中的谐波传输。文中将自适应逆控制的方法应用于APF的控制来合成阻性负载,在补偿谐波和无功的同时,阻尼系统的谐波传输,将系统的功率因数校正为1。采用自适应逆控制方法,不需要知道广义有源滤波器的确切参数,逆控制器系统可以自动跟踪电路参数而实时建模。仿真和实验结果证实所提出的算法的有效性。
