- 积分
- 10123
- 回帖
- 0
- 西莫币
-
- 贡献
-
- 威望
-
- 存款
-
- 阅读权限
- 120
- 最后登录
- 1970-1-1
该用户从未签到
|
The Simulink model, which implements the closed loop vector control of the motor speed, is shown on the right. The element which couples to MagNet is the red component with the MagNet logo.
The link component is designed to allow MagNet to take advantage of symmetry, by allowing the currents and/or voltages to be scaled in the transfer between Simulink and MagNet. In this case the four windings of each phase are connected in a series-parallel configuration, so the current and the voltage are both scaled by a factor of two in the Simulink component. Shown here is the mesh used by MagNet for its part of the simulation. At each time step, as the rotor changes position, the airgap is remeshed, which allows motional effects to be modeled quickly and accurately.
Using vector control a feedback loop monitors the motor speed and varies the motor torque to maintain a desired speed. The graph here shows the commanded speed (1800 rpm, shown in green) and the actual speed (shown in blue). The transient simulation starts in Simulink, which invokes MagNet transparently to jointly run its electromagnetic simulation. While both simulations are running they are constantly passing data back and forth to synchronize the voltages and currents.
This graph shows the vector voltages commanded by the feedback circuit. The system blocks in the lower left quandrant of the circuit implement an approximate inverse model of the motor, which means that the speed feedback need only generate small corrections to these voltages.
The graph at right shows the phase voltages commanded by the controller, which are obtained from the vector voltages by a DQ to ABC transformation. The element which performs this transformation is a user defined S-Function which implements the mathematical operations.
MagNet also takes the mechanical loads on the motion component into account, as well as velocity effects such as back emf. The resulting phase currents (shown here at right) are calculated by performing a finite element analysis, and are returned to Simulink.
This graph shows the actual vector currents. A limiter component in the feedback loop keeps the commanded current magnitude under 10 Amps. These currents are obtained from the phase currents using a user-defined ABC to DQ transformation element.
The previous graphs were generated by "Scope" blocks, which is just one of the many ways of extracting data from Simulink. Once the simulation is complete, MagNet's post-processor can be invoked to plot the magnetic quantities, such as flux linkage and torque, as well as fields, such as flux density and current density. The magnetic torque on the rotor is plotted here.
The link which orchestrates the data exchange between Simulink and MagNet is designed to allow different time steps in each application while both are running a transient simulation. In this example MagNet is running with a time step of only 0.2 ms, while Simulink is using a finer time step. A summary of the simulation data follows. |
|
加群请注明论坛用户名及所从事专业，否则不予通过
|小黑屋|手机版|Archiver|西莫电机圈
( 浙ICP备10025899号-3 ) 
浙公网安备：33028202000436号
IP卡
发表于 2009-5-24 13:41
提升卡
置顶卡
喧嚣卡
变色卡
显身卡
发表于 2009-5-24 20:43