PWM Generator
生成脉冲宽度调制信号或波形
库:
Simscape /
Electrical /
Control /
Pulse Width Modulation
描述
PWM Generator 模块实现 PWM 发生器。脉冲宽度调制技术通过在满功率传输和无功率传输之间快速切换，来控制从一个电气组件到另一个电气组件的功率传输。
工作原理
当占空比大于载波计数器值时，PWM Generator 模块输出 1，否则输出 0。您可以通过指定计时器周期 Tper 来设置每个周期的持续时间。您可以通过指定以下三种载波计数器类型之一来更改 PWM 输出的初始输出或相位：
递增计数器 - PWM 输出信号在
on周期开始时初始化。下图显示了载波计数器信号和相应的 PWM 输出。
递减计数器 - PWM 输出信号在
off周期开始时初始化。下图显示了载波计数器信号和相应的 PWM 输出。
增减计数器 - PWM 输出信号在
on周期的中途初始化。下图显示了载波计数器信号和相应的 PWM 输出。
示例
DC 电机控制
此示例展示了 DC 电机的级联速度控制结构。采用 PWM 控制的四象限斩波器为该 DC 电机供电。Control 子系统包括外层转速控制环、内层电流控制环和 PWM 生成模块。总仿真时间 (t) 为 4 秒。在 t = 1.5 秒时，负载转矩增加。在 t = 2.5 秒时，参考转速从 1000 rpm 变为 2000 rpm。
HESM 转矩控制
Control the torque in a hybrid excitation synchronous machine (HESM) based electrical-traction drive. Permanent magnets and an excitation winding excite the HESM. A high-voltage battery feeds the SM through a controlled three-phase converter for the stator windings and through a controlled four quadrant chopper for the rotor winding. An ideal angular velocity source provides the load. The Control subsystem uses an open-loop approach to control the torque and a closed-loop approach to control the current. At each sample instant, the torque request is converted to relevant current references. The current control is PI-based. The simulation uses several torque steps in both the motor and generator modes. The Visualization subsystem contains scopes that allow you to see the simulation results.
HESM 速度控制
Control the rotor angular velocity in a hybrid excitation synchronous machine (HESM) based electrical-traction drive. Permanent magnets and an excitation winding excite the HESM. A high-voltage battery feeds the HESM through a controlled three-phase converter for the stator windings and through a controlled four quadrant chopper for the rotor winding. An ideal torque source provides the load. The Control subsystem includes a multi-rate PI-based cascade control structure. The control structure has an outer angular-velocity-control loop and three inner current-control loops. The Visualization subsystem contains scopes that allow you to see the simulation results.
SM 转矩控制
Control the torque in a synchronous machine (SM) based electrical-traction drive. A high-voltage battery feeds the SM through a controlled three-phase converter for the stator windings and a controlled four quadrant chopper for the rotor winding. An ideal angular velocity source provides the load. The Control subsystem uses an open-loop approach to control the torque and a closed-loop approach to control the current. At each sample instant, the torque request is converted to relevant current references. The current control is PI-based. The simulation uses several torque steps in both motor and generator modes. The task scheduling is implemented as a Stateflow® state machine. The Visualization subsystem contains scopes that allow you to see the simulation results.
SM 速度控制
Control the rotor angular velocity in a synchronous machine (SM) based electrical-traction drive. A high-voltage battery feeds the SM through a controlled three-phase converter for the stator windings and a controlled four quadrant chopper for the rotor winding. An ideal torque source provides the load. The Control subsystem includes a multi-rate PI-based cascade control structure which has an outer angular-velocity-control loop and three inner current-control loops. The task scheduling in the Control subsystem is implemented as a Stateflow® state machine. The Visualization subsystem contains scopes that allow you to see the simulation results.
端口
输入
输出
参数
扩展功能
版本历史记录
在 R2017b 中推出
