基于STM32F767两路互补SPWM波(HAL库)

SPWM波指的是占空比呈正弦规律变化的PWM波,生成方式是在定时器中断中调整PWM波的占空比。

对于互补的两路SPWM波,一路为低电平 ‘0’ 时,另一路为高电平 ‘1’,即两路是互补的。

对于STM32F7,使用高级定时器TIM1可以方便地生成互补SPWM波。步骤如下:

1、确定载波周期 Tc,也即是每个SPWM波的周期。对于逆变电路,常采用20kHz,也即 Tc =  50us;

2、确定基波周期 Tb,此处取50Hz,即 Tb = 20ms;

3、计算取点数N,Tb / Tc = 20ms/50us = 4000;半个周期内则为  N = 2000点;

4、计算占空比,Di = sin(i*pi / N), i = 1, 2, 3, ..., N;

5、确定最大最小占空比,例如最小占空比 Dmin = 0,最大占空比Dmax = 100%;

6、计算并修改定时器的比较值。将占空比为0%时,定时器的比较值设置为Cmin = 0;将占空比为100%时,定时器的比较值设为Cmax = 5399;则每中断一次,占空比的值设为 Cmax*Di,直接在中断里完成计算。

根据以上计算,可以修改最小占空比和最大占空比,也可以修改基波与载波频率。

以下是具体定时器配置与中断服务函数程序,基于STM32F767IGBT:

 

//使用高级定时器 1 完成
//Update--2019.6.3
//sin_k =    TIM1_ARR / 200.0 * (float)(spwm_max_duty - spwm_min_duty ) ;    //正弦波的比例系数,一个简单的数学代换
//sin_b = TIM1_ARR / 200.0 * (float)(spwm_max_duty + spwm_min_duty ) ; //正弦波的截距
    
#include "timer1.h"
#include "led.h"
#include "math.h"

TIM_HandleTypeDef      TIM1_Handler;         //定时器句柄 
TIM_OC_InitTypeDef     TIM1_CH1Handler;     //定时器3通道4句柄
TIM_BreakDeadTimeConfigTypeDef BreakDeadTime_Config;

#define PWM_GPIO        GPIOA
#define PWM_PIN1        GPIO_PIN_8      
#define PWM_PIN2        GPIO_PIN_7

#define TIM1_ARR        5399

//SPWM波相关计算
//sin_points -- 一个周期内中断计算的正弦点数,20KHz载波,Tc = 50us,基波周期 Tb = 50us * sin_points
//Tb = 20Hz  = 50ms = 50,000us, sin_points = 1000
//Tb = 100Hz = 10ms = 10,000us , sin_points =  200

//(-sin_k + sin_b ) / TIM1_ARR = spwm_min_duty %
//( sin_k + sin_b ) / TIM1_ARR = spwm_max_duty %,反解出 sin_k, sin_b
// sin_k = TIM1_ARR / 200.0 * (float)(spwm_max_duty - spwm_min_duty )
// sin_b = TIM1_ARR / 200.0 * (float)(spwm_max_duty + spwm_min_duty )        

uint8_t   spwm_min_duty    =    10;                    //SPWM波最小占空比
uint8_t   spwm_max_duty    =    90;                  //SPWM波最大占空比

uint16_t  count = 0;
uint16_t  sin_points =    200;
uint16_t  cc1_value;                                    //比较寄存器 1的值,修改改变占空比

float          sin_k,sin_b;


//TIM1 PWM部分初始化 
//PWM输出初始化
//arr:自动重装值
//psc:时钟预分频数
void TIM1_PWM_Init(u16 arr,u16 psc)
{ 
      //时钟配置
    TIM1_Handler.Instance = TIM1;            //定时器3
    TIM1_Handler.Init.Prescaler = psc;       //定时器分频
    TIM1_Handler.Init.CounterMode=TIM_COUNTERMODE_UP;//向上计数模式
    TIM1_Handler.Init.Period=arr;          //自动重装载值
    TIM1_Handler.Init.ClockDivision=TIM_CLOCKDIVISION_DIV1;
    HAL_TIM_PWM_Init(&TIM1_Handler);       //初始化PWM,会调用HAL_TIM_PWM_Init(*)
    
    
      //PWM配置
    TIM1_CH1Handler.OCMode=TIM_OCMODE_PWM1; //模式选择PWM1
    TIM1_CH1Handler.Pulse=arr/2;            //设置比较值,此值用来确定占空比,默认比较值为自动重装载值的一半,即占空比为50%
    TIM1_CH1Handler.OCPolarity = TIM_OCPOLARITY_HIGH;//输出比较极性为高         
    TIM1_CH1Handler.OCNPolarity = TIM_OCPOLARITY_HIGH;
    TIM1_CH1Handler.OCIdleState = TIM_OCIDLESTATE_SET;
    TIM1_CH1Handler.OCNIdleState = TIM_OCIDLESTATE_SET;
    HAL_TIM_PWM_ConfigChannel(&TIM1_Handler,&TIM1_CH1Handler,TIM_CHANNEL_1);//配置TIM1通道1
      
     //死区时间配置
     //https://blog.csdn.net/DZRYWYBL/article/details/82527889 
    BreakDeadTime_Config.OffStateRunMode = TIM_OSSR_DISABLE;  
    BreakDeadTime_Config.OffStateIDLEMode = TIM_OSSI_DISABLE;  
    BreakDeadTime_Config.LockLevel = TIM_LOCKLEVEL_OFF;  
    BreakDeadTime_Config.DeadTime = 0X00; //0x00~0xFF,当设置为0xFF时,50us周期,约有4.68us死区时间;0x0F约有100ns死区时间
    BreakDeadTime_Config.BreakState = TIM_BREAK_DISABLE;  
    BreakDeadTime_Config.BreakPolarity = TIM_BREAKPOLARITY_HIGH;  
    BreakDeadTime_Config.AutomaticOutput = TIM_AUTOMATICOUTPUT_DISABLE;  
    HAL_TIMEx_ConfigBreakDeadTime(&TIM1_Handler, &BreakDeadTime_Config);


     //中断配置
    HAL_NVIC_SetPriority(TIM1_CC_IRQn,1,3);    //设置中断优先级,抢占优先级1,子优先级3
    HAL_NVIC_EnableIRQ(TIM1_CC_IRQn);          //开启ITM3中断  
    //开启PWM并使能中断
    HAL_TIM_PWM_Start_IT(&TIM1_Handler, TIM_CHANNEL_1); //开启PWM输出并使能中断
    HAL_TIMEx_PWMN_Start(&TIM1_Handler, TIM_CHANNEL_1); //打开互补通道
}

//定时器底层驱动,时钟使能,引脚配置
//此函数会被HAL_TIM_PWM_Init()调用
//htim:定时器句柄
void HAL_TIM_PWM_MspInit(TIM_HandleTypeDef *htim)
{
    GPIO_InitTypeDef GPIO_Initure;
    __HAL_RCC_TIM1_CLK_ENABLE();            //使能定时器3
    __HAL_RCC_GPIOA_CLK_ENABLE();
    __HAL_RCC_GPIOB_CLK_ENABLE();
    
    GPIO_Initure.Pin=PWM_PIN1 | PWM_PIN2;   //PWM Pin
    GPIO_Initure.Mode=GPIO_MODE_AF_PP;      //复用推完输出
    GPIO_Initure.Pull=GPIO_PULLUP;          //上拉
    GPIO_Initure.Speed=GPIO_SPEED_HIGH;     //高速
    GPIO_Initure.Alternate=GPIO_AF1_TIM1;   //PA8复用为TIM1_CH1
    HAL_GPIO_Init(PWM_GPIO,&GPIO_Initure); 
      
}

//设置TIM通道4的占空比
//compare:比较值
void TIM_SetTIM1Compare1(u32 compare)
{
    TIM1->CCR1=compare; 
}


//定时器1中断服务函数
void TIM1_CC_IRQHandler(void)    //注意名称与通用计时器不同,多了 CC
{
    HAL_TIM_IRQHandler(&TIM1_Handler);
}

//定时器1中断服务函数调用
void HAL_TIM_OC_DelayElapsedCallback(TIM_HandleTypeDef *htim)
{
    if(htim==(&TIM1_Handler))
    {
          count ++;
          if(count ==  sin_points)
              count = 0;
                
          sin_k =    TIM1_ARR / 200.0 * (float)(spwm_max_duty - spwm_min_duty ) ;    //正弦波的比例系数,一个简单的数学代换//更正为相减
          sin_b = TIM1_ARR / 200.0 * (float)(spwm_max_duty + spwm_min_duty ) ;       //正弦波的截距//更正为相加
          cc1_value = (uint16_t) (sin_k * sin( (double)count * 6.28318 / (double)sin_points) + sin_b);    //正弦值计算,得到SPWM波占空比
          TIM_SetTIM1Compare1(cc1_value);
    }
}

 主函数配置为

TIM1_PWM_Init(5400-1,2-1);     //216M / (5400 * 2 ) = 20K

 

 

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