3 Phase Motor Control PWM with dead time and phase shift

[christiaan2]

Posted on July 15, 2015 at 16:12

Hi

I have adapted the program found below from the example 7PWM_Output in the StdPeriph library examples. My aim is to create 3 PWM channels each with it's respective complimentary output as well as inserted dead time and a 60 degree phase shift between each channel: Channel 1 PWM = 0� Channel 2 PWM = 60� Channel 3 PWM = 120� As the program stands the 3 PWM signals and the complementary signals are correct as well as the dead time. My problem is that I cannot figure out how to insert the phase shifts. I am also having trouble identifying the current clock speed. I am using the STM32F103RBT6 Nucleo board with the Cortex M4 @72MHz Code: &sharpinclude ''stm32f10x.h'' TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure; TIM_OCInitTypeDef  TIM_OCInitStructure; TIM_BDTRInitTypeDef TIM_BDTRInitStructure; uint16_t TimerPeriod = 0; uint16_t Channel1Pulse = 0, Channel2Pulse = 0, Channel3Pulse = 0; void RCC_Configuration(void); void GPIO_Configuration(void); int main(void) {     /* System Clocks Configuration */   RCC_Configuration();   /* GPIO Configuration */   GPIO_Configuration();   /* TIM1 Configuration --------------------------------------------------- */     /* Compute the value to be set in ARR regiter to generate signal frequency at 10 Khz */   TimerPeriod = (SystemCoreClock / 90000 ) - 1;   /* Compute CCR1 value to generate a duty cycle at 50% for channel 1 and 1N */   Channel1Pulse = (uint16_t) (((uint32_t) 5 * (TimerPeriod - 1)) / 10);   /* Compute CCR2 value to generate a duty cycle at 50%  for channel 2 and 2N */   Channel2Pulse = (uint16_t) (((uint32_t) 5 * (TimerPeriod - 1)) / 10);   /* Compute CCR3 value to generate a duty cycle at 50%  for channel 3 and 3N */   Channel3Pulse = (uint16_t) (((uint32_t) 5 * (TimerPeriod - 1)) / 10);   /* Time Base configuration */   TIM_TimeBaseStructure.TIM_Prescaler = 0;   TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;   TIM_TimeBaseStructure.TIM_Period = TimerPeriod;   TIM_TimeBaseStructure.TIM_ClockDivision = 0;   TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;   TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);   /* Channel 1, 2,3 and 4 Configuration in PWM mode */   TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;   TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;   TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;   TIM_OCInitStructure.TIM_Pulse = Channel1Pulse;   TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;   TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;   TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;   TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;   TIM_OC1Init(TIM1, &TIM_OCInitStructure);   TIM_OCInitStructure.TIM_Pulse = Channel2Pulse;   TIM_OC2Init(TIM1, &TIM_OCInitStructure);   TIM_OCInitStructure.TIM_Pulse = Channel3Pulse;   TIM_OC3Init(TIM1, &TIM_OCInitStructure);   /* Dead time configuration (3.7 us) */   TIM_BDTRInitStructure.TIM_DeadTime = 30;   TIM_BDTRConfig(TIM1, &TIM_BDTRInitStructure);          /* TIM1 counter enable */   TIM_Cmd(TIM1, ENABLE);   /* TIM1 Main Output Enable */   TIM_CtrlPWMOutputs(TIM1, ENABLE);   while (1)   {     } } void RCC_Configuration(void) {   /* TIM1, GPIOA, GPIOB and AFIO clocks enable */   RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 | RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE); } /* Configure the TIM1 Pins. */ void GPIO_Configuration(void) {   GPIO_InitTypeDef GPIO_InitStructure;   /* GPIOA Configuration: Channel 1, 2 and 3 as alternate function push-pull */   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10;   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;   GPIO_Init(GPIOA, &GPIO_InitStructure);   /* GPIOB Configuration: Channel 1N, 2N and 3N as alternate function push-pull */   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15;   GPIO_Init(GPIOB, &GPIO_InitStructure); } Any help will be appreciated. Thank you! #stm32-nucleo