TI DSP实现SVPWM技术详解与应用

需积分: 43 79 浏览量更新于2024-07-22 9 收藏 341KB PDF 举报

"这篇TI应用报告SPRA524详细阐述了SVPWM（空间向量脉宽调制）在三相电压源逆变器中的实现方法，特别适合TI DSP初学者学习。报告中不仅介绍了SVPWM的基本原理，还提供了两种不同的实现策略：一种利用TMS320C24x/F24x DSP的常规比较函数，另一种则是通过TMS320C24x/F24x DSP的SVPWM硬件模块。同时，报告提供了TMS320F243/1的完整代码示例，并讨论了一个完整的交流感应电机控制应用，以展示这两种方法的有效性。报告附带了实施例的PWM波形和电机电流的实验数据进行分析。" SVPWM（空间向量脉宽调制）是一种先进的脉宽调制技术，尤其适用于三相电压源逆变器的控制，如交流感应电机和永磁同步电机。它的核心思想是将三相空间电压矢量分解成基本的两相电压矢量，通过优化开关模式来逼近理想正弦波电压，从而提高逆变器的效率和输出质量。 TI的TMS320C24x/F24x系列DSP芯片因其高速处理能力和丰富的外设接口，成为SVPWM算法的理想选择。本报告首先深入讲解了SVPWM的理论基础，包括空间电压矢量的概念、基本操作以及如何通过脉宽调制来实现这些矢量。第一种实现策略是利用DSP的常规比较功能，通过软件编程来确定开关模式。这种方法灵活性高，但可能需要更多的CPU周期来计算开关时刻。报告提供了具体的代码示例，帮助读者理解如何在TMS320F243/1上实现这一过程。第二种策略是利用TMS320C24x/F24x的专用SVPWM硬件模块。这种硬件加速方案可以显著减少CPU负担，提高系统的实时性。报告详细介绍了如何配置和使用这个硬件模块，同样提供TMS320F243/1的代码示例。为了验证这两种方法的有效性，报告还介绍了一个完整的交流感应电机控制系统的设计。这个系统结合了SVPWM算法，展示了如何通过控制电机电流波形来优化电机性能。实验数据显示了不同实现方式下的电机电流，对比分析了它们在实际应用中的表现。这篇TI应用报告是理解并掌握SVPWM在TI DSP上实现的重要参考资料，不仅提供了理论知识，还有实用的代码示例，对于电机控制领域的工程师和学生来说，具有很高的参考价值。

Application Report

SPRA524

Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined

Switching Patterns 8

PAC ;

Sach cmp_2 ; 0.5C

Tp: D15 (integer)

; Calculate compare value 3 based on 0.5

-0.5

)Tp

LACC #t1_period_ ; Calculate 0.5*C0

SUB cmp_1 ;

SUB cmp_2 ; 0.5*C

Tp = (1-0.5*C1 -0.5*C2)Tp: D15

BGEZ cmp0_big0 ; continue if bigger than zero

ZAC ; zero it if less than zero

cmp0_big0 sfr ; divide by 2

SACH cmp_0 ; 0.25*C

Tp: D15 (integer)

Note that the

scaling notation is equivalent to the more popular

notation. Their

relationship is

(15-

). Therefore, the notation

x means that the decimal point is at

bit[15-

]. Whenever possible, the code examples in this report use maximum scaling to

increase resolution and accuracy. For example, since the range of phase angle,

, is 0 to

(or 0 to 6.283), it is designated as a

3 (or

12) number for maximum resolution.

Therefore the digital representation,

, for

is related to

, i.e., scaled up by

2 to the 12

power.

It is necessary to know which sector the reference output voltage is in to determine the

switching time instants and sequence. For applications where the reference output

voltage vector is given in the form of magnitude and phase angle, such as the program

example attached, sector determination is obvious. For applications where the reference

output voltage is in terms of vector [

]

, such as where the output voltage vector is

derived from an inner current control loop in the

frame, the following algorithm can be

used to determine the sector of the reference voltage vector. First calculate

ref1

ref2

and

ref3

based on equation 9, below.

qdref

ref

UUv

Uqv

30sin60sin

--=

(equation 9)

Secondly, calculate

=sign(

ref1

)+2*sign(

ref2

)+4*sign(

ref3

). Thirdly, refer to Table 2

below to map

to the sector of

out

Table 2. Determination of the Sector of

out

Based on N

123456

Sector

150324

The code examples in this document are based on knowing the phase angle of the

reference voltage

out

. Therefore, the look-up tables are all in term of sector number of

out

. The same look-up tables can easily be rearranged in terms of

instead when the

reference voltage is given in terms of vector [

]

Application Report

SPRA524

Space-Vector PWM With TMS320C24x/F24x Using Hardware and Software Determined

Switching Patterns 9

As mentioned above, the reference voltage vector

out

is actually the desired three-phase

output voltages mapped to the

frame through d-q transformation. When the desired

output voltages are three-phase sinusoidal voltages with 120-degree phase shift,

out

becomes a revolving vector with the same frequency and a magnitude equal to the

corresponding line-to-line rms voltages. The envelope of the hexagonal formed by the

basic space vectors, as shown in Figure 3, is the locus of maximum

out

. Therefore, the

magnitude of

out

must be limited to the shortest radius of this envelope when

out

is a

revolving vector. This gives a maximum magnitude of

for

out

Correspondingly, the maximum rms values of the line-to-line and phase output voltages

are

and

, which is

times higher than that which an original sinusoidal

PWM technique can generate. For the same reason, the bus voltage (

) needed for a

motor rated at

rate

is determined by

dc rate

for SV PWM technique.

SV PWM Waveform Patterns

The arrangement of the order of U

, U

, O

000

and or O

111

in each PWM period is

another problem that must be resolved. Different switching orders result in different

waveform patterns. Two symmetric switching orders, one that can be easily implemented

with TMS320C24x/F24x by software-determined toggling sequences and another

implemented by the SV PWM hardware module on the TMS320C24x/F24x, are

discussed in this section. Table 3 is a brief comparison between the two switching

patterns.

Table 3. Hardware and Software Determined SV PWM Switching Pattern Comparison

Switching

Pattern

CPU Overhead

(Instruction Cycle)

Memory Usage

(Word)

# Switching Dead Band

Imbalance

H/W determined 27 31 4 Yes

S/W determined 33 41 6 No

Software-Determined Switching Pattern

Figure 4 below shows the waveform for each sector of a symmetric switching scheme.

This scheme can easily be implemented with the TMS320C24x/F24x using software

determined switching order for the three PWM channels. Figure 5 is another illustration of

the switching scheme, where the arrows indicate for each sector the order of the first and

second basic space vectors. This switching scheme can be represented by (

000

111

000

), where

can be 0, 120 and 240. It has the following

properties:

Each PWM channel switches twice per every PWM period except when the duty

cycle is 0% or 100%.

There is a fixed switching order among the three PWM channels for each sector.

Every PWM period starts and ends with

000

The amount of

000

inserted is the same as that of

111

in each PWM period.

剩余43页未读，继续阅读

zllx555

粉丝: 1
资源: 1

TI DSP实现SVPWM技术详解与应用

TI给的SVPWM原理及编程实现 DQ

三电平SVpwmC程序

dsp控制的svpwm完整程序

SVPWM.rar_2407 SVPWM_svpwm 2812 代码_svpwm dsp_svpwm实现_svpwm程序

svpwm.zip_SVPWM DSP_SVPWM the DSP_svpwm

SVPWM.zip_SVPWM DSP_SVPWM程序DSP_svpwm的dsp程序_tms320c32_基于dsp的svpwm

SVPWM.zip_DSP SVPWM_SVPWM DSP_svpwm_svpwm 2812 C_svpwm c

eetop.cn_svpwm.rar_DSP SVPWM_SVPWM DSP_dsp_dsp 电机_dsp电机控制

SVPWM.rar_SVPWM波形产生_SVPWM的DSP实现_dsp产生svpwm_svpwm专用芯片

SVPWM.zip_SVPWM DSP_SVPWM using DSP_f28335 SPWM_f28335 svPWM_svp

最新资源