恒压频比控制（V/F）是变频器中应用最广泛的一种控制方式，采用这种控制方式研制的变频器系统结构简单，成本低廉，适用于风机、水泵等对调速系统动态性能要求不高的场合。目前这种变频器的经济性和通用性深受市场的青睐。鉴于此，本文利用TMS320LF2407 DSP作为控制芯片，采用恒压频比的控制方式和空间矢量调制策略研制了一台变频器的样机，并对一些关键的问题给予理论分析并提出实现的方法。本文主要内容如下： 1．阐述了电压正弦脉宽调制（SPWM）技术和空间矢量脉宽调制（SVPWM）技术，对二者的特点进行比较，并将空间矢量脉宽调制技术用于实际变频器系统中。 2．详细分析死区产生的机理和空间矢量PWM中死区效应对输出电压的影响，并结合空间矢量图，讨论了输出电压矢量位置与三相电流方向的关系。在此基础上，提出了一种新型的死区补偿策略，将三相电流分成六个区域，并在每个区域只对其中一相输出电压进行补偿。该方法通过判断输出电压矢量的角度来获取三相电流的方向，避免了电流检测中多个零点的现象。 3．以二极管构成三相桥式不可控全波整流电路，并以 IPM作为功率器件构成逆变电路组成的交-直-交电压源型变频系统主电路；同时以TMS320LF2407为中央处理器，设计控制电路，它包括主控模块、电流电压采样模块、转子位置采集模块、显示模块和键盘输入模块；并在CCS环境下，利用C语言和汇编语言混合编写程序。 4．研制出一台样机，并对所研制的样机进行试验。实验结果证明，系统中电机电流的谐波失真较小，直流母线电压利用率比常规的正弦波脉宽调制（SPWM）有了较大的提高，功率器件的开关损耗较小。本系统具有控制简单、外围电路较少、性能价格比高等优点，适合于风机、水泵用变频器的性能要求。

The constant ratio of voltage to frequency control, which also called constant V/F control, is one of the most popular controls in inverter application. With its’ simple structure and low cost, constant V/F control is applied to some low dynamic performance applications such as fan, water pump and so forth. At present, there is a big market for this inverter due to its economy and popularity. In this paper, a specimen of the inverter system adopted a TMS320LF2407 DSP chip as its controller by using constant V/F control and space vector PWM technique is designed. Some key problems are analyzed in theory and methods of them are put forward. The main content in this paper is as following. 1．After elaborating SPWM and SVPWM technology, their characteristics are compared in order to find which suits the practical application. Finally, SVPWM technology will be adopted. 2．The paper expatiates on the reason of dead-time in theory, analyzes the influence of dead-time in SVPWM on output voltage and discusses the relation between the output voltage vector position and the three-phase current direction by using space vector graph. A new method, which divides the three-phase current into six regions and compensates only one phase output voltage in every region, to compensate the dead-time is put forward. Judging the angle of output voltage vector to acquire the direction of three-phase current, this method can avoid an appearance of many zeros when current is detected. 3．Three-phase bridge incontrollable full-wave rectifier circuit and the inverter circuit constitute the main circuit of AC-DC-AC voltage source inverter system. In this system, the rectifier part is composed of diodes and the inverter part is made up of IPM. The control part, which takes a TMS320LF2407 chip as the central processor, includes central controlling module, current and voltage sampling module, rotor location collecting module, display module and keyboard module. Each subroutine is written with C language and assembly language in CCS environment. 4．Finally a specimen of the inverter system is designed. After having a performance examination, the result proves that the harmonic distortion of motor current is small, the usage factor of direct-current voltage is higher than the conventional SPWM technology and the power switch losts slightly. This system has the advantages of simple control, little peripheral, high performance and low price, which will meet the demands of the inverter using in fan and water pump.