DSP中数据标幺化处理问题？

你好。
电压和电流的基值可以独立设定，在做算法的时候统一使用标幺值就可以了。需要注意的是，传感器的测量范围以及标幺值对于实际值的限制。
比较容易的标幺值基值选取方法可以选择为ADC采样得到最大值对应的实际值。电流基值请考虑正负对应关系。

您好，您的建议我看了，谢谢，但是您说的做算法的时候统一使用标幺值是什么意思啊？统一使用标幺值的准则是什么呢？怎么做呢 ？谢谢？现在我要测量输出电压与指令电压比较进入PI调节器后生成两相电流的有功电流指令，然后与输入检测电流通过clark，park变换得到的输入有功电流比较进入PI调节器再生成SVPWM指令电压信号去控制。

Jay ，您好！
我看了TMS320C2000 Motor Control Primer中PU System Modle and Base Values （http://processors.wiki.ti.com/index.php/TMS320C2000_Motor_Control_Primer）中标幺化和基值的选取原则，对于其中描述的电流标幺化及基准值，角频率标幺化及基准值及磁链标幺化及基准值的选取没疑问，但是对于电压 文中是选取三相逆变器控制电机为对象，母线电压400V，那么Vbase为(400/1.732),请问这个原则是什么？如果此时的电流为电机电流的相电压峰值或者传感器最大允许测量值范围，那么此时电压的基准值是不是也要选取电机侧的电压的峰值为基准值，但事实上直流母线上的电压相比较电机侧的交流电压更高，这个时候当系统中电压电流出现的最大值不是同为输出侧或者输出侧的时候请问怎么去选取基准值？麻烦您了？

In electrical engineering, a per-unit system is the expression of system quantities as fractions of a defined base unit quantity. Calculations are simplified because quantities expressed as per-unit (between -1 and +1) are the same regardless of the voltage, current etc level. Advantages of using the pu system for motor control applications include:

• Once the base values are initialized in the code, the code will handle the rest and the parameter dependency will be minimized.
  
• Migrating to a new custom design system will be as easy as modifying the base values.
  
• For fixed point devices, pu system allows the user to reduce the amplitude of the variables in order to get a fractional part with a maximum precision.
  

Conversion of per-unit quantities to volts, ohms, or amperes requires knowledge of the base that the per-unit quantities were referenced to. In the TI DMC systems, the base values are selected as the maximum measurable quantity of the peak of phase voltage, current etc. by the ADC. This is directly related to the current and voltage sensing circuits and the voltage dividers used to down-scale the actual voltage or current quantities to ADC input voltage range, which is typically 3 to 3.3V. Later, the measured voltage by ADCs will be converted to put quantity in the code. The calculation of the pu values can be formulated as:



The selection of the base quantities is relative and can be any appropriate value as long as it is consistent within the whole system. For instance, assuming that the peak of the maximum measurable phase current is 20A on a DMC kit, the base current value can be selected as 20 where ±1pu represents ±20A in the code.



Similarly, the base voltage can be selected as the peak of maximum measurable phase voltage in the system. Assuming that the dc bus voltage is 400V, base voltage is selected as 400V/√3.

你好。
Vbase为(400/1.732)是因为采用SVPWM时，三相逆变器可以输出的最大相电压为VDC/sqrt(3)。
根据你对系统的描述，电压的基值与电流基值并没有直接地联系。电压基值的选择影响到的是系统能够输出的最大电压值，即当电压指令给定为1的时候的电压大小。而电流的基值选择，则决定了能够输出最大的有功电流大小。基值选择不当，只会在极限边缘状态时对系统产生影响。例如，给定电压指令很大时，由于电流基值的限制，在电流达到极限输出时，电压反馈仍未能达到给定要求，那么就需要考虑改变电流的基值。
总之，电压基值可以选择你需要输出的最大电压值作为基值，电流则可以选择与之匹配的一个值，同时考虑限流保护等因素。