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请教功率换算的问题。请看看是否对,难道不能计算只能实测后设定吗?

qiuyu 在 2013-8-12 詢問的問題
最後回覆由wangmingdong@phoibos.cn於2015-10-9提供

图中电流互感器2000:1

 

电压互感器1:1

 

 

            ADE7878功率转换计算不对,请看下面的计算对否?

电压计算

#define VOL_MAX                    0X3FF6A6         //0.5V峰值输入对应的满量程正玄波信号的有效值

#define VOL_FULL_SCALE          353.6                          //0.5V输入峰峰值对应0.3536有效值,电压变比为1000:1故当输入                                                                                                                                          // 故电压有效值为353.6V时满量程

电压 Voltage =AVRMS * VOL_FULL_SCALE / VOL_MAX;

 

电流计算:

 

#define CUR_MAX                                     0X3FF6A6

#define CUR_RATIOFULL_SCALE          14.14    //0.5V输入峰峰值对应0.353553390V有效值,

                                                                                                            //对应I=0.3535534V/50R=0.0070710678A=7.0710678mA

                                                                                                            //1:2000电流互感器对应14.1421356A

Current =  AIRMS * CUR_RATIOFULL_SCALE / CUR_MAX; 

 

功率计算

#define POWER_MAX                         0X1FF6A6B

#define POWER_FULL_SCALE          5000   // 353.6*14.14 =5000

 

功率转换: Watt = AWATT * POWER_FULL_SCALE / POWER_MAX;

 

按照以上公式计算的电压电流都没问题,但是功率计算总是不对。。。

 

結果