一种变频器的输出电流直流零偏的检测方法及系统技术方案

一种变频器的输出电流直流偏零的检测方法及系统，在变频器的负载电机处于空载稳速状态时，以变频器的电流采样电路的零点漂移为起点，根据预设的初始步长逐渐改变闭环调节电流，并提取负载电机的转速信号中与变频器的输出频率一致的谐波分量幅值，确定用于搜索直流零偏的搜索步长(S101)；在负载电机处于空载稳速状态时，以零点漂移为起点，根据搜索步长逐步改变闭环调节电流，并检测负载电机的转速信号中与变频器的输出频率一致的最小谐波分量幅值，确定直流零偏(S102)。该方法和系统考虑了电流传感器和采样电路的频率特性，也考虑了由于逆变桥的非线性特性和PWM调制所引入的谐波中的直流分量，检测得到的直流零偏比较准确。

A method and system for detecting the DC zero bias of the output current of a frequency converter

Method and system for detecting partial zero current output of an inverter in inverter, the electrical load in the no-load steady state, zero drift to the inverter current sampling circuit as the starting point, to gradually change the current closed-loop regulation according to the initial step of presupposition, and extract the harmonic amplitude of the output frequency signal of the motor and load speed inverter consistent, DC bias is determined for the search step search (S101); in the electrical load in the no-load steady state, with zero drift as a starting point, according to the search step change current loop regulation, and detect the output frequency of the speed signal of the load motor and inverter in the minimum harmonic amplitude of the same, sure DC bias (S102). The method and system consider the frequency characteristics of current sensor and sampling circuit, and also consider the nonlinearity of inverter bridge and the DC component of harmonic introduced by PWM modulation. The detected DC bias is more accurate.

【技术实现步骤摘要】
【国外来华专利技术】PCT国内申请，说明书已公开。

【技术保护点】
PCT国内申请，权利要求书已公开。

【技术特征摘要】
【国外来华专利技术】PCT国内申请，...

【专利技术属性】
技术研发人员：刘军锋，徐铁柱，王玉雷，
申请(专利权)人：深圳市英威腾电气股份有限公司，
类型：发明
国别省市：广东,44