Current Control using Pulsed Current Sampling Considering Sampling Points and Sensor Positions for Single-Phase Inverter

摘要

Conventional power converter circuits include two types of current sensors, one for current control and the other for overcurrent protection. Recently, research has been conducted on current sensors intended to be integrated inside power modules. These sensors are supposed to protect a power device from overcurrent. In addition, power converter circuits must implement current sensors for ac-side current control. Normally, these current sensors are used independently; thus, two types of sensors are required. However, if the sensors for protection could also undertake current control, then the sensor for current control can be eliminated. The current waveform of power devices is in the form of pulsed waveforms. Thus, a sampling technique considering sensor position and synchronous sampling is necessary. This paper proposes a control procedure for output current using current sensors integrated inside the power modules. It is clear that the relationship between the sensor position and the sampling point for unipolar-modulated single-phase inverters. The validity of the proposed method is proved through an experiment with common current sensors installed in series with the power device. In addition, it should be considered that a practical current has the frequency characteristics, so the simulation including sensor characteristics was performed. Finally, the validity of a current control method is experimentally confirmed.