The study of the harmonic impedance measurement

Harmonic impedance of system is the important parameter for the harmonic suppression and it is also useful to the design of filter, circuit analysis, et al. Generally, a controllable harmonic perturbation is used and injected into the target circuit port, and then harmonic impedance can be captured by the corresponding harmonic voltage and current. In this paper, a circuit design of harmonic impedance measurement is proposed, in which each functional modules is comprised of analogue circuit, and it can generate a controllable current disturbance into the target system. The system impedance is calculated by using the current and the corresponding voltage, which are captured by the data acquisition circuits. By using the PSCAD, a simulation of measurement circuit is established. In simulation, the measuring results are coincident with the theoretical value, which validate the effectiveness of the circuit design.