Resonant (P+RES) controller applied to voltage source inverter with minimum DC link capacitor

Abstract

Voltage source inverters use large electrolytic capacitors in order to decouple the energy between the utility and the load, keeping the DC link voltage constant. Decreasing the capacitance reduces the distortion in the inverter input current but this also affects the load with low-order harmonics and generate disturbances at the input voltage. This paper applies the P+RES controller to solve the challenge of regulating the output current by means of controlling the magnitude of the current space vector, keeping it constant thus rejecting harmonic disturbances that would otherwise propagate to the load. This work presents a discussion of the switching and control strategy.

Design, analysis and performance of a bidirectional solar inverter with a global and independent maximum power extraction technique

“…As an alternative in light of these negative aspects, the use of the P+Res controller eliminates the steady‐state error for sinusoidal references due to a high gain obtained from the resonant pole inserted at the reference frequency. In addition, good single‐phase results were obtained by the authors of [5, 23, 25, 26] using P+Res type 2 given by (10). This non‐ideal controller has an adjustable bandwidth parameter ( w c ) since the grid frequency varies across a narrow range of values.…”

Robust nested loop control scheme for LCL‐filtered inverter‐based DG unit in grid‐connected and islanded modes

“…The main requirement of the outer loop controller is the continuous reference generation for the inner current control loop. In literature, some of the authors use the PI controller, resonance controller [21,22]; however, the robustness is not explained for the uncertainty. The outer loop controls the active and reactive power separately in dq frame.…”