No abstract

No abstract

This paper presents a neutral point voltage control strategy for the three-level active neutral point clamped (ANPC) converter using selective harmonic elimination pulsewidth modulation (SHE-PWM). The control strategy introduces a small change in the switching angles, which varies the duty cycle of the zero-level switching state, controls the neutral point current and, therefore, the neutral point voltage. The decision to vary a given switching angle takes into account the polarity of the output currents and the voltage across the lower dc-link capacitor. The effectiveness of the proposed strategy is verified through extensive simulation studies and experimentally validated using a low power laboratory prototype. Index Terms-Active neutral point clamped converter (ANPC), neutral point voltage control, pulse-width modulation (PWM), selective harmonic elimination (SHE).

In this paper, a complete simulation model of a grid-connected single-phase two-stage photovoltaic (PV) system with associated controllers is presented. The simulation model is developed in PSCAD/EMTDC simulation program. The component models of the grid-connected PV system include a PV array, a dc-dc boost converter, a voltage source converter (VSC) and an LCL filter. Components of the LCL filter, the dclink capacitor of the VSC and the inductor of the dc-dc boost converter are established theoretically and that are used in modelling the grid-connected PV system. The control architecture of the presented system incorporates a synchronous reference frame phase-locked-loop (s-PLL), a stationary frame current controller, a dc-link voltage controller, a dc-dc boost converter controller and a maximum power point tracking (MPPT) algorithm. Control design methodologies are described in detail. Simulation studies confirm that the modelling and control design approaches taken are robust and lead to a system with acceptable performance. Abstract-In this paper, a complete simulation model of a gridconnected single-phase two-stage photovoltaic (PV) system with associated controllers is presented. The simulation model is developed in PSCAD/EMTDC simulation program. The component models of the grid-connected PV system include a PV array, a dc-dc boost converter, a voltage source converter (VSC) and an LCL filter. Components of the LCL filter, the dc-link capacitor of the VSC and the inductor of the dc-dc boost converter are established theoretically and that are used in modelling the grid-connected PV system. The control architecture of the presented system incorporates a synchronous reference frame phase-locked-loop (s-PLL), a stationary frame current controller, a dc-link voltage controller, a dc-dc boost converter controller and a maximum power point tracking (MPPT) algorithm. Control design methodologies are described in detail. Simulation studies confirm that the modelling and control design approaches taken are robust and lead to a system with acceptable performance.

No abstract