Predictive Control of a Back-to-Back NPC Converter-Based Wind Power System

Abstract

Abstract-As wind power technology points to increase power ratings, the implementation based on a permanent-magnet synchronous generator with a full power converter is expanding its market share. Multilevel converters, as for example, neutralpoint clamped converters, are therefore well suited for this application. Predictive current control presents similar dynamic response and reference tracking than other well-established control methods, but working at lower switching frequencies, and providing extensive flexibility to apply either on-line or off-line different control laws to the same plant. In this work, the predictive current control is applied to the both sides of the backto-back neutral-point clamped converter connecting a permanent-magnet synchronous wind power generator to the grid. Dc-link neutral-point balance is achieved by means of the predictive control algorithm, which considers the redundant switching states of the back-to-back neutral-point clamped converter. Reduced number of commutations, current spectrum control, and compliance with the low voltage ride-through requirement are carried out with the predictive control. The obtained experimental results confirm the suitability of the proposed control approach.

Analysis and Control of Low-Voltage Ride-Through Capability Improvement for PMSG Based on an NPC Converter Using an Interval Type-2 Fuzzy Logic System

“…ωe depicts electric angular frequency. vs denotes a terminal voltage generated by PMSG described in (3) [14]- [17] -.…”

“…If e e is x and ė ė is y then V V is w (12) All 25 rules and membership functions for IT-2 FLC are selected. The inference system uses the max method for the Join aggregation and operation and the min-method for the Meet implication and operation [18].…”

“…The second method is static synchronous compensator (STATCOM) that voltage regulation is greatly enhanced in both the steady and transient states [11], but STATCOM has disadvantages, such as high cost and additional hardware. In another way, a predictive control protection system is presented as the most successful LVRT strategy for a PMSG based on WECS [12]. However, the predictive control protection system has difficulty implemented to control topologies of grid-side (GSC) and machine-side converter (MSC) because of nonlinearity and uncertainties of power system.…”

Finite-Set Model Predictive Control for Eight-Switch Three-Phase NPC Converter with DC-Link Voltages Fluctuation Suppression

“…Besides, compared to the traditional diode rectifier, it has following advantages: 1) low-harmonic distortion of grid-side currents; 2) unity power factor operation; 3) controlled DC-link output voltage. Due to these salient merits, numerous investigations are devoted toward the application of three-level NPC in balanced grids [5][6].…”

A Simple Braking Method for Six-Phase Induction Motor Drives With Unidirectional Power Flow in the Base-Speed Region

“…Nevertheless, regenerative braking requires bidirectional power flow, which is typically achieved using active front-end rectifiers and a back-to-back arrangement of voltage source converters (VSCs). Even though this topology is commonly used in high-power applications (traction and wind energy systems [2][3][4][5], to name a few), in many induction motor drives the use of diode front-end rectifiers is preferred due to the lower cost and improved reliability [6]. In such a case, the braking power cannot be delivered to the grid and needs to be absorbed somewhere.…”