Fault Tolerant Control of DC-Link Voltage Sensor for Three-Phase AC/DC/AC PWM Converters

Abstract

In this paper, a fault detection scheme for DC-link voltage sensor and its fault tolerant control strategy for three-phase AC/DC/AC PWM converters are proposed, where the Luenberger observer is applied to estimate the DC-link voltage. The Luenberger observer is based on a converter model, which is derived from the voltage equations of a grid-side converter and the power balance on a DC link. A fault of the voltage sensor is detected by comparing the measured value of the DC-link voltage with the estimated one. When a sensor fault is detected, a fault tolerant control strategy is performed, where the estimated DC-link voltage is used for the feedback control. The estimation error from the observer is about 1.5 V, which is sufficiently accurate for feedback control. In addition, it is shown that the observer performance is robust to parameter variations of the converter. The validity of the proposed method has been verified by simulation and experimental results.

Sensor Fault Detection, Localization, and System Reconfiguration with a Sliding Mode Observer and Adaptive Threshold of PMSM

“…In fact, a variation of the DC-link voltage causes the output of the control loop to change and the PWM signals to vary to maintain the desired speed or torque. This phenomenon can affect the perfect management of the electrical power and its transfers of the rectifier-inverter and machine [3], [10]- [13], [19]. Software redundancy (virtual sensor) should be set up in our system to monitor the DC-link voltage sensor to avoid the undesirable consequences of the DC-link voltage faults on performance or possibly on the safety of the operating electrical system.…”

“…The specified requirements, such as protection, safety, and continuity of service, mainly protect users and electrical systems from electrical drive system faults [1]- [3].…”

“…Different fault-tolerant operation methods that involve reconfiguring topologies and control strategies are adopted to improve the reliability of electrical systems [3], [6], [8]- [14].…”

“…The reliability of power conversion systems was analyzed and investigated in [3], [4], [8], [9], [20], and [21]. Approximately 38% of the faults in the voltage-source power conversion systems were due to the failures of power devices, such as the insulated-gate bipolar transistor (IGBT) (short-circuit and open-switch faults) [8].…”

A Modified LADRC-Based DC-Link Voltage Controller for Photovoltaic Grid-Connected Inverters

“…Recently, control strategies, using observers, have also been implemented in dc-link voltage regulation [16][17][18]. Considering the fault condition of the dc-link voltage sensor, a control method based on Luenberger observer was employed in [16], which can improve system stability through fault-tolerant control.…”