Reduction of DC-bus voltage ripples and capacitors for single-phase PWM-controlled rectifiers

Abstract

The problem of voltage/current ripples is a primary concern for DC systems, e.g. those with fuel cells and batteries.It could seriously deteriorate the system performance on both the source side and the load side. In this paper, a single-phase PWM-controlled rectifier is taken as an example to analyse the ripple energy that causes the voltage ripples on the DC bus. Moreover, a ripple-current compensator is proposed to absorb/inject ripple energy from/to the DC bus so that the voltage ripples are reduced actively. The compensator is a boostlbuck converter with an auxiliary capacitor having a voltage higher than the DC-bus voltage. A repetitive controller is then proposed to compensate the ripple energy on the DC bus instantaneously, with a fixed switching frequency. Simulation results are presented to demonstrate that the proposed strategy is able to reduce the voltage ripples on the DC bus considerably. As a result, the DC bus capacitor can be reduced significantly in order to achieve the same level of voltage ripples.

Control of Ripple Eliminators to Improve the Power Quality of DC Systems and Reduce the Usage of Electrolytic Capacitors

“…The voltage of the auxiliary capacitor is higher than the DC-bus voltage, which helps improve the efficiency performance [26], the current tracking performance and reduce the required capacitance to achieve the same performance. Compared to the conference version [1] of this paper, the new contributions of this paper include 1) analysing and revealing how active control strategies can help reduce voltage ripples and reduce total capacitance, which paves a way to design high performance controllers for different types of ripple eliminators; 2) quantifying the level of capacitance reduction, which is independent from applications and topologies; 3) optimizing the controller for ripple eliminators in which only one instead of two repetitive controllers are now required without affecting the system performance; 4) experimentally verifying the performance of the active control strategies.…”

“…The boost topology in [25], where a flicker-free AC-DC LED driver with a flyback PFC converter was designed and the strategy, is taken as an example, because of its high efficiency compared to buck-type topologies [26], to demonstrate the performance improvement by designing a suitable controller. This topology was also investigated in the conference version [1] of this paper and also in [27] and [28]. It is a bidirectional boost converter that is able to divert the ripple current instantaneously.…”

Model Predictive Direct Power Control for Active Power Decoupled Single-Phase Quasi-<italic>Z</italic> -Source Inverter

“…This method demonstrated excellent ability to eliminate the 2ω power from the dc side of inverter with small capacitances in the dc link and the APF. Proportionalintegral (PI) [13], proportional-resonant (PR) [14], [15], and repetitive control (RC) [16] were devoted to those APF devices for ensuring quality performance.…”

Design principle of flexible protected controller for modular multilevel converter under unbalanced grid conditions

“…The DC link voltage ripple is also very important, especially to the back-to-back or multiterminal HVDC systems. Moreover, the oscillation of the instantaneous active power may deteriorate the system efficiency and the power factor [9,10].…”