Fixed- and variable-frequency sliding mode controller–maximum power point tracking converter for two-stage grid-integrated photovoltaic system employing nonlinear loads with power quality improvement features

Abstract

This article presents a reliable and efficient photovoltaic sliding mode voltage-controlled maximum power point tracking DC-DC converter-active power filter integration system to supply real power to grid. This integrated active power filter system performs power quality enhancement features to compensate current harmonics to make distortion-free grid supply current and reactive power employing nonlinear loads. The proposed proportional-integral-derivative-based sliding mode controller is designed with fixed-frequency pulse-width modulation based on equivalent control approach. The main objective of this paper is to design a photovoltaic system with a new sliding surface to force the photovoltaic voltage to follow the reference maximum power point voltage with the alleviation of slow transient response and disadvantages of chattering effects of variable-frequency hysteresis modulation sliding mode controller-maximum power point tracking. The perturbations caused by the uncertainties in climatic conditions and converter output bulk oscillations during grid integration are also mitigated. The features of the proposed photovoltaic-active power filter integration system are confirmed at different operating conditions through PSIM simulation software, and its performance is also compared with a conventional variable-frequency sliding mode-controlled maximum power point tracking. The obtained simulation and experimental results give good dynamic response under various operating conditions of environmental and local load conditions.

Distributed Generation: A Review on Current Energy Status, Grid-Interconnected PQ Issues, and Implementation Constraints of DG in Malaysia

“…Previously, SMC would require different switching frequencies in its mode of operation, which leads to more harmonics problems. In regards to the grid-interconnection RES, SMC are also prone to a high chattering magnitude due to the effects of renewable intermittency [146,147]. Therefore, there are notable works on improving the drawback of the SMC control technique by fixing a constant switching frequency through deployment of a dual loop control structure along with the conventional PI controller [147].…”

“…The proposed SMC could attend all types of voltage sag issues but suffers from minor chattering and oscillation, which causes high power switching losses during the compensation. The SMC control technique is present in applications of the FACTS device for synchronous generation [145], speed control of a DC motor [146,147], and DC-DC converter [148].…”

Robust sliding mode controller for buck DC converter in off-grid applications

“…Themajor advantage is the guaranteed stability and the robustness against model uncertainties and external disturbances [11], [12]. Many non-linear techniques have been presented, for example, feedback linearization [13], [14], backstepping methods [15], [16], proportional-integral-derivative-based sliding mode controller [17], nonlinear H-infinity fuzzy control [18], and sliding mode controllers [19]- [21], fuzzy logic sliding mode controllers [10], [12], [22], [23]. In off-grid photovoltaic application, as shown in [1] and for energy storage system, as in [9] sliding mode control is used for DC-DC converter.…”

FFT-based selective harmonic current control of AC filter capacitors for audible noise analysis

“…Besides the above linear controllers, some nonlinear controllers have been applied to harmonic control, such as Model predictive control (MPC), Repetitive control (RC) and Sliding Mode control (SMC), etc. 15,[18][19][20] Since the amplitude spectrum extracted by FFT algorithm is DC component, the discrete PI regulator can also be used to track the reference amplitude with zero steady-state error. On the other hand, the system inherent delay would result in the phase deviation, caused by the digital sample delay and system impedance.…”

“…Besides the above linear controllers, some nonlinear controllers have been applied to harmonic control, such as Model predictive control (MPC), Repetitive control (RC) and Sliding Mode control (SMC), etc. 15,18–20…”