A Fixed-Frequency Sliding-Mode Controller for Fourth-Order Class-D Amplifier

Abstract

Since the parasitic voltage ringing and switching power losses limit the operation of active devices at elevated frequencies; therefore, a higher‐order inductor‐capacitor (LC) filter is commonly used, which offers extended attenuation above the cutoff frequency and thus, improves the total harmonic distortion (THD) of the amplifier. This paper applies the concept of integral sliding‐mode control to a fourth‐order class‐D amplifier. Two fixed‐frequency double integral sliding‐mode (FFDISM) controllers are proposed, where one uses the inductor current while the other involves the capacitor current feedback. Their equivalent control equations are derived, but from the realization viewpoint, the controller using the capacitor current feedback is advantageous and, therefore, is selected for final implementation. The performance of the proposed FFDISM controller for fourth‐order GaN class‐D amplifier is confirmed using simulation and experimental results.

Applications of Power Electronics

“…In [18], a synchronous reference frame control design methodology is provided for shunt power filters, while the sliding mode control and one-cycle controller design and stability performance of a class-D amplifier and boost power factor correction are discussed in [19,20], respectively.…”

Carrier-Based Double Integral Sliding-Mode Controller of Class-D Amplifier

“…The design steps using the concept of equivalent control are listed as follows [18], [19]: 1) Derive the switch-model of the half-bridge class-D amplifier by analyzing all the switching states. This step results in a state-space model, with the output voltage and inductor current as state variables.…”

“…An attempt to reduce the THD will be vestigial if the magnitude of the noise is not reduced using a lowpass filter. Therefore, although not shown in the figure, The opamp Cmp3 serves as a proportional integral (PI-type) controller, where capacitor C F together with resistors R F , R G , and R H determine the controller gains as given in equation (19). Since the summation amplifier cancels the bias, V b is applied to the non-inverting input of the opamp to maintain the mid-point biasing for further operations.…”

Applications of Power Electronics

“…This special issue with 49 published articles has gained a great deal of attention from both academia and industry, clearly showing the growth in significance of "Applications of Power Electronics" in the current research and development arena. The accepted articles cover broad topics in the field of power electronics, and they are categorized into seven different focus areas: T1: Fault Diagnosis, Reliability and Condition Monitoring [14][15][16][17]; T2: Modeling, Control and Design of Power Electronic Converters [18][19][20][21][22][23][24][25]; T3: Electrical Machines, Drives and Traction Systems [26][27][28][29][30][31][32][33][34]; T4: Distributed Power Generation and e-Grid [35][36][37][38][39][40][41][42][43][44][45][46]; T5: Emerging Power Electronic Technologies (Pulsed Power, Energy Storage, Others) [47][48][49][50][51]; T6: Energy Access and Micro-Grids [52][53][54][55][56]; T7: Wireless Power Transfer Systems…”