Specific order harmonics compensation algorithm and digital implementation for multi‐level active power filter

Abstract

A specific harmonic compensation control based on the nth specific order d-q transformation in the nth synchronous coordinates is proposed in this study. The distorted load currents are transformed into the nth-dq components in the separate nth harmonic frequency channels. These components corresponding to the specific nth harmonics are individually controlled in closed-loop by the decoupling regulators, which can track the amplitude and phase angle of the specific order harmonic with zero steady-state error. Meanwhile the current references would be transformed to voltage references. Therefore, the voltage references generated by these separate harmonic control channels could be accumulated together to form the final real-time modulation voltage references to drive the voltage-source inverter including two-level and multi-level structures. The control algorithm is analysed and its parameters are designed. The three-level active power filter simulation and a small-scale prototype are established. The simulation and experimental results indicate that the harmonics can be specific eliminated and controlled. The total harmonic distortion of source currents could be reduced from 20 to 0.5% with the specific filtering of 5th, 7th, …, 31st harmonics. 2 Operation principle The specific harmonic elimination control is configured as Fig. 1. It consists of separate control channels including active/reactive

Harmonic Adaptability Remote Testing Method for Offshore Wind Turbines

“…Different harmonic detection strategies can be adopted for harmonic compensation in traditionally used schemes of series APF [25,29]. Single or selective harmonic compensation has been investigated in recent years [26,27]. The series APF can generate an opposite direction compensation harmonic voltage whose magnitude is equal to the deviation from the required harmonic distortion set by the standards.…”

“…According to the frequency to be damped and the selected damping method, the controller parameters are designed to make sure that the proposed method works effectively, that's to eliminate the reference signal tracking error and phase lag because of the concerned wideband frequency in the testing. For harmonics of low amplification, the proposed method can be applied directly with properly selected parameters (the control strategy can be found in Section 4) [25,26]. For the harmonics of high amplification, the SHD method is used to reduce the amplification by synthesizing an adjustable impedance (the control scheme can be found in Section 5) [20][21][22].…”

“…Active power filters (APFs) are regarded as powerful tools to deal with power quality problems [23][24][25]. Research works related to selective or specific order harmonics compensation and damping strategies have been investigated deeply [26][27][28]. Different design techniques and control schemes suitable for wide-band frequency have also been proposed for tackling undesired drawbacks, such as phase lag and tracking accuracy of reference signals [29][30][31][32].…”

Sintonización del controlador en cascada PI-STA para aplicaciones de filtros activos de potencia

“…Donde id * es la referencia de corriente activa y permite la transferencia de potencia activa hacia el bus de cd, lo cual a su vez permite la regulación del voltaje de cd; iq * es la referencia de corriente reactiva que permite compensar potencia reactiva; finalmente, ih * es la componente que permite compensar corrientes armónicas. Las componentes iq * e ih * son obtenidas a través del proceso mostrado en la Figura 2, el cual involucra el uso de la transformada DQ monofásica (Jayathilaka et al, 2018;Shu, Lin, Ziwei, Yin, & Zhou, 2017), denotada en este trabajo como TDQ y que es mostrada en (9). Para la aplicación de TDQ se necesita la corriente demandada por la carga iz y su componente en cuadratura iz90 (señal iz retrasada 90°), estas señales entran a la TDQ, para posteriormente obtener a la salida dos señales denotadas como Idz e Iqz, las cuales representan las componentes de corriente activa y reactiva, respectivamente, que son demandadas por la carga.…”

Adaptive fuzzy hysteresis band current control for reducing switching losses of hybrid active power filter

“…These harmonic and interharmonic current components may cause several effects, such as overloads in transmission lines and transformers, destructive effects on reactive power compensation equipment, malfunctioning of protection relays, and pulsating and braking torque production in rotating electrical machines [1]. Active power filter (APF) solutions have been drawing the attention of various researchers for a couple of decades for the suppression of harmonics [2][3][4][5][6][7]. Hybrid active power filter (HAPF) systems have already been preferred [8][9][10][11][12][13] for the reduction of harmonics because of their known advantages [14] as compared to traditional APF systems, especially when the load is induction melting furnace (IMF) [15,16].…”