DC Offset Compensation Algorithm in the Grid Voltage of Single-phase Grid-connected Inverter

2019 ◽  
Author(s):  
Tae-Seong Kim ◽  
Seon-Hwan Hwang ◽  
Jin-soo Kim ◽  
Jong-Won Park
Keyword(s):  
Single Phase ◽  
Grid Voltage ◽  
Dc Offset ◽  
Compensation Algorithm ◽  
Offset Compensation ◽  
Grid Connected Inverter

scholarly journals DC Offset Error Compensation Algorithm for PR Current Control of a Single-Phase Grid-Tied Inverter

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2308 ◽  
Author(s):  
Jae Lee ◽  
Seon-Hwan Hwang
Keyword(s):  
Fundamental Frequency ◽  
Error Compensation ◽  
Single Phase ◽  
Detection Method ◽  
Current Control ◽  
Dc Offset ◽  
Phase Current ◽  
Compensation Algorithm ◽  
Dc Component ◽  
Offset Error

In a single-phase grid-tied inverter, the direct current (DC) offset error included in the measured grid side phase current has various causes, such as a non-ideal current sensor, unbalanced power supply of an operational amplifier, and nonlinear features of analog components in interface circuits, etc. If the DC offset error is included in the measured current, it causes the secondary harmonic of fundamental frequency and the DC component in grid phase current which result in degradation of inverter performance. In this paper, a theoretical detection method of the secondary harmonic of the fundamental frequency and a DC component in grid phase current for a proportional-resonant (PR) current control system is introduced. Based on the detection method, an algorithm for compensating DC offset error is also presented for single-phase grid-tied inverters. Simulation results and experimental verification of the DC offset error compensation algorithm are shown in this paper.

scholarly journals An Adaptive Frequency Phase-Locked Loop Based on a Third Order Generalized Integrator

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 309 ◽  
Author(s):  
Heng Du ◽  
Qiuye Sun ◽  
Qifu Cheng ◽  
Dazhong Ma ◽  
Xu Wang
Keyword(s):  
Single Phase ◽  
Power Grid ◽  
Phase Locked Loop ◽  
Frequency Change ◽  
Third Order ◽  
Vector Method ◽  
Grid Voltage ◽  
Dc Offset ◽  
Voltage Frequency ◽  
Frequency Changes

In this paper, the basic principle and characteristics of a phase-locked loop (PLL) in a single phase grid-connected system are analyzed, and this paper introduces one type virtual orthogonal voltage vector method based on a third order generalized integrator (TOGI) to construct an alpha and beta static coordinate system. The TOGI structure can eliminate the DC offset in a voltage signal or zero offset in the sampling process, and ensure the amplitude of the virtual orthogonal signal is consistent. At the same time, the adaptive frequency estimation unit is introduced, which can effectively deal with the power grid voltage frequency changes and ensure the accuracy of PLL. MATLAB (R2012a, MathWorks, Natick, MA, USA) is used to simulate the variation of power grid voltage frequency, DC component injection, harmonics injection and other parameters, and the performance of PLL is adequately verified. In addition, a 5kW single-phase energy router experimental platform is built to verify the proposed PLL. The experimental results show that the PLL can well track the frequency change of the grid voltage and eliminate the DC offset, so as to achieve accurate phase tracking.

scholarly journals DC offset rejection in a frequency-fixed second-order generalized integrator-based phase-locked loop for single-phase grid-connected applications

2022 ◽  
Vol 7 (1) ◽  
Author(s):  
Issam A. Smadi ◽  
Bayan H. Bany Fawaz
Keyword(s):  
Single Phase ◽  
Dynamic Performance ◽  
Phase Error ◽  
Phase Locked Loop ◽  
Second Order ◽  
Frequency Variation ◽  
Grid Voltage ◽  
Dc Offset ◽  
Grid Synchronization ◽  
Grid Connected Converters

AbstractFast and accurate monitoring of the phase, amplitude, and frequency of the grid voltage is essential for single-phase grid-connected converters. The presence of DC offset in the grid voltage is detrimental to not only grid synchronization but also the closed-loop stability of the grid-connected converters. In this paper, a new synchronization method to mitigate the effect of DC offset is presented using arbitrarily delayed signal cancelation (ADSC) in a second-order generalized integrator (SOGI) phase-locked loop (PLL). A frequency-fixed SOGI-based PLL (FFSOGI-PLL) is adopted to ensure better stability and to reduce the complexity compared with other SOGI-based PLLs. A small-signal model of the proposed PLL is derived for the systematic design of proportional-integral (PI) controller gains. The effects of frequency variation and ADSC on the proposed PLL are considered, and correction methods are adopted to accurately estimate grid information. The simulation results are presented, along with comparisons to other single-phase PLLs in terms of settling time, peak frequency, and phase error to validate the proposed PLL. The dynamic performance of the proposed PLL is also experimentally validated. Overall, the proposed PLL has the fastest transient response and better dynamic performance than the other PLLs for almost all performance indices, offering an improved solution for precise grid synchronization in single-phase applications.

scholarly journals Compensation of offset for SRF-PLL in grid-connected inverters

2015 ◽  
Vol 18 (3) ◽  
pp. 5-15
Author(s):  
Tho Quang Tran ◽  
Anh Viet Truong ◽  
Hoan Van Trao ◽  
Phuong Minh Le
Keyword(s):  
Data Conversion ◽  
Accurate Estimation ◽  
Grid Voltage ◽  
Dc Offset ◽  
Estimated Parameters ◽  
Synchronous Reference Frame ◽  
Simulation Results ◽  
Offset Compensation ◽  
Frequency Phase

The grid-connected inverters that use synchronous reference frame based phaselocked loop SRF-PLL are applied very popular. The function of SRF-PLLs is fast and accurate estimation of frequency, phase angle, and magnitude of grid voltage. The power quality of the current injected into the grid depends on these estimated parameters. The measurements or processes of data conversion can typically introduce the dc offset in the measured grid voltage. The dc offset is one of the reasons for causing errors for the estimated parameters of the grid voltage and causes injected current with harmonic distortions. This paper proposes a technique of dc offset compensation for SRF-PLL based on the Second Order Generalized Integrator (SOGI). The simulation results validated the performance and robustness of the proposed technique.

Sign in / Sign up

Export Citation Format

Share Document