Comparative study of single-phase phase-locked loops for grid-connected inverters under non-ideal grid conditions

Xu, Jinming; Qian, Hao; Bian, Shengyiyang; Hu, Yuan; Xie, Shaojun

doi:10.17775/cseejpes.2019.02390

Cited by 30 publications

(8 citation statements)

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“…For the second-stage passive filter, the relationship between uo2 and us2 can be expressed as (12) Then the deviation angular γ2 and the cutoff frequency ωc2 can be derived as (13) The impact of increasing r6 or C2 is similar to that of increasing r3 or C1. Ideally, the relationship between the input low-frequency current is1 and the output voltage uo2 can be expressed as (14) where the equivalent sampling resistance re can be calculated out as (15) When the measured current is zero, the digital zero drift detected by AD converter fluctuates within a specific range. If the resolution of AD converter is 12 bits and the maximum value of the input analog voltage is 3.3V, the current detection error Ie caused by digital zero drift can be calculated out as (16) where τ is the range width of the digital zero drift, and J is the ratio of current transformer.…”

Section: Current Detection Strategymentioning

confidence: 99%

“…The fluctuation or distortion of AC voltage can cause zero crossing offset. And owing to the noise in the digital signal of voltage measurement, the multiple zeros appear in the judgment results [13][14][15] . For the single-phase power grid system, the voltage phase detection can be achieved using the phase locked loop (PLL) method based on a stationary coordinate system or a synchronous coordinate system.…”

Section: Introductionmentioning

confidence: 99%

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Non-Destructive Calibration Scheme for Online Monitoring Device of Metal Oxide Arrester

Wang,

Dong,

Ding

et al. 2024

IEEE Access

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The reliability of online monitoring device for metal oxide arrester (MOA) is the prerequisite for ensuring the MOA normal operation. For online monitoring device, this paper proposes the nondestructive calibration scheme which can improve maintenance efficiency. The on-site calibration device consists of current source, ammeter, micro-current detector and control unit. There are two key technologies involved in the on-site calibration device, the one is the phase locked loop (PLL) for current source, the other is the high precision current detection for ammeter and micro-current detector. The proposed PLL of the reference voltage can generate low delay orthogonal signals and eliminate the second harmonic disturbances caused by the crystal oscillator error of microcontroller unit (MCU). The experimental results show the effectiveness of the proposed calibration scheme.

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Section: Current Detection Strategymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Non-Destructive Calibration Scheme for Online Monitoring Device of Metal Oxide Arrester

Wang,

Dong,

Ding

et al. 2024

IEEE Access

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“…The conventional PLL is composed of a voltage controlled oscillator (VCO), a loop filter (LF), and a phase detector (PD) (Xu, Qian, Bian, Hu, and Xie, 2020). Normally, the PD is of the multiplier type, whose output consists of a DC term that has the phase information of the input signal and an AC term that should be filtered by the LF (Awad, Svensson, and Bollen, 2005).…”

Section: Phase-locked Loopmentioning

confidence: 99%

PLL wrap function for synchronization in phase jump disturbances

2021

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Synchrony plays a major role in the interconnection process between local electric power generation systems and the electrical grid. Grid phase disturbances prevent the generation system from maintaining synchrony. Therefore, an efficient phase tracking method is necessary in order to detect phase jumps and abrupt changes in amplitude. In this paper, we propose a software-designed method to strengthen phase tracking based on the wrap process of a second-level Phase Locked Loop (PLL). The term ‘wrap’ means establishing the phase values of the reference signal in intervals of π to match it with the values obtained from the PLL output (sync pulse). To quantify phase error, a mathematical transformation of the time domain to the frequency domain is implemented. The validity of the proposed wrap function is verified using electrical disturbances.

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“…Proportional integral (PI) based current controller is employed to control the single-phase grid-connected inverter due to its great advantage of providing infinite gain at the steady-state operating point, which gives zero steady-state error. However, this type of controller can not be implemented directly for single-phase gridconnected inverter, where it is required to create a second quantity that would be in quadrature with the available physical one [5]- [10].…”

Section: Introductionmentioning

confidence: 99%

“…Thus, the estimated phase angle 𝜃 𝑃𝐿𝐿 , which is equal to the grid phase angle could be obtained, and this is achieved by using PI controller that serves as loop filter (LF) to regulate 𝑉 𝑞 to zero value and then send the error to voltage controlled oscillator (VOC) which is represented by integrator as shown in Figure 2. The transfer function from 𝑉 𝑔𝑟𝑖𝑑 to 𝑉 𝛼𝛽 could be obtained with the help of Mason formula [5], [20], [21].…”

mentioning

confidence: 99%

Single-phase grid-connected power control in dq synchronous reference frame with space vector modulation using FPGA

Al-Khayyat

Al-Safi

Hameed

2023

IJEECS

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This paper presents the performance of controlling the active and reactive power of single-phase grid connected inverter by dq synchronous reference frame and space vector modulation (SVM) which is implemented by using field programmable gate array (FPGA) due to the flexibility they offer in comparison to other digital signal processors, hence it become the standard instruments for implementing various types of pulse width modulation (PWM) digital signal processors (DSPs). The SVM method has used because of its superiority in terms of harmonic distortion, switching losses and utilization of direct current (DC) bus. The synchronization is achieved by using second order generalized integrator (SOGI) due to its simple structure, certain filtering ability and frequency adaptability, in which the phase locked loop (PLL) ensures high performance for single-phase inverter. The active and reactive inverter current has been controlled and decoupled from each other and the dynamic response has been improved and became fast with proper feed-forward and decoupling grid voltage term. The system has simulated by MATLAB and the result shows robust control of injected grid current, active and reactive power control and DC link voltage control.

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Comparative study of single-phase phase-locked loops for grid-connected inverters under non-ideal grid conditions

Cited by 30 publications

References 0 publications

Non-Destructive Calibration Scheme for Online Monitoring Device of Metal Oxide Arrester

Non-Destructive Calibration Scheme for Online Monitoring Device of Metal Oxide Arrester

PLL wrap function for synchronization in phase jump disturbances

Single-phase grid-connected power control in dq synchronous reference frame with space vector modulation using FPGA

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