Online capacitance estimation of DC-link electrolytic capacitors for three-phase AC/DC/AC PWM converters using recursive least squares method
نویسندگان
چکیده
A novel online capacitance estimation method for a DC-link capacitor in a three-phase AC/DC/AC PWM converter is prepared. At no load, a controlled AC current with a lower frequency than the line frequency is injected into the input side, which then causes AC voltage ripples at the DC output side. By extracting the AC voltage and current components on the DC output side using digital filters, the capacitance can then be calculated using the recursive least squares method. The proposed method can be simply implemented with only software and no additional hardware. Experimental results confirm that the estimation error is less than 0.26%.
منابع مشابه
On-Line Capacitance Estimation of DC-Link Capacitor by Input Current Injection for PWM Converters
Abstract : In this paper, a novel on-line capacitance estimation of dc link capacitor using input current injection is proposed for the ac/dc PWM converters. At no load, a controlled input current at a lower frequency than the line frequency is injected into the input side, which causes the dc voltage ripples at the output side. With the ac voltage and current ripple components on the dc side e...
متن کاملبررسی و ساخت یک مبدل مستقیم فرکانس بدون نیاز به خازن و سلف در مدار واسط dc
In this paper a direct ac-ac converter with low distortion input/output waveforms is investigated. Direct ac-ac converters using self-commutated semiconductor switches, also known as matrix converters, have recently attracted the attention of researchers. However, these converters are still under development due to the problems associated with the commutation of bidirectional switches employed ...
متن کاملA New Pulsating Power Elimination Method for Single-Phase PWM AC/DC Converters with Minimum Voltage and Current Stress
An inherent problem of single-phase rectifiers is the existence of a pulsating portion in the input power, which pulsates at twice the grid frequency. If this pulsating power is transferred to the DC-link, it causes a significant amount of second-order harmonic at the output voltage. Since in many applications, such a high level of DC oscillation is not acceptable, so the pulsating power must b...
متن کاملMinimizing the Dc-link Capacitance of a Two-stage Pv-inverter by Predictive Current Control – Increasing Reliability and Reducing Cost by Means of Control
The goal of this work is to reduce the DC-link capacitance of a two-stage single-phase inverter so much that the use of film capacitors becomes feasible in both, price and volume. Film capacitors instead of electrolytic capacitors could increase lifetime and reliability of the inverter, especially in high-temperature applications like module-integrated micro-inverters. For the capacitance reduc...
متن کاملNeural Network Implementation of a Three Phase Regulated PWM AC to Dc Convener with Input Unbalance Correction
Under unbalanced supply condition low order harmonics will appear at the input and output terminals of the PWM AC to DC converter. Based on the positive and negative sequence components, an unbalanced transfer matrix in terms of the input phase voltages is derived. An on-line method using a neural network (NN) is used to implement this transfer matrix. It is shown that by using an additional lo...
متن کامل