• Title, Summary, Keyword: Small-signal model

Search Result 362, Processing Time 0.046 seconds

Study on Small-signal Modeling and Controller Design of DC-DC Dual Active Bridge Converters (DC-DC Dual Active Bridge 컨버터의 소신호 모델링 및 제어기 설계에 관한 연구)

  • Lee, Won-Bin;Choi, Hyun-Jun;Cho, Jin-Tae;Jung, Jee-Hoon
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.22 no.2
    • /
    • pp.159-165
    • /
    • 2017
  • Small-signal modeling and controller design methodology are proposed to improve the dynamics and stability of a DC-DC dual active bridge (DAB) converter. The state-space average method has a limitation when applied to the DAB converter because its state variables are nonlinear and have zero average values in a switching period. Therefore, the small-signal model and the frequency response of the DAB converter are derived and analyzed using a generalized average method instead of conventional modeling methods. The design methodology of a lead-lag controller instead of the conventional proportional-integral controller is also proposed using the derived small-signal model. The accuracy and performance of the proposed small-signal model and controller are verified by simulation and experimental results with a 500 W prototype DAB converter.

Advanced Small-Signal Model of Multi-Terminal Modular Multilevel Converters for Power Systems Based on Dynamic Phasors

  • Hu, Pan;Chen, Hongkun;Chen, Lei;Zhu, Xiaohang;Wang, Xuechun
    • Journal of Power Electronics
    • /
    • v.18 no.2
    • /
    • pp.467-481
    • /
    • 2018
  • Modular multilevel converter (MMC)-based high-voltage direct current (HVDC) presents attractive technical advantages and contributes to enhanced system operation and reduced oscillation damping in dynamic MMC-HVDC systems. We propose an advanced small-signal multi-terminal MMC-HVDC based on dynamic phasors and state space for power system stability analysis to enhance computational accuracy and reduce simulation time. In accordance with active and passive network control strategies for multi-terminal MMC-HVDC, the matchable small-signal stability models containing high harmonics and dynamics of internal variables are conducted, and a related theoretical derivation is carried out. The proposed advanced small-signal model is then compared with electromagnetic-transient and traditional small-signal state-space models by adopting a typical multi-terminal MMC-HVDC network with offshore wind generation. Simulation indicates that the advanced small-signal model can successfully follow the electromechanical transient response with small errors and can predict the damped oscillations. The validity and applicability of the proposed model are effectively confirmed.

Modeling and Small-Signal Analysis of Controlled On-time Boost Power Factor Correction Circuit (도통 시간 제어형 승압형 역률보상회로의 모델링과 소신호 해석)

  • Park, Hyo-Gil;Hong, Seong-Su;Choe, Byeong-Jo
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.49 no.5
    • /
    • pp.364-370
    • /
    • 2000
  • A large-signal average model for the controlled on-time boost power factor correction(PFC) circuit is developed and subsequently linearized resulting in a small-signal model for the PFC circuit. Ac analyses are performed using the small-signal model, revealing new results new on small-signal dynamics of the PFC circuit. The analysis results and model predictions are confirmed with experimental measurements on 200W prototype PFC circuit.

  • PDF

Fundamental Small-signal Modeling of Li-ion Batteries and a Parameter Evaluation Using Levy's Method

  • Zhang, Xiaoqiang;Zhang, Mao;Zhang, Weiping
    • Journal of Power Electronics
    • /
    • v.17 no.2
    • /
    • pp.501-513
    • /
    • 2017
  • The fundamental small-signal modeling of lithium-ion (Li-ion) batteries and a parameter evaluation approach are investigated in this study to describe the dynamic behaviors of small signals accurately. The main contributions of the study are as follows. 1) The operational principle of the small signals of Li-ion batteries is revealed to prove that the sinusoidal voltage response of a Li-ion battery is a result of a sinusoidal current stimulation of an AC small signals. 2) Three small-signal measurement conditions, namely stability, causality, and linearity, are proved mathematically proven to ensure the validity of the frequency response of the experimental data. 3) Based on the internal structure and electrochemical operational mechanism of the battery, an AC small-signal model is established to depict its dynamic behaviors. 4) A classical least-squares curve fitting for experimental data, referred as Levy's method, are introduced and developed to identify small-signal model parameters. Experimental and simulation results show that the measured frequency response data fit well within reading accuracy of the simulated results; moreover, the small-signal parameters identified by Levy's method are remarkably close to the measured parameters. Although the fundamental and parameter evaluation approaches are discussed for Li-ion batteries, they are expected to be applicable for other batteries.

Small-Signal Modeling and Controller Design of Grid-Connected Inverter for Solid State Transformer (반도체 변압기용 단상 계통 연계형 인버터의 소신호 모델링과 제어기 설계)

  • Kim, Bo-Gyeong;Lee, Jun-Young;Lee, Soon-Sinl;Jung, Jee-Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.66 no.1
    • /
    • pp.40-47
    • /
    • 2017
  • In this paper, a small signal model for grid-connected inverter with unipolar pulse width modulation method is presented. Small-signal analysis allows to predict the stability and dynamics of the inverter. To regulate output voltage and to achieve power factor correction, inverter has two control loops. Loop gains are useful to identify the stability for multi-loop controlled system. Based on small-signal model, controllers are designed to improve audio susceptibility and output impedance characteristics. Proposed small-signal model and controllers are verified by PSIM simulation and experiments.

SMALL-SIGNAL MODEL FOR A CONTROLLED ON-TIME BOOST POWER FACTOR CORRECTION CIRCUIT

  • Kang, Yonghan;Choi, Byungcho
    • Proceedings of the KIPE Conference
    • /
    • /
    • pp.642-647
    • /
    • 1998
  • A new small-signal model for the controlled on-time boost power factor correction (PFC) circuit is presented. The proposed small-signal model is valid up to high frequencies over lKHz. The model can be used in designing the voltage feedback compensation of PFC circuits, the control bandwidth of which is maximized with auxiliary means of removing the low-frequency ripple from the output. The accuracy of the model is confirmed by a 200W experimental hardware

  • PDF

A Control Strategy Based on Small Signal Model for Three-Phase to Single-Phase Matrix Converters

  • Chen, Si;Ge, Hongjuan;Zhang, Wenbin;Lu, Song
    • Journal of Power Electronics
    • /
    • v.15 no.6
    • /
    • pp.1456-1467
    • /
    • 2015
  • This paper presents a novel close-loop control scheme based on small signal modeling and weighted composite voltage feedback for a three-phase input and single-phase output Matrix Converter (3-1MC). A small non-polar capacitor is employed as the decoupling unit. The composite voltage weighted by the load voltage and the decoupling unit voltage is used as the feedback value for the voltage controller. Together with the current loop, the dual-loop control is implemented in the 3-1MC. In this paper, the weighted composite voltage expression is derived based on the sinusoidal pulse-width modulation (SPWM) strategy. The switch functions of the 3-1MC are deduced, and the average signal model and small signal model are built. Furthermore, the stability and dynamic performance of the 3-1MC are studied, and simulation and experiment studies are executed. The results show that the control method is effective and feasible. They also show that the design is reasonable and that the operating performance of the 3-1MC is good.

New Discrete-time Small Signal Model of Average Current Mode Control for Current Response Prediction (평균전류모드제어의 전류응답예측을 위한 새로운 이산시간 소신호 모델)

  • Jung Young-Seok
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.10 no.3
    • /
    • pp.219-225
    • /
    • 2005
  • In this paper, a new discrete-time small signal model of an average current mode control is proposed to predict the inductor current responses. Compared to the peak current mode control, the analysis of the average current mode control is difficult because of its presence of an compensation network. By utilizing sampler model, a new discrete-time small signal model is derived and used to predict the behaviors of an inductor current of average current mode control employing generalized compensation networks. In order to show the usefulness of the proposed model, prediction results of the proposed model are compared to those of the circuit level simulator, PSIM and experiment.

Small-Signal Modeling and Control Design of Asymmetrical Half Bridge DC/DC Converter (시비율 비대칭 하프 브릿지 컨버터의 소신호 해석 및 전압 제어 루우프 설계)

  • Bang Sang-Hyun;Lim Wonseok;Kang Yonghan;Choi Byungcho
    • Proceedings of the KIPE Conference
    • /
    • /
    • pp.538-541
    • /
    • 2002
  • Dynamic analysis and compensation design for an asymmetrical half bridge do-dc converter are presented. A small-signal model is developed using the averaging method. Based on the proposed small-signal average model, the open loop transfer functions of the power stage were obtained and used for the compensation design. All theoretical predictions are validated by experiments on a prototype converter.

  • PDF

Small Signal Modeling for the PWM Series Resonant Converter (PWM-SRC) (펄스-폭 변조방식의 직렬공진 컨버터의 소신호 모델링)

  • Choi, Hyun-Chil
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.48 no.11
    • /
    • pp.1441-1447
    • /
    • 1999
  • A discrete time domain modeling is presented for the pulse-width modulated series resonant converter (PWM-SRC) with a discontinuous current mode. This nonlinear system is linearized about its equilibrium state to obtain a linear discrete time model for the investigation of small signal performances such as the stability and transient response. The usefulness of this small signal model is verified through the dynamic simulation.

  • PDF