深圳大学学报理工版

建立逆变侧电流单环反馈控制LCL型并网逆变器数学模型,研究数字控制延时对系统稳定性的影响,得出系统稳定控制下的约束延时区间.为减小数字控制延时,通过前移脉宽调制比较寄存器装载时刻的方法,在未提高采样频率的情况下将采样延时减小为采样周期的1/2,使系统达到临界稳定状态; 对比分析结果表明,采用参数优化的方法对传统相位补偿算法进行改进,在提高系统相位裕度的同时能降低系统高频增益,提高系统稳定性.仿真和实验结果验证了改进方法的有效性.

We establish a mathematical model of LCL-type grid-connected inverter with single-loop control of the inverter-side current and obtain the constraint delay interval of stable system by analyzing the relationship between the digital control delay and system stability. In order to reduce the digital control delay, we decrease the sampling delay from one sampling period to 1/2 sampling period and make the system reach the critical stable state without increasing the sampling frequency by moving forward the register loading time of the pulse width modulation. It is found that compared with the traditional compensation algorithm based on lead-leg compensator, the adoption of parameter optimization method in this paper can not only improve phase margin, but also reduce the high frequency gain of the system, thus increasing stability of the system. The experimental results demonstrate the feasibility of the proposed control strategy.

引言
1 系统模型及稳定域分析
2 控制策略分析及控制器设计
3 仿真与实验验证
4 结语

图1 LCL型的单相并网逆变器拓扑[2]<br/>Fig.1 Topology of LCL-type single phase grid-connected inverter[2]

图1 LCL型的单相并网逆变器拓扑[2]
Fig.1 Topology of LCL-type single phase grid-connected inverter[2]

图2 逆变侧电流反馈控制连续域控制框图<br/>Fig.2 Control block diagram of continuous model of inverter-side current feedback control

图2 逆变侧电流反馈控制连续域控制框图
Fig.2 Control block diagram of continuous model of inverter-side current feedback control

图3 典型PWM对称规则采样示意图<br/>Fig.3 Schematic diagram of typical PWM symmetry regular sampling

图3 典型PWM对称规则采样示意图
Fig.3 Schematic diagram of typical PWM symmetry regular sampling

图4 不同Td下GOPEN(z)的伯德图<br/>Fig.4 Bode diagram of GOPEN(z) with different Td

图4 不同Td下GOPEN(z)的伯德图
Fig.4 Bode diagram of GOPEN(z) with different Td

图5 本研究方法控制框图<br/>Fig.5 Control diagram of the proposed method

图5 本研究方法控制框图
Fig.5 Control diagram of the proposed method

图6 基于超前补偿器的相位补偿方法伯德图<br/>Fig.6 Bode diagrams of phase compensation method based on lead compensator

图6 基于超前补偿器的相位补偿方法伯德图
Fig.6 Bode diagrams of phase compensation method based on lead compensator

图7 系统开环伯德图<br/>Fig.7 Bode diagram of the open loop system

图7 系统开环伯德图
Fig.7 Bode diagram of the open loop system

图8 入网电流仿真波形<br/>Fig.8 The simulation waveforms of line current

图8 入网电流仿真波形
Fig.8 The simulation waveforms of line current

图9 LCL参数扰动下入网电流仿真波形<br/>Fig.9 The simulation waveform of line current under disturbance of LCL parameters

图9 LCL参数扰动下入网电流仿真波形
Fig.9 The simulation waveform of line current under disturbance of LCL parameters

图10 并网电流满载稳态实验波形<br/>Fig.10 The experimental waveforms of line current

图10 并网电流满载稳态实验波形
Fig.10 The experimental waveforms of line current

图11 入网电流满载与半载之间的跳变<br/>Fig.11 The experimental transient response of line current with reference current changing

图11 入网电流满载与半载之间的跳变
Fig.11 The experimental transient response of line current with reference current changing

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备注

引言

1 系统模型及稳定域分析

2 控制策略分析及控制器设计

3 仿真与实验验证

4 结语

期刊信息

备注

引言

1 系统模型及稳定域分析

2 控制策略分析及控制器设计

3 仿真与实验验证

4 结 语

期刊信息

4 结语