CN107196547B - 一种三相双buck并网逆变器的对称全周期调制方法 - Google Patents

一种三相双buck并网逆变器的对称全周期调制方法 Download PDF

Info

Publication number
CN107196547B
CN107196547B CN201710479421.0A CN201710479421A CN107196547B CN 107196547 B CN107196547 B CN 107196547B CN 201710479421 A CN201710479421 A CN 201710479421A CN 107196547 B CN107196547 B CN 107196547B
Authority
CN
China
Prior art keywords
buck
phase
bridge arm
positive
period
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201710479421.0A
Other languages
English (en)
Other versions
CN107196547A (zh
Inventor
吕林娜
肖岚
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nanjing University of Aeronautics and Astronautics
Original Assignee
Nanjing University of Aeronautics and Astronautics
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nanjing University of Aeronautics and Astronautics filed Critical Nanjing University of Aeronautics and Astronautics
Priority to CN201710479421.0A priority Critical patent/CN107196547B/zh
Publication of CN107196547A publication Critical patent/CN107196547A/zh
Application granted granted Critical
Publication of CN107196547B publication Critical patent/CN107196547B/zh
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02MAPPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/53Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/537Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
    • H02M7/5387Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
    • H02M7/53871Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current
    • H02M7/53873Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current with digital control
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02MAPPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00Details of apparatus for conversion
    • H02M1/12Arrangements for reducing harmonics from ac input or output
    • H02M1/126Arrangements for reducing harmonics from ac input or output using passive filters
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02MAPPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/53Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/537Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
    • H02M7/5387Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
    • H02M7/53871Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current
    • H02M7/53875Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current with analogue control of three-phase output

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)

Abstract

本发明公开了一种三相双buck并网逆变器的对称全周期调制方法,本发明中的对称全周期调制方法下的桥臂开关管驱动信号由调制波和一组交错180°的高频三角载波比较获得,桥臂开关管同一开关周期内导通时间互补,但是导通时序不互补,而是中心对称,因此成为对称全周期调制。本发明提出的对称全周期调制方法下,双buck桥臂输出电流纹波减小,有利于减小级联的CL滤波器尺寸,在保证进网电流谐波含量不变情况下滤波电容和网侧滤波电感值都可进一步减小,使双buck逆变器系统的功率密度提高,更有利于双buck拓扑应用在并网逆变器中。

Description

一种三相双buck并网逆变器的对称全周期调制方法
技术领域
本发明涉及DC-AC并网变换器技术领域,具体涉及一种应用于三相双buck拓扑中的对称全周期调制方法。
背景技术
双buck拓扑作为传统桥式拓扑的一种可替代拓扑,在桥臂开关管之间串联电感,将电感中点引出作为桥臂中点,在开关管关断期间为了提供电感电流续流回路,需要在电感和开关管相连的端点串联一个二极管,构成了开关管、二极管、电感相连的正/负buck单元,因此每相双buck桥臂可以视作由正负两个buck单元组合而成。传统桥式拓扑中为了防止桥臂直通必须在开关管驱动信号中加入死区时间,死区会影响桥臂输出正负电压脉冲的分配,引入低频谐波分量。而双buck拓扑作为一种无死区拓扑,其桥臂电感避免了开关管直接串联在直流母线上,不存在桥臂开关管直通问题,无须在开关管驱动信号中加入死区。
因为二极管的存在,双buck拓扑中的正/负buck单元仅能流过单向电流。根据正/负buck单元在整个工频周期的工作模式,可将其分为半周期工作和全周期工作。半周期工作模式下,正/负buck单元根据桥臂输出电流方向分时工作于电流的正负半周,正/负buck单元中的开关管仅在半个工频周期内高频开关,二极管和开关管协同工作。因为buck单元中的单向电感电流中存在高频纹波,电流的开关周期平均值在线性调制下无法减小至零,在正/负buck单元切换的电流过零时刻将出现明显的电流畸变。电流畸变会引入大量低频谐波电流,难以通过滤波器滤除,会导致进网电流的谐波含量增大。
传统全周期工作模式下,双buck桥臂开关管和桥式拓扑中桥臂上下开关管驱动逻辑相同,在整个工频周期内高频互补开通关断,即互补全周期。因为buck单元仅能流过单向电流,为了提供桥臂输出的交流电流,正/负buck单元间存在一个直流环流,环流大小为桥臂输出交流电流幅值的1/2。正/负buck单元中电流的交流分量相同,为桥臂输出交流电流的1/2。正/负buck单元开关管互补开关,即正buck单元的开关管和负buck单元的二极管同时导通,负buck单元的开关管和正buck单元的二极管同时导通。因此正/负buck单元中点电位相同,两个电感等效并联工作,电感电流纹波相同,桥臂输出电流纹波为电感电流纹波两倍。为了充分抑制桥臂输出电流中电流纹波对应的高频分量,以满足网侧电流的并网标准,滤波器尺寸要设计得很大。
正/负buck单元开关管互补全周期工作时,其交流回路等效并联工作,正/负buck单元各提供一半的桥臂输出交流电流。但是桥臂输出等效滤波电感值减小,为正/负buck单元电感并联值,桥臂输出电流的纹波增大,增大了滤波器的尺寸,降低了系统的功率密度。因此,提出合适的全周期调制策略减小桥臂输出电流纹波,是将双buck拓扑应用于DC-AC并网逆变器所需解决的重要问题。
发明内容
发明目的:本发明针对上述背景技术的不足,提供一种应用于双buck拓扑中的全周期调制方法,减小双buck桥臂输出电流的电流纹波,降低滤波器设计要求,减小滤波器设计尺寸,提高双buck拓扑应用于DC-AC并网逆变器时的功率密度和输出性能。
技术方案:
一种三相双buck并网逆变器的对称全周期调制方法,所述三相双buck并网逆变器包括三相双buck桥臂及三相LCL滤波器;所述双buck桥臂由正负buck单元组合而成所述正/负buck单元由开关管、二极管、电感构成;正/负buck单元中的电感同时作为LCL滤波器的桥臂侧滤波电感;通过对称全周期PWM调制产生三相双buck桥臂中正/负buck单元的开关管驱动信号,对称全周期PWM调制由每一相调制波和载波经过比较器后的逻辑信号实现;三相调制波两两相差120°,三相载波相同,每一相由两个比较器输出正负buck单元两个驱动信号。
具体步骤如下:
步骤1:生成一组频率、幅值相同,且交错180°的高频三角波作为载波,其频率为开关管的开关频率,其幅值和载波幅值之间比值为调制比的倒数;交错的载波分别送至比较器1的同相端和比较器2的反相端,对应相桥臂的调制波送至比较器1的反相端和比较器2的同相端;
步骤2:以比较器1输出的逻辑信号作为对应相桥臂正buck单元开关管的驱动逻辑信号,以比较器2输出的逻辑信号作为负buck单元开关管的驱动逻辑信号;正buck单元和负buck单元等效为交错并联工作,桥臂输出电流的等效开关频率提高一倍,纹波减小一半。
有益效果:
一相桥臂中两个开关管的驱动信号在开通时间上仍然是互补的,但是在导通时序上不是互补关系,而是中心对称导通,此时正/负buck单元可以视作交错并联,桥臂输出电流的纹波为交错并联后的电流纹波,等效开关频率提高。对于正/负buck单元中电流纹波,仅和所在buck单元的开关管占空比相关,而开关管占空比由调制波决定,和开关管导通时序无关。
本发明的对称全周期调制方法,利用双buck拓扑中开关管无直通的特点,引入两个开关管同时导通的模态,使双buck桥臂中的两个开关管导通时序由传统的互补导通变为中心对称导通。正/负buck单元各自的工作模态不变,但组合后从并联工作变为交错并联工作的状态,桥臂输出电流纹波减小,等效开关频率增加,可以有效减小滤波器的尺寸,提高逆变器功率密度。
附图说明
附图1为本发明所述的三相双buck LCL并网逆变器主电路拓扑图;
附图2为本发明所述的对称全周期调制方法的实现示意图;
附图3为本发明所述的对称全周期调制方法下一个开关周期内一相双buck桥臂工作模态图;
附图4为本发明所述的对称全周期调制方法和传统互补全周期调制方法下驱动信号及电流波形图;
附图5为本发明所述的对称全周期调制方法下三相桥臂输出电流波形图。
以上附图中的主要符号名称:Cdc直流侧电容;S1-S6:开关管;D1-D6:快恢复功率二极管;La1/La2:正/负buck单元电感;C:交流滤波电容;Lg:网侧滤波电感;Udc:直流母线电流;idc:直流侧输入电流;ia1/ia2:正/负buck单元电流;ia/b/ci:桥臂输出电流;ia/b/cg:网侧电流;ua/b/c/g:电网电压;P:直流母线正端;N:直流母线负端;A1/A2:正/负buck单元桥臂中点;A0:双buck桥臂中点;umod:调制波;uc:高频三角载波;ug_S1/2:开关管S1/2驱动信号。
具体实施方式
下面结合附图对本发明作更进一步的说明。
图1所示的是三相双buck LCL并网逆变器主电路拓扑,三相双buck桥臂及直流侧电容并联在直流母线上,buck单元中的电感同时作为LCL滤波器的变流器侧滤波电感。一相桥臂结构图由正负两个buck单元构成。以A相桥臂为例,开关管S1,二极管D2,电感La1构成正buck单元;开关管S2,二极管D1,电感La2构成负buck单元,正负buck单元组合成双buck桥臂。
图2是对称全周期调制的实现方法,调制波和一组交错180°的高频三角载波分别经过比较器后作为双buck桥臂正/负buck单元中两个开关管的驱动信号。
图3是A相桥臂在一个开关周期内的工作模态:模态1为开关管S1,S2同时导通;模态2为开关管S1,S2关断且二极管D1,D2导通续流;模态3为开关管S1导通,二极管D1导通续流;模态4为开关管S2导通,二极管D2导通续流。其中开关管S1,S2驱动信号是中心对称的,在调制波正半周,开关管S1的占空比大于0.5,此时一个开关周期内的工作模态由模态1,模态2,模态3构成;在调制波负半周,开关管S1的占空比小于0.5,一个开关周期内的工作模态有模态1,模态2,模态4构成。
图4是在调制波正半周,双buck桥臂开关管对称全周期调制和互补全周期调制下,桥臂开关管驱动信号、正负buck单元电流及桥臂输出电流波形。传统互补全周期调制方法下,在开关管S1导通时开关管S2关断,二极管D1导通续流;在开关管S2导通时开关管S1关断,二极管D2导通续流。互补全周期调制下的正负buck单元等效为并联工作,正负buck单元的电感相同时其电感电流纹波也相同,其合成的桥臂输出电流纹波为buck单元电感电流纹波的两倍。对称全周期调制方法和互补全周期调制方法相比,开关管S1,S2的导通时间不变,因此正负buck单元各自的工作情况不变,电感电流及其电流纹波和互补全周期调制方法下相同;保持开关管S1的驱动信号不变,将对称全周期调制方法开关管S2的驱动信号移相180°,即得到对称全周期调制的驱动信号。对称全周期调制下的正负buck单元等效为交错并联工作,正负buck单元的电感电流纹波交错并联后,纹波幅值减小且纹波频率为开关频率的两倍。
忽略滤波电感上基波压降时,调制波表达式可以近似为
其中,umod为调制波,m为调制比,Ugsinθ为网侧相电压,Udc为直流侧电压。
互补全周期调制下和对称全周期调制下,开关管S1的占空比相同,和调制波关系为
Figure BDA0001328964920000051
互补全周期调制下,正buck单元电感电流纹波可以根据开关管S1导通时段内电流上升来确定
Figure BDA0001328964920000052
其中,L为buck单元电感感值,Ts为开关周期,Δibuck+为正buck单元电流纹波。
负buck单元电感电流纹波和正buck单元相同,桥臂输出电流纹波Δi为正/负buck单元电流纹波两倍
Figure BDA0001328964920000053
对称全周期调制下,桥臂输出电流纹波可以根据(d-1/2)Ts时段内电流变化来确定,在该阶段内正buck单元和负buck单元电流变化率相同,因此
Figure BDA0001328964920000054
对比式(4)和式(5),互补全周期调制和对称全周期调制下电流纹波最大值分别为
Figure BDA0001328964920000055
因此,采用对称全周期调制,桥臂输出电流纹波最大值仅为传统互补全周期调制的1/2,而电流纹波的等效开关频率为实际开关频率的两倍。以上为图4所示的调制波正半周的分析,调制波负半周时的情况和正半周时类似,此时式(5)和式(6)中的umod需要改为-umod
图5是三相桥臂输出电流的仿真波形图,仿真时直流母线电压Udc为700V,三相交流相电压幅值为311V,调至比m为0.88。根据式(5)可知桥臂输出电流纹波在调制波umod为零时达到最小值零,在调制波绝对值为0.5时达到最大值。
并网逆变器进网电流总谐波含量及单次谐波含量都有要求,桥臂输出电流中的高频纹波电流经过级联的CL滤波器滤波后应满足进网电流标准,忽略阻尼电阻时,进网电流到桥臂输出电流的传递函数为
Figure BDA0001328964920000061
其中,Ig为网侧电流,Ii为桥臂输出电流,Lg为网侧滤波电感,C为滤波电容。对于传统互补全周期调制,桥臂输出电流纹波的频率为开关频率,其在网侧电流中的衰减率可表示为
Figure BDA0001328964920000062
对于对称全周期调制,桥臂输出电流纹波频率为开关频率两倍,幅值为互补全周期调制是桥臂输出电流纹波的一半,因此其在网侧电流中的衰减率为互补全周期调制衰减率的两倍即可
对比式(8)和式(9),对称全周期调制和传统互补全周期调制相比,级联的CL滤波器乘积可减小约1/8。在保证进网电流谐波含量不增加的前提下,可以有效地减小滤波器的体积尺寸。选取对称全周期调制下网侧电感值为互补全周期调制下网侧电感值1/8时的仿真结果,在互补全周期调制下进网电流THD为2.7%左右,开关频率附近边频谐波含量为0.8%左右;在对称全周期调制下进网电流THD为2.5%左右,两倍开关频率附近边频谐波含量为1%左右。
以上所述仅是本发明的优选实施方式,应当指出:对于本技术领域的普通技术人员来说,在不脱离本发明原理的前提下,还可以做出若干改进和润饰,这些改进和润饰也应视为本发明的保护范围。

Claims (1)

1.一种三相双buck并网逆变器的对称全周期调制方法,其特征在于:
所述三相双buck并网逆变器包括三相双buck桥臂及三相LCL滤波器;所述双buck桥臂由正/负buck单元组合而成;所述正/负buck单元由开关管、二极管、电感构成;正/负buck单元中的电感同时作为LCL滤波器的桥臂侧滤波电感;通过对称全周期PWM调制产生三相双buck桥臂中正/负buck单元的开关管驱动信号,对称全周期PWM调制由每一相调制波和载波经过比较器后的逻辑信号实现;三相调制波两两相差120°,三相载波相同,每一相由两个比较器输出正/负buck单元两个驱动信号;
具体步骤如下:
步骤1:生成一组频率、幅值相同,且交错180°的高频三角波作为载波,其频率为开关管的开关频率,其幅值和载波幅值之间比值为调制比的倒数;交错的载波分别送至比较器1的同相端和比较器2的反相端,对应相桥臂的调制波送至比较器1的反相端和比较器2的同相端;
步骤2:以比较器1输出的逻辑信号作为对应相桥臂正buck单元开关管的驱动逻辑信号,以比较器2输出的逻辑信号作为负buck单元开关管的驱动逻辑信号。
CN201710479421.0A 2017-06-22 2017-06-22 一种三相双buck并网逆变器的对称全周期调制方法 Active CN107196547B (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201710479421.0A CN107196547B (zh) 2017-06-22 2017-06-22 一种三相双buck并网逆变器的对称全周期调制方法

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710479421.0A CN107196547B (zh) 2017-06-22 2017-06-22 一种三相双buck并网逆变器的对称全周期调制方法

Publications (2)

Publication Number Publication Date
CN107196547A CN107196547A (zh) 2017-09-22
CN107196547B true CN107196547B (zh) 2020-01-10

Family

ID=59879485

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710479421.0A Active CN107196547B (zh) 2017-06-22 2017-06-22 一种三相双buck并网逆变器的对称全周期调制方法

Country Status (1)

Country Link
CN (1) CN107196547B (zh)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110429847B (zh) * 2019-08-19 2021-05-04 西安爱科赛博电气股份有限公司 一种双Buck逆变器开关管驱动信号生成方法及电路
CN114665736B (zh) * 2022-03-21 2022-11-22 深圳市正浩创新科技股份有限公司 脉宽调制方法、脉宽调制装置以及逆变系统
CN116054618A (zh) * 2023-01-17 2023-05-02 西安千帆翼科技合伙企业(有限合伙) 一种交错并联四相四桥臂逆变电路

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7061214B2 (en) * 2003-11-25 2006-06-13 Texas Instruments Incorporated Single inductor dual output buck converter with frequency and time varying offset control
CN100384072C (zh) * 2004-07-01 2008-04-23 南京航空航天大学 双输出双降压式半桥逆变器及控制、调制方法
CN102223101A (zh) * 2011-06-21 2011-10-19 盐城工学院 双降压全桥并网逆变器的控制方法
CN103051241A (zh) * 2013-01-11 2013-04-17 南京航空航天大学 自环流三相双降压ac/dc变流器

Also Published As

Publication number Publication date
CN107196547A (zh) 2017-09-22

Similar Documents

Publication Publication Date Title
CN102185514B (zh) 一种单相三电平逆变器
CN103532420B (zh) 双三电平在线拓扑可切换型逆变器
CN102856916A (zh) 一种单相光伏逆变器无功控制方法及电路
CN110798074A (zh) 一种级联型单相交流转直流隔离变换器
CN107134937B (zh) 一种三电平多脉冲输出无变压器型逆变电路
CN103326606B (zh) 一种单相五电平逆变器
CN103036397B (zh) 单级单相大升压比级联电压型准阻抗源变换器
Xu et al. Improved SVPWM schemes for Vienna rectifiers without current distortion
CN107196547B (zh) 一种三相双buck并网逆变器的对称全周期调制方法
CN106505894A (zh) 一种改进型三电平变流器拓扑结构及其调制方法
CN102255544A (zh) Dc/ac逆变电路
CN104092400A (zh) 一种z源三电平t型逆变器及其调制方法
CN104638971A (zh) 一种光伏并网逆变器及其控制方法
CN103618336B (zh) 整流式高频链并网逆变器的输出数字调制电路及控制系统
CN103107728A (zh) 电压电流混源型并网逆变器拓扑
CN105978376A (zh) 并网逆变电路及其控制方法
CN103560654B (zh) 全桥逆变器驱动方法及全桥逆变器
CN111884532B (zh) 适用于三相高频链矩阵变换器的无窄脉冲调制方法
CN103036398A (zh) 单级单相大升压比串联电压型准阻抗源变换器
CN110071652B (zh) 一种低漏电流五开关非隔离单相光伏并网逆变器及并网系统
CN102118035B (zh) 一种并网逆变器
CN110943633B (zh) 一种三电平单相单级升压逆变器及其控制方法
CN107465358B (zh) 单相五电平变换器及其采用的调制方法
CN217883245U (zh) 一种三相三电平变流器电路
CN108683345B (zh) 一种基于SiC二极管的三相改进型双Buck/Boost变流器

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant