变频器和滤波器课件.ppt

1、 变频器和滤波器 分类和应用分类和应用2变频器和滤波器应用范围变频器和滤波器应用范围1.变频器.失真.2.变频器.谐波失真.3.变频器.电磁干扰.(噪声)4.附件 I.Norm UNE-EN 61800-3/A11:20025.附件 II.滤波器摘要.目录目录3变频器失真变频器失真14变频器造成的失真只要有以下两类:Variable Speed DrivesDISTORTIONS变频器造成的失真变频器造成的失真1.谐波失真:产生于.2.电磁噪声:产生于.我们分析他们的形成和采用不同的方法减少它们我们分析他们的形成和采用不同的方法减少它们,特别是采用不同的滤波器特别是采用不同的滤波器.5变频器变

2、频器谐波失真谐波失真26什么是什么是“谐波谐波”?Variable Speed DrivesDISTORTIONS谐波失真谐波失真现已证实任何周期的波形(方波,三角波,)都可以由不同相序和频度的正弦波叠加而成.所有这些下弦波就组成了谐波的分量.Harmonic content of a squared wave7输入谐波电流会产生哪些影响输入谐波电流会产生哪些影响?Variable Speed DrivesDISTORTIONS谐波失真谐波失真 谐波增加了导电体和变压器的RMS值，这“额外”的电流值是不真实的（它不能工作），但是因为这个电流，变压器和导线都必须增加截面积来阻止导体的过热影响。输

3、入电压波形失真，能产生以下重要影响：它能影响使用单相电压的设备比如计算机和其它的低压设备.对设备分发系统产生不需要的共振.8输入谐波电流的影响？输入谐波电流的影响？Variable Speed DrivesDISTORTIONS谐波失真谐波失真 功率因素下降.变压器.电线.等的过载 功率因素修正电容的过载.9怎样补偿输入谐波失真怎样补偿输入谐波失真?Variable Speed DrivesDISTORTIONS谐波失真谐波失真1.输入电抗器又称电抗感应器.可置于整流桥输入端，实现以下两个功能:一方面保护整流桥，免于受电网电压波动的影响.另一方面,他们过滤掉谐波，使电流正弦波平滑.他们也可置于

4、直流总线.但此方案使整流桥得不到相应的保护,但此方案不失为一个低成本的方案.2.使用有源谐波滤波器.他们分析变频器产生的谐波分量，同时产生极性相反的谐波分量与之相互抵消.10怎样补偿输入谐波失真怎样补偿输入谐波失真?Variable Speed DrivesDISTORTIONS谐波失真谐波失真3.安装12脉冲系统.如果我们把整流桥分成两个整流桥输入 每个整流桥输入电压互相错开30度相位角,在理论上11次以下的谐波分量将得到有效的控制.因此，变压器需要有两个副边，一个是星连接，一个是三角连接。负载的一半将由第一个副边提供,剩下的由第二个副边提供，他们产生相差 30 相位角的电流.这可以很容易看

5、到 5th and 7th 谐波完全消失.11 12 脉冲整流系统脉冲整流系统.Variable Speed DrivesDISTORTIONS谐波失真谐波失真1212 脉冲整流系统脉冲整流系统.Variable Speed DrivesDISTORTIONS谐波失真谐波失真当整流桥导通时，输入电压比总线电压高.输入电抗器避免了完全充电并且使波形更加平滑，得到适合的方形波.1312 脉冲整流系统脉冲整流系统.Variable Speed DrivesDISTORTIONS谐波失真谐波失真我们可以假设一个理想的整流系统,假设一些方波信号输入作为参考.考虑有两个副边输入,解释如前,输入两相差 30

6、 相位电流给整流器,结果就是一个更平滑的电流提供给逆变部分:14变频器变频器电磁干扰（噪声）电磁干扰（噪声）315Variable Speed DrivesELECTRIC INTERFERENCES(NOISE)电磁噪声电磁噪声电磁噪声产生于逆变桥逆变桥.当晶体管换向的时候，会干扰电流信号(switch over ON and OFF and vice versa).正是由于此，电磁噪声是一个高频的电流信号，耦合变频器与电机之间的电流，同时也会产生幅射.处理以下两方面的干扰是很有必要的:内部信号传导外部信号幅射16Variable Speed DrivesELECTRIC INTERFERE

7、NCES(NOISE)RADIATED EMIRADIATED EMI电磁噪声幅射可以通过以下方法来解决:使用金属导体共地.使用屏蔽电缆.变频器本身的金属外壳.Power wires screened17Variable Speed DrivesELECTRIC INTERFERENCES(NOISE)CONDUCED EMICONDUCED EMI噪声内部信号传导干扰可以通过以下两种途径来解决:推荐使用 (射频干扰)也称(电磁兼容).Regulation which controls the selection of these filters is.See details on Annex

8、 I.噪声耦合到变频器输入信号18Variable Speed DrivesELECTRIC INTERFERENCES(NOISE)CONDUCED EMICONDUCED EMI噪声内部信号传导干扰可以通过以下两种途径来解决:使用,假设相关噪音为共模噪音，也就是说噪音信号相连的存在于相与地之间和电机绕组与大地之间的电容。这噪音对轴承存在危害。使用,in case of the coupled noise is differential noise,that means,noise signal coupled to the capacitances existing between pha

9、ses.This noise will produce isolation drillings and additionally will increase the dV/dt factor.These filters can be:假设相关噪音为微分噪音，也就是说，通过线间电容 (output coils in series,one per phase),in all output phases.噪声耦合到电机电流.19Variable Speed DrivesELECTRIC INTERFERENCES(NOISE)dV/dtdV/dt滤波器的功能滤波器的功能可以检测到变频器输出波形如下:

10、This is the result of the inverter bridge action.Show film20Variable Speed DrivesELECTRIC INTERFERENCES(NOISE)dV/dt滤波器的功能滤波器的功能若把波形放大,可以看到波形的角度并非 90 直角:DrivedV/dtLosses132kW800V/s1380W132kW4000V/s1100W21Variable Speed DrivesELECTRIC INTERFERENCES(NOISE)dV/dt滤波器的功能滤波器的功能通过增加 dV/dt 斜坡可以的减少变频器损耗,这样就充许变

11、频器损耗更小的功率，因此他们的更小DrivedV/dtLosses132kW800V/s1380W132kW4000V/s1100W增大dV/dt斜坡这种方法最大的危害就是：会在变频器输出端产生尖锐的过脉冲电压，此电压远远高过电机输出.此电压可以通过跟其他品牌变频器比较而对比出来:Actual measurement on competitor drive of 200A on load22Variable Speed DrivesELECTRIC INTERFERENCES(NOISE)dV/dt滤波器的功能滤波器的功能为解决此问题,研究出 IGBTs的门极电阻,保证尖峰脉冲不超过限值.Ac

12、tual measurement on a drive of 200A on load:CompetitorRg 门极电阻，控制负载的“电容量”使之与 IGBT一致.Actual measurement on a drive of 200A on load:23Variable Speed DrivesELECTRIC INTERFERENCES(NOISE)dV/dt滤波器的功能滤波器的功能 集成了 输出滤波器.此滤波器,前面解释过,由线圈组成,串联在输出端，它执行着过滤尖峰脉冲的作用.The result:Actual measurement on a drive of 200A on l

13、oad:Power Supply1st Level:Electronic2nd Level:Cooling3rd Level:Filters24Variable Speed DrivesELECTRIC INTERFERENCES(NOISE)CONDUCED EMICONDUCED EMI最后,需有一个滤波器 处理由斩波信号转换成 正弦波信号:这就是 (LC电路在变频器输出端).噪声依赖于电容和dV/dt因素.电容在安装时是可变量.dV/dt 依赖于变频器.若 dV/dt 减小到可以几乎忽略的情况下,噪声也就几乎消失了.The result:25Annex INorm UNE-EN 6180

14、0-3/A11:2002426Annex IELECTRO-MAGNETIC COMPATIBILITYNORM UNE-EN 61800-3/A11:2002NORM UNE-EN 61800-3/A11:2002Limits application in the measurement of the Conduced PerturbationsNowadays exist several norms about EMC according to the 89/336/EEC directive that refer to the variable speed drive or to tho

15、se equipments incorporating drives.Specific norms for drives Adjustable speed electrical power drive systems.Part 3:EMC product standard including specific test methods.27Annex IELECTRO-MAGNETIC COMPATIBILITYNORM UNE-EN 61800-3/A11:2002NORM UNE-EN 61800-3/A11:2002NormClassifying CriteriaApplication

16、LimitFirst environmentNon restricted distributionLimit 1Restricted distributionLimit 2Second environmentInput current 100ALimit 3Input current 100ALimit 4Where:First Environment:Includes domestic or residential use.It includes also,places directly connected,without intermediate transformers,to a pow

17、er supply distribution system of low energy which additionally gives supply to buildings used for domestic uses(cinemas,theatres,shopping centres,hospitals,).Second Environment:(Named also industrial).It includes all places different from those which are directly connected to a power supply distribu

18、tion system of low energy which additionally gives supply to buildings used for domestic uses(factories and facilities supplied with transformer of medium voltage to low voltage).28Annex IELECTRO-MAGNETIC COMPATIBILITYNORM UNE-EN 61800-3/A11:2002NORM UNE-EN 61800-3/A11:2002NormWhere:Non-Restricted D

19、istribution:Marketing modality where the power supply of the drive does not depend on the customer or user regarding to EMC issues for the application of operation.Restricted Distribution:Marketing modality where the manufacturer limits the supplying of the drive to those customers or users which,in

20、 an independent or together way,have technical competence on the EMC requirements for the application of operation.Classifying CriteriaApplication LimitFirst environmentNon restricted distributionLimit 1Restricted distributionLimit 2Second environmentInput current 100ALimit 3Input current 100ALimit

21、429Annex IIFilters Summary530Annex IIFILTERS SUMMARYFILTER TYPESFILTER TYPESSummarizing:谐波失真谐波失真无源滤波器:输入电抗器(阻抗感应器)直流感应器三相输入感应器有源滤波器电磁噪声电磁噪声幅射噪声传导噪声金属导电屏蔽电缆金属外壳屏蔽EMC 滤波器(or RFI filter).过波耦合输入电流信号噪声输出共模滤波器.过滤流经马达的电磁噪声.dV/dt 滤波器(differential mode noise)Output Inductances in series(1 per phase)Iron Dust Toroids(1 per phase)正弦波输出滤波器(LC circuit)谢谢！谢谢！PresentationVARIABLE SPEED DRIVES AND FILTERSClassification and ApplicationRealizedPilar NavarroOrganizedMarketing Departmentwww.power-2006 Power Electronics,S.L.