低压开关柜和母线槽动热稳定校验(中)
本帖最后由 bzp4891 于 2017-12-15 09:31 编辑二、短路电流的热效应和电动力效应
低压配电系统的电源来自于地区大中型电力系统，配电用电力变压器的容量远小于系统容量，因此短路电流可按远离发电机端，即无限大容量的网络短路进行考虑，短路电流周期分量不衰减。短路稳态电流data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAA4AAAAVCAMAAABBhy+7AAAAAXNSR0IArs4c6QAAAEVQTFRFAAAAAAAAAABmADqQAGa2OgAAOgBmOjqQOpDbZgAAZgA6Zrb/kDoAkNv/tmYAtv//25A62////7Zm/7aQ/9uQ//+2///bQ37FNgAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAaklEQVQoU6WQyxKAIAhFoaemoZL6/5+aNjRDLdrEsOAx93IGgF/BiOiUQ3x0EIegltWPSbXFGn2bv6RAXcooBiIlMchzZ6heSOhyKttebKsiYqfIa9IHZXoDkGGFWqxreeyyzUsAwun9qBOrIAO+/wATogAAAABJRU5ErkJggg===对称短路电流初始值data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAA4AAAAWCAMAAADHE10VAAAAAXNSR0IArs4c6QAAAFFQTFRFAAAAAAAAAABmADqQAGa2OgAAOgBmOjqQOpDbZgAAZgA6ZgBmZrb/kDoAkDo6kNv/tmYAtv+2tv/btv//25A62////7Zm/7aQ/9uQ//+2///bNjiCfgAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAe0lEQVQoU32Q0Q6DIAxFW91UBs5OC6P8/4cqS43VmBEeKOUeDgDcD/Hzezpa4j9+OUoOPNzlEiIG0+BTBdwYBpSxjeasuBMy/YsC1WhCBWiUFJCf1aGMakI/krwmcduKEatF7qO9UHd3HRqSURUXtvndvyN3CxA+ru9fAfGZBTkUsTIQAAAAAElFTkSuQmCC，短路电流峰值data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAA4AAAAXCAMAAAAMT46wAAAAAXNSR0IArs4c6QAAAE5QTFRFAAAAAAAAAAA6AABmADqQAGa2OgA6OgBmOpDbZgAAZgA6ZgBmZrb/kDoAkDpmkNvbkNv/tmYAtmY6tv//25A62////7Zm/9uQ//+2///bwoEl7gAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAZElEQVQoU5VQSQ6AIAykiAsKWmTt/z+qMUHrxaW3SWatED/PqcgUZNvP+gCN5+RHp6IHzs0dchhenGj2ZCW6IzGARLEuFkzRprqUEQWDaV+V+7NeUJEVIAsAV50y3WYkuH2kBmxNygSAmccl8gAAAABJRU5ErkJggg==出现在短路发生后的半周期（0.01s）内的瞬间，其值可按下式计算：
data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAGkAAAAaCAMAAACD6oJnAAAAAXNSR0IArs4c6QAAAHJQTFRFAAAAAAAAAAA6AABmADqQAGaQAGa2OgAAOgA6OgBmOjqQOpDbZgAAZgA6ZgBmZjoAZjqQZrb/kDoAkDo6kDpmkNvbkNv/tmYAtmY6tv//25A625Bm27Zm29v/2/+22////7Zm/7aQ/9uQ/9u2//+2///b3j49uQAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAABzklEQVRIS+1Ua1PDIBAkVo0afBQ1tPgoIvz/v+jdEUgIxFBnOv3iTaftJMftsrd3jP3HmRVQzRgnpeKe+5PWH4vbp0MlkryszSwX1NeVQE5UZGroxJb573lIeIRvLjIRy/krvBRCOJFXY+5lzyQ8t3yznxehU0eGwjKqpLO5OzDZQTkqax88nP+lUyFUk1PJWZDEsiizQhQMjUjfj1TO8qsP1CChVmUIyzvLy0rsQnskYVB1y4kUnJqQLhhCxkGMbcHezu7uRIPlglzMtJ4JQH16IH/LGCnuUvdA8PQYY289XSJ43InAHygMoiVtYuamZsJBYsvnfjAtFFfhJrGJIxI1Rpdx6U65enRxNbe4E5t9WEWjW0g9IjXIRcbEsjUbgnqQ6wyCoschyP8aS04c4TvnRLw1jB6OpPzF7pJaS32ZpkLVdyLsW4DkB2OT+fwpe99bjv8UbpHdq2i2SzbGHGRhWvxOUuEFER70BiQ9SATY/hSDW0/VAGBQp2p1TFNLG2hu3wEwPEYq5jbbWyXTJ6lqfTvLTic7CV08HeilwaLm16ZiEVAKPl9hlGAEmqYO6IhUYotKSdomFHGlLF/lD6lF7cMcryPFkV9PPVPGD64sIyJUmcEbAAAAAElFTkSuQmCC
式中data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABQAAAAXCAMAAAA8w5+RAAAAAXNSR0IArs4c6QAAAEtQTFRFAAAAAAAAAAA6AABmADqQAGa2OgAAOgBmOpDbZgAAZgA6ZgBmZrb/kDoAkNvbkNv/tmYAtmY6tv//25A62////7Zm/9uQ//+2///btjDFHgAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAj0lEQVQoU7WQUQ+DIAyEy3Q6nMw6BPz/v3RX9rC2Pu8SSKDJfXcl+otKCGGl7/1TlteZbptm5uFNlMdD/53pTsQ4Wi0+WtR2MhSEGBjBshiwTHk8WrQYgiXYNg/VCZA+UeLux4KSAizQ3NF1knt/pbBe4rVlg5PLXBCizi4zFuCRAKGcjYFgT9+2b8EV09E/5kIF9GfaCT0AAAAASUVORK5CYII=为短路电流峰值系数，取决于线路总感抗data:image/png;base64,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和总阻抗data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAB0AAAAWCAMAAAALimf+AAAAAXNSR0IArs4c6QAAAEhQTFRFAAAAAAAAAAA6AABmADqQAGa2OgAAOgA6OgBmOpDbZgAAZrb/kDoAkDo6kNv/tmYAtmY6tv//25A62////7Zm/9uQ//+2///bq4JymwAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAkklEQVQoU8VR7Q6DMAiEuemmbrja2vd/U/mYSTXwe5e0abhwd1CAvyGjYgoCpNsHgOTykLovQOlfLlnn+xqz2yhdKu8gS6CEvjATDLG2F+JJhdhWDsA2PvguQ+OhJVU/zJeGLT0Tv3ksfguStqN8nZqT6KrQuqLBTK++g4UqS9FnCJllpAjlqUvx+820zj5L103uPO4Fp9Xb8TEAAAAASUVORK5CYII=的比值，可以通过查
图4-14获得。当不需要精确计算时通常采用简化公式：
data:image/png;base64,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
式中n为表7的系数。
配电线路发生短路故障时，在断路器或熔断器切断短路故障的这段时间内，短路电流仍然会流过低压开关柜内的母线、电缆和元器件，产生热效应和电动力效应。
短路电流在导体和电器中引起的热效应：
data:image/png;base64,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-----（式2-1）
式中：data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAA4AAAAVCAMAAABBhy+7AAAAAXNSR0IArs4c6QAAAEVQTFRFAAAAAAAAAABmADqQAGa2OgAAOgBmOjqQOpDbZgAAZgA6Zrb/kDoAkNv/tmYAtv//25A62////7Zm/7aQ/9uQ//+2///bQ37FNgAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAaklEQVQoU6WQyxKAIAhFoaemoZL6/5+aNjRDLdrEsOAx93IGgF/BiOiUQ3x0EIegltWPSbXFGn2bv6RAXcooBiIlMchzZ6heSOhyKttebKsiYqfIa9IHZXoDkGGFWqxreeyyzUsAwun9qBOrIAO+/wATogAAAABJRU5ErkJggg==为短路电流稳态值，单位kA;
data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAVCAMAAAB44J7gAAAAAXNSR0IArs4c6QAAAE5QTFRFAAAAAAAAAAA6AABmADqQAGa2OgAAOgA6OpDbZgAAZgA6ZgBmZrb/kDoAkGaQkNu2kNv/tmYAtv/btv//25A62////7Zm/9uQ//+2///b69yZKAAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAcklEQVQoU7VPSQ6AIAwsouJWBUGk//+ohUQt3u2pmclsAP8c4VAbR7VIgFDxdRJy7VFJCCsaII1fz8beCqcyF7S/AcKcJzzTnDmnfXkip5e8s1dZFNkqCPsid6LyaSyk6cljobGEel+f0jyp2ca30jvmAiNGBJILoA+8AAAAAElFTkSuQmCC为短路电流持续时间（即断路器或熔断器的动作时间），单位s。当低压断路器设置有短路短延时保护时，data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAVCAMAAAB44J7gAAAAAXNSR0IArs4c6QAAAE5QTFRFAAAAAAAAAAA6AABmADqQAGa2OgAAOgA6OpDbZgAAZgA6ZgBmZrb/kDoAkGaQkNu2kNv/tmYAtv/btv//25A62////7Zm/9uQ//+2///b69yZKAAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAcklEQVQoU7VPSQ6AIAwsouJWBUGk//+ohUQt3u2pmclsAP8c4VAbR7VIgFDxdRJy7VFJCCsaII1fz8beCqcyF7S/AcKcJzzTnDmnfXkip5e8s1dZFNkqCPsid6LyaSyk6cljobGEel+f0jyp2ca30jvmAiNGBJILoA+8AAAAAElFTkSuQmCC为短延时时间，例如MT框架断路器短延时时间范围为0.1-0.4s；瞬动保护时data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAVCAMAAAB44J7gAAAAAXNSR0IArs4c6QAAAE5QTFRFAAAAAAAAAAA6AABmADqQAGa2OgAAOgA6OpDbZgAAZgA6ZgBmZrb/kDoAkGaQkNu2kNv/tmYAtv/btv//25A62////7Zm/9uQ//+2///b69yZKAAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAcklEQVQoU7VPSQ6AIAwsouJWBUGk//+ohUQt3u2pmclsAP8c4VAbR7VIgFDxdRJy7VFJCCsaII1fz8beCqcyF7S/AcKcJzzTnDmnfXkip5e8s1dZFNkqCPsid6LyaSyk6cljobGEel+f0jyp2ca30jvmAiNGBJILoA+8AAAAAElFTkSuQmCC为按最大分断时间考虑，例如MT框架断路器瞬动保护最大分断时间80ms，塑壳断路器NSX瞬动保护最大分断时间50ms，但是当故障电流大于25倍NSX断路器额定电流时由于其具有能量脱扣功能，最快动作时间只有5ms,此时data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAVCAMAAAB44J7gAAAAAXNSR0IArs4c6QAAAE5QTFRFAAAAAAAAAAA6AABmADqQAGa2OgAAOgA6OpDbZgAAZgA6ZgBmZrb/kDoAkGaQkNu2kNv/tmYAtv/btv//25A62////7Zm/9uQ//+2///b69yZKAAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAcklEQVQoU7VPSQ6AIAwsouJWBUGk//+ohUQt3u2pmclsAP8c4VAbR7VIgFDxdRJy7VFJCCsaII1fz8beCqcyF7S/AcKcJzzTnDmnfXkip5e8s1dZFNkqCPsid6LyaSyk6cljobGEel+f0jyp2ca30jvmAiNGBJILoA+8AAAAAElFTkSuQmCC为5ms。熔断器保护时短路电流持续时间data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAVCAMAAAB44J7gAAAAAXNSR0IArs4c6QAAAE5QTFRFAAAAAAAAAAA6AABmADqQAGa2OgAAOgA6OpDbZgAAZgA6ZgBmZrb/kDoAkGaQkNu2kNv/tmYAtv/btv//25A62////7Zm/9uQ//+2///b69yZKAAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAcklEQVQoU7VPSQ6AIAwsouJWBUGk//+ohUQt3u2pmclsAP8c4VAbR7VIgFDxdRJy7VFJCCsaII1fz8beCqcyF7S/AcKcJzzTnDmnfXkip5e8s1dZFNkqCPsid6LyaSyk6cljobGEel+f0jyp2ca30jvmAiNGBJILoA+8AAAAAElFTkSuQmCC为熔断时间（弧前时间data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABMAAAAVCAMAAACT1yXjAAAAAXNSR0IArs4c6QAAAFRQTFRFAAAAAAAAAAA6AABmADqQAGa2OgAAOgBmOpDbZgAAZgA6ZgBmZrb/kDoAkGaQkNvbkNv/tmYAtmY6tv/btv//25A62/+22////7Zm/9uQ//+2///b7sdLswAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAfUlEQVQoU72QwRKDIAxEE1FblFhooQL5//80OnaGAc7NLbvJ7EsA/lJMzyYnoqk0JpSaKtWNe73LVA8BZN2JGGwTG5RvtE4EOOXz6pkG63D86gsrzSjb7xehSbPyoSDL2kAUMxQUUfwwAVNx6N2nx2f7YZzPyYuVCzq4MnQAr9IFX2PhQCEAAAAASUVORK5CYII=+燃弧时间data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAA8AAAAVCAMAAACuRUSFAAAAAXNSR0IArs4c6QAAAE5QTFRFAAAAAAAAAAA6AABmADqQAGa2OgAAOgA6OpDbZgAAZgA6ZgBmZrb/kDoAkJC2kNu2kNv/tmYAtv/btv//25A62////7Zm/9uQ//+2///bkb3FggAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAa0lEQVQoU62P2xKAIAhEMbtZUZqm8v8/GjXTiD7HC7OwswcAfi/CucqMahOaUHENYuL6S/oJ5RIgmyaus1V80L7STRw47fPKlsjYx5rGt0WOCYVEyEe6QkqThbwUEmtCfe4fit/oDtOcwssbursD8e7VQ6MAAAAASUVORK5CYII=），如下图所示：短路电流在导体和电器中引起的电动力效应：如前所述，对于平行布置的三相水平母线，当短路电流通过时，中间相所处的情况最为严重，最大作用力data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABkAAAAVCAMAAACE9bUqAAAAAXNSR0IArs4c6QAAAEhQTFRFAAAAAAAAAAA6AABmADqQAGa2OgAAOgA6Oma2OpDbZgAAZmY6Zrb/kDoAkNv/tmYAtmY6tv//25A62////7Zm/9uQ//+2///bKKtdWgAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAkklEQVQoU71Q2xbCMAgDdVedddhu//+nBuqZnMlelydKOEkaotOQuaL5d5TLk2gZh4C5zli+QO+wToGO3ajOOj2Cf1kCE9xDsC19VEW6vXUtLnadt7jJBbG5tF9zcYzNiX9MYjyWsRYizFqBGjWUsbDveWW70Sylw6FX1ldpcR4ylKFfK/GFoYoBcWAG5zvmQ3wAQgYFbv3eA7YAAAAASUVORK5CYII=为:data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAKEAAAAeCAMAAABzE44kAAAAAXNSR0IArs4c6QAAAH5QTFRFAAAAAAAAAAA6AABmADqQAGa2OgAAOgA6OgBmOjqQOmZmOma2OpDbZgAAZgA6ZgBmZma2Zra2ZrbbZrb/kDoAkDpmkGaQkNu2kNvbkNv/tmYAtmY6trZmttuQtv+2tv/btv//25A625CQ2//b2////7Zm/7aQ/9uQ//+2///b+3DlBQAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAC1UlEQVRYR81Xi1LbMBCMkzSlgAttXCCiBUTj2v7/H+ztniSfSfyYjjuxhgmJY++t7vb2lNXq4qvMPl2cwwgBd7twhk2xXzjD+u5t4QzL7XGBDOs8S/3hl9go9dfDqlwfmLoFytBpVavPylDYvo8Iscx0TU12U2TZxmCGUF5REB6ImiG824fXILam0EA+eIzAnbqNPAcgweTNHmh1PtGVmmJ7bIpEURSlZBw8o9rJq5MLTaFXvRBMH2xDlMMJ8Yoa8u0Z7lmTPrqonxKBmaTNGzcYFqHowKQm/3DBn3brWHv46x1Q1Mxj2ke56Q0OMeu8TYFhaArB2xTb2XR5KgQZLAeMuim+S6mgUYQE7PSGQpHxTJsWwzC91buIXeddJigczAYC7V3i4sCqrrBN6rgjffucC20UpS97QezIgIVMVY7VAAFlCGzbVVMrJi5eSZmDWCGV6mZijQcZJnWiZUhMsM3FWDETKyWgG19kiiSEM0XoF9lvWzl3xgEUI1b5nA4jkmaPSt8erSDkSrTBwYxQdH79pGeKVt3mFJR0eVLl2CmtN6Uqoy5p8QOxba+H5h4rGDuk2n3TMwUtTLPTSnfgvEEbsaVLDLR9BQdEeQexu05r89xLlIcJsXItqos9JcRF4gwfhX4OAlVjqaPjRIaRCe1cxaDYYI6DNAovzdT8eBU7d73NqeKQV69Sk8ESerH6IpqRa7DkOJLOU9QNkCFGYJiY8SigXgKdCja6cJdtXu6rq183cEAMi+enItt/dCETKgy7VN34leJpsTnCZl3Wn+jEAwz7ArtbGWHabMHL56TYUSN0FtyYCe9aZl9Y2ZP8/TkIQ1HS68OsB9/3l7uf298JUwZ1YoyhHXpsJCPYkxP5iLLWj7k5DcyRSaFQt5gUb3QmeNw/VHwOVv0Y1stIbnEM7fSiHCcNmv+btX50nh0n2fiFGHIA4VC+2MVfN1N/IS10F38BvUY+dVpXcgoAAAAASUVORK5CYII=----（式2-2）公式中：L为铜排的长度，单位米；D为三相铜排的相间距，单位为米；data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAA4AAAAXCAMAAAAMT46wAAAAAXNSR0IArs4c6QAAAD9QTFRFAAAAAAAAAAA6AABmADqQAGa2OgA6OpDbZgAAZrb/kDoAkDpmkNv/tmYAtv//25A62////7Zm/9uQ//+2///bkkA9LAAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAAXklEQVQoU4WQ2w6AIAxDqYrijYrw/9/q0ITMRKFPa3baZDOmpX04FJIW2wqUPdF7DVebops0e46btmw0pdUHWAK5hOgkTJlDHh5Rzohu/rPSTwVDVNg7q/S2Afh6yQXiNANJjPCwRAAAAABJRU5ErkJggg== 为短路电流峰值,单位kA；
对比（式1-1）和（式2-1）：低压成套设备固有的热稳定值：data:image/png;base64,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------（式1-1）短路电流流过导体在保护电器动作时间内产生的热效应：data:image/png;base64,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-----（式2-1）只要：data:image/png;base64,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，则成套设备的热稳定满足要求。由于成套设备的短时耐受时间t一般为1s，断路器动作的时间最长不超过0.4s（短延时），所以一般情况下热稳定校验只要满足下面关系式即可：data:image/png;base64,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对比（式1-2）和（式2-2）：低压成套设备固有的能承受的电动力：data:image/png;base64,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-----（式1-2）短路电流流过导体时产生的电动力：data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAKEAAAAeCAMAAABzE44kAAAAAXNSR0IArs4c6QAAAH5QTFRFAAAAAAAAAAA6AABmADqQAGa2OgAAOgA6OgBmOjqQOmZmOma2OpDbZgAAZgA6ZgBmZma2Zra2ZrbbZrb/kDoAkDpmkGaQkNu2kNvbkNv/tmYAtmY6trZmttuQtv+2tv/btv//25A625CQ2//b2////7Zm/7aQ/9uQ//+2///b+3DlBQAAAAF0Uk5TAEDm2GYAAAAJcEhZcwAAEnQAABJ0Ad5mH3gAAAAZdEVYdFNvZnR3YXJlAE1pY3Jvc29mdCBPZmZpY2V/7TVxAAAC1UlEQVRYR81Xi1LbMBCMkzSlgAttXCCiBUTj2v7/H+ztniSfSfyYjjuxhgmJY++t7vb2lNXq4qvMPl2cwwgBd7twhk2xXzjD+u5t4QzL7XGBDOs8S/3hl9go9dfDqlwfmLoFytBpVavPylDYvo8Iscx0TU12U2TZxmCGUF5REB6ImiG824fXILam0EA+eIzAnbqNPAcgweTNHmh1PtGVmmJ7bIpEURSlZBw8o9rJq5MLTaFXvRBMH2xDlMMJ8Yoa8u0Z7lmTPrqonxKBmaTNGzcYFqHowKQm/3DBn3brWHv46x1Q1Mxj2ke56Q0OMeu8TYFhaArB2xTb2XR5KgQZLAeMuim+S6mgUYQE7PSGQpHxTJsWwzC91buIXeddJigczAYC7V3i4sCqrrBN6rgjffucC20UpS97QezIgIVMVY7VAAFlCGzbVVMrJi5eSZmDWCGV6mZijQcZJnWiZUhMsM3FWDETKyWgG19kiiSEM0XoF9lvWzl3xgEUI1b5nA4jkmaPSt8erSDkSrTBwYxQdH79pGeKVt3mFJR0eVLl2CmtN6Uqoy5p8QOxba+H5h4rGDuk2n3TMwUtTLPTSnfgvEEbsaVLDLR9BQdEeQexu05r89xLlIcJsXItqos9JcRF4gwfhX4OAlVjqaPjRIaRCe1cxaDYYI6DNAovzdT8eBU7d73NqeKQV69Sk8ESerH6IpqRa7DkOJLOU9QNkCFGYJiY8SigXgKdCja6cJdtXu6rq183cEAMi+enItt/dCETKgy7VN34leJpsTnCZl3Wn+jEAwz7ArtbGWHabMHL56TYUSN0FtyYCe9aZl9Y2ZP8/TkIQ1HS68OsB9/3l7uf298JUwZ1YoyhHXpsJCPYkxP5iLLWj7k5DcyRSaFQt5gUb3QmeNw/VHwOVv0Y1stIbnEM7fSiHCcNmv+btX50nh0n2fiFGHIA4VC+2MVfN1N/IS10F38BvUY+dVpXcgoAAAAASUVORK5CYII=----（式2-2）只要：data:image/png;base64,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，则成套设备的动稳定满足要求。由于电动力与峰值电流的平方成正比，所以动稳定校验只需要满足下面关系式即可：data:image/png;base64,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感谢分享，学习了
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