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公开(公告)号：US4978897A
公开(公告)日：1990-12-18
申请号：US514896
申请日：1990-04-26
CPC分类号： H02P3/18 , H02P27/026
摘要： An electric motor has first, second and third stator windings supplied by a source of alternating voltage having three phases A, B and C, respectively. A separate thyristor switch assembly couples each stator winding to an alternating voltage phase when said switch means is rendered conductive by a trigger signal. When the speed of the motor is above a first predefined level, the thyristor switch assemblies are triggered, in response to the polarity of the voltage between phases A and B being opposed to the polarity of back emf voltage induced across the third winding, to apply current through said first and second stator windings. However, when the speed of the motor is below the first predefined level, the thyristor switch assemblies are triggered, in response to the polarity of the voltage betwen phases B and C being opposed to the polarity of back emf voltage induced across the third winding, to apply current through said second and third stator windings. Subsequently when the speed of the motor further decreases below a second predefined level, current is applied through said second and third stator windings during every cycle of the voltage between phases B and C.
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公开(公告)号：US5003241A
公开(公告)日：1991-03-26
申请号：US312357
申请日：1989-02-15
申请人： Timothy M. Rowan , John C. Merrison
发明人： Timothy M. Rowan , John C. Merrison
IPC分类号： H02P3/18
CPC分类号： H02P3/18
摘要： An AC electric motor can be braked by applying current pulses to the motor when the polarity of the supply voltage is opposed to the polarity of the back electromotive force (emf) voltage across a stator coil of the motor. This current application continues until the motor has stopped. The stoppage is detected by sensing when the current is being applied during every cycle of the supply voltage. Thereafter, the polarity pattern of back emf voltage induced across each of the motor stator coils is sensed. The occurrence of a back emf voltage polarity pattern that remains unchanged for a given number of cycles is detected. Thereafter, a change in this pattern is sensed and the braking current application either ceases or continues for an additional predetermined interval.
摘要翻译： 当电源电压的极性与电动机的定子线圈上的反电动势（emf）电压的极性相反时，通过向电动机施加电流脉冲可以制动交流电动机。 这个当前的应用程序继续，直到电机停止。 通过在电源电压的每个周期期间检测何时施加电流来检测停止。 此后，感测在每个电机定子线圈上感应的反电动势电压的极性图案。 检测到对于给定数量的周期保持不变的反电动势电压极性图案的发生。 此后，感测到该模式的变化，并且制动电流应用停止或继续另外的预定间隔。
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公开(公告)号：US4862052A
公开(公告)日：1989-08-29
申请号：US165538
申请日：1988-03-08
CPC分类号： H02P3/18
摘要： An electric motor is braked by sensing the polarity of voltage of the alternating electricity for powering the motor and sensing the polarity of the voltage induced in the motor by the back electromotive force. When these polarities are opposite the electricity is applied to the motor to generate a braking torque. The application of the electricity is stopped a given interval after it begins to be applied during consecutive voltage cycles. This interval is derived from the time period between when braking commenced to when the electricity was applied during consecutive cycle.
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公开(公告)号：US5008608A
公开(公告)日：1991-04-16
申请号：US456910
申请日：1989-12-26
CPC分类号： H02P27/02
摘要： A three-phase motor is operated by a controller having sets of thyristors which trigger electricity from each phase of a supply to the motor. The controller measures the interval .phi. between the voltage and the current when one phase of the motor makes a zero crossing and measures the interval .gamma. when the thyristors are non-conductive during a half-cycle of the voltage for one phase. A control angle .theta. is calculated according to the equation .theta.=.phi.+K.gamma., where K is a positive number. The control angle .theta. is compared to a reference value to derive an error value. The times at which the thyristors are triggered is controlled in response to the error value. To start the motor, the reference value is gradually decreased to trigger the thyristors progressively earlier during each half cycle of the supply voltage. To stop the motor, the reference value is gradually increased to trigger the thyristors progressively later during each half cycle of the supply voltage.
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公开(公告)号：US4996470A
公开(公告)日：1991-02-26
申请号：US380050
申请日：1989-07-14
申请人： Timothy M. Rowan , John C. Merrison
发明人： Timothy M. Rowan , John C. Merrison
IPC分类号： H02P3/18
CPC分类号： H02P3/18
摘要： The speed of an induction motor is reduced by initially using dynamic electrical braking to slow the motor to a speed at which it will not remain synchronized to the A.C. supply frequency. At this point, A.C. cycle skipping is employed to apply current to the motor at an effective frequency which is a fundamental frequency component of the A.C. supply line frequency. The motor becomes synchronized at this fundamental frequency component. If desired, the motor can be brought to a complete stop by discontinuing the cycle skipping and using the dynamic braking again for a given period of time. This technique provides a very controlled stopping of the motor enabling equipment driven by the motor to be accurately positioned.
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公开(公告)号：US07135833B2
公开(公告)日：2006-11-14
申请号：US11261352
申请日：2005-10-28
IPC分类号： H02P3/18
CPC分类号： G02B21/16 , G01J1/04 , G01J1/0411 , G01J1/0414 , G01J1/0429 , G01J1/044 , G01J1/0455 , G01J1/0462 , G01N21/956 , G02B17/06 , G02B17/061 , G02B21/04
摘要： A method and apparatus for braking an AC motor in the higher portion of its speed range includes substantially reducing flux before applying reverse torque commands to brake the motor. A DC link bus regulator is employed to prevent increases in bus voltage and frequency.
摘要翻译： 用于在其速度范围的较高部分中制动AC电动机的方法和装置包括在施加反向转矩命令以制动电动机之前大幅减少通量。 采用DC链路总线调节器来防止总线电压和频率的增加。
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公开(公告)号：US4916370A
公开(公告)日：1990-04-10
申请号：US343439
申请日：1989-04-26
CPC分类号： H02P3/18
摘要： An electric motor is braked by applying pulses of current to a winding of the motor creating a negative torque which slows the motor. In order to detect when the motor has stopped and as a consequence, when to discontinue applying the current pulses, a periodic determination is performed as to whether the back emf voltage induced in a winding of the motor is within a range of defined values, such as between a positive reference voltage level and a negative reference voltage level. The application of pulses of current is terminated a given interval from when a predetermined number of consecutive determinations all indicate that the back emf voltage is within the range. The length of the given interval is derived from the amount of time between when the electricity began to be applied to brake the motor and the occurrence of the predetermined number of consecutive determinations.
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8.发明授权公开(公告)号：US07268514B2
公开(公告)日：2007-09-11
申请号：US11002011
申请日：2004-11-30
CPC分类号： B66B5/0031 , B66B1/30
摘要： A method and apparatus for stopping an AC motor that is controlling a load while detecting mechanical brake slippage of a mechanical brake for holding the load against movement includes a controller for decreasing torque-producing current commands from the drive while a speed regulator is commanding zero speed, sensing movement of the load while the speed regulator is commanding zero speed, detecting movement of the load past a pre-determined distance limit, and increasing torque to support the load and prevent further movement of the load. The controller will again decrease torque-producing current commands from the drive, and again checking for movement of the load, and upon sensing no load movement upon reaching zero torque, then shutting off the motor.
摘要翻译： 一种用于在检测用于保持负载抵抗运动的机械制动器的机械制动器滑动的同时控制负载的AC电动机的停止方法和装置包括用于在速度调节器指令零速度时减少来自驱动器的转矩产生电流命令的控制器 在速度调节器指令零速度时检测负载的运动，检测负载的运动超过预定的距离极限，以及增加转矩以支持负载并防止负载的进一步移动。 控制器将再次降低来自驱动器的扭矩产生电流指令，并再次检查负载的运动，并且在达到零转矩时检测到无负载运动，然后关闭电机。
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公开(公告)号：US5298847A
公开(公告)日：1994-03-29
申请号：US875912
申请日：1992-04-29
CPC分类号： H02P21/18
摘要： A non-invasive system for accurately determining the counter EMF or speed voltages in an electric motor during motor operation. The system includes a mechanism for determining the phase angle of the stator current within the dq frame of reference and a mechanism for transforming feedback voltages into a new frame of reference defined by this phase angle. The speed voltage values thereby detected are free from stator resistance effects and represent parameters of improved accuracy which can be used in motor control functions.
摘要翻译： 一种用于在电动机运行期间精确地确定电动机中的电动势或速度电压的非侵入式系统。 该系统包括用于确定dq参考系中定子电流的相位角的机构，以及用于将反馈电压变换成由该相位角定义的新的参考系的机构。 由此检测到的速度电压值没有定子电阻效应，并且表示可用于电动机控制功能的改进的精度的参数。
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公开(公告)号：US5140248A
公开(公告)日：1992-08-18
申请号：US504110
申请日：1990-04-03
IPC分类号： H02M7/5387 , H02P27/08
CPC分类号： H02P27/08 , H02M7/53873 , H02P21/24 , H02M2007/53876
摘要： An open-loop pulse width modulation (PWM) motor control for an induction motor includes a voltage regulator loop which is wrapped around a current regulator. When a load is suddenly encountered by the motor, voltage drops at the output of the current regulator. This is sensed and fed back to a voltage regulator and to a current limiter which then adjust the input signal to the current regulator to prevent an overcurrent that will trip a circuit protection device. The voltage regulator and current limiter may be implemented in either analog or digital circuitry.
摘要翻译： 用于感应电动机的开环脉宽调制（PWM）电机控制器包括一个围绕电流调节器缠绕的电压调节器回路。 当电机突然遇到负载时，电流调节器的输出端电压下降。 这被感测并反馈到电压调节器和电流限制器，然后电流限制器将输入信号调整到电流调节器以防止会使电路保护装置跳闸的过电流。 电压调节器和限流器可以在模拟或数字电路中实现。
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