摘要:
The present invention relates to a method of controlling a power converter (20) of a synchronous machine system (10), the method comprising sampling phase-current values between the power converter (20) and the synchronous machine (30); selecting a reference frame; regulating a current vector to align with the selected reference frame, the selected reference frame having a direct-axis component and a quadrature-axis component; estimating rotor speed and position as a function of instantaneous power; adjusting the selected reference frame, based on estimated rotor position, to synchronize the selected reference frame with a magnetic axis of the rotor, thereby generating a synchronized floating frame; and applying the synchronized floating frame to control the power converter (20). The present invention also related to a power converter controlling apparatus (100) for controlling a power converter (20) of a synchronous machine system (10) without use of a machine position sensor.
摘要:
A method of controlling a power converter (20) of a motor drive system (10)controls the power converter (20) during a first operating mode by applying a current control scheme, which sets power converter commands to control torque current flowing from the power converter (20) to the motor (30) to achieve desired motor speed; and initiates a second operating mode when power supply to the power converter (20) is interrupted. The second operating mode includes controlling negative torque current between the power converter (20) and the motor (30) so that mechanical energy from the motor (30) charges an element (58) on a power supply side of the power converter (20). The first operating mode is resumed when the input power recovers. Torque current between the power converter (20) and the motor (30) is also controlled to limit a maximum transient DC bus voltage.
摘要:
A method and apparatus control a power converter (20) of a motor drive system. The power converter (20) is controlled during a first operating mode by applying a current control scheme, which sets power converter commands to control active and reactive current components flowing from the power converter (20) to the motor (30) to achieve desired motor speed; and a fault protection scheme is executed during a second operating mode. The fault protection scheme generates power converter commands to reduce the active current component flowing from the power converter (20) to the motor (30) is substantially zero. The first operating mode will be resumed upon receiving the restart command if the motor speed is above a pre-set shutdown threshold.
摘要:
A method and apparatus control a power converter (20) of an AC motor drive system (10). The method and apparatus: generate a field current regulating signal to control a field current component flowing from the power converter (20) to the AC motor (30), thereby achieving field current regulation; generate a torque current regulating signal to control a torque current component flowing from the power converter (20) to the AC motor (30), thereby achieving torque current regulation, the torque current regulation having lower priority than the field current regulation; and execute a close-loop field weakening control scheme, which generates a field weakening control command as a function of the difference between a torque current regulation voltage demand and voltage available for torque current regulation. The field current regulating signal is adjusted in accordance with the field weakening control signal to selectively reduce back EMF of the AC motor (30), thereby enabling the step of generating a toque current regulating signal to achieve a toque current component needed to drive the AC motor (30) at a desired speed despite a limitation on DC voltage available to the power converter (20).
摘要:
A synchronous bi-directional active power conditioning system (11) suitable for wide variable frequency systems or active loads such as adjustable speed drives which require variable voltage variable frequency power management systems is disclosed. Common power electronics building blocks (100, 200) (both hardware and software modular blocks) are presented which can be used for AC-DC, DC-AC individually or cascaded together for AC-DC-AC power conversion suitable for variable voltage and/or wide variable frequency power management systems. A common control software building block (2, 5) includes a digital control strategy/algorithm and digital phase lock loop method and apparatus which are developed and implemented in a digital environment to provide gating patterns for the switching elements (3, 6) of the common power-pass modular power electronics building blocks (100, 200).