Eaton Intelligent Power Limited

Eaton Corporation

Xiaomeng Cheng

Yilun Chen

Huaqiang Li

Qian Zhang

Dongxiao Wu

Kayle Wang

Peijun Zhu

The present invention disclose a method and apparatus for pulse-width modulation (PWM) of a variable-frequency drive (VFD), the method comprising: for each sector of a space vector graph for PWM of the VFD, identifying at least two possible clamping phases in switching between the vectors in the sector; comparing currents in multiple phases in at least one PWM cycle; in the sector of the space vector graph corresponding to the PWM cycle, determining the possible clamping phase with the maximum current in the at least two possible clamping phases; and clamping the determined possible clamping phase with the maximum current.

Method and apparatus for pulse-width modulation of a variable-frequency drive

A control system and method of a VFD-based pump. The control system controls an electric motor via a VFD, and the electric motor drives the pump. The control system comprises: an anti-ripple injection module for injecting an anti-ripple signal into a control path, the anti-ripple signal causing pressure ripples in the pump output to be at least partially cancelled. Further a pump system, comprising: a VFD, an electric motor, and a pump, wherein the VFD comprises the control system stated above.

Control system and method of a VFD-based pump and pump system

An anti-ripple injection method for injecting an anti-ripple signal into a control system of a pump is disclosed. The control system controls an electric motor via an electric motor drive, and the electric motor drives the pump. The anti-ripple signal causes pressure ripples in the pump output to be at least partially cancelled. The anti-ripple injection method includes: injecting an anti-ripple signal of any waveform into the control system, the anti-ripple signal being represented by the following equation: f(&#x3b8;)=&#x3a3;Acos(m&#x3b8;+&#x3b8;), wherein &#x3b8; is the rotation angle of the motor shaft, m is the order of a signal harmonic in the anti-ripple signal, Aand &#x3b8;are parameters with respect to the msignal harmonic. A control system of a pump including the anti-ripple injection apparatus, and a pump system including the control system are also disclosed.

Anti-ripple injection method and apparatus and control system of a pump

A servo pump control system () and a corresponding servo pump control method are disclosed. The servo pump control system () comprises a pressure controller () configured to receive a first control signal, and directly or indirectly provide a second control signal to the electric motor; and the pressure controller () configured to automatically commission at least one parameter without any manual adjustment.

Servo pump control system and method

A system and method for speed regulation of a VFD circuit via an anti-windup control scheme that provides consistent speed response with no overshoot is disclosed. A control system for operating the VFD circuit includes a feedback controller programmed to receive a speed of a motor operating responsive to an initial torque command and process the speed of the motor to generate a feedback controller output. A feedforward controller of the control system is programmed to process a speed reference to generate a feedforward controller output. A command module of the control system is programmed to determine a torque command based on the processed outputs of the feedback and feedforward controllers and operate the VFD circuit to control the motor according to the torque command.

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Shanghai, China

Xiaomeng Cheng