Eaton Intelligent Power Limited

Eaton Corporation

Yilun Chen

Xiaomeng Cheng

Li Yu

Jack Gu

Qizhou Chen

Tianyu Chen

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 circuit for driving an actuator including a closing coil and an opening coil, the circuit including a first electrical switch, a second electrical switch, a third electrical switch, a first diode, a second diode, a third diode, and a capacitor electrically connected to a second terminal of the third electrical switch. The circuit is structured such that controlling the state of the first, second, and third transistors causes current flowing through the circuit to flow through one of the closing coil and the opening coil and to not flow through the other of the closing coil and the opening coil.

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Shanghai, China

Yilun Chen