公开(公告)号：US20040004514A1

公开(公告)日：2004-01-08

申请号：US10609273

申请日：2003-06-26

Applicant: International Rectifier Corp.

Inventor： Brian R. Pelly

IPC: H03B001/00

CPC classification number: H02M1/12 ,  H02M5/458 ,  H02M2001/123 ,  H02P29/50 ,  H02P2201/07

Abstract: An active filter for reducing the common mode current in a pulse width modulated drive circuit driving a load, said drive circuit comprising an a-c source, a rectifier connected to said a-c source and producing a rectified output voltage connected to a positive d-c bus and a negative d-c bus, a PWM inverter having input terminals coupled to said positive d-c bus and negative d-c bus and having a controlled a-c output, a load driven by said a-c output of said PWM inverter, a ground wire extending from said load, and a current sensor for measuring the common mode current in said drive circuit in said ground wire, said current sensor producing an output current related to said common mode current, said active filter comprising a first and second MOSFET transistor, each having first and second main electrodes and a control electrode, and an amplifier driving a respective one of the transistors; said first electrode of said first and second transistor coupled to a common node, said second electrodes of said first and second transistors being coupled to said positive d-c bus and said negative d-c respectively; each of said amplifiers having an input coupled to said output of said current sensor and each having an output connected to a respective one of said control electrodes; and a d-c isolating capacitor connecting said common node of said first electrode of said first and second transistors to said ground wire.

公开(公告)号：US20010045863A1

公开(公告)日：2001-11-29

申请号：US09816590

申请日：2001-03-23

Applicant: International Rectifier Corp.

Inventor： Brian R. Pelly

IPC: H03B001/00

CPC classification number: H02M1/12 ,  H02M5/458 ,  H02M2001/123 ,  H02P29/50 ,  H02P2201/07

Abstract: An active filter reduces the common mode current in the ground wire of a PWM controlled motor drive circuit. The active filter is, in part, integrated into an integrated circuit chip and contains a buffer amplifier which drives two junction type or MOSFET transistors linearly to divert common mode current from a ground wire and through the transistors. The transistors are connected between positive and negative d-c busses which supply d-c power to a PWM inventor which drives an a-c motor, producing the common mode ground current in its grounded frame. A current transformer monitors the common mode current and its output is coupled to the input of the buffer amplifier to control the transistors. An internal power supply for the amplifiers is formed at the nodes between two current sources and two zener diodes which are connected between the d-c bus conductors. Headroom control circuits are disclosed to insure sufficient headroom voltage for each of the transistors under all input a-c voltage conditions.

Abstract translation: 有源滤波器降低PWM控制电机驱动电路的接地线中的共模电流。 有源滤波器部分地集成到集成电路芯片中，并且包含缓冲放大器，其驱动两个结型或MOSFET晶体管，以使共模电流从地线和晶体管转移。 晶体管连接在正和负d-c总线之间，该总线向驱动a-c电机的PWM发明者提供d-c电源，在接地的框架中产生共模接地电流。 电流互感器监视共模电流，其输出耦合到缓冲放大器的输入端以控制晶体管。 在两个电流源和连接在d-c总线导体之间的两个齐纳二极管之间的节点处形成用于放大器的内部电源。 公开了裕量控制电路，以在所有输入a-c电压条件下为每个晶体管确保足够的裕量电压。