# US 2015/0145461 A1 · Input emi filter for motor drive including an active rectifier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0145461 A1 - Document ID: US20150145461A1 - Status: Published application - Kind: A1 - Application number: 14/175,121 - Filed: 2014-02-07 - Published: 2015-05-28 - Earliest claimed: 2013-11-22 - Assignees: Hamilton Sundstrand Corporation - Applicants: Hamilton Sundstrand Corporation - Inventors: Gregory I. Rozman; Francis A. Carcia; Gabriel Ackerman - Web page: https://patentgrep.com/patent/US20150145461A1 ## CPC - H02P 29/50: Reduction of harmonics - H02M 1/12: Arrangements for reducing harmonics from AC input or output - H02M 1/44: Circuits or arrangements for compensating for electromagnetic interference in converters or inverters - H04B 3/28: Reducing interference caused by currents induced in cable sheathing or armouring - H04B 3/30: Reducing interference caused by unbalanced currents in a normally balanced line - G01R 19/2509: {Details concerning sampling, digitizing or waveform capturing} - G01R 19/2513: {Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging} - G01R 31/007: {using microprocessors or computers} - H02M 1/123: {Suppression of common mode voltage or current} - H04B 2203/5475: adapted for drill or well combined with data transmission - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - H04B: TRANSMISSION - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A poly-phase motor drive includes an input EMI filter having a poly-phase filter input and a poly-phase filter output and an active rectifier connected to the filter output. The input EMI filter includes notch filters tuned at active rectifier and motor drive inverter switching frequencies and diverts common-mode current into DC bus. The active rectifier has a DC output. A motor drive inverter is connected to the DC output. The motor drive inverter has a poly-phase motor control output. ## Claims ### Claim 1 A poly-phase motor drive comprising: an input filter having a poly-phase filter input and a poly-phase filter output; an active rectifier including a boost inductor, the active rectifier is connected to the filter output and has a DC output; and a motor drive inverter connected to the DC output, the motor drive inverter having a poly-phase motor control output. ### Claim 2 (depends on 1) The poly-phase motor drive of claim 1, wherein the input filter comprises: a high-frequency common mode inductor connected to the poly-phase filter input; a plurality of common mode filter components connected to the high-frequency common mode inductor; and a differential mode damped inductive capacitance filter interconnected with the common mode filter components. ### Claim 3 (depends on 2) The poly-phase motor drive of claim 2, wherein the differential mode filter is a T-type LC filter; wherein the common mode filter components include a high frequency common mode inductor and are connected to a first shunt-type notch filter. ### Claim 4 (depends on 3) The poly-phase motor drive of claim 3, comprising the shunt-type notch filters and said first shunt type notch filters is tuned to a switching frequency of the active rectifier. ### Claim 5 (depends on 4) The poly-phase motor drive of claim 4, further comprising a second shunt-type notch filter, and wherein the second shunt type notch filters is tuned to a switching frequency of the motor drive inverter. ### Claim 6 (depends on 5) The poly-phase motor drive of claim 5, wherein the switching frequency of the first shunt-type notch filter and the switching frequency of the second shunt-type notch filter are different frequencies. ### Claim 7 (depends on 3) The poly-phase motor drive of claim 3, wherein the common mode filter further comprises a first common mode choke inductor and a second common mode choke inductor , wherein said first common mode choke inductor has a first core material and said second common mode choke inductor has a second core material. ### Claim 8 (depends on 7) The poly-phase motor drive of claim 7, wherein the first core material is a nanocrystalline material, and the second core material is a ferrite material. ### Claim 9 (depends on 1) The poly-phase motor drive of claim 1, wherein the input filter comprises: a high frequency common-mode choke connected to said poly-phase filter input and having a poly-phase high frequency common-mode choke output; a differential mode inductor block connected to said poly-phase high frequency common-mode choke output and having a poly-phase differential mode inductor block output; a first notch filter connected to the poly-phase high frequency common-mode choke output; a second notch filter connected to the poly-phase differential mode inductor block output; a first common mode choke connected to the poly-phase differential mode inductor block output and having a poly-phase first common mode choke output; a common mode capacitor connected to the poly-phase first common mode choke output; a second common mode choke connected to the poly-phase first common mode choke output and having a poly-phase second common mode choke output; and a differential mode capacitor/resistor block connected to said poly-phase second common mode choke output having an output of said poly-phase filter output. ### Claim 10 (depends on 9) The poly-phase motor drive of claim 9, wherein said first notch filter is connected to a common floating point connection via a first impedance block; said second notch filter is connected to the common floating point connection via a second impedance block said common mode capacitor is connected to the common floating point connection via a third impedance block said differential mode capacitor block is connected to the common floating point connection via a fourth impedance block, and said common floating point is connected to DC bus mid-point capacitors. ### Claim 11 (depends on 9) The poly-phase motor drive of claim 9, wherein each of said first notch filter, said second notch filter, and said common mode capacitor are connected to a floating point connection via a first impedance block; said differential mode capacitor block is connected to said common floating point connection via a second impedance block; said floating point connection is connected to a neutral via a third impedance block, and said second impedance block is connected to DC bus mid-point capacitors ### Claim 12 A method for filtering a poly-phase motor drive comprising: filtering common mode noise at an input of an active rectifier; and filtering differential mode noise at an input of the active rectifier. ### Claim 13 (depends on 12) The method of claim 12, wherein the step of filtering EMI noise at the input of the active rectifier comprises filtering EMI noise in a first frequency band corresponding to a switching frequency of the active rectifier using a first notch filter. ### Claim 14 (depends on 12) The method of claim 12, wherein the step of filtering EMI noise at the input of the active rectifier comprises filtering EMI noise in a second frequency band corresponding to a switching frequency of a motor drive inverter using a second notch filter. ### Claim 15 (depends on 12) The method of claim 12, where the step of filtering EMI noise at an input of an active rectifier comprises passing said input through a first common mode choke constructed with a first core material and passing said input through a second common mode choke constructed with a second core material different from said first core material.