# US 10,246,294 B2 · Bus capacitor bank configuration for a regenerative drive > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,246,294 B2 - Document ID: US10246294B2 - Status: Granted - Kind: B2 - Application number: 15/104,101 - Filed: 2013-12-18 - Published: 2017-02-02 - Granted: 2019-04-02 - Earliest claimed: 2013-12-18 - Assignees: Otis Elevator Company - Applicants: Otis Elevator Company - Inventors: Ismail Agirman; Steven M. Millett; HanJong Kim - Web page: https://patentgrep.com/patent/US10246294B2 ## CPC - B66B 1/302: {for energy saving} - B66B 11/04: Driving gear {; Details thereof, e.g. seals (braking devices acting on the driving gear B66B5/02; of mining-hoist winding devices B66B15/08)} - H02P 27/08: with pulse width modulation - B66B 9/00: Kinds or types of lifts in, or associated with, buildings or other structures (characterised by control systems B66B1/00; apparatus for raising or lowering persons on stages of theatres A63J5/12) - B66B: ELEVATORS; ESCALATORS OR MOVING WALKWAYS ({apparatus for raising or lowering persons on theatrical stages or the like A63J5/12} ; funicular railbound systems with rigid ground-supported tracks and cable traction, e.g. cliff railways, B61B9/00; arrangements of ammunition handlers in vessels B63G3/00; hoists, lifts, or conveyors for loading or unloading in general B65G; braking or detent devices controlling normal movements of winding drums or barrels B66D; ship-lifting devices E02C; garages for many vehicles with mechanical means for lifting vehicles E04H6/12; hoists for feeding ammunition or projectiles to launching apparatus or to loading mechanisms F41A9/00) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract A regenerative elevator drive device, a method for buffering energy of a regenerative elevator drive device, and an elevator system are disclosed. The regenerative elevator drive device may include an inverter having a plurality of power components and a converter having a plurality of power components. The regenerative drive may further include a direct current (DC) link bridging the inverter and the converter, the DC link including a first capacitor bridging the inverter and the converter and a second capacitor in parallel with the first capacitor. The regenerative elevator drive device may be a multi-level regenerative drive device. ## Claims ### Claim 1 A regenerative drive device, comprising: an inverter having a plurality of power components; a converter having a plurality of power components; a direct current (DC) link bridging the inverter and the converter, the DC link comprising: one or more internal capacitors bridging the inverter and the converter; an external capacitor in parallel with the one or more internal capacitors wherein the capacitance of the external capacitor is greater than the capacitance of at least one of the one or more internal capacitors; and an inductor located directly between the external capacitor and the one or more internal capacitors. ### Claim 2 (depends on 1) The regenerative drive device of claim 1, wherein the one or more internal capacitors are film capacitors. ### Claim 3 (depends on 1) The regenerative drive device of claim 1, wherein the external capacitor is an electrolytic capacitor, and wherein the one or more internal capacitors are film capacitors. ### Claim 4 (depends on 1) The regenerative drive device of claim 1, wherein drive device is an elevator drive. ### Claim 5 (depends on 1) The regenerative drive device of claim 1, wherein at least one member of the plurality of power components of the inverter is an insulated-gate bipolar transistor. ### Claim 6 (depends on 1) The regenerative drive device of claim 1, wherein at least one member of the plurality of power components of the converter is an insulated-gate bipolar transistor. ### Claim 7 (depends on 1) The regenerative drive device of claim 1, wherein the regenerative drive is a multi-level regenerative drive, wherein the one or more internal capacitors comprises a plurality of internal capacitors. ### Claim 8 (depends on 7) The regenerative drive device of claim 7, wherein the capacitance of the external capacitor is greater than a capacitance of the plurality of internal capacitors, wherein the capacitance of the plurality of internal capacitors comprises a combination of the capacitance of each of the plurality of internal capacitors. ### Claim 9 (depends on 7) The regenerative drive device of claim 7, wherein the plurality of power components of the inverter and the plurality of power components of the converter are arranged having a T-type topology. ### Claim 10 (depends on 7) The regenerative drive device of claim 7, wherein the plurality of power components of the inverter and the plurality of power components of the converter are arranged having a neutral-point-clamped topology. ### Claim 11 (depends on 7) The regenerative drive device of claim 7, wherein the plurality of power components of the inverter and the plurality of power components of the converter are arranged having an advanced T-type neutral point clamped topology. ### Claim 12 (depends on 11) The regenerative drive device of claim 11, wherein at least one member of the plurality of power components of the inverter and at least one member of the plurality of power components of the converter is a reverse-blocking insulated-gate bipolar transistor. ### Claim 13 A method for buffering energy in a regenerative elevator drive device, the regenerative elevator drive device including a inverter having a plurality of power components and a converter having a plurality of power components, the method comprising: providing a direct current (DC) link bridging the inverter and the converter, the DC link comprising: one or more internal capacitors bridging the inverter and the converter for energy buffering; an external capacitor in parallel with the one or more internal capacitors for energy buffering, wherein the capacitance of the external capacitor is greater than the capacitance of at least one of the one or more internal capacitors; and an inductor located directly between the external capacitor and the one or more internal capacitors. ### Claim 14 (depends on 13) The method of claim 13, wherein the regenerative elevator drive device is a multi-level regenerative elevator drive device. ### Claim 15 An elevator system, comprising: an elevator car disposed in a hoistway; a motor operatively connected to the elevator car, the motor generating a thrust force to move the elevator car within the hoistway; a power source operatively connected to the motor, the power source supplying power to the motor; and a regenerative elevator drive device operatively connected to the power source and the motor, the regenerative elevator drive device comprising: an inverter having a plurality of power components; a converter having a plurality of power components; and a direct current (DC) link bridging the inverter and the converter, the DC link comprising: one or more internal capacitors bridging the inverter and the converter; an external capacitor in parallel with the one or more internal capacitors, wherein the capacitance of the external capacitor is greater than the capacitance of at least one of the one or more internal capacitors; and an inductor located directly between the external capacitor and the one or more internal capacitors. ### Claim 16 (depends on 15) The elevator system of claim 15, wherein the regenerative elevator drive device is a multi-level regenerative elevator drive device. ### Claim 17 (depends on 16) The elevator system of claim 16, wherein the plurality of power components of the inverter and the plurality of power components of the converter are arranged having a neutral point clamped, a T-type, or an advanced T-type neutral point clamped topology. ### Claim 18 (depends on 15) The elevator system of claim 15, wherein the external capacitor is accessible independent of the regenerative elevator drive device. ### Claim 19 (depends on 15) The elevator system of claim 15, wherein at least one member of the plurality of power components of the inverter and at least one member of the plurality of power components for the converter is an insulated-gate bipolar transistor. ### Claim 20 (depends on 17) The elevator system of claim 17, wherein at least one member of the plurality of power components of the inverter and at least one member of the plurality of power components for the converter is a reverse-blocking insulated-gate bipolar transistor.