# US 10,374,527 B2 · Regenerative braking system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,527 B2 - Document ID: US10374527B2 - Status: Granted - Kind: B2 - Application number: 14/584,114 - Filed: 2014-12-29 - Published: 2015-07-09 - Granted: 2019-08-06 - Earliest claimed: 2014-01-09 - Assignees: Beckman Coulter, Inc. - Applicants: Beckman Coulter, Inc. - Inventors: Jason L. Hessler; Ronald T. Keen - Web page: https://patentgrep.com/patent/US10374527B2 ## CPC - H02P 3/14: by regenerative braking - B04B 9/10: Control of the drive; Speed regulating {(for solid bowl screw centrifuges B04B1/2016)} - H02J 3/1892: the arrangements being an integral part of the loads or of their control circuits - H02P 23/26: Power factor control [PFC] - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - B04B: CENTRIFUGES (high-speed drum mills B02C19/11; domestic spin driers D06F; analysing, measuring or monitoring physical or chemical properties of samples during centrifuging, see the relevant subclasses for these procedures, e.g. G01N) - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY ## Abstract A circuit for delivering electrical energy to an AC mains connection is disclosed. The circuit includes a voltage source and a switch connected between the voltage source and the AC mains connection. The switch operates to transfer current from the voltage source to the AC mains. The circuit further includes a controller to control the switch. The controller operates to generate a simulated signal that represents a waveform of the AC mains without any distortion present on the waveform of the AC mains. ## Claims ### Claim 1 A circuit to deliver electrical energy between a load and an AC mains, the circuit comprising: a switchable device coupling the load to the AC mains; and a controller including a synthesizer, a voltage control loop, and a current control loop, wherein the circuit is configured to transfer current from the AC mains to the load in a first operating mode and to transfer current from the load to the AC mains in a second operating mode, the load in the second operating mode producing a load voltage, and wherein the synthesizer synthesizes a rectified sine signal synchronized with the AC mains, wherein the voltage control loop generates a voltage signal as the difference between the load voltage and a reference voltage, and wherein the current control loop drives the switchable device in proportion to the product of the voltage signal and the rectified sine signal. ### Claim 2 (depends on 1) The circuit of claim 1, further comprising an edge detector coupled to the AC mains and to the synthesizer, the edge detector configured to produce a sync signal corresponding to the zero-crossing points of the AC mains. ### Claim 3 (depends on 1) The circuit of claim 1, wherein the switchable device includes a switching bridge rectifier. ### Claim 4 (depends on 1) The circuit of claim 1, wherein the load includes a motor coupled to an inverter, the motor in the second operating mode decelerating to deliver current through the inverter producing the load voltage. ### Claim 5 (depends on 1) The circuit of claim 1, further comprising an inductor disposed between the AC mains and the switchable device. ### Claim 6 (depends on 4) The circuit of claim 4, wherein the motor includes an AC induction motor. ### Claim 7 An inverter system of an instrument for transferring power between an AC mains and a load, the instrument having a normal mode of operation in which current is drawn from the AC mains to the load and a regenerative mode of operation in which current is transferred from the load to the AC mains, the load producing a load voltage in the regenerative mode of operation, the inverter system comprising: at least one inductor electrically coupled to the AC mains; a switching device electrically coupled between the at least one inductor and the load; and a controller comprising: a reference signal generator for synthesizing a simulated reference signal synchronized with a line voltage signal; a voltage control loop for generating an error voltage, the error voltage corresponding to an error between a load voltage and a reference voltage; and a current control loop for controlling the switching device based on the product of the reference signal and the error voltage. ### Claim 8 (depends on 7) The inverter system of claim 7, further comprising an edge detector configured to detect zero-crossing points of the line voltage signal, the edge detector being electrically coupled to the AC mains and the reference signal generator. ### Claim 9 (depends on 7) The inverter system of claim 7, further comprising a current sensor arranged and configured to measure current flow through the at least one inductor, wherein the controller electrically coupled to the current sensor, the switching device and the load and configured to receive a current sense signal from the current sensor to match the current sense signal with the product of the reference signal and the error voltage. ### Claim 10 (depends on 7) The inverter system of claim 7, wherein the current control loop generates a drive signal in proportion to the product of the reference signal and the error voltage. ### Claim 11 (depends on 7) The inverter system of claim 7, wherein the voltage control loop includes a voltage monitor electrically coupled to the load. ### Claim 12 (depends on 7) The inverter system of claim 7, wherein the voltage control loop includes a voltage inverter for inverting the voltage feedback signal during the regenerative mode of operation. ### Claim 13 (depends on 7) The inverter system of claim 7, wherein the switching device is a bridge rectifier. ### Claim 14 (depends on 7) The inverter system of claim 7, wherein the reference signal is configured to have a rectified sine waveform. ### Claim 15 (depends on 2) The circuit of claim 2, wherein the sync signal comprises a square waveform signal. ### Claim 16 (depends on 7) The inverter system of claim 7, wherein the reference signal simulates the waveform of the AC mains, without distortion effects of the AC mains.