# US 2013/0278235 A1 · Systems and methods for dynamic ac line voltage regulation with energy saving tracking > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0278235 A1 - Document ID: US20130278235A1 - Status: Published application - Kind: A1 - Application number: 13/867,006 - Filed: 2013-04-19 - Published: 2013-10-24 - Earliest claimed: 2012-04-19 - Assignees: Varentec, Inc. - Applicants: Varentec, Inc. - Inventors: Deepakraj M. Divan; Anish Prasai - Web page: https://patentgrep.com/patent/US20130278235A1 ## CPC - G05F 1/12: wherein the variable actually regulated by the final control device is AC (G05F1/625 takes precedence) - G05F 1/253: the transformers including plural windings in series between source and load (G05F1/247 takes precedence) - H02J 3/16: by adjustment of reactive power - H02J 3/18: Arrangements for adjusting, eliminating or compensating reactive power in networks - H02M 5/12: for conversion of voltage or current amplitude only - H02J 3/12: Arrangements for adjusting voltage in AC networks by changing a characteristic of the network load - Y02E 40/30: Reactive power compensation - G05F: SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - 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) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract Systems and methods for dynamic AC line voltage regulation are provided. A simple and cost-effective method for achieving AC line voltage regulation in AC systems including split-phase systems, of which the voltage for each voltage line may be regulated over a specified range, is provided. Buck and boost regulation is achieved for lowering or increasing the line voltage, respectively, with reference to the incoming grid voltage. Systems for dynamic AC line voltage regulation may comprise an AC/AC converter which uses fractionally rated switches and magnetics that handle only a fraction of the load current, resulting in lower costs. The use of an AC snubber further provides safe and robust switching of the main switching devices by eliminating failure prone switching sequences that are dependent on accurate assessment of voltage and/or current polarity for AC or bi-directional switches. ## Claims ### Claim 1 A voltage regulation system, comprising: a converter comprising a set of switches, and a transformer comprising a primary winding and a set of secondary windings, the primary winding coupled to a neutral line, each of the set of secondary windings coupled to a corresponding AC line; and a control module regulating a duty cycle of the converter. ### Claim 2 (depends on 1) The voltage regulation system of claim 1, wherein the control module determines a duty cycle according to a desired voltage of an AC line, wherein the converter generates an additive or a subtractive voltage to be injected in series with the voltage of the AC line in response to the duty cycle of the converter. ### Claim 3 (depends on 1) The voltage regulation system of claim 1, wherein the control module comprises a first control loop and a second control loop in parallel to the first control loop. ### Claim 4 (depends on 3) The voltage regulation system of claim 3, wherein the set of switches are regulated according to the first control loop when the voltage and the current of the voltage regulation system are within a predetermined range. ### Claim 5 (depends on 3) The voltage regulation system of claim 3, further comprising a bypass switch coupled across the primary winding of the transformer, wherein the set of switches are disabled and the bypass switch is enabled according to the second control loop when a line current is above a threshold. ### Claim 6 (depends on 5) The voltage regulation system of claim 5, wherein the bypass switch comprises a thyristor pair and a relay. ### Claim 7 (depends on 1) The voltage regulation system of claim 1, further comprising an active snubber comprising a switch, a resistor, a diode, and a capacitor, wherein the voltage across the capacitor is regulated to track the incoming line voltage when the polarity of the incoming line voltage is positive. ### Claim 8 (depends on 1) The voltage regulation system of claim 1, wherein the voltage regulation system is coupled across a distribution transformer comprising a center-tapped secondary winding. ### Claim 9 (depends on 8) The voltage regulation system of claim 8, further comprising an electromagnetic interference (EMI) filter coupled to the distribution transformer. ### Claim 10 (depends on 1) The voltage regulation system of claim 1, further comprising an energy saving tracking module. ### Claim 11 (depends on 10) The voltage regulation system of claim 10, wherein the energy saving tracking module tracks a variation of real and reactive power consumed when the line voltage varies. ### Claim 12 (depends on 11) The voltage regulation system of claim 11, wherein the energy saving tracking module determines a sensitivity metric measuring the percent change in real and reactive power to a small imperceptible change in line voltage. ### Claim 13 (depends on 11) The voltage regulation system of claim 11, wherein the energy saving tracking module determines a voltage point corresponding to a minimum power consumption and regulates the line voltage to the voltage point.