# US 2017/0256944 A1 · Power control circuit and method for stabilizing a power supply > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0256944 A1 - Document ID: US20170256944A1 - Status: Published application - Kind: A1 - Application number: 15/474,715 - Filed: 2017-03-30 - Published: 2017-09-07 - Earliest claimed: 2010-10-04 - Assignees: City University of Hong Kong; Versitech Limited - Inventors: Shu Yuen Ron HUI; Chi Kwan LEE; Felix Fulih WU - Web page: https://patentgrep.com/patent/US20170256944A1 ## CPC - H02J 3/18: Arrangements for adjusting, eliminating or compensating reactive power in networks - H02J 3/00142: {Oscillations concerning frequency} - H02J 3/12: Arrangements for adjusting voltage in AC networks by changing a characteristic of the network load - H02J 3/16: by adjustment of reactive power - H02J 3/1814: having reactive elements actively controlled by bridge converters, e.g. unified power flow controllers [UPFC] or controlled series voltage compensators - H02J 3/1842: having reactive elements actively controlled by bridge converters, e.g. active filters or static compensators [STATCOM] - Y02E 40/10: Flexible AC transmission systems [FACTS] - Y02E 40/20: Active power filtering [APF] - Y02E 40/30: Reactive power compensation - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract The present invention provides a power control circuit connectable to a load adapted to receive a power supply, the power control circuit adapted to absorb power from the power supply and adapted to deliver power to the power supply to stabilize at least one electrical parameter of the power supply. The present invention also provides an associated method of stabilizing at least one electrical parameter of a power supply connectable to a load, the method including absorbing power from the power supply or delivering power to the power supply. The at least one electrical parameter of the power supply includes parameters such as voltage and frequency. ## Claims ### Claim 1 A power control circuit having an input side and an output side, the power control circuit connectable on the input side to AC mains and connectable on the output side to a non-critical load, the power control circuit adapted to receive power from the AC mains when connected and to deliver power to the AC mains to stabilize a frequency of the AC mains. ### Claim 2 (depends on 1) A power control circuit according to claim 1 wherein the power absorbed and delivered by the power control circuit includes reactive power, or active power, or both. ### Claim 3 (canceled) ### Claim 4 (canceled) ### Claim 5 (canceled) ### Claim 6 (canceled) ### Claim 7 (depends on 1) A power control circuit according to claim 1 wherein the power control circuit maintains the AC mains at a nominal supply frequency. ### Claim 8 (depends on 7) A power control circuit according to claim 7 wherein the non-critical load has a load voltage and the power control circuit decreases the load voltage when the frequency of the AC mains is lower than the nominal supply frequency. ### Claim 9 (depends on 7) A power control circuit according to claim 7 wherein the non-critical load has a load voltage and the power control circuit increases the load voltage when the frequency of the AC mains is higher than the nominal supply frequency. ### Claim 10 (depends on 9) A power control circuit according claim 9 wherein the load voltage is increased to exceed a nominal supply voltage. ### Claim 11 (depends on 7) A power control circuit according to claim 7 wherein the non-critical load has a load voltage and the power control circuit provides an auxiliary voltage to increase or decrease the load voltage. ### Claim 12 (depends on 1) A power control circuit according to claim 1 including a power controller for absorbing and delivering power thereby enabling the power control circuit to absorb and deliver power. ### Claim 13 (depends on 12) A power control circuit according to claim 12 wherein the power controller absorbs and delivers reactive power, or active power, or both. ### Claim 14 (depends on 12) A power control circuit according to claim 12 wherein the power controller is a reactive power controller. ### Claim 15 (depends on 12) A power control circuit according to claim 12 wherein the power controller is connected in series with the AC mains and the non-critical load. ### Claim 16 (depends on 12) A power control circuit according to claim 12 wherein the power controller is connected in parallel across the non-critical load. ### Claim 17 (depends on 12) A power control circuit according to claim 12 including a second power controller, and wherein the first power controller is connected in series with the AC mains and the non-critical load, and the second power controller is connected in parallel across the first power controller and the non-critical load. ### Claim 18 (depends on 17) A power control circuit according to claim 17 wherein the first and second power controllers are interconnected through a power transfer connection. ### Claim 19 (depends on 18) A power control circuit according to claim 18 wherein the power transfer connection includes an energy storage element. ### Claim 20 (depends on 19) A power control circuit according to claim 19 wherein the energy storage element is a capacitor connected in parallel across both the first and second power controllers. ### Claim 21 (depends on 18) A power control circuit according to claim 18 wherein either or both the first and second power controllers absorb and deliver power to the other of the first and second power controllers through the power transfer connection, and the other of the first and second power controllers absorbs and delivers power to the AC mains or to the non-critical load. ### Claim 22 (depends on 18) A power control circuit according to claim 18 wherein the first power controller absorbs and delivers active power to the second power controller through the power transfer connection, and the second power controller absorbs and delivers active power to the AC mains. ### Claim 23 (depends on 18) A power control circuit according to claim 18 wherein the second power controller absorbs and delivers power to the first power controller through the power transfer connection, and the first power controller absorbs and delivers power to the non-critical load. ### Claim 24 (depends on 12) A power control circuit according to claim 12 including a second power controller, and wherein the first power controller is connected in series with the AC mains and the non-critical load, and the second power controller is connected in parallel across the non-critical load. ### Claim 25 (depends on 12) A power control circuit according to claim 12 wherein the power controller includes a power inverter and an energy storage element. ### Claim 26 (depends on 25) A power control circuit according to claim 25 wherein the energy storage element is a capacitor or an inductor. ### Claim 27 (depends on 25) A power control circuit according to claim 25 wherein the power inverter has at least two levels. ### Claim 28 (depends on 25) A power control circuit according to claim 25 wherein the power inverter is a pulse-width modulation power inverter. ### Claim 29 (canceled) ### Claim 30 (canceled) ### Claim 31 (canceled) ### Claim 32 (canceled) ### Claim 33 (canceled) ### Claim 34 (canceled) ### Claim 35 (canceled) ### Claim 36 (canceled) ### Claim 37 (depends on 1) A power control circuit according to claim 1 including a frequency controller for detecting the frequency of the AC mains and providing a frequency control signal based on whether the frequency of the AC mains is above or below a nominal supply frequency, the power control circuit referring to the frequency control signal to absorb or deliver power when the frequency of the AC mains is above or below the nominal supply frequency, thereby maintaining the AC mains at the nominal supply frequency. ### Claim 38 (depends on 37) A power control circuit according to claim 37 wherein the frequency control signal is provided to a power controller for absorbing and delivering power thereby enabling the power control circuit to absorb and deliver power. ### Claim 41 (depends on 1) A power control circuit according to claim 1 wherein the non-critical load is a hot water heater or a lighting non-critical load. ### Claim 42 (depends on 1) A power control circuit according to claim 1 wherein the power control circuit is provided integrally with the non-critical load. ### Claim 43 (depends on 1) A power control circuit according to claim 1 including a bypass circuit having a bypass switch operable to connect the AC mains directly to the non-critical load through the bypass circuit. ### Claim 44 (depends on 1) A power control circuit according to claim 1 wherein the AC mains has a dynamically changing power profile and the power of the non-critical load follows the dynamically changing power profile. ### Claim 45 (depends on 1) A power control circuit according to claim 1 wherein the AC mains is generated by one or more dynamically changing renewable energy sources. ### Claim 46 A method, comprising: providing a power control circuit having an input side and an output side, the power control circuit connectable on the input side to AC mains and connectable on the output side to a non-critical load; and stabilizing a frequency of the AC mains when connected, wherein the stabilizing comprises: storing power from the AC mains; and delivering the power to the AC mains. ### Claim 47 (depends on 46) A method according to claim 46 wherein the power being absorbed and being delivered includes reactive power, or active power, or both. ### Claim at position 46 48-50. (canceled) ### Claim 51 (depends on 46) A method according to claim 46 further including delivering power to the non-critical load to stabilize the frequency of the AC mains. ### Claim 52 (depends on 46) A method according to claim 46 wherein the method includes maintaining the AC mains at a nominal supply frequency. ### Claim 53 (depends on 52) A method according to claim 52 wherein the non-critical load has a load voltage and the method includes decreasing the load voltage when the frequency of the AC mains is lower than the nominal supply frequency. ### Claim 54 (depends on 52) A method according to claim 52 wherein the non-critical load has a load voltage and the method includes increasing the load voltage when the frequency of the AC mains is higher than the nominal supply frequency. ### Claim 55 (depends on 54) A method according to claim 54 wherein the load voltage is increased to exceed a nominal supply voltage. ### Claim 56 (depends on 52) A method according to claim 52 wherein the non-critical load has a load voltage and the method includes providing an auxiliary voltage to increase or decrease the load voltage. ### Claim 57 (depends on 46) A method according to claim 46 including providing a power controller for absorbing and delivering power. ### Claim 58 (depends on 57) A method according to claim 57 wherein the power controller is connected in series with in series with the AC mains and the non-critical load. ### Claim 59 (depends on 57) A method according to claim 57 wherein the power controller is connected in parallel across the non-critical load. ### Claim 60 (depends on 57) A method according to claim 57 including providing a second power controller, wherein the first power controller is connected in series with the AC mains and the non-critical load, and the second power controller is connected in parallel across the first power controller and the non-critical load. ### Claim 61 (depends on 57) A method according to claim 57 including providing a second power controller, wherein the first power controller is connected in series with the AC mains and the non-critical load, and the second power controller is connected in parallel across the non-critical load. ### Claim 62 (canceled) ### Claim 63 (canceled) ### Claim 64 (depends on 46) A method according to claim 46 including providing a frequency controller for detecting the frequency of the AC mains and providing a frequency control signal based on whether the frequency of the AC mains is above or below a nominal supply frequency, referring to the frequency control signal to absorb or deliver power when the frequency of the AC mains is above or below the nominal supply frequency, thereby maintaining the AC mains at the nominal supply frequency. ### Claim 65 (depends on 46) A method according to claim 46 including providing a power control circuit for absorbing and delivering power. ### Claim 66 (depends on 65) A method according to claim 65 wherein the power control circuit is provided integrally with the non-critical load. ### Claim 67 (depends on 46) A method according to claim 46 wherein the AC mains has a dynamically changing power profile and power is absorbed from the AC mains or delivered to the AC mains such that the power of the non-critical load follows the dynamically changing power profile.