# US 9,882,387 B2 · Reactive power compensation system and method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,882,387 B2 - Document ID: US9882387B2 - Status: Granted - Kind: B2 - Application number: 15/600,818 - Filed: 2017-05-22 - Published: 2017-11-30 - Granted: 2018-01-30 - Earliest claimed: 2016-05-31 - Assignees: Lsis Co., Ltd. - Applicants: Lsis Co., Ltd. - Inventors: Yong-Kil Choi - Web page: https://patentgrep.com/patent/US9882387B2 ## CPC - H02J 3/1821: using shunt compensators - H02J 3/01: Arrangements for reducing harmonics or ripples - H02J 3/16: by adjustment of reactive power - H02J 3/1864: using reactive elements connected in series with semiconductor switches, e.g. static VAR compensators [SVC], thyristor-controlled reactors [TCR] or thyristor-switched capacitors [TSC] - H02J 3/26: Arrangements for eliminating or reducing asymmetry in polyphase networks - H03K 17/72: having more than two PN junctions; having more than three electrodes; having more than one electrode connected to the same conductivity region - Y02E 40/10: Flexible AC transmission systems [FACTS] - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract The present disclosure relates to a reactive power compensation system includes a first measurement unit, a second measurement unit, a reactive power compensation unit, and a controller. The first measurement unit measures impedance of each of at least one load. The second measurement unit measures a voltage and current provided to the at least one load. The reactive power compensation unit compensates the leading reactive power or the lagging reactive power. The controller monitors a change of the impedance in real time, checks a change of the voltage or current according to the change of the impedance, and controls the reactive power compensation unit according to a result of the check to compensate the leading reactive power or the lagging reactive power. ## Claims ### Claim 1 A reactive power compensation system which compensates leading reactive power or lagging reactive power, the system comprising: a first measurement unit configured to measure impedance of each of at least one load; a second measurement unit configured to measure a voltage and current provided to the at least one load; a reactive power compensation unit configured to compensate the leading reactive power or the lagging reactive power; and a controller configured to monitor a change of the impedance in real time, check a change of the voltage or current according to the change of the impedance, and control the reactive power compensation unit according to a result of the check to compensate the leading reactive power or the lagging reactive power, wherein the controller determines based on the change of the voltage or current whether a specific load causing the change of the impedance is a Thyristor-switched load or a Thyristor-controlled load. ### Claim 2 (depends on 1) The reactive power compensation system of claim 1, wherein the reactive power compensation unit comprises: a Thyristor-controlled compensation unit that compensates the leading reactive power; and a Thyristor-switched compensation unit that compensates the lagging reactive power. ### Claim 3 (depends on 2) The reactive power compensation system of claim 2, wherein the controller determines that the specific load is a Thyristor-switched load when a phase of current is ahead of a phase of a voltage, and generates a first control signal to compensate the leading reactive power and provides the first control signal to the Thyristor-controlled compensation unit. ### Claim 4 (depends on 3) The reactive power compensation system of claim 3, wherein the first control signal is a signal to adjust the phase of current to be synchronized with the phase of a voltage. ### Claim 5 (depends on 2) The reactive power compensation system of claim 2, wherein the controller determines that the specific load is a Thyristor-controlled load when a phase of a voltage is ahead of a phase of current, and generates a second control signal to compensate the lagging reactive power and provides the second control signal to the Thyristor-switched compensation unit. ### Claim 6 (depends on 5) The reactive power compensation system of claim 5, wherein the second control signal is a signal to adjust the phase of a voltage to be synchronized with the phase of current. ### Claim 7 A method of compensating reactive power, the method comprising: measuring impedance of each of at least one load; measuring a voltage and current provided to the at least one load; monitoring a change of the impedance in real time; checking a change of the voltage or current according to the change of the impedance; and compensating leading reactive power or lagging reactive power according to a result of the check, wherein the checking of the change of the voltage or current comprises determining based on the change of the voltage or current whether a specific load causing the change of the impedance is a Thyristor-switched load or a Thyristor-controlled load. ### Claim 8 (depends on 7) The method of claim 7, further comprising: determining that the specific load is a Thyristor-switched load when a phase of current is ahead of a phase of a voltage; and generating a first control to compensate the leading reactive power. ### Claim 9 (depends on 7) The method of claim 7, further comprising: determining that the specific load is a Thyristor-controlled load when a phase of a voltage is ahead of a phase of current; and generating a second control signal to compensate the lagging reactive power.