# US 11,909,330 B2 · Current control device and power conversion system employing same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,909,330 B2 - Document ID: US11909330B2 - Status: Granted - Kind: B2 - Application number: 17/500,519 - Filed: 2021-10-13 - Published: 2022-07-14 - Granted: 2024-02-20 - Earliest claimed: 2021-01-11 - Assignees: Delta Electronics (Shanghai) Co., Ltd. - Applicants: Delta Electronics (Shanghai) Co., Ltd. - Inventors: Guoqiao Shen; Guojin Xu; Ning He; Daidong Pan - Web page: https://patentgrep.com/patent/US11909330B2 ## CPC - H02M 1/0025: {Arrangements for modifying reference values, feedback values or error values in the control loop of a converter} - H02M 7/538: in a push-pull configuration (H02M7/5375 takes precedence {; with oscillating arrangements H02M7/53832, H02M7/53846}) - G05F 1/56: using semiconductor devices in series with the load as final control devices (G05F1/461 takes precedence) - H02M 1/32: Means for protecting converters other than automatic disconnection - H02M 3/1584: {with a plurality of power processing stages connected in parallel} - H02M 3/285: {Single converters with a plurality of output stages connected in parallel (parallel operation of a plurality of converters in DC distribution networks H02J1/10)} - H02M 1/007: {Plural converter units in cascade (push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826)} - H02M 1/008: {Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators} - H02M 7/219: in a bridge configuration - 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) - G05F: SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES ## Abstract A current control device and a power conversion system employing the current control device are provided. The current control device controls N power conversion unit(s), where N is a positive integer. The N power conversion units are connected in parallel when N is greater than 1. Each power conversion unit includes a signal input terminal and a current-controlled output terminal electrically connected to an external circuit. The current control device includes a first current sensor and an error compensator. The first current sensor samples a current flowing through the external circuit and acquires a sampling value. The error compensator receives the sampling value and a reference value and generates a compensation value accordingly, and outputs N current command(s) to the N power conversion unit(s) respectively according to the reference value and the compensation value. ## Claims ### Claim 1 A current control device configured to control N power conversion unit(s), wherein N is an integer greater than or equal to 1, the N power conversion units being connected in parallel when N is greater than 1, each of the N power conversion unit(s) comprising a signal input terminal and a current-controlled output terminal electrically connected to an external circuit, the current control device comprising: a first current sensor coupled between the current-controlled output terminal and the external circuit, to sample a current flowing through the external circuit and to acquire a current sampling value; and an error compensator electrically connected to the N power conversion unit(s) and the first current sensor, wherein the error compensator receives the current sampling value and a current reference value and generates a compensation value accordingly, and wherein the error compensator outputs N current command(s) to the N power conversion unit(s) respectively according to the current reference value and the compensation value, wherein the error compensator comprises a compensation unit and a calculation unit, the compensation unit generates the compensation value according to the current sampling value and the current reference value, and wherein the calculation unit outputs the N current command(s) to the N power conversion unit(s) according to the current reference value and the compensation value. ### Claim 2 (depends on 1) The current control device according to claim 1, wherein N is greater than 1, and a sum of the N current commands is equal to a sum of the current reference value and the compensation value. ### Claim 3 (depends on 2) The current control device according to claim 2, wherein the N current commands are equal. ### Claim 4 (depends on 1) The current control device according to claim 1, wherein the compensation unit performs a subtraction operation to the current sampling value and the current reference value to acquire a current error, and wherein the compensation unit generates the compensation value by regulating the current error and limiting compensation amplitude. ### Claim 5 (depends on 1) The current control device according to claim 1, wherein the calculation unit adds the compensation value to the current reference value to obtain a sum, wherein the current command equals the sum when N equals 1, and the calculation unit divides the sum into the N current commands when N is greater than 1. ### Claim 6 (depends on 1) The current control device according to claim 1, wherein the error compensator further comprises a first low-pass filter and a second low-pass filter, the first low-pass filter being coupled between the first current sensor and the compensation unit to receive and filter the current sampling value and outputting the filtered current sampling value to the compensation unit, the second low-pass filter being coupled to the compensation unit to receive and filter the current reference value and outputting the filtered current reference value to the compensation unit. ### Claim 7 (depends on 6) The current control device according to claim 6, wherein a time delay of the second low-pass filter is substantially equal to a sum of time delays of the power conversion unit, the first current sensor, and the first low-pass filter. ### Claim 8 (depends on 1) The current control device according to claim 1, wherein the power conversion unit is one of a DC/DC converter, an AC/AC converter, and a DC/AC converter. ### Claim 9 (depends on 1) The current control device according to claim 1, wherein the power conversion unit comprises a second current sensor configured to detect a current flowing through the corresponding power conversion unit, and a sampling accuracy of the second current sensor is lower than a sampling accuracy of the first current sensor. ### Claim 10 (depends on 1) The current control device according to claim 1, wherein the external circuit is one of a load and a power source. ### Claim 11 A power conversion system, comprising: a power grid, an inverter, and N power conversion unit(s) connected to each other, wherein N is an integer greater than or equal to 1, the N power conversion units being connected in parallel when N is greater than 1, each of the N power conversion unit(s) comprising a signal input terminal and a current-controlled output terminal electrically connected to an external circuit; and a current control device configured to provide current command(s) to the N power conversion unit(s) for controlling current(s) flowing through the N power conversion unit(s), wherein the current control device comprises: a first current sensor coupled between the current-controlled output terminal and the external circuit, to sample a current flowing through the external circuit and to acquire a current sampling value; and an error compensator electrically connected to the N power conversion unit(s) and the first current sensor, wherein the error compensator receives the current sampling value and a current reference value and generates a compensation value accordingly, and wherein the error compensator outputs N current command(s) to the N power conversion unit(s) respectively according to the current reference value and the compensation value, wherein the error compensator comprises a compensation unit and a calculation unit, the compensation unit generates the compensation value according to the current sampling value and the current reference value, and wherein the calculation unit outputs the N current command(s) to the N power conversion unit(s) according to the current reference value and the compensation value. ### Claim 12 (depends on 11) The power conversion system according to claim 11, wherein the error compensator of the current control device is disposed in a controller configured to control the N power conversion unit(s). ### Claim 13 (depends on 11) The power conversion system according to claim 11, comprising N external circuit(s) and N current control device(s), the N external circuit(s) being respectively electrically connected to the N power conversion unit(s), the N current control device(s) being respectively corresponding to the N power conversion unit(s), the error compensator of each of the N current control device(s) being disposed in the corresponding power conversion unit, and the first current sensor of each of the N current control device(s) being configured to detect a current flowing through the corresponding external circuit. ### Claim 14 (depends on 11) The power conversion system according to claim 11, wherein the external circuit is one of a battery and a power generator. ### Claim 15 A current controller to control a power converter having a first terminal and a second terminal electrically connected to an external circuit, the current controller comprising: a first current sensor coupled between the second terminal and the external circuit to acquire a current sampling value associated with a current flowing through the external circuit; and an error compensator electrically connected to the power converter and the first current sensor, wherein the error compensator receives the current sampling value from the first current sensor and generates a compensation value based on the current sampling value and a current reference value, and wherein the error compensator outputs to the power converter a current command calculated based on the current reference value and the compensation value, wherein the error compensator comprises a compensation unit and a calculation unit, the compensation unit generates the compensation value according to the current sampling value and the current reference value, and wherein the calculation unit outputs the calculated current command to the power converter according to the current reference value and the compensation value. ### Claim 16 (depends on 15) The current controller of claim 15, wherein the error compensator further comprise: a first low-pass filter coupled between the first current sensor and the compensation unit, wherein the first low-pass filter receives and filters the current sampling value, and outputs the filtered current sampling value to the compensation unit; and a second low-pass filter coupled to the compensation unit, wherein the second low-pass filter receives and filters the current reference value, and outputs the filtered current reference value to the compensation unit. ### Claim 17 (depends on 15) The current controller of claim 15, wherein the power converter comprises a plurality of power conversion units connected in parallel between the first and second terminals, wherein the error compensator outputs a plurality of current commands respectively to the power conversion units, a sum of said plurality of current commands being equal to a sum of the current reference value and the compensation value. ### Claim 18 (depends on 15) The current controller of claim 15, wherein the power converter comprises a second current sensor to detect a current flowing through the power converter, a sampling accuracy of the second current sensor being lower than that of the first current sensor.