Power conversion apparatus having multi-level structure
A power conversion apparatus according to an embodiment of the present invention comprises: a plurality of converters connected to a plurality of cell strings, respectively, and one control unit for applying a control signal to each of plurality of converters, wherein the plurality of converters constitute a multi-level.
1 . A power conversion apparatus comprising:
a plurality of converters each connected to a plurality of cell strings;
a plurality of auxiliary power supply unit configured to supply driving power to each of the plurality of converters; and
a control unit configured to apply a control signal for each of the plurality of converters,
wherein the plurality of converters constitute a multi-level,
wherein each of plurality of the auxiliary power supply unit comprises two-stage regulators connected in a cascade,
wherein the two-stage regulators comprise a step-down regulator and a step-up regulator,
wherein, when a preset target voltage of the auxiliary power supply is lower than a lowest voltage among the plurality of cell strings, the step-down regulator operates, and
wherein, when the preset target voltage of the auxiliary power supply is higher than a highest voltage among the plurality of cell strings, the step-up regulator operates.
2 . The power conversion apparatus according to claim 1 ,
wherein the plurality of converters receive the control signals and perform maximum power point tracking control.
3 . The power conversion apparatus according to claim 1 ,
wherein the plurality of converters are connected in cascode.
4 . The power conversion apparatus according to claim 1 ,
wherein the control unit monitors at least one of input signals of the plurality of converters, output signals of the plurality of converters, or currents flowing in inductors included in each of the plurality of converters.
5 . The power conversion apparatus according to claim 4 ,
wherein the control unit transmits the monitored at least one of the input signals, the output signals, or the currents to outside through power line communication (PLC).
6 . The power conversion apparatus according to claim 4 ,
wherein the control unit comprises:
a first control unit configured to apply the control signals so that the plurality of converters perform maximum power point tracking control; and
a second control unit configured to monitor at least one of the currents flowing in the inductors included in each of the plurality of converters, and to transmit the monitored at least one of the currents to outside.
7 . The power conversion apparatus according to claim 1 ,
wherein the control unit individually generates the control signal for each of the plurality of converters corresponding to each of the plurality of cell strings according to an output signal of each of the plurality of cell strings.
8 . The power conversion apparatus according to claim 1 ,
wherein the control signals for the plurality of converters are applied in synchronization.
9 . The power conversion apparatus according to claim 1 ,
wherein the control signals for the plurality of converters are applied with a predetermined phase difference.
10 . The power conversion apparatus according to claim 9 ,
wherein the phase difference varies according to a number of the plurality of converters constituting the multi-level.
11 . The power conversion apparatus according to claim 1 ,
wherein the control signal for one of the plurality of converters comprises a PWM signal for a switching device included in the one of the plurality of converters.
12 . The power conversion apparatus according to claim 1 ,
wherein each of the plurality of the cell strings comprises one or more cells.
13 . A solar module comprising:
a plurality of cell strings each comprising one or more solar cells;
a plurality of converters connected to each of the cell strings respectively;
a plurality of auxiliary power supply unit configured to supply driving power to each of the plurality of converters; and
a control unit configured to monitor information of each of the plurality of converters and apply a control signal to each of the plurality of converters according to the monitored information,
wherein the plurality of converters constitute a multi-level,
wherein each of plurality of the auxiliary power supply unit comprises two-stage regulators connected in a cascade,
wherein the two-stage regulators comprise a step-down regulator and a step-up regulator,
wherein, when a preset target voltage of the auxiliary power supply is lower than a lowest voltage among the plurality of cell strings, the step-down regulator operates, and
wherein, when the preset target voltage of the auxiliary power supply is higher than a highest voltage among the plurality of cell strings, the step-up regulator operates.
14 . The solar module according to claim 13 ,
wherein the plurality of converters are connected in cascode.
15 . The solar module according to claim 13 ,
wherein the control unit monitors at least one of input signals of the plurality of converters, output signals of the plurality of converters, or currents flowing in inductors included in each of the plurality of converters.
16 . The solar module according to claim 15 ,
wherein the control unit transmits the monitored at least one of the input signals, the output signals, or the currents to outside through power line communication (PLC).
17 . The solar module according to claim 15 ,
wherein the control unit comprises:
a first control unit configured to apply the control signals so that the plurality of converters perform maximum power point tracking control; and
a second control unit configured to monitor at least one of the currents flowing in the inductors included in each of the plurality of converters, and transmit the monitored at least one of the currents to outside.
18 . The solar module according to claim 13 ,
wherein the control unit individually generates the control signal for each of the plurality of converters corresponding to each cell string according to an output signal of each of the plurality of cell strings.
19 . The solar module according to claim 13 ,
wherein the control signals for the plurality of converters are applied in synchronization or applied with a predetermined phase difference.
20 . The solar module according to claim 19 ,
wherein the phase difference varies according to a number of the plurality of converters constituting the multi-level.