JP2010238010A5 - - Google Patents

Description

First converter control device provided by aspects of the present invention includes a plurality of power supplies, a plurality of DC / DC converter connected respectively to the output terminals of said plurality of power supply devices, and the plurality of power supply devices One of a connection state provided between the plurality of DC / DC converters, wherein the plurality of output ends are not connected to each other, and a connection state where at least two output ends are connected among the plurality of output ends. Connection means for setting the connection state, and an inverter connected to all the output terminals of the plurality of DC / DC converters, converting DC power output from these DC / DC converters into AC power and outputting the AC power to the system. was applied to the system interconnection inverter system, a converter control device for controlling driving of the plurality of DC / DC converter, any two of said DC / By comparing the C converter input voltage, and a determination means for output of the power supply devices connected thereto, it is determined whether or not it is connected to each other, said output end by said discriminating means being connected to each other The plurality of DC / DC converters connected to the power supply device determined to be output a PWM signal generated based on the output efficiency of the power supply device group including the plurality of power supply devices whose output ends are connected to each other. For the DC / DC converter connected to the power supply device that is determined by the determining means that the output end is not connected to any of the other output ends, the output efficiency of the determined power supply device is determined. PWM signal output means for outputting a PWM signal generated in this manner.

According to this configuration, a PWM signal corresponding to a power supply device group composed of a plurality of power supply devices whose output ends are connected to each other is input to the DC / DC converter connected to these power supply devices, and the output end is connected to the other end. A PWM signal corresponding to a power supply device that is not connected to any of the output terminals is input to a DC / DC converter connected to the power supply device. Therefore, it is not necessary to switch the PWM signal generation method in accordance with the connection state of the output terminals of the respective power supply devices. Since the input voltage of the DC / DC converter that is originally input to generate the PWM signal is used to determine whether the output terminals are connected to each other, the hardware configuration of the conventional converter control device is changed. Can be used.

In a preferred embodiment of the present invention, when the determining means determines that all the output terminals of the plurality of power supply devices are connected to each other, the plurality of power supply devices are determined to be in a parallel state. And determining means for determining that the plurality of power supply devices are in an independent state when it is determined that none of the output ends of the plurality of power supply devices is connected to another output end, and the PWM signal When the determination unit determines that the parallel state is established, the output unit outputs all the DC / DC PWM signals generated based on the output efficiency of the power supply unit group including all the power supply units connected in parallel. and outputs to the converter, when it is determined that the independent state by the judging means, a PWM signal generated based on the output efficiency of each power supply connected to the power supply DC / Respectively output to C converter.

In a preferred embodiment of the present invention, the PWM signal output means includes a power supply for a DC / DC converter connected to any one of the plurality of power supply devices among the plurality of DC / DC converters. A PWM signal for controlling the power output from the device to be maximized is output, and among the plurality of DC / DC converters, a plurality of power supply devices having the output terminals connected to each other are connected. The plurality of DC / DC converters output PWM signals for control so that the power of the power supply device group output from the power supply devices is maximized.

In a preferred embodiment of the present invention, when the difference between the input voltage of one DC / DC converter and the input voltage of the other DC / DC converter is equal to or less than a predetermined value, the discrimination means It is determined that the output terminal of the power supply device connected to the converter and the output terminal of the power supply device connected to the other DC / DC converter are connected to each other, and the input voltage of the one DC / DC converter is determined. When the difference between the input voltage of the other DC / DC converter is larger than the predetermined value, the output terminal of the power supply device connected to the one DC / DC converter and the other DC / DC converter are connected. It is determined that the output terminals of the power supply device are not connected to each other .

The grid-connected inverter system provided by the second aspect of the present invention includes a plurality of power supply devices , a plurality of DC / DC converters respectively connected to output terminals of the plurality of power supply devices, and the plurality of power supplies. Any of a connection state in which the plurality of output ends are not connected to each other and a connection state in which at least two of the plurality of output ends are connected is provided between the device and the plurality of DC / DC converters Connecting means for setting the connection state, converter control means for controlling the driving of the plurality of DC / DC converters , and all output terminals of the plurality of DC / DC converters. a system interconnection inverter system including an inverter for outputting to the system converts DC power to be output to the AC power, the converter control unit By comparing input voltages of any two of the DC / DC converters, it is possible to determine whether the output terminals of the power supply devices connected to the DC / DC converters are connected to each other; The plurality of DC / DC converters connected to the power supply devices that are determined to have the output terminals connected to each other are based on the output efficiency of the power supply device group that includes the plurality of power supply devices that have the output terminals connected to each other. For the DC / DC converter connected to the power supply device that outputs the generated PWM signal and is determined that the output terminal is not connected to any of the other output terminals by the determining means, the determined And a PWM signal output means for outputting a PWM signal generated based on the output efficiency of the power supply device .

According to this configuration, the connection state of the output terminals of the respective power supply devices can be switched by the connection means . Therefore, the If you sunlight status changes to some of the power supply after installing each power supply, even when changing the part to a power unit group constituted by different power supplies in performance, the output end of the connection This can be handled by switching the state. Further, it is not necessary to switch the PWM signal generation method in accordance with the switching of the connection means .

The voltage comparison unit 91 compares the voltage values V1, V2, and V3 input from the voltage sensors 81, 82, and 83, respectively, and determines whether the connection device 3 is in a parallel state or an independent state. is there. The voltage comparison unit 91 outputs the determination result as a signal to the PWM signal generation unit 92 . In the present embodiment, when the connection device 3 is in a parallel state, the voltages on the input side of the DC / DC converters 41, 42, and 43 are equal, and when the connection device 3 is in an independent state, the DC / DC converter 41 , 42 and 43 are used to determine the state of the connection device 3 by utilizing the different voltages on the input side.

When the difference between the voltage value V3 and the voltage value V1 is equal to or less than the predetermined voltage value ΔV (S4: YES), that is, when it is determined that the voltage value V3 and the voltage value V1 are the same voltage, It is determined that there is a signal, and a signal indicating the parallel state is output to the PWM signal generator 92 (S5).

Note that if the difference between the voltage value V2 and the voltage value V3 is equal to or smaller than the predetermined voltage value ΔV in step S3, it may be determined that the parallel state is established, and step S4 may be omitted and the process may proceed to step S5. Further, when the difference between the voltage value V1 and the voltage value V2 is equal to or smaller than the predetermined voltage value ΔV in step S2, it is determined that the state is in parallel , and steps S3 and S4 are omitted and the process proceeds to step S5. .

In the flowchart shown in the figure, if the difference between the voltage value V2 and the voltage value V3 is equal to or smaller than the predetermined voltage value ΔV in step S13 (S13: YES), the process proceeds to step S15. If the voltage value V1 and the voltage value V2 are the same voltage and the voltage value V2 and the voltage value V3 are the same voltage, the voltage value V3 and the voltage value V1 need not be compared and are in a parallel state. This is because it can be estimated. If the difference between the voltage value V2 and the voltage value V3 is not less than or equal to the predetermined voltage value ΔV in step S13 (S13: NO), the process proceeds to step S17. This is because if the voltage value V1 and the voltage value V2 are the same voltage and the voltage value V2 and the voltage value V3 are different, it can be estimated that the voltage value V3 and the voltage value V1 are different without being compared. is there. Similarly, if the difference between the voltage value V2 and the voltage value V3 is equal to or smaller than the predetermined voltage value ΔV in step S18 (S18: YES), it can be estimated that the voltage value V3 and the voltage value V1 are different. Proceed to 20 .