JP5665639B2 - Power supply - Google Patents

Description

  The present invention relates to a power supply device that turns on an LED using solar power generation, and relates to, for example, a technique for improving power conversion efficiency.

  In recent years, electric power systems using solar power generation are rapidly spreading toward the realization of a low-carbon society. In the lighting industry, there is a growing need for LED lighting fixtures that have lower power consumption and longer life than incandescent and fluorescent lighting fixtures. The currently mainstream photovoltaic power generation system converts sunlight into a DC voltage with a solar module combined with a solar panel, and inputs the output voltage to a power converter. The power converter is a device that boosts the input DC voltage by a booster circuit, and converts it into an AC voltage of commercial frequency by an inverter drive circuit and an AC filter circuit. This power converter is generally called a power conditioner. This is a mechanism in which the commercial AC voltage output from the power conditioner is distributed to each device (for example, Patent Document 1).

  Patent Document 1 is a system for lighting LED lighting fixtures by photovoltaic power generation. A DC voltage output from a solar module is boosted by a booster circuit, a constant current circuit is used to generate a constant DC current and flow it to the LED. The LED is caused to emit light (for example, Patent Document 2).

JP 2002-116830 A JP 2009-200372 A

  However, since the LED is a light emitting element that is lit by direct current, for example, when the LED lighting device is lit in the solar power generation system of Patent Document 1, the direct current voltage of the solar module is boosted by the booster circuit of the power conditioner, and the inverter Since it is converted into a high frequency voltage by the drive circuit and converted into a commercial AC voltage by the AC filter circuit, power loss occurs. Furthermore, since the commercial AC voltage output from the power conditioner is converted again into a DC voltage by the LED lighting device, there is a problem that power loss due to the circuit is further added.

  For example, when the LED lighting is turned on in the solar power generation system of Patent Document 2, if the output voltage of the solar module is low, such as at night or when it is cloudy, a predetermined LED current cannot be supplied. There is a problem that requires a device to be installed.

  Therefore, an object of the present invention is to provide a power supply device that reduces the conversion loss of the DC voltage output from the solar module 100.

The power supply device of this invention is
Having a plurality of solar panels for converting sunlight into DC voltage, inputting the DC voltage output from the solar module that outputs the DC voltage from the plurality of solar panels, and converting the input DC voltage to AC A power conversion unit that converts the voltage into a voltage and supplies the converted AC voltage to a light source lighting device that turns on the light source;
A DC voltage detection circuit for detecting the magnitude of the DC voltage output from the solar module;
The DC voltage output from the solar module, a DC voltage power transmission path capable of transmitting power directly to the light source lighting device without going through the power converter,
A direct power transmission mode in which the direct current voltage output from the solar module is directly transmitted to the light source lighting device via the direct current voltage power transmission path according to the magnitude of the direct current voltage detected by the direct current voltage detection circuit. And a switching control unit that switches between an AC voltage supply mode in which the AC voltage converted by the power conversion unit is supplied from the power conversion unit to the light source lighting device.

  By this invention, the loss of the power conversion at the time of supplying the electric power based on a solar module to a LED lighting apparatus can be suppressed.

1 is a system configuration diagram of an LED lighting system 1000 using photovoltaic power generation according to Embodiment 1. FIG. FIG. 3 shows an arrangement example of the LED lighting system 1000 according to the first embodiment. FIG. 3 is a circuit block diagram of the power conditioner 200 according to the first embodiment. FIG. 3 is a circuit block diagram of LED lighting apparatus 600 according to Embodiment 1. FIG. 3 is an operation sequence diagram of the LED lighting system 1000 according to the first embodiment. 1 is a configuration diagram of an LED illumination system 1000 in the case of a single LED illumination device in Embodiment 1. FIG. FIG. 6 is a layout diagram of an LED lighting system 1000 using photovoltaic power generation according to Embodiment 2. The figure which shows the AC / DC switching circuit of FIG. 7 concretely. FIG. 10 is another layout diagram of LED lighting system 1000 using photovoltaic power generation in the second embodiment. The figure which shows the AC / DC switching circuit of FIG. 9 concretely.

Embodiment 1 FIG.
FIG. 1 shows an LED lighting system 1000 (power supply device) using photovoltaic power generation according to the first embodiment.
FIG. 2 is a diagram illustrating an example in which the LED lighting system 1000 of FIG. 1 is installed in a three-story building.

The LED lighting system 1000 using solar power generation in FIG. 1 will be described.
The LED lighting system 1000
(1) a solar module 100 in which a plurality of solar panels 101 are combined;
(2) a power conversion device 200 (power conditioner: hereinafter referred to as a power conditioner 200) connected to the solar module 100;
(3) An AC / DC switching circuit 300 that is connected to the output end of the power conditioner 200 and receives supply of the AC voltage and the DC voltage to the LED lighting device by receiving control from the control circuit 500;
(4) a DC voltage detection circuit 400 that detects the magnitude of the DC voltage output by the solar module 100;
(5) a control circuit 500 (switching control unit) that controls the power conditioner 200 (power conversion unit) and the AC / DC switching circuit 300 based on the voltage detected by the DC voltage detection circuit 400;
(6) It consists of a plurality of LED lighting devices 600 (light source lighting devices) connected to the AC / DC switching circuit 300. As shown in FIG. 2, the LED lighting system 1000 includes a solar module 100, a power conditioner 200, an AC / DC switching circuit 300, a DC voltage detection circuit 400, and a control on the roof of a building (for example, a three-story building). A circuit 500 is installed, and LED lighting devices 600a, 600b,. The LED lighting device may be referred to as an LED lighting device 600 when it is not particularly necessary to distinguish between them.

(AC / DC switching circuit 300)
The AC / DC switching circuit 300
(1) Switches SW1 and SW2 connected to the wiring between the LED lighting devices from the output of the solar module 100,
(2) switches SW3 and SW4 connected to the wiring between the output of the power conditioner 200 and the LED lighting device;
(3) “Switches SW5 and SW6” (external voltage supply units) connected between the commercial power supply wiring and the switches SW3 and SW4.
(4) The AC / DC switching circuit 300 switches the switch SW <b> 1 to the switch SW <b> 6 under the control of the control circuit 500, and supplies the power supplied to the LED lighting device to the DC voltage from the solar module 100 and the AC voltage from the power conditioner 200. Or it switches to the alternating voltage from commercial alternating current power supply 1 (external alternating current power supply). The switches SW1 to SW6 use switches such as MOSFETs, transistors, or relays.
(5) Note that the DC line 700 and the switches SW1 and SW2 in FIG. 1 are a DC voltage transmission path capable of transmitting the DC voltage output from the solar module 100 directly to the LED lighting device without passing through the power conditioner 200. Configure.

(Control circuit 500)
The control circuit 500 controls the output of the power conditioner 200 and switching of the switch SW1 to the switch SW6 according to the DC voltage level detected by the DC voltage detection circuit 400. The control circuit 500 converts the DC voltage output from the solar module 100 into a DC voltage transmission path configured by the DC line 700 and the switches SW1 and SW2 according to the magnitude of the DC voltage detected by the DC voltage detection circuit 400. The direct power transmission mode in which power is transmitted directly to the LED lighting device via the power supply and the alternating voltage supply mode in which the AC voltage converted by the power conditioner 200 is supplied from the power conditioner 200 to the LED lighting device are switched.

  FIG. 3 is a circuit block diagram showing an internal circuit of the power conditioner 200 shown in FIG. The internal circuit of the power conditioner 200 includes a booster circuit 210, an inverter drive circuit 220, an AC filter circuit 230, a booster control circuit that controls these circuits, an inverter control circuit, and the like. The configuration in FIG. 3 is an example, and is not limited to the circuit configuration in FIG. Other circuit configurations may be used as long as a DC voltage is input and a commercial frequency AC voltage is output.

  FIG. 4 is a circuit block diagram showing an internal circuit of the LED lighting device 600 of FIG. The LED lighting device 600 includes a booster circuit 610, a constant current circuit 620, and a boost control circuit and a constant current control circuit that control these circuits. The LED lighting device 600 can operate with any voltage regardless of whether an AC voltage is supplied from the AC / DC switching circuit 300 or a DC voltage is supplied.

(Description of operation)
Next, the whole operation | movement of the LED lighting system 1000 by sunlight output change is demonstrated.

FIG. 5 is an example of a change in DC voltage output from the solar module 100 in one day. (A)-(f) has shown the following.
FIG. 5A is a waveform diagram of an output voltage waveform output by the solar module 100.
FIG. 5B is a state diagram showing the on / off states of the switches SW1 and SW2.
FIG. 5C is a state diagram showing the on / off states of the switches SW3 and SW4.
FIG. 5D is a state diagram showing the on / off states of the switches SW5 and SW6.
FIG. 5E is a waveform diagram showing an output voltage waveform of the power conditioner 200.
FIG. 5F is a waveform diagram showing an input voltage waveform input to the LED lighting device 600.

  As shown in FIG. 5A, when the daytime is fine, the DC voltage level output from the solar module 100 is large during the daytime and is set to V1. Sunlight gradually decreases in the evening and becomes zero at night. In the morning, sunlight rises little by little, and again reaches a predetermined DC voltage level V1 in the daytime.

  The LED lighting device 600 is designed so that desired brightness is obtained at the DC voltage level V1.

  In FIG. 5, in the daytime, the solar module 100 generates a voltage sufficient to turn on the LED lighting device 600. The control circuit 500 short-circuits (turns on) the switches SW1 and SW2 of the AC / DC switching circuit 300, and opens (turns off) the switches SW3 to SW6. Therefore, the LED lighting device 600a and the like operate by supplying power only with the DC voltage output from the solar module 100. At this time, the control circuit 500 stops the output operation of the power conditioner 200.

  5, in the evening, when the output voltage of the solar module 100 gradually decreases, the first threshold voltage V (1) of the DC voltage detection circuit 400 is reached. The first threshold voltage V (1) is set to a level at which the LED lighting device 600 cannot maintain desired brightness. When the first threshold voltage V (1) is reached, a signal is input from the DC voltage detection circuit 400 to the control circuit 500. When this signal is input, the control circuit 500 opens the switches SW1, SW2, SW5, and SW6 and shorts the switches SW3 and SW4. Therefore, the LED lighting device 600a and the like operate by supplying power at the output voltage of the power conditioner 200.

  In FIG. 5, the sunlight output voltage further decreases from evening to night, and the power conditioner 200 can no longer output a desired output voltage. The operation limit input voltage of the power conditioner 200 is set to the second threshold value V (2).

  In FIG. 5, when the output voltage of the solar module 100 decreases and becomes less than the second threshold voltage V (2), the DC voltage detection circuit 400 outputs a control signal to the control circuit 500. When this control signal is input, the control circuit 500 opens the switches SW1 and SW2 and shorts the switches SW3 to SW6. Thereby, the LED lighting apparatus 600 operates by supplying power from a commercial power source. At this time, the control circuit 500 stops the output operation of the power conditioner 200.

  In FIG. 5, it becomes sunrise from night, the output voltage of the solar module 100 increases and reaches the second threshold voltage V (2) (the output voltage of the solar module 100 is the second threshold voltage V (2). Then, a control signal is output from the DC voltage detection circuit 400 to the control circuit 500. With this control signal, the control circuit 500 opens the switches SW1, SW2, SW5, and SW6, and switches the switches SW3 and SW4. The LED lighting device 600 is operated by supplying power from the power conditioner 200.

  In FIG. 5, sunrise occurs from night, the output voltage of the solar module 100 rises, exceeds the second threshold voltage V (2), and the LED lighting device 600 is lit by supplying power with the power conditioner 200. When the first threshold voltage V (1) is reached (when the first threshold voltage is exceeded), the DC voltage detection circuit 400 outputs a control signal to the control circuit 500, and the control circuit 500 is triggered by this control signal. Opens the switches SW4 to SW6 by short-circuiting the switches SW1 and SW2. Therefore, the LED lighting device 600 operates by supplying power only from the output voltage of the solar module 100. At this time, the control circuit 500 stops the output operation of the power conditioner 200.

  As described above, when the output voltage output from the solar module 100 exceeds the first threshold voltage V (1), the control circuit 500 operates the AC / DC switching circuit 300 to output the solar module 100. The voltage is directly input to the LED lighting device 600 and the output operation of the power conditioner 200 is stopped. Therefore, the power conversion loss by the power conditioner 200 can be reduced.

  In addition, in Embodiment 1, although the case where the LED lighting system 1000 was installed in a three-story building was demonstrated, it is clear that you may install in another building.

  FIG. 6 is a diagram showing a case where there is one LED lighting device 600. In Embodiment 1 described above, the case where a plurality of LED lighting devices 600a and the like are used as the LED lighting system 1000 has been described. However, as shown in FIG. 6, the number of LED lighting devices 600 may be one. Absent.

Embodiment 2. FIG.
The second embodiment will be described with reference to FIGS. In the second embodiment, a case where a plurality of AC / DC switching circuits 300 are provided will be described.

First, a description will be given with reference to FIGS.
FIG. 7 shows a case where the AC / DC switching circuit 300 for each floor is provided for the LED lighting device on each floor. In FIG. 7, the LED lighting system 1000 includes an AC / DC switching circuit 300 (3) for the third floor, an AC / DC switching circuit 300 (2) for the second floor, and an AC / DC switching circuit 300 (1) for the first floor.
FIG. 8 is a diagram showing a specific configuration of the AC / DC switching circuit 300 of FIG. In FIG. 8, only the first floor and the second floor are shown in order to simplify the configuration, and each floor has a case where two LED lighting devices are provided. As shown in FIGS. 7 and 8, the LED lighting system 1000 includes an AC / DC switching circuit 300 for each floor for the LED lighting device on each floor.

  The solar module 100, the power conditioner 200, the DC voltage detection circuit 400, the control circuit 500, and the AC / DC switching circuits 300 (1), 300 (2), and 300 (3) are installed on the roof of the building. To the LED lighting device installed on each floor.

  In general, when DC is intermittently connected with a switch, it is easy to draw an arc on the contact of the switch, and in the worst case, the switch may not be cut off or the switch contact may be welded to cause a failure of the switch element. This becomes more noticeable as the connected load is larger.

  Therefore, the AC / DC switching circuit 300 is divided into AC / DC switching circuits 300 (1) to 300 (3), and direct current is distributed to each floor, thereby reducing the DC current flowing through the DC switching switch of the AC / DC switching circuit 300. be able to. This can reduce the stress on the DC changeover switch.

  9 and 10 are diagrams showing examples in which each LED lighting device is provided with a DC switching circuit unit 300-1 (a switch unit having SW1 and SW2). FIG. 10 is a diagram showing a specific configuration of the DC switching circuit unit 300-1 of FIG. In FIG. 10, only the third floor is shown for simplification, and two LED lighting devices 603a and 603b are shown. 7 and 8 of the second embodiment, the case where the AC / DC switching circuit 300 (1) and the like are provided on each floor has been described. However, as shown in FIGS. 9 and 10, the DC / DC switching circuit unit of the AC / DC switching circuit 300 is provided. 300-1 may be arranged in the vicinity of each LED lighting device 600. As shown in FIG. 10, the DC voltage transmission path composed of the DC line 700 and the switches SW1 and SW2 branches for each LED lighting device and is turned on by receiving control in each branch. A DC switching circuit unit 300-1 (switch unit) that conducts power transmission of the DC voltage output from the solar module 100 to the LED lighting device is disposed. When the control circuit 500 switches to the direct power transmission mode described in the first embodiment, the control circuit 500 performs control to turn on the switches SW1 and SW2 of the DC switching circuit unit 300-1 arranged in each branch, and the power control 200 Stop the operation.

  Thus, by providing the direct current switching circuit unit 300-1 corresponding to each LED lighting device, the stress applied to the switch element at the time of direct current switching can be equivalent to one LED lighting device. Therefore, the stress applied to the switch element at the time of DC switching can be further reduced.

  1000 LED lighting system, 100 solar module, 200 power converter, 300 AC / DC switching circuit, 400 DC voltage detection circuit, 500 control circuit, 600 LED lighting device, 700 DC line, SW1 to SW6 switch.

Claims (4)

Having a plurality of solar panels for converting sunlight into DC voltage, inputting the DC voltage output from the solar module that outputs the DC voltage from the plurality of solar panels, and converting the input DC voltage to AC A power conversion unit that converts the voltage into a voltage and supplies the converted AC voltage to a light source lighting device that turns on the light source;
A DC voltage detection circuit for detecting the magnitude of the DC voltage output from the solar module;
The DC voltage output from the solar module, a DC voltage power transmission path capable of transmitting power directly to the light source lighting device without going through the power converter,
A direct power transmission mode in which the direct current voltage output from the solar module is directly transmitted to the light source lighting device via the direct current voltage power transmission path according to the magnitude of the direct current voltage detected by the direct current voltage detection circuit. And a switching control unit that switches between an AC voltage supply mode in which the AC voltage converted by the power conversion unit is supplied from the power conversion unit to the light source lighting device. The power converter is
Supplying the AC voltage to a plurality of the light source lighting devices;
The DC voltage transmission path is
A switch that branches for each of the plurality of light source lighting devices, and that conducts transmission of the DC voltage output from the solar module to the light source lighting device by being turned on by receiving control in each branch. Part is placed,
The switching control unit
2. The power supply device according to claim 1, wherein when switching to the direct power transmission mode, control is performed to turn on the switch unit disposed in each of the branches, and the operation of the power conversion unit is stopped. . The switching control unit
When the magnitude of the DC voltage detected by the DC voltage detection circuit is greater than a preset first threshold value, the mode is switched to the direct power transmission mode, and when the magnitude is less than the first threshold value, the mode is switched to the AC voltage supply mode. The power supply device according to claim 1, wherein the power supply device is a power supply device. The power supply device further includes:
Connected to the output end of the power converter, and supplied with an AC voltage output from an external AC power source by receiving control, the AC voltage from the external AC power source is supplied to the output end via the output end. An external voltage supply unit for supplying to the light source lighting device;
The switching control unit
When the magnitude of the DC voltage detected by the DC voltage detection circuit is less than the second threshold, the external voltage supply unit is provided with a second threshold that is smaller than the first threshold. The power supply apparatus according to claim 3, wherein an AC voltage output from the external AC power supply is supplied to the output terminal of the power conversion unit by controlling.

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