JP2012054142A - Led lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED lighting system which controls the power supply to LED lighting devices so as to effectively utilize the maximum generated power of a solar battery and to consume the whole of the power thereof, thereby decreasing a change to a commercial power supply source as much as possible even if the power generation amount of the solar battery varies.SOLUTION: In the LED lighting system, the power obtained from a solar battery 1 is supplied to LED lighting devices 4 and 5-9, and when the power is insufficient, power is supplemented from a commercial power supply source 2. The solar battery 1 always operates at a maximum output power, and an power control section 34 in an power control unit 3 controls the power consumption of the LED lighting devices 4-9 so that the whole of the output power of the solar battery 1 is consumed. In the LED lighting devices 4-9, the light adjustment control sections 43-93 receiving a control signal from the power control section 34 control constant current circuits 41-91 to control the magnitude of current ILED 4-9 being supplied to LED units 42-92 including LED elements.

Description

  The present invention relates to an LED lighting system using a solar cell as a power source.

  Conventionally, a storage battery has been provided, and when the generated power of the solar cell is greater than the power consumed by the device, such as charging power, surplus generated power is returned to the commercial power source and sold to the power company. In the case where the storage battery is insufficiently charged due to the above-described causes and the necessary lighting power cannot be supplied to the LED element, an LED lighting device is proposed that secures illuminance by supplying power from a commercial power source (Patent Document 1).

  In addition, a power supply device that supplies electric power from a commercial power source has been proposed in the case where the output from the solar battery decreases at night or the like without a storage battery (Patent Document 2).

  By the way, it is inevitable that the output from the solar cell fluctuates depending on the amount of solar radiation, etc. However, in response to these fluctuations, the operating point of the solar cell is changed to always take out the maximum output (MPPT: Maximum Power Point Tracking). ) To effectively extract the electric power from the solar cell.

JP 2007-82270 A JP 61-167341 A

Akira Takano, et al., Photovoltaic Power Generation Association, “Design and Construction of Photovoltaic Power Generation System” 3rd edition, Ohmsha, September 20, 2006, chapter 3 P36-P37

However, in a solar power generation system that does not have a storage battery and does not sell power to an electric power company, surplus power cannot be processed. Therefore, even if control (MPPT) for extracting maximum power from the solar battery is performed, load power is higher than that. If it is less, it is necessary to discard the power, which reduces power efficiency.
Further, in the case of a system that switches between power from a solar battery and power from a commercial power source, if frequent switching to the commercial power source occurs, extra electricity costs are generated.

Therefore, in the LED lighting system, there is a problem to be solved in that the maximum generated power of the solar cell is effectively used so that switching to the commercial power source is reduced as much as possible even if the power generation amount of the solar cell changes.
An object of the present invention is to provide an LED illumination system capable of avoiding extra electricity bills by switching to a commercial power source as much as possible even when the amount of power generated by a solar cell changes.

  In order to solve the above problems, an LED lighting system according to the present invention uses a solar cell as a power source, receives output power data from an MPPT circuit, and controls the power value of the lighting device so as to consume the maximum generated power. It is characterized by that. That is, this LED lighting system always operates at the maximum output power in an LED lighting system that supplies power obtained from a solar cell to an LED lighting device and replenishes power from a commercial power source when the power is insufficient. The power consumption of the LED lighting device is controlled so as to consume all the output power of the solar cell.

  According to the present LED lighting system, the solar cell is always controlled to operate at the maximum output power, and the power consumption of the LED lighting device is controlled so as to match the maximum generated power. All the generated power can be consumed by the LED lighting device.

  Also, in this LED lighting system, when there are a plurality of LED lighting devices, the power value of the LED lighting device with low priority is controlled, so the LED lighting device with high priority eliminates the change in illuminance as much as possible, and due to the illuminance change The influence can be suppressed.

  The LED lighting system further includes a power control unit that supplies power to each LED lighting device and controls a power value in each LED lighting device, and the power control unit is obtained by the solar cell. MPPT unit that operates to receive maximum power and take out the maximum power, power measurement unit that measures the power consumption of the entire LED lighting device, power from the MPPT unit, and power supplemented from commercial power supply The power addition unit, and the supply power amount output from the MPPT unit and the power consumption amount measured by the power measurement unit are compared, and all the power output from the MPPT unit is consumed by the LED lighting device. Thus, it can be assumed that a power control unit that controls the power consumption of the LED lighting device is provided. Furthermore, in the LED lighting system, each LED lighting device receives a power supply from the power adding unit of the power control unit and outputs a constant power, and the constant power from the constant power circuit. An LED unit including an LED element that is turned on when supplied, and a control signal for controlling the power consumption from the power control unit of the power control unit, and controls a power value output from the constant power circuit It can be assumed that a light control unit is provided.

According to this LED lighting system, the frequency of switching to the commercial power source can be reduced by controlling the power consumption of the LED lighting device while efficiently taking out the maximum power for the illumination from the solar cell, and the commercial power source is used. This can reduce the electricity bill.
In addition, even when there are multiple LED lighting devices or when the power generation amount of the solar panel varies, the power value of each LED lighting device is automatically set according to the variation, so dimming adjustment manually There is no need to do.
In addition, for example, by controlling the power value of low-priority lighting devices such as windows and warehouses where changes in illuminance are not anxious, even if the illuminance is changed to adjust power consumption, The influence can be reduced.

It is a block diagram which shows one Embodiment of the LED lighting system by this invention. It is a flowchart which shows an example of operation | movement of the electric power control part in the LED lighting system by this invention.

  FIG. 1 shows a block configuration which is an embodiment of an LED lighting system according to the present invention. The power from the solar cell 1 is controlled by the MPPT unit 31 of the power control unit 3 so that the maximum power is taken out. This power is voltage-converted by the DC / DC converter 32, and the power measuring unit 33 measures the current consumption supplied to the entire LED illumination through the power measuring unit 33, and passes through the power adding unit 36, for example, six units. To the LED lighting devices 4-9. The power adding unit 36 is configured by diode connection as shown in the figure, and the power from the solar cell 1 is preferentially set by setting the input voltage from the solar cell 1 higher than the input voltage from the commercial power source. Are supplied to the LED lighting devices 4 to 9. Here, although six LED lighting devices were used, the number is not limited to this. The power control unit 34 compares the power amount output from the MPPT unit 31 with the power consumption amount measured by the power measurement unit 33, and the power output from the MPPT unit 31 is all in the LED lighting devices 4 to 9. The power consumption of the LED lighting devices 4 to 9 is controlled so as to be consumed.

  A commercial power supply 2 is also connected to the power control unit 3. When the amount of power generated by the solar cell is small due to lack of sunlight or at night, the power from the solar cell 1 decreases and the input voltage on the solar cell side of the power adding unit 36 decreases. It is turned on and power is supplied from a commercial power source. Even if power is replenished from the commercial power supply, all the generated power of the solar cell 1 is supplied to the LED lighting device (load) by the MPPT control and balanced by the power adding unit 36. The shortage is supplied from commercial power. That is, when the power from the solar cell 1 is insufficient, the power from the commercial power source 2 is converted into a DC voltage by the AC / DC conversion unit 35, and the power addition unit 36 compensates for the power shortage from the solar cell 1. It is supplied to the lighting devices 4-9.

  Since the LED lighting devices 4 to 9 have the same configuration, the LED lighting device 4 will be described. A constant current circuit 41 that receives power from the power adding unit 36 and controls the current to a predetermined value as a constant power circuit is provided. The constant current circuit 41 supplies a constant current to the LED unit 42 on which the LED element is mounted. Drive with. The LED unit 42 can change the luminous intensity of the LED element by changing the input constant current value. The constant current value output from the constant current circuit 41 is controlled by the dimming control unit 43 that receives a signal from the power control unit 34 of the power control unit 3. Here, the light control is performed by changing the current value of the LED unit 42, but the ON / OFF duty of the supplied power may be changed by PWM (Pulse Width Modulation).

  An example of the operation of the current control unit 34 of the power control unit 3 for the LED lighting devices 4 to 9 is shown in a flowchart in FIG. The operation of the power control unit 34 will be described based on FIG. In step 11 (abbreviated as “S11”, the same applies hereinafter), the power control unit 34 reads the generated power Pin of the current solar cell from the MPPT 31. Pin is controlled by MPPT 31 to output the maximum power. In S <b> 12, the power consumption Pout of the entire LED lighting devices 4 to 9 is read from the power measuring unit 33.

  In S13, the supplied power (Pin × η) is compared with the power consumption Pout. Here, η (eta) is the conversion efficiency of the DC / DC converter 32 and is set to, for example, about 0.95 (= 95%). The supplied power (Pin × η) is the power that can be actually supplied to the entire LED lighting devices 4 to 9. If the power consumption Pout is greater than the supplied power (Pin × η), the dimming control units 43, 53,... 93 are controlled in a direction to decrease the LED illumination current ILEDi (i = 4 to 9) in S15. However, if the current ILEDi is lowered too much, the required illuminance cannot be obtained. Therefore, in S14, the current value is compared with the lower limit value IMIN. In this case, the insufficient power is replenished from the commercial power source 2. Here, even if the current ILEDi of all the LED lighting devices 4 to 9 is not lowered, the current ILEDi of a specific LED lighting device that does not bother the change in illuminance, for example, by being installed near a window or in a warehouse, is lowered. It may be.

  On the other hand, if the supplied power (Pin × η) is larger than the consumed power Pout in S13, the generated power of the solar cell 1 has a margin, and the current ILEDi is increased in S17. However, if the current ILEDi is excessively increased, the LED element is deteriorated or broken. In S16, the current ILEDi is not increased when compared with the upper limit value IMAX. In this case, surplus power from the solar cell 1 that cannot be consumed by the LED lighting device is discarded. Therefore, if the solar cell 1 is installed so that the maximum power generation amount of the solar cell 1 is equal to IMAX, cost performance is improved. If the power consumption Pout is equal to the supplied power (Pin × η) in S13, this state is maintained.

  By controlling in this way, it operates so that the generated power from the solar cell and the power consumption of the LED lighting device become equal, so the maximum power obtained by MPPT can be used efficiently. In other words, when lighting is constantly turned on, such as in a commercial facility, excessive power consumption of the solar cell does not occur much by matching the power consumption of all LED lighting devices with the maximum output of the solar cell. In addition, the number of installed solar cell panels can be minimized. Furthermore, when the output of the solar cell is reduced, the power consumption of the LED lighting is reduced within the generated power of the solar cell by performing dimming control of the LED lighting instead of immediately replenishing the insufficient power by relying on the commercial power supply. As a result, it is possible to reduce power consumption by performing illumination within the generated power of the solar cell and using a commercial power source as much as possible.

DESCRIPTION OF SYMBOLS 1 Solar cell 2 Commercial power supply 3 Electric power control unit 4,5, ... 9 LED lighting apparatus 31 MPPT part (MPPT: Maximum Power Point Tracking)
32 DC / DC conversion unit 33 Power measurement unit 34 Power control unit 35 AC / DC conversion unit 36 Power addition unit 41, 51, ... 91 Constant current circuit 42, 52, ... 92 LED unit 43, 53, ... 93 Dimming control Part

Claims (8)

In an LED lighting system that supplies power obtained from a solar cell to an LED lighting device and replenishes power from a commercial power source when the power is insufficient,
The LED lighting system, wherein the power consumption of the LED lighting device is controlled so as to consume all the output power of the solar cell that always operates at the maximum output power. The LED lighting system according to claim 1.
The LED illumination system comprising a plurality of the LED illumination devices, wherein the power consumption control is performed from the LED illumination device having a low priority. The LED lighting system according to claim 1 or 2,
A power control unit for supplying power to each LED lighting device and controlling a power value in each LED lighting device;
The power control unit includes an MPPT unit that operates to receive maximum power from the input of power obtained by the solar cell, a power measurement unit that measures power consumption of the entire LED lighting device, and the MPPT unit. A power adding unit that adds power supplemented from the commercial power source and power supplied from the commercial power supply, and compares the amount of power supplied from the MPPT unit with the amount of power consumed measured by the power measuring unit, and outputs from the MPPT unit An LED lighting system comprising: a power control unit that controls the power consumption of the LED lighting device so that all the electric power to be consumed is consumed by the LED lighting device. The LED lighting system according to claim 3.
Each of the LED lighting devices includes a constant power circuit that receives power supplied from the power adding unit of the power control unit and outputs constant power, and an LED element that lights up when supplied with the constant power from the constant power circuit And a dimming control unit that receives a control signal for controlling the power consumption from the power control unit of the power control unit and controls a power value output from the constant power circuit. LED lighting system characterized by the above. The LED lighting system according to claim 4.
The LED power system, wherein the constant power circuit changes the power value by current value control or pulse width control. The LED lighting system according to claim 3 or 4,
The power control unit controls the dimming control unit in a direction to decrease the amount of power supplied to each LED unit when the power consumption is larger than the supply power amount.
The power control unit compares the amount of power supplied to each LED unit with a lower limit value, and if the power amount falls below the lower limit value, the power control unit reduces the power amount without reducing the power amount. LED lighting system characterized by being replenished from The LED lighting system according to claim 3 or 4,
The power control unit controls the dimming control unit in a direction to increase the amount of power supplied to each LED unit when the supplied power amount is larger than the consumed power amount,
The power control unit compares the power amount supplied to the LED units with an upper limit value, and discards surplus power without increasing the power amount when the power amount exceeds the upper limit value. LED lighting system characterized. The LED lighting system according to claim 3 or 4,
The power control unit controls the dimming control unit to maintain the amount of power supplied to each LED unit when the supplied power amount is equal to the consumed power amount. system.

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