Solar power supply system and driving method of same

A solar power supply system includes a load device, a solar panel that converts light energy into electrical energy, an energy storage device storing the electrical energy from the solar panel, a charge/discharge control device, and a transformer device. The charge/discharge control device selects one of the energy storage device and the solar panel as an operation power supply to the charge/discharge control device and generates an output voltage. The transformer device transforms the output voltage of the charge/discharge control device into a driving voltage to drive the load device. A feedback circuit generates a feedback signal according to an actual power consumption of the load device. A power detector detects an instant output power of the charge/discharge control device. A power regulator minimizes the output power of the charge/discharge control device according to the instant output power of the charge/discharge control device and the actual power consumption of the load device.

BACKGROUND

1. Technical Field

The present disclosure relates solar power supply systems, and more particularly, to solar power supply systems and driving method capable of automatically adjusting output power of the solar power supply systems according to power consumption of a load device.

2. Description of Related Art

Solar cells are employed to convert incident solar radiation energy into electrical energy. Solar power supply systems typically employ a solar cell as a power source to drive a load device. Moreover, solar power supply systems also include a transformer device for transforming the electrical energy from the solar cell into a driving voltage to drive a load device. However, the transformer device does not automatically adjust its output power according to power consumption of the load device or different load devices. Therefore, transformation efficiency of the transformer device is low and the solar power supply systems using the transformer device have a low efficiency.

Therefore, a new solar power supply system and a driving method of the same are desired to overcome the above-described shortcomings.

DETAILED DESCRIPTION

Reference will now be made to the drawings to describe various inventive embodiments of the present disclosure in detail, wherein like numerals refer to like elements throughout.

Referring toFIG. 1, a solar power supply system100according to one embodiment of the present disclosure is shown. The solar power supply system100includes a solar panel10, a charge/discharge control device20, an energy storage device30, a transformer device40, and a load device50.

The solar panel10collects light energy and converts the light energy into electrical energy. The energy storage device30stores the electrical energy from the solar panel10, where the electrical energy can serve as a backup power supply to drive the load device50. The charge/discharge control device20controls a charge process of the energy storage device30if the energy storage device30is fully charged. The charge/discharge control device20controls a discharge process of the energy storage device30if the solar panel10normally works and generates an electrical energy.

The transformer device40is connected between the charge/discharge control device20and the load device50. The transformer device40transforms an output voltage provided from the charge/discharge control device20into a driving voltage and provides the driving voltage to drive the load device50.

The transformer device40includes a feedback circuit42. The feedback circuit42detects an output power of the transformer device40and generates a feedback signal according to the output power of the transformer device40. The output power of the transformer device40is approximately equal to a power consumption of the load device50. That is, the feedback signal also denotes power consumptions of the load devices50. The transformer device40provides different output power to different load devices50, correspondingly. In one embodiment, the feedback circuit42detects the driving voltage and a corresponding driving current outputted from the transformer device40to the load device50, and then calculates the output power of the transformer device40according to the driving voltage and the corresponding driving current. In one embodiment, the transformer device40can be a direct current (DC) to DC converter or a DC to alternating current (AC) converter.

The charge/discharge control device20is connected between the solar panel10and the energy storage device30. The charge/discharge control device20receives the electrical energy from the solar panel10and transforms the electrical energy into a charge voltage for charging the energy storage device30until the energy storage device30is fully charged. The charge/discharge control device20also connects to the transformer device40and provides the output voltage to the transformer device40. The charge/discharge control device20selects one of the energy storage devices30and the solar panel10as its operation power supply.

The charge/discharge control device20includes a power detector22and a power regulator24. The power regulator24connects to both the power detector22and the feedback circuit42.

The power detector22detects an instant output power of the charge/discharge control device20. In one embodiment, the power detector22instantly detects the output voltage and a corresponding output current of the charge/discharge control device20, and then calculates the instant output power of the charge/discharge control device20according the output voltage and the corresponding output current of the charge/discharge control device20.

The power regulator24receives not only the instant output power of the charge/discharge control device20from the power detector22, but also the feedback signal from the feedback circuit42. In one embodiment, when different load devices50are connected to the transformer device40, the power regulator24automatically minimizes the output power of the charge/discharge control device40according to the instant output power of the charge/discharge control device20and the power consumptions of the load devices50. In this embodiment, the power regulator24reasonably adjusts the output voltage and the corresponding output current of the charge/discharge control device20according to the instant output power of the charge/discharge control device20and the feedback signal to adjust the output power of the charge/discharge control device20.

Alternatively, when the load device50works from a first operation mode to a second operation mode to arise different power consumption, the power regulator24can also automatically minimize the output power of the charge/discharge control device according to the instant output power of the charge/discharge control device20and the feedback signal.

Because the output voltage of the charge/discharge control device20can automatically be adjusted according to the power consumption of the load device50, that is, the power supply to the transformer device40can be adjusted according to the power consumption of the load device50. Therefore, the transforming efficiency of the transformer device40is improved. Furthermore, because the output power of the charge/discharge control device20is automatically minimized according to the power consumption of the load device50, the transforming efficiency of the charge/discharge control device20is also improved. Thus, by employing the charge/discharge control device20and the transformer device40, the solar power supply system100saves power.

Referring toFIG. 2, a driving method of the solar power supply system100is described as following.

First, the feedback circuit42detects the power consumption of the load device50. In one embodiment, when a new load device50is connected to the transformer device40, the feedback circuit42detects the replacement of the load device50by detecting the actual power consumption of new load device50and generates a corresponding feedback signal. In this embodiment, the feedback circuit42detects a driving voltage and a driving current output from the transformer device40. The feedback circuit42calculates the actual power consumption of the new load device50by multiplying the driving voltage and a driving current of transformer device40.

Second, the power detector22detects an initial output power of the charge/discharge control device20. In one embodiment, after the load device50is replaced by the new load device50, the power detector22detects an initial output voltage and a corresponding initial output current of the charge/discharge control device20. The power detector22calculates the initial output power of the charge/discharge control device20by multiplying the initial output voltage and the corresponding initial output current of the charge/discharge control device20.

Third, the power regulator24of the charge/discharge control device20receives both the initial output power of the charge/discharge control device20and the actual power consumption of the new load device50. In this embodiment, the power regulator24receives the initial output power of the charge/discharge control device20from the power detector22of the charge/discharge control device20. The power regulator24receives the feedback signals from the feedback circuit42. The feedback signals denote the actual power consumption of the new load device50.

Fourth, the power regulator24automatically minimizes the output power of the charge/discharge control device20according to the initial output power of the charge/discharge control device20and the actual power consumption of the new load device50. In this embodiment, the power regulator24, reasonably adjusts the initial output voltage and the corresponding initial output current of the charge/discharge control device20according to the initial output power of the charge/discharge control device20, and the new power consumption of the load device50to minimize the output power of the charge/discharge control device20.

In this embodiment, when the transformer device40connects to an old load device50, an output voltage and an output current of the charge/discharge control device20provided to the transformer device40are defined as a primary output voltage and a primary output current. An output power calculated by multiplying the primary output voltage and the primary output current is defined as a primary output power of the charge/discharge control device20.

When the transformer device40connects to a new load device50with less power consumption, the transformer device40provides a new output power to drive the new load device50. The feedback circuit42generates a new feedback signal according to the new output power and sends the new feedback signal to the power regulator24. The new feedback signal also denotes the new power consumption of the new load device50.

After the new output power provided by the transformer device40approximately reaches a constant value, the power detector22detects an initial output voltage and an initial output current of the charge/discharge control device20to calculate an initial power of the charge/discharge control device20.

After that, the power regulator24slightly decreases the initial output voltage of the charge/discharge control device20to a reference output voltage and provides the reference output voltage to the transformer device40. After the new output power provided by the transformer device40, approximately reaches the constant value again, the power detector22detects a reference current of the charge/discharge control device20corresponding to the reference output voltage. Then the power detector22calculates a reference power of the charge/discharge control device20by multiplying the reference current and the reference output voltage.

If the reference power is less than the initial output power, the power regulator24gradually decreases the initial output voltage of the charge/discharge control device20until the calculated reference power reaches a minimum value. On the contrary, if the reference power is larger than the initial output power, the power regulator24gradually increases the initial output voltage of the charge/discharge control device20until the calculated reference power reaches a minimum value.