TW201539956A - Low-light solar boost converter and control method therefor - Google Patents

Abstract

The present disclosure provides a low-light solar boost converter and a control method therefore. The control method comprises: the boost converter starting to operate in a PWM mode; determining whether the voltage of the input terminal is larger than a reference input voltage, the boost converter operating in the PWM mode when the voltage of the input terminal is larger than the reference input voltage, otherwise the boost converter operating in a burst mode, wherein a burst period of the burst mode increases when the voltage of the input terminal decreases; during the burst mode determining whether the voltage of the output terminal is less than a first preset output voltage, the boost converter operating in the PWM mode when the voltage of the output terminal is less than the first preset output voltage, otherwise the boost converter operating in the burst mode. And the on-switch period of burst mode is proportional to the output voltage of solar panel. The switching loss is reduced as the incident light intensity is low.

Description

Low illumination solar boost converter and control method thereof

The invention relates to a boost converter, and in particular to a low illumination solar boost converter and a control method thereof.

Solar energy is a promising clean energy source. Even though many design and manufacturing technologies were invented in the last fifty to six decades, efficiency and cost structures remain the core issues of this clean energy collection. Based on outdoor predictable solar illumination and indoor low-light illumination, photovoltaic energy collection is still not popular in our lives. Improvements in efficiency and design have recently been invented more because of environmental pollution and energy exhaustion. Solar panels with ruthenium-based crystal modification and plated structure have been introduced to the market every year. However, photovoltaic energy conversion is still the bottleneck of this clean energy pole.

Today, there are various types of current collection methods depending on the types of solar panels. Due to the durability and cost structure, germanium-based solar panels are the most likely source of solar energy compared to III-V compounds, II-VI compounds, organic thin films, and the like. Common collector techniques as listed below still have some disadvantages. For example: regulated output boost, unable to respond to fluctuations in the power supply, and unable to adapt to changes in the environment. The rectified output Burst mode depends only on the condition of the load, and the Burst period is set only in the condition of a single mode. Switch-cap pumping boost has high electromagnetic interference (EMI) and low conversion efficiency, and is limited by the final voltage conversion ratio. Fixed frequency burst period (Fixed frequency and burst period) Switch boost), the balance between load and energy conversion cannot be adjusted.

Embodiments of the present invention provide a low illumination solar boost converter and a control method thereof, which utilize rectification switching control of an input voltage to reduce loss of energy conversion in low illumination.

Embodiments of the present invention provide a low illumination solar boost converter having an input end and an output end. The input end is coupled to the solar receiving unit, the output end is coupled to the load, and the low illumination solar boost converter includes a boost converter and a pulse width. Modulation controller and switching controller. The boost converter is coupled to the input and the output. The pulse width modulation controller is coupled to the boost converter and provides a plurality of pulses to the boost converter to adjust the voltage at the output. When the voltage at the input is greater than a reference input voltage, the pulse width modulation controller operates in a PWM mode. When the voltage at the input terminal is not greater than the reference input voltage, the pulse width modulation controller operates in a Burst mode, and one of the burst modes is caused by a decrease in the voltage of the input terminal. increase. The switching controller is coupled to the pulse width modulation controller to determine whether the voltage at the output terminal is less than a first set output voltage value. When the voltage of the output terminal is less than the first set output voltage value, the switching controller controls the pulse width modulation controller to operate in the pulse width modulation mode. When the voltage of the output terminal is not less than the first set output voltage value, the switching controller controls the pulse width modulation controller to operate in the burst mode.

Embodiments of the present invention provide a control method for a low illumination solar boost converter. The low illumination solar boost converter has an input end and an output end, and the control method includes the following steps. First, the low illumination solar boost converter is initially operated in a pulse width modulation mode (PWM mode). Then, it is judged whether the voltage at the input terminal is greater than a reference input voltage. When the voltage at the input is greater than the reference input voltage, the low illumination solar boost converter operates in a pulse width modulation mode. Conversely, when the voltage at the input terminal is not greater than the reference input voltage, the low-illuminance solar boost converter is operated in a burst mode, one of the burst modes The time increases as the voltage at the input decreases. Then, when operating in the burst mode, it is determined whether the voltage at the output terminal is less than a first set output voltage value. When the voltage at the output terminal is less than the first set output voltage value, the low illumination solar boost converter is operated in a pulse width modulation mode. Conversely, when the voltage at the output is not less than the first set output voltage value, the low illumination solar boost converter is operated in a burst mode.

In summary, the embodiment of the present invention provides a low-illuminance solar boost converter and a control method thereof, and the load condition is known according to the output terminal voltage value, and the boost converter can be operated in the burst mode when the load is light. The burst cycle time of the burst mode is increased as the voltage of the input terminal decreases, that is, the burst period of the burst mode increases as the illuminance is lower. Further, it is also determined whether to leave the burst mode and enter the pulse width modulation mode according to the load condition.

The detailed description of the present invention and the accompanying drawings are to be understood by the claims The scope is subject to any restrictions.

1‧‧‧Adaptable solar collector

10‧‧‧Solar receiving unit

11, 21‧‧‧ boost converter

12‧‧‧Charging power controller

13‧‧‧Power storage unit

131‧‧‧temperature sensor

P1‧‧‧ input

P2‧‧‧ output

Vin, Vo, Vin', Vo', Vref, VLX, Vout‧‧‧ voltage

Iin, Io, Iin', Io', I-Vin, IL‧‧‧ current

121‧‧‧Load line control unit

TS‧‧‧temperature sensing signal

SGND, PGND, OCP, VCC, CC, LX, FB, REF‧‧‧ endpoints

2‧‧‧Low illumination solar boost converter

22‧‧‧ Pulse width modulation controller

23‧‧‧Switch controller

211‧‧‧Inductance

212, 213‧‧‧Optoelectronics

20‧‧‧ integrated circuit

VIN‧‧‧ input

OUT‧‧‧ output

201‧‧‧ pulse width comparator

202‧‧‧ ramp generator

203‧‧‧Oscillator

204‧‧‧Error amplifier

205‧‧‧ bandgap reference circuit

206‧‧‧Restrictor

207‧‧‧ Zero-crossing rate comparator

208‧‧‧Overcurrent protector

2081‧‧‧ comparator

R‧‧‧resistance

C‧‧‧ capacitor

S100, S110, S120, S130, S140, S150, S160, S200, S210, S220, S230, S240, S250, S260, S215, S217‧‧

OSC‧‧‧ pulse signal

EN_OSC‧‧‧ burst cycle time

FIG. 1 is a circuit block diagram of an adaptive solar power collecting device according to an embodiment of the present invention.

2 is a circuit diagram of a low illumination solar boost converter according to an embodiment of the present invention.

FIG. 3 is a flowchart of a method for controlling a low illumination solar boost converter according to an embodiment of the present invention.

4 is a flow chart of a method for controlling a low illumination solar boost converter according to another embodiment of the present invention.

FIG. 5 is a signal waveform diagram of a low illumination solar boost converter provided by an example of the present invention.

6 is a letter of a low illumination solar boost converter provided by another example of the present invention. Waveform.

7 is a signal waveform diagram of a low illumination solar boost converter provided by another example of the present invention.

FIG. 8 is a signal waveform diagram of a low illumination solar boost converter provided by another example of the present invention.

9 is a signal waveform diagram of a low illumination solar boost converter provided by another example of the present invention.

[Example of Low Illumination Solar Boost Converter and Control Method Therefor]

Embodiments of the present invention further improve low-illuminance photovoltaic energy collection. The output voltage of the solar collector can be based on monitoring the solar power collection capacity and adjusting the switching rate of the conversion, thereby providing an effective method for saving more energy conversion loss during low illumination collection.

Please refer to FIG. 1. FIG. 1 is a circuit block diagram of an adaptive solar power collecting device according to an embodiment of the present invention. The adaptive solar power collecting device 1 includes a solar receiving unit 10, a boost converter 11, and a charging power controller 12. The solar energy receiving unit 10 is typically a solar panel having a plurality of solar cells. The adaptive solar power collecting device 1 transmits the power of the solar receiving unit 10 to at least one power storage unit 13.

The boost converter 11 has an input terminal P1 and an output terminal P2. The input terminal P1 of the boost converter 11 is coupled to the solar receiving unit 10, and the boost converter 11 receives the power of the solar receiving unit 10 through the input terminal P1. The solar receiving unit 10 supplies an input voltage Vin and an input current Iin to the boost converter 11. The charging power controller 12 is coupled to the output terminal P2 of the boost converter 11, senses the supply voltage Vo of the output terminal P2 of the boost converter 11 (in the input end of the charging power controller 12 is Vin'), and generates charging. The voltage Vo' and the charging current Io' are charged to the at least one power storage unit 13. The charging power controller 12 is supplied in accordance with the output from the output terminal P2 of the boost converter 11. The pressure Vo is used as a feed-forward control, and the charging current Io' is adjusted. The feed-forward control can self-adjust the collection of solar panel energy and store it in a rechargeable storage (power storage unit 13). Regardless of the amount of energy that can be collected by the solar panel, as long as the energy collected is greater than the energy consumed by the boost converter 11 and the charging power controller 12.

The embodiment of the present invention utilizes the charging power controller 12 to have a solar panel (solar cell) having a current collecting capability that can be adapted to the load. For different illumination intensities of incident light, each solar cell has its own individual output (collection) capability. If the collector load does not match the power output to the solar cell, the output voltage of the solar cell may collapse and fall to near ground potential, or decrease the voltage value under heavy load current conditions. Embodiments of the present invention provide feedforward control to adjust the output stage (post stage) of the photoelectric conversion. In each boosting clock cycle, the voltage value converted from the collected photo-voltaic to the subsequent stage is automatically adjusted to take into account the output capability of the photovoltaic cell from the previous stage.

The power storage unit 13 is usually a secondary battery such as a lithium nickel battery or a lithium iron battery, but the present invention is not limited thereto. The power storage unit 13 is coupled to the charging power controller 12, and the power storage unit 13 receives the charging voltage Vo' and the charging current Io' to be charged. The power storage unit 13 further includes a temperature sensor 131 that senses the temperature of the power storage unit 13 and provides a temperature sensing signal TS to the charging power controller 12. The temperature sensor 131 may instruct the charging power controller 12 to stop charging the power storage unit 13 with the temperature sensing signal TS when the temperature of the power storage unit 13 is too high. Thereby, the temperature of the power storage unit 13 is prevented from being too high and the danger is caused. The charging power controller 12 can adjust the load line when the adaptive solar power collecting device 1 charges the power storage unit 13 according to the supply voltage Vo.

Further, at low illumination, the loss of energy conversion of the boost converter 11 of FIG. 1 affects the output power that the boost converter 11 can provide. In order to reduce the loss of energy conversion in low illumination, the embodiment of the present invention further designs the control method of the boost converter 11.

Please refer to FIG. 1 and FIG. 2 simultaneously. FIG. 2 is a circuit diagram of a low illumination solar boost converter according to an embodiment of the present invention. The low illumination solar boost converter 2 has an input terminal VIN (ie, the input terminal P1 of the boost converter 11 and a voltage of Vin) and an output terminal OUT (ie, the output terminal P2 of the boost converter 11 having a voltage of Vo). The input terminal VIN is coupled to the solar energy receiving unit 10 shown in FIG. 1 , and the output terminal OUT is coupled to a load (for example, the charging power controller 12 shown in FIG. 1 or directly coupled to the power storage unit 13 ). The low illumination solar boost converter 2 can be implemented by using the packaged integrated circuit 20 with the coupled inductor 211. In terms of circuit architecture, the low illumination solar boost converter 2 includes a boost converter 21, a pulse width modulation controller 22, a switching controller 23, a pulse width comparator 201, a ramp generator 202, an oscillator 203, Error amplifier 204, bandgap reference circuit 205, current limiter 206, zero-crossing rate comparator 207 and overcurrent protector 208.

The boost converter 21 is a DC boost converter. The boost converter 21 includes an inductor 211 and at least one transistor 212, 213 coupled to the inductor 211. In FIG. 2, the transistor 213 is a P-type transistor having a back gate, and the transistor 212 is an N-type transistor. The boost converter 21 is coupled to the input terminal VIN and the output terminal OUT. One end of the inductor 211 is coupled to the input terminal VIN, and the other end of the inductor 211 (end point LX) is coupled to at least one transistor (212, 213), and the at least one transistor (the transistor 213 in FIG. 2) is used for The output terminal OUT is coupled. The boost converter 21 of Figure 2 is for illustrative purposes only and is not intended to limit the invention. Those skilled in the art can change the connection relationship between the inductor 211 and the coupled transistor according to actual needs, and can also change the number of transistors coupled to the inductor according to actual needs. In short, the boost converter 11 has at least one transistor coupled to the output terminal OUT, and the pulse width modulation controller generates a pulse of 22 for controlling the switching of the transistor.

The pulse width modulation controller 22 is coupled to the boost converter 21 to provide a plurality of pulses to the boost converter 21 to adjust the voltage of the output terminal OUT. In the present embodiment, the pulses generated by the pulse width modulation controller 22 are used to control the switching of the transistors 212, 213. Pulse width when the voltage at input VIN is greater than a reference input voltage The modulation controller 22 operates in a pulse width modulation mode (PWM mode), even if the low illumination solar boost converter 2 operates in a pulse width modulation mode. When the voltage of the input terminal VIN is not greater than the reference input voltage, the pulse width modulation controller 22 operates in a Burst mode, and one of the burst modes, the burst cycle time EN_OSC, is the voltage of the input terminal VIN. The function (ie, EN_OSC=f(Vin)), and the burst cycle time EN_OSC increases as the voltage at the input terminal VIN decreases.

The switching controller 23 is coupled to the pulse width modulation controller 22 to determine whether the voltage of the output terminal OUT is less than a first set output voltage value V1. When the voltage of the output terminal OUT is less than the first set output voltage value V1, the switching controller 23 controls the pulse width modulation controller 22 to operate in the pulse width modulation mode. When the voltage of the output terminal OUT is not less than the first set output voltage value V1, the switching controller 23 controls the pulse width modulation controller 22 to operate in the burst mode.

The pulse width of the pulse width modulation controller 22 is controlled by the pulse width comparator 201, and the pulse width comparator 201 uses the triangular wave generated by the ramp generator 202 (the ramp generator 202 generates a triangular wave according to the oscillator 203) as a reference signal. The triangular wave is compared with the output voltage of the error amplifier 204 to provide a signal for controlling the pulse width to the pulse width modulation controller 22. The two input terminals of the error amplifier 204 are respectively coupled to the feedback terminal FB and the reference terminal REF, and the error amplifier 204 returns the voltage of the terminal FB (the feedback signal generated according to the voltage or current of the output terminal OUT) and the reference. The voltage at the terminal REF is compared, wherein the voltage at the reference terminal REF is related to the voltage generated by the bandgap reference circuit 205, wherein the voltage Vref of the reference terminal REF is 1.258 V is by way of example only and is not intended to limit the invention. The current limiter 206, the zero-crossing ratio comparator 207 and the overcurrent protector 208 are coupled to the pulse width modulation controller 22 for use as a protection circuit. The overcurrent protector 208 is implemented, for example, by a comparator 2081, a resistor R and a capacitor C. . In addition, the other terminals SGND, PGND, OCP, VCC, CC, and circuit connection relationship of the integrated circuit 20 in FIG. 2 are only for exemplification and are not intended to limit the present invention. The integrated circuit 20 can add other auxiliary functions such as a Smith-Trigger and a Power Good signal. It is omitted here.

Please refer to FIG. 2 and FIG. 3 simultaneously. FIG. 3 is a flowchart of a method for controlling a low illumination solar boost converter according to an embodiment of the present invention. First, in step S100, the low-illuminance solar boost converter 2 is caused to operate in a pulse width modulation mode (PWM mode). Then, in step S110, it is determined whether the voltage of the input terminal VIN is greater than a reference input voltage (VIN_REF, not shown), and the reference input voltage can be used to determine whether the boost converter is to be operated in a pulse width modulation. The basis of the variable mode, when the input voltage is too low (not greater than the reference input voltage), it means that the illuminance of the sun may be low and cannot provide a large amount of energy, so the boost converter needs to save power consumption. When the voltage of the input terminal VIN is greater than the reference input voltage (VIN_REF), step S120 is performed to operate the low-illuminance solar boost converter 2 in the pulse width modulation mode. After step S120, step S110 is performed again. On the contrary, when the voltage of the input terminal VIN is not greater than the reference input voltage (VIN_REF), step S130 is performed to operate the low-illuminance solar boost converter 2 in a burst mode, one of the burst modes The cycle time EN_OSC increases as the voltage at the input terminal VIN decreases.

Then, when operating in the burst mode, step S140 is performed to determine whether the voltage of the output terminal OUT is less than the first set output voltage value V1. When the voltage of the output terminal OUT is less than the first set output voltage value V1, step S150 is performed to operate the low-illuminance solar boost converter 2 in the pulse width modulation mode. On the other hand, when the voltage of the output terminal OUT is not smaller than the first set output voltage value V1, step S130 is performed again to operate the low-illuminance solar boost converter 2 in the burst mode. After step S150, step S160 is performed to monitor whether the current I_load of the output terminal OUT is less than the set load current for a set time ΔT. When the current I_load of the output terminal OUT is less than the set load current, step S130 is performed again to operate the low-illuminance solar boost converter 2 in the burst mode. On the other hand, when the current I_load of the output terminal OUT is not less than the set load current, step S150 is performed again to operate the low-illuminance solar boost converter 2 in the pulse width modulation mode. The purpose of step S160 is only to use the setting. Time ΔT to detect the current at the output terminal OUT to avoid the stability of the entire system affected by noise or current fluctuations. It should be noted that in other embodiments, step S160 may be replaced with other decision actions to determine whether to maintain the operation in the pulse width modulation mode or to operate in the burst mode, for example, using the same as step S140. (or similar) steps to determine whether to leave the pulse width modulation mode and enter burst mode.

Please refer to FIG. 3 and FIG. 4 simultaneously. FIG. 4 is a flowchart of a method for controlling a low illumination solar boost converter according to another embodiment of the present invention. The flowchart of FIG. 4 is substantially the same as the flowchart of FIG. 3, except that steps S215 and S217 are added, and other steps S200, S220, S230, S240, S250, and S260 are respectively performed with steps S100, S120, and S130 of FIG. S140, S150, and S160 are the same. The same steps will not be described again, and only the steps added in FIG. 4 will be described here. After the step of determining whether the voltage of the input terminal VIN is less than the reference input voltage (VIN_REF) (S210), the step S215 and the step S217 are further included before the step (S230) of operating in the burst mode. In step S215, it is determined whether the voltage of the output terminal OUT is greater than the second set output voltage value V2. When the voltage of the output terminal OUT is greater than the second set output voltage value V2, the low-illuminance solar boost converter 2 is operated in the burst mode, that is, the process proceeds to step S230. When the voltage of the output terminal OUT is not greater than the second set output voltage value V2, the low-illuminance solar boost converter 2 is operated in the pulse width modulation mode, that is, the process proceeds to step S217, and after the end of step S217, the process proceeds to step S215. Steps S215 and S217 are used to detect that the output terminal OUT is overloaded or lightly loaded before the burst mode is performed. At the same time, the functions of step S215 and step S240 are substantially the same to detect the load condition, wherein the second set output voltage value V2 may be the same as or different from the first set output voltage value V1, and the present invention is not limited thereto.

Please refer to FIG. 2 and FIG. 5 to FIG. 9 at the same time. FIG. 5 shows the voltage value VLX of the terminal LX, the current I-Vin of the input terminal VIN, and the inductance 211 when the voltage (Vin) of the input terminal VIN is 1.2V. The current IL and the pulse signal OSC generated by the pulse width modulation transformer 22. Figure 6 shows the burst week when the voltage at the input terminal VIN is 1.2V. The time period EN_OSC is 979us. FIG. 7 shows a signal waveform diagram when the voltage (Vin) of the input terminal VIN is 1.1 V, and the circuit is changed from the Burst mode to the PWM mode and then changed to the burst mode. The load current in the pulse width modulation mode is 25 mA. Figure 8 shows that when the voltage (Vin) at the input VIN is 3V, the burst cycle time EN_OSC is shortened to 399us. Figure 9 shows the signal waveform of the circuit changing from Burst mode to PWM mode and then changing to burst mode when the voltage (Vin) of the input terminal VIN is 3V. The load current in the pulse width modulation mode is 200 mA. As is apparent from Fig. 9, the interval (burst cycle time EN_OSC) of the burst signal OSC is shorter than that of Fig. 7.

[Possible effects of the examples]

In summary, the low-illuminance solar boost converter and the control method thereof according to the embodiments of the present invention can learn the load condition according to the voltage value of the output terminal, and can operate the boost converter in the burst mode in a light load condition. The burst cycle time of the burst mode is increased as the voltage of the input terminal decreases, that is, the burst period of the burst mode is also increased when the illuminance is lower. Further, it is also determined whether to leave the burst mode and enter the pulse width modulation mode according to the load condition. Thereby, more energy conversion loss can be saved in low illumination current collection, and energy conversion efficiency can be improved.

The above description is only an embodiment of the present invention, and is not intended to limit the scope of the invention.

S100, S110, S120, S130, S140, S150, S160‧‧‧ steps flow

Claims (10)

A low-illuminance solar boost converter has an input end and an output end, the input end is coupled to a solar receiving unit, the output end is coupled to a load, and the low-illuminance solar boost converter comprises: a boost converter And a pulse width modulation controller coupled to the boost converter to provide a plurality of pulses to the boost converter to adjust the voltage of the output, wherein the input When the voltage of the terminal is greater than a reference input voltage, the pulse width modulation controller operates in a PWM mode, and when the voltage of the input terminal is not greater than the reference input voltage, the pulse width modulation control The device operates in a Burst mode, and one of the burst modes is increased as the voltage of the input terminal decreases; a switching controller coupled to the pulse width modulation controller, Determining whether the voltage of the output terminal is less than a first set output voltage value, and when the voltage of the output terminal is less than the first set output voltage value, the switching controller controls the pulse width modulation The controller operates in the pulse width modulation mode, and when the voltage of the output terminal is not less than the first set output voltage value, the switching controller controls the pulse width modulation controller to operate in the burst mode. The low illumination solar boost converter according to claim 1, wherein the switching controller determines whether the voltage of the output terminal is greater than a second set output voltage value, and when the voltage of the output terminal is greater than the second set output voltage value The switching controller causes the pulse width modulation controller to operate in the burst mode, and when the voltage of the output terminal is not greater than the first set output voltage value, the switching controller causes the pulse width modulation controller Operate in this pulse width modulation mode. A low illumination solar boost converter according to claim 1 wherein the boost converter is a DC-boost converter. The low illumination solar boost converter of claim 1, wherein the boost converter has at least one transistor coupled to the output, the pulse width modulation The pulses generated by the variable controller are used to control the switching of the transistor. A control method for a low illumination solar boost converter, the low illumination solar boost converter having an input end and an output end, the control method comprising: causing the low illumination solar boost converter to start operating at a pulse width modulation a PWM mode; determining whether the voltage of the input terminal is greater than a reference input voltage; and operating the low-illuminance solar boost converter in the pulse width modulation mode when the voltage of the input terminal is greater than the reference input voltage When the voltage of the input terminal is not greater than the reference input voltage, the low-illuminance solar boost converter is operated in a Burst mode, and one of the burst modes is followed by the input The voltage of the terminal is increased; when operating in the burst mode, determining whether the voltage of the output terminal is less than a first set output voltage value; when the voltage of the output terminal is less than the first set output voltage value, The low illumination solar boost converter operates in the pulse width modulation mode; and when the voltage of the output terminal is not less than the first set output voltage value, The low illumination solar boost converter is operated in the burst mode. The control method of the low-illuminance solar boost converter according to claim 5, wherein after the step of determining whether the voltage of the input terminal is less than the reference input voltage, before the step of operating the burst mode, the method further comprises: determining Whether the voltage of the output terminal is greater than a second set output voltage value; when the voltage of the output terminal is greater than the second set output voltage value, causing the low illumination solar boost converter to operate in the burst mode; When the voltage at the output terminal is not greater than the second set output voltage value, the low illumination solar boost converter operates in the pulse width modulation mode. The control method of the low illumination solar boost converter according to claim 5, wherein the low illumination solar boost converter is operated at the pulse width when the voltage of the output terminal is less than the first set output voltage value After the step of modulation mode, more The method includes: monitoring whether the current of the output terminal is less than a set load current within a set time; and operating the low-illuminance solar boost converter in the burst mode when the current of the output terminal is less than the set load current; When the current of the output terminal is not less than the set load current, the low illumination solar boost converter is operated in the pulse width modulation mode. The control method of the low illumination solar boost converter according to claim 5, wherein the low illumination solar boost converter comprises a boost converter, a pulse width modulation controller, and a switching controller, the switching control The controller is configured to control the pulse width modulation controller to generate a plurality of pulses for controlling the boost converter to adjust the voltage of the output terminal. A method of controlling a low illumination solar boost converter according to claim 8 wherein the boost converter is a DC-boost converter. The control method of the low-illuminance solar boost converter according to claim 8 , wherein the boost converter has at least one transistor coupled to the output, and the pulse width modulation controller generates the A pulse is used to control the switching of the transistor.