TWI460977B - Voltage supply system and converter therein, and voltage regulating method - Google Patents

Description

Voltage supply system and converter therein and voltage adjustment method

The present invention relates to a voltage supply system, and more particularly to a current transformer in a voltage supply system.

Embedded power supplies typically use special processes such as multiple layers of thick copper printed circuit boards (PCBs) and surface-mount power devices to reduce size and increase reliability in wireless networks, fiber-optic network devices, servers, and data storage. And other fields have a wide range of applications.

In general, when traditional fully-adjusted converters are used in the field of embedded power supplies, their efficiency is often limited and cannot be effectively improved. For example, in a fully-adjusted converter, the output voltage of the power module is compared with a fixed reference voltage via feedback, and the control module adjusts the driving signal according to the comparison result, thereby adjusting the output voltage of the power module. . Therefore, the magnitude of the output voltage is mainly determined by the comparison of the fixed reference voltage and the feedback voltage. Secondly, in order to make the power module generate corresponding output voltage according to the input voltage, the winding turns ratio of the transformer in the power module must be set relatively small to ensure that the power module can still generate and fix the reference at the minimum input voltage. The corresponding output voltage of the voltage allows the power module to operate in a Full-Regulated state. Otherwise, the excessive turns ratio of the winding in the transformer will cause the power module to fail to generate an output voltage corresponding to the fixed reference voltage. The power module loses the feedback adjustment function according to the output voltage.

However, due to the aforementioned selection of the limited winding turns ratio, when the power supply When the module is operated at high input voltage, the output inductor is usually subjected to a very high volt-second value (V×t), which causes the output inductor to have a larger core or more winding turns, so it is directly limited. The power density of the power module and the efficiency of the power module cannot be improved.

SUMMARY OF THE INVENTION The present invention is directed to a voltage supply system, a converter thereof, and a voltage adjustment method for gradually adjusting an output voltage converted from an input voltage when an input voltage is increased to reduce a volt-second that the output inductor is subjected to. value.

One embodiment of the present invention relates to a current transformer including a power module, a feedback module, and a control module. The power module is configured to convert an input voltage into an output voltage. The feedback module is electrically connected to the power module to generate a feedback voltage corresponding to the output voltage. The control module is electrically connected to the power module and the feedback module, and the control module is configured to compare a duty cycle reference value and a duty cycle value, and accordingly generate a variable reference voltage according to the comparison result of the two, and use The variable reference voltage and the feedback voltage are compared, and the duty cycle value is adjusted according to the result of the comparison.

In an embodiment of the invention, when the input voltage changes, the control module adjusts the variable reference voltage and adjusts the duty cycle value accordingly, and generates a drive control signal corresponding to the adjusted duty cycle value to control the power mode. group.

In still another embodiment of the present invention, the control module further includes a first comparison circuit and a first operation circuit. The first comparison circuit is configured to compare the duty cycle reference value with the duty cycle value to generate a duty cycle difference. The first operational circuit is electrically connected to the first comparison circuit for calculating the duty ratio difference Generate and adjust the variable reference voltage.

In another embodiment of the present invention, the control module further includes a second comparison circuit, a second operation circuit, and a drive signal generation circuit. The second comparison circuit is electrically connected to the first operation circuit and the feedback module for comparing the variable reference voltage and the feedback voltage to generate an error voltage. The second operational circuit is electrically coupled to the second comparison circuit for calculating the error voltage to generate and adjust the duty cycle value. The driving signal generating circuit is electrically connected to the second computing circuit and the power module for receiving the adjusted duty cycle value generated by the second computing circuit and generating a driving control signal corresponding to the adjusted duty cycle value .

In a second embodiment of the present invention, the first comparison circuit is electrically connected to the second operation circuit and configured to receive the adjusted duty cycle value generated by the second operation circuit.

In still another embodiment of the present invention, the first comparison circuit is electrically connected to the driving signal generating circuit and is used to extract the duty ratio value from the driving signal generating circuit.

In still another embodiment of the present invention, the driving control signal of the control power module is outputted by the control module and fed back to the control module, and the first comparison circuit is configured to receive the feedback driving control signal to self-drive the control signal. Draw the corresponding duty cycle value.

In another embodiment of the invention, as the input voltage increases, the variable reference voltage gradually increases, and the control module adjusts the duty cycle value to gradually increase.

Another embodiment of the present disclosure is directed to a voltage supply system including a high voltage bus, a low voltage bus, a current transformer, and a plurality of supply voltage generating circuits. The converter is electrically connected to the high voltage bus and the low voltage bus The converter includes at least a control module, and the control module compares a duty cycle reference value and a duty cycle value, and generates and adjusts a result according to the comparison between the duty cycle reference value and the duty cycle value. The variable reference voltage is adjusted according to the result of comparing the variable reference voltage with a feedback voltage, and a driving control signal corresponding to the adjusted duty ratio value is generated to adjust the output voltage of the converter. A plurality of supply voltage generating circuits are connected in parallel with each other, electrically connected to the low voltage bus, and each is used to convert the output voltage of the converter into a supply voltage to the load.

In an embodiment of the invention, the control module of the converter further includes a first comparison circuit and a first operation circuit. The first comparison circuit is configured to compare the duty cycle reference value with the duty cycle value to generate a duty cycle difference. The first operational circuit is electrically coupled to the first comparison circuit for calculating a duty cycle difference to generate and adjust a variable reference voltage.

In another embodiment of the present invention, the control module of the converter further includes a second comparison circuit, a second operation circuit, and a drive signal generation circuit. The second comparison circuit is electrically connected to the first operational circuit for comparing the variable reference voltage and the feedback voltage to generate an error voltage. The second operational circuit is electrically coupled to the second comparison circuit for calculating the error voltage to generate and adjust the duty cycle value. The driving signal generating circuit is electrically connected to the second computing circuit for receiving the adjusted duty cycle value generated by the second computing circuit and generating a driving control signal corresponding to the adjusted duty cycle value.

In a second embodiment of the present invention, the first comparison circuit is electrically connected to the second operation circuit and configured to receive the adjusted duty cycle value generated by the second operation circuit.

In still another embodiment of the present invention, the first comparison circuit is electrically connected The signal generating circuit is configured to draw the duty cycle value from the driving signal generating circuit.

In still another embodiment of the present invention, the driving control signal is outputted by the control module and fed back to the control module, and the first comparison circuit is configured to receive the feedback driving control signal, and take corresponding signals from the self-driving control signal. Empty ratio value.

In another embodiment of the present invention, when one of the input voltages of the converter changes, the control module adjusts the variable reference voltage, and when the input voltage increases, the variable reference voltage gradually increases, and the control module adjusts the duty. The ratio value is gradually increased, and the output voltage adjusted according to the drive control signal is gradually increased.

Yet another embodiment of the present disclosure is directed to a voltage adjustment method including: comparing a duty cycle value with a duty cycle reference value; and generating a result corresponding to the duty cycle reference value and the duty cycle value comparison result a variable reference voltage; comparing the variable reference voltage with a feedback voltage; and adjusting the duty cycle value according to a result of comparing the variable reference voltage with the feedback voltage, and generating a driving control signal corresponding to one of the adjusted duty cycle values, The input voltage is converted to one of the adjusted output voltages by driving a control signal.

In another embodiment of the invention, the duty cycle value is generated and adjusted by an arithmetic circuit.

In a second embodiment of the invention, the drive control signal is generated by a drive signal generating circuit, and the duty cycle value compared to the duty cycle reference value is taken from the drive signal generating circuit.

In yet another embodiment of the invention, the duty cycle value compared to the duty cycle reference value is derived from the drive control signal.

In still another embodiment of the present invention, the foregoing voltage adjustment method further includes When the input voltage changes, the variable reference voltage is adjusted, wherein as the input voltage rises, the variable reference voltage gradually increases, and the duty ratio value is gradually increased as it is adjusted.

According to the technical content of the present invention, by applying the foregoing embodiments of the present invention, the working efficiency of the converter can be improved without increasing the volume of the output inductor, and the power density can be smoothly increased.

The embodiments are described in detail below with reference to the accompanying drawings, but the embodiments are not intended to limit the scope of the invention, and the description of the structure operation is not intended to limit the order of execution, any component recombination The structure, which produces equal devices, is within the scope of the present invention. In addition, the drawings are for illustrative purposes only and are not drawn to the original dimensions.

"Coupling" or "connecting" as used herein may mean that two or more elements are in direct physical or electrical contact with each other, or indirectly in physical or electrical contact with each other, or two or more The components operate or act on each other.

1 is a circuit diagram of a voltage supply system according to an embodiment of the invention. The voltage supply system 100 includes a high voltage bus 110, a converter 120, a low voltage bus 130, and a plurality of supply voltage generating circuits 140. The converter 120 is electrically connected between the high voltage bus 110 and the low voltage bus 130 for receiving an input voltage Vin through the high voltage bus 110 and converting the input voltage Vin into an output voltage Vout via the low voltage bus 130. The supply voltage generating circuit 140 is electrically connected to the low voltage bus line 130 in parallel with each other, and is configured to convert the output voltage Vout of the converter 120 into a supply voltage to provide corresponding Load 150.

FIG. 2 is a schematic circuit diagram of a converter according to an embodiment of the invention. The converter 200 shown in FIG. 2 can be applied to the voltage supply system 100 shown in FIG. 1, but is not limited thereto. As shown in FIG. 2, the converter 200 includes at least a power module 220, a feedback module 240, and a control module 260a. The power module 220 is configured to convert the input voltage Vin into an output voltage Vout. The feedback module 240 is electrically connected to the power module 220 and configured to generate a feedback voltage Vf corresponding to the output voltage Vout. The control module 260a is electrically connected to the feedback module 240 and the power module 220, and is used for comparing a duty ratio reference value Dref and a duty ratio value Dc according to the duty ratio reference value Dref and duty. The result of the comparison with the value Dc correspondingly generates a variable reference voltage Vref for comparing the variable reference voltage Vref with the feedback voltage Vf, and adjusting the duty value Dc according to the result of comparing the variable reference voltage Vref with the feedback voltage Vf. In practice, the duty cycle reference value Dref can be fixed to a certain value or ratio (eg, 50%) according to actual needs.

It should be noted that the duty cycle reference value Dref and the duty cycle value Dc herein may refer to actual values, and may also be signals corresponding to the general exponential value. In other words, the control module 260a can be configured to receive signals corresponding to both the duty ratio reference value Dref and the duty ratio value Dc, and compare the signals corresponding to the two.

In one embodiment, when the input voltage Vin changes, the control module 260a adjusts the variable reference voltage Vref and adjusts the duty value Dc accordingly, and the control module 260a generates a duty ratio value Dc corresponding to the adjusted duty ratio. Driving the control signal Sc to control the power module 220 to input the input voltage Vin The operation of the line conversion further adjusts the output voltage Vout of the converter 200.

In practice, the control module 260a or the following control module (such as the control module 260b in FIG. 4 or the control module 260c in FIG. 5) can each pass through a digital controller (or control) Chip) or analog controller (or control chip) to achieve.

Structurally, the power module 220 can include a first switching element S1, a second switching element S2, a first voltage dividing capacitor C1, a second voltage dividing capacitor C2, a first rectifier switch SR1, a second rectifier switch SR2, and a filter inductor L1. And the filter capacitor Co. The first switching element S1 and the second switching element S2 are electrically connected in parallel with the first voltage dividing capacitor C1 and the second voltage dividing capacitor C2, respectively, and are controlled by the driving control signal Sc outputted by the control module 260a, and each is turned on (or Turn on) or cut off (or turn off). The first voltage dividing capacitor C1 is connected in series with the second voltage dividing capacitor C2 to divide the input voltage Vin to provide a corresponding voltage to the primary winding of the transformer Tr. The first rectifying switch SR1 and the second rectifying switch SR2 are connected to the secondary winding of the transformer Tr for synchronous rectification. The filter inductor L1 and the filter capacitor Co are connected in series with the first rectifier switch SR1 for filtering.

Secondly, the feedback module 240 can include at least a first impedance Z1 and a second impedance Z2 for dividing the output voltage Vout, thereby generating a feedback voltage Vf corresponding to the output voltage Vout.

In another embodiment, the feedback module 240 can also be used to shunt the output current of the corresponding output voltage Vout, thereby generating a feedback current signal corresponding to the output current. The control module 260a can compare the feedback current signal with a variable reference current signal (here, the variable reference current signal can be generated by comparing the duty cycle reference value and the duty cycle value), and then The result of the comparison of the feed current signal with the variable reference current signal adjusts the duty cycle value. In other words, the feedback signal generated by the feedback module 240 may be a feedback voltage signal or a feedback current signal, and the function and operation of the control module 260a may be appropriately adjusted corresponding to the feedback voltage signal or the feedback current signal.

Further, the control module 260a includes at least a first comparison circuit 262, a first operation circuit 264, a second comparison circuit 266, a second operation circuit 268, and a drive signal generation circuit 270. The first comparison circuit 262 is configured to compare the duty ratio reference value Dref and the duty ratio value Dc to generate a duty ratio difference value Derr. The first operation circuit 264 is electrically connected to the first comparison circuit 262 for calculating the duty ratio difference Derr to generate and adjust the variable reference voltage Vref. The second comparison circuit 266 is electrically connected to the first operation circuit 264 and the feedback module 240 for comparing the variable reference voltage Vref and the feedback voltage Vf generated by the feedback module 240 to generate the error voltage Verr. The second operation circuit 268 is electrically connected to the second comparison circuit 266 for calculating the error voltage Verr to generate and adjust the duty value Dc. The driving signal generating circuit 270 is electrically connected to the second computing circuit 268 and the power module 220 for receiving the duty value Dc generated by the second operating circuit 268 and generating a duty ratio value Dc corresponding to the adjusted duty. Drive control signal Sc.

In this embodiment, the first comparison circuit 262 is electrically connected to the second operation circuit 268 for receiving the duty value Dc generated by the second operation circuit 268, and the duty value Dc is used by the second operation circuit 268. Generated and adjusted, and the adjusted duty cycle value Dc is further fed back to the first comparison circuit 262 for comparison with the duty cycle reference value Dref.

FIG. 3 is a schematic diagram showing corresponding changes of an input voltage, a variable reference voltage, a duty cycle value, and an output voltage according to an embodiment of the invention. Refer to Figures 2 and 3 simultaneously. When the input voltage Vin rises or shifts to a higher level at time t1, since the variable reference voltage Vref cannot be immediately changed correspondingly, the control module 260a first adjusts the duty ratio value Dc accordingly (for example: adjustment accounted for The null ratio value Dc is less than the duty ratio reference value Dref), so that the output voltage Vout does not change immediately, but the output voltage Vout and its corresponding feedback voltage Vf are changed again as the duty ratio value Dc is gradually increased. The reference voltage Vref varies.

Then, during the period from time t1 to time t2, since the duty ratio value Dc is smaller than the duty ratio reference value Dref, after the feedback duty value Dc is compared and processed, the first operation circuit 264 performs comparison and operation. As a result, the variable reference voltage Vref is gradually increased until the variable reference voltage Vref is equal to the feedback voltage Vf (ie, at time t2), and at the same time, after the gradually increasing variable reference voltage Vref is compared and processed, the second operational circuit 268 will also adjust the duty value Dc according to the comparison and operation result, so that the duty value Dc is gradually increased until the duty value Dc is equal to the duty reference value Dref (ie, at time t2).

In addition, the driving signal generating circuit 270 generates a corresponding driving control signal Sc according to the duty value Dc that changes during the period t1 to t2, so that the power module 220 adjusts the converted output voltage Vout according to the driving control signal Sc, and The adjusted output voltage Vout also rises to a stable value at time t2, which in turn causes the converter 200 to enter a new steady state.

Compared with the prior art, in the foregoing embodiment, the operation mode of adjusting the duty ratio value Dc and further changing the reference voltage Vref can be lost. When the input voltage Vin changes, the output voltage Vout of the converter 200 is not changed immediately, but varies with the reference voltage Vref. In this way, the converter 200 can gradually adjust the output voltage Vout when the input voltage Vin changes, thereby reducing the volt-second value (V×t) that the output inductor is subjected to, so that the output inductor is not limited to have to have The larger the number of cores or more winding turns, the power density of the power module 220 can be increased, and the efficiency of the converter can be further increased.

4 is a circuit diagram of a converter according to another embodiment of the present invention. In the present embodiment, the first comparison circuit 262 of the control module 260b is electrically connected to the driving signal generating circuit 270, and is used to extract the duty ratio value from the driving signal generating circuit 270. Dc compares the duty ratio value Dc and the duty ratio reference value Dref in the drive signal generating circuit 270.

The connection and operation relationship between the control module 260b and the power module 220 and the feedback module 240 are similar to the foregoing, and thus will not be described again. In addition, the connection and operation relationship of the components in the control module 260b are similar to those of the embodiment shown in FIG. 2, and thus will not be described herein.

Figure 5 is a circuit diagram of a converter according to another embodiment of the present invention. Compared with FIG. 2, in the embodiment, the first comparison circuit 262 of the control module 260c is configured to receive the drive control signal Sc that is output back to the control module 260c by the control module 260c, and compares The duty ratio value Dc and the duty ratio reference value Dref in the self-driving control signal Sc are extracted.

The connection and operation relationship between the control module 260c and the power module 220 and the feedback module 240 are similar to those described above, and thus will not be described herein. In addition, control The connection and operation relationship of the components in the module 260c are similar to those of the embodiment shown in FIG. 2, and thus will not be described herein.

FIG. 6 is a flow chart of a voltage adjustment method according to an embodiment of the invention. For the sake of clarity and convenience of explanation, please refer to Figs. 2 and 6 simultaneously for the description of the following embodiments. First, a duty ratio value Dc and a duty ratio reference value Dref are compared (step 602), and then a variable reference voltage Vref is generated correspondingly according to a comparison result of the duty ratio value Dc and the duty ratio reference value Dref (step 604). Next, the variable reference voltage Vref is compared with the feedback voltage Vf (step 606), and the duty value Dc is adjusted according to the comparison result of the variable reference voltage Vref and the feedback voltage Vf until the duty ratio value Dc is equal to the duty ratio reference value. Dref (step 608). Finally, the power module 220 converts the input voltage Vin into the adjusted output voltage Vout according to the drive control signal Sc corresponding to the duty value Dc (step 610).

In an embodiment, the duty value Dc in the voltage adjustment method described above may be generated and adjusted by the second operation circuit 268.

In an embodiment, the foregoing voltage adjustment method may further include adjusting the variable reference voltage Vref when the input voltage Vin changes. When the input voltage Vin rises, the variable reference voltage Vref gradually increases, and the duty ratio value Dc is also gradually increased by adjustment.

In another embodiment, the duty ratio value Dc in the voltage adjustment method can be extracted from the driving signal generating circuit 270. When the input voltage Vin rises, the variable reference voltage Vref gradually increases, and the duty ratio value Dc also increases. It gradually increases as it adjusts.

In still another embodiment, the duty ratio value Dc in the voltage adjustment method is extracted from the driving control signal Sc, and the driving control signal Sc is as shown in FIG. The control module 260c outputs the back feedback control module 260c and is received by the first comparison circuit 262. When the input voltage Vin rises, the variable reference voltage Vref gradually increases, and the duty value Dc is also gradually increased by adjustment.

The steps mentioned in this embodiment can be adjusted according to the actual situation except for the specific order, and the flowchart shown in FIG. 6 is only an embodiment, and is not intended to limit the present invention. .

According to the embodiment of the present invention, the embodiment of the present invention can be used to gradually adjust the output voltage when the input voltage changes, thereby reducing the volt-second value (V×t) that the output inductor is subjected to, so that the output inductor It is not limited to a core having a larger size or more winding turns, and it is not necessary to increase the volume of the core of the output inductor to avoid saturation of the core of the output inductor, and the power density of the power module 220 can also be increased. The efficiency can be further improved.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. The scope is subject to the definition of the scope of the patent application attached.

100‧‧‧Voltage supply system

110‧‧‧High voltage busbar

120, 200‧‧ ‧ converter

130‧‧‧ Low voltage busbar

140‧‧‧Supply voltage generation circuit

150‧‧‧load

220‧‧‧Power Module

240‧‧‧ Feedback Module

260a, 260b, 260c‧‧‧ control module

262‧‧‧First comparison circuit

264‧‧‧First operational circuit

266‧‧‧Second comparison circuit

268‧‧‧second arithmetic circuit

270‧‧‧Drive signal generation circuit

602, 604, 606, 608, 610‧‧ steps

1 is a circuit diagram of a voltage supply system according to an embodiment of the invention.

FIG. 2 is a schematic circuit diagram of a converter according to an embodiment of the invention.

FIG. 3 is a schematic diagram showing corresponding changes of an input voltage, a variable reference voltage, a duty cycle value, and an output voltage according to an embodiment of the invention.

FIG. 4 is a schematic circuit diagram of a converter according to another embodiment of the invention.

FIG. 5 is a schematic circuit diagram of a converter according to another embodiment of the invention.

FIG. 6 is a flow chart of a voltage adjustment method according to an embodiment of the invention.

200‧‧‧ converter

220‧‧‧Power Module

240‧‧‧ Feedback Module

260a‧‧‧Control Module

262‧‧‧First comparison circuit

264‧‧‧First operational circuit

266‧‧‧Second comparison circuit

268‧‧‧second arithmetic circuit

270‧‧‧Drive signal generation circuit

Claims (20)

A converter includes at least: a power module for converting an input voltage into an output voltage; a feedback module electrically coupled to the power module for generating the output voltage Corresponding to a feedback voltage; and a control module electrically connected to the power module and the feedback module, wherein the control module is configured to compare a duty cycle reference value and a duty cycle value, according to the The result of comparing the duty cycle reference value with the duty cycle value correspondingly generates a variable reference voltage for comparing the variable reference voltage and the feedback voltage, and comparing the variable reference voltage with the feedback voltage according to the result Adjust the duty cycle value. The converter of claim 1, wherein the control module adjusts the variable reference voltage and adjusts the duty cycle value correspondingly when the input voltage changes, and the control module generates a corresponding adjustment One of the duty cycle values drives a control signal to control the power module. The converter of claim 1, wherein the control module further comprises: a first comparison circuit for comparing the duty reference value and the duty value to generate a duty ratio difference; And a first operational circuit electrically coupled to the first comparison circuit for calculating the duty cycle difference to generate and adjust the variable reference voltage. The converter of claim 3, wherein the control module further comprises: a second comparison circuit electrically coupled to the first operational circuit and the feedback module for comparing the variable reference voltage and the feedback voltage to generate an error voltage; a second operational circuit, and the second Comparing a circuit electrical connection for calculating the error voltage to generate and adjust the duty cycle value; and a driving signal generating circuit electrically connected to the second computing circuit and the power module for receiving the The adjusted duty cycle value generated by the second operational circuit produces the drive control signal corresponding to the adjusted duty cycle value. The converter of claim 4, wherein the first comparison circuit is electrically connected to the second operation circuit and configured to receive the adjusted duty cycle value generated by the second operation circuit. The converter of claim 4, wherein the first comparison circuit is electrically coupled to the drive signal generating circuit and configured to extract the duty cycle value from the drive signal generating circuit. The converter of claim 4, wherein the driving control signal for controlling the power module is outputted by the control module and fed back to the control module, and the first comparison circuit is configured to receive the feedback of the driving And a control signal for extracting the corresponding duty cycle value from the drive control signal. The converter of claim 1, wherein the variable reference voltage is gradually increased when the input voltage is raised, and the control module adjusts the duty The ratio is gradually increasing. A voltage supply system, the voltage supply system comprising: at least one high voltage bus; a low voltage bus; a converter electrically connected between the high voltage bus and the low voltage bus, wherein the converter comprises at least one control module The control module is configured to compare a duty cycle reference value and a duty cycle value, and generate and adjust a variable reference voltage according to the result of comparing the duty cycle reference value with the duty cycle value, and then according to the Comparing the variable reference voltage with a feedback voltage to adjust the duty cycle value, and generating a drive control signal corresponding to one of the adjusted duty cycle values to adjust an output voltage of the converter; and a plurality of The supply voltage generating circuits are electrically connected in parallel to each other to the low voltage bus, and are each configured to convert the output voltage of the converter into a supply voltage to a load. The voltage supply system of claim 9, wherein the control module of the converter further comprises: a first comparison circuit for comparing the duty cycle reference value and the duty cycle value to generate a share And a first operational circuit electrically coupled to the first comparison circuit for calculating the duty cycle difference to generate and adjust the variable reference voltage. The voltage supply system of claim 10, wherein the converter The control module further includes: a second comparison circuit electrically coupled to the first operational circuit for comparing the variable reference voltage and the feedback voltage to generate an error voltage; a second operational circuit, The second comparison circuit is electrically connected to calculate the error voltage to generate and adjust the duty cycle value, and a driving signal generating circuit electrically connected to the second computing circuit for receiving the second The adjusted duty cycle value produced by the operational circuit and the drive control signal corresponding to the adjusted duty cycle value. The voltage supply system of claim 11, wherein the first comparison circuit is electrically connected to the second operation circuit and configured to receive the adjusted duty value generated by the second operation circuit. The voltage supply system of claim 11, wherein the first comparison circuit is electrically connected to the drive signal generating circuit and configured to extract the duty cycle value from the drive signal generating circuit. The voltage supply system of claim 11, wherein the driving control signal is outputted by the control module and fed back to the control module, and the first comparison circuit is configured to receive the feedback of the driving control signal. The corresponding duty cycle value is extracted from the drive control signal. The voltage supply system of claim 11, wherein the control module adjusts the variable reference power when an input voltage of the converter changes When the input voltage is increased, the variable reference voltage is gradually increased, and the control module adjusts the duty ratio to gradually increase, and the output voltage adjusted according to the driving control signal is gradually increased. A voltage adjustment method includes: comparing a duty cycle value and a duty cycle reference value; and generating a variable reference voltage according to a result of comparing the duty cycle reference value with the duty cycle value; Comparing the variable reference voltage and a feedback voltage; and adjusting the duty cycle value according to a result of comparing the variable reference voltage with the feedback voltage, and generating a driving control signal corresponding to one of the adjusted duty cycle values, An input voltage is converted to an adjusted one of the output voltages by a drive control signal corresponding to the duty cycle value. The voltage adjustment method of claim 16, wherein the duty cycle value is generated and adjusted by an arithmetic circuit. The voltage adjustment method of claim 16, wherein the driving control signal is generated by a driving signal generating circuit, and the duty ratio value compared with the duty reference value is extracted from the driving signal generating circuit . The voltage adjustment method of claim 16, wherein the duty cycle value compared to the duty cycle reference value is derived from the drive control signal. The voltage adjustment method of claim 16, further comprising: adjusting the variable reference voltage when an input voltage changes; wherein the variable reference voltage is gradually increased when the input voltage is raised, and the duty ratio is increased The value is gradually increased as it is adjusted.