Power supply device and power modulation method thereof

Abstract

A power supply device and its power modulation method are disclosed. The power supply device includes multiple parallel power channels. According to the power modulation method, the duty cycle of each pulse width modulation (PWM) signal is reset to zero near the zero-crossing point of the input voltage, and after a set period, the duty cycle of each power channel is restored based on the changed PWM signals of each power channel. The power supply device and its power modulation method provided by this invention perform channel switching near the zero-crossing point of the input voltage, which can ensure the stability of the input current after switching, improve the overall power factor of the power supply device, and increase the utilization rate of the power grid.

Description

Technical Field

[0001] This invention relates to the field of power supply technology, and more specifically, to a power supply device and its power modulation method. Background Technology

[0002] PFC (Power Factor Correction) correction in traditional high-power electrical appliances requires bulky inductors and power devices that can withstand large currents (such as IGBTs (Insulated Gate Bipolar Transistors) and diodes), which places high demands on circuit hardware.

[0003] like Figure 1 As shown, a conventional AC / DC converter (Alternating current / Direct current) 10 includes a rectifier bridge 11, an output capacitor C0, a first inductor L1, a first diode D1, a first transistor M1, a first resistor R1, and a control unit 12. The first inductor L1, the first diode D1, and the first transistor M1 correspond to the first power supply channel, which controls and adjusts the system power according to the first pulse width modulation (PWM) signal PWM1.

[0004] The rectifier bridge 11 converts AC power into DC input voltage VIN. The input voltage VIN provides charge to the output capacitor C0 through the power supply channel, and provides a stable output voltage V0 through the output capacitor C0 to provide DC power to the load LOAD.

[0005] The first transistor M1 is connected in series between the intermediate node of the first inductor L1 and the first diode D1 and the negative output terminal of the rectifier bridge 11. The first transistor M1 is turned on and off according to the control unit 12 to control the charging of the output capacitor C0. The first resistor R1 is connected in series between the first transistor M1 and the negative output terminal of the rectifier bridge 11 to sample its current and provide a first sampled current signal to the control unit 12.

[0006] The first transistor M1, the first inductor L1, and the first diode D1 constitute the main power circuit. When the first transistor M1 is turned on, the first inductor L1 is charged according to the input voltage VIN. When the first transistor M1 is turned off, the first inductor L1 discharges and charges the output capacitor C0, so as to provide a stable voltage power supply to the load through the output capacitor C0.

[0007] The control unit 12 adjusts the power factor of the AC / DC converter 10 based on the duty cycle of the first pulse width modulation signal PWM1 provided by the first sampled current signal ADC1, the output voltage VIN and the output voltage V0.

[0008] For high-power electrical appliances, the first inductor L1, the first diode D1, and the first transistor M1 of a single first power channel need to withstand large currents, generate a lot of heat, and have high requirements for hardware quality. Summary of the Invention

[0009] In view of the above problems, the purpose of this invention is to provide a power supply device and its power modulation method, thereby realizing stable control of multi-phase power supply, enabling effective application in power supply devices with multiple power channels, reducing the hardware requirements of each power channel, and reducing costs.

[0010] According to one aspect of the present invention, a power supply device is provided, comprising:

[0011] A rectifier bridge is used to convert AC voltage into DC input voltage.

[0012] Multiple power supply channels connected in parallel, each power supply channel having an input terminal connected to the input voltage and an output terminal connected to the load to provide an output voltage, and the multiple power supply channels receiving pulse width modulation signals for switching; and

[0013] Before the switching of the multiple power channels is performed, the control unit determines whether the input voltage of the multiple power channels has reached a set threshold. If the input voltage is less than or equal to the set threshold, the control unit clears the duty cycle of the pulse width modulation signal of the multiple power channels. After the duty cycle is cleared to zero for a set period, the control unit generates the switched pulse width modulation signal and controls the multiple power channels to perform the switching.

[0014] Optionally, the switching includes changing the power channel, increasing or decreasing the number of power channels that need to be turned on, turning on all or some of the power channels, or turning off all or some of the power channels.

[0015] Optionally, the control unit is configured to perform the switching based on a comparison between the total power of the currently active power channel and the load power, and the average on-time of each of the multiple power channels.

[0016] Optionally, the control unit is configured to obtain the load power based on the current sampling signal of the currently enabled power channel.

[0017] Optionally, the control unit is configured to acquire the pulse width modulation signal after switching of the power channel to be activated by the following operation:

[0018] Determine the number of power channels that need to be activated, and obtain the phase difference between the power channels that need to be activated based on the number; and

[0019] The pulse width modulation signal of the power channel to be turned on is phase-shifted according to the phase difference to obtain the switched pulse width modulation signal.

[0020] Optionally, the control unit is configured to perform the following phase-shifting operation:

[0021] Identify the main power channel among the power channels that need to be activated;

[0022] The pulse width modulation signal of the main power channel is phase-shifted according to the phase difference to obtain the pulse width modulation signal after switching of other power channels that need to be turned on.

[0023] Optionally, the control unit is configured to determine the main power channel by performing the following operations:

[0024] Obtain the power channels that need to be turned on before and after the switch, and identify the main power channel among them.

[0025] Optionally, the control unit is further configured to:

[0026] If there is no power channel that needs to be turned on before and after the switch, the pulse width modulation signal after the switch is generated according to the system clock and system status.

[0027] Optionally, the control unit is further configured to enter a shutdown state if all power channels are turned off after the switch.

[0028] Optionally, the start and end times of the set period correspond to the low-level center point or the high-level center point of the pulse width modulation signal of the main power supply channel.

[0029] Optionally, the control unit obtains the phase difference between the power channels that need to be turned on using the following formula:

[0030]

[0031] in, Let m be the phase difference, and m be the number of power channels that need to be activated, where m is an integer greater than 1.

[0032] The switched pulse width modulation signal is based on the phase difference Equal phase interval.

[0033] Optionally, each of the multiple power supply channels includes:

[0034] The main power circuit includes a power switch and a power element connected in series. The power switch is turned on or off under the control of the pulse width modulation signal. The main power circuit supplies power to the load.

[0035] Optionally, the main power circuit is any one of a ground-type Buck power circuit, a virtual-ground-type Buck power circuit, a flyback power circuit, a Buck-boost power circuit, or a Boost power circuit.

[0036] According to another aspect of the present invention, a power modulation method for a power supply device is provided, the power supply device including a rectifier bridge for converting AC voltage into an input voltage; multiple power channels connected in parallel, each power channel having an input terminal connected to the input voltage and an output terminal connected to a load to provide an output voltage; the power modulation method of the power supply device includes:

[0037] The control unit detects whether the input voltage of the multiple power supply channels reaches a set threshold based on the channel switching signal. If the input voltage is less than or equal to the set threshold, the duty cycle of the pulse width modulation signal of the multiple power supply channels is cleared.

[0038] After the duty cycle of the multiple power supply channels reaches a set period, the pulse width modulation signal after the switching of the multiple power supply channels is obtained.

[0039] Optionally, the switching includes changing the power channel, increasing or decreasing the number of power channels that need to be turned on, turning on all or some of the power channels, or turning off all or some of the power channels.

[0040] Optionally, the control unit is configured to perform the switching based on a comparison between the total power of the currently active power channel and the load power, and the average on-time of each of the multiple power channels.

[0041] Optionally, it also includes:

[0042] The load power is obtained based on the current sampling signal of the currently active power channel.

[0043] Optionally, the step of obtaining the pulse width modulation signal after switching the activated power channels includes: determining the number of power channels to be activated, and obtaining the phase difference between the power channels to be activated based on the number; and

[0044] The pulse width modulation signal of the power channel to be turned on is phase-shifted according to the phase difference to obtain the switched pulse width modulation signal.

[0045] Optionally, it also includes:

[0046] Identify the main power channel among the power channels that need to be activated;

[0047] The pulse width modulation signal of the main power channel is phase-shifted according to the phase difference to obtain the pulse width modulation signal after switching of other power channels that need to be turned on.

[0048] Optionally, it also includes:

[0049] Obtain the power channels that need to be turned on before and after the switch, and determine the main power channel among them.

[0050] Optionally, it also includes:

[0051] In the absence of a power channel that needs to be turned on before and after the switch, the pulse width modulation signal after the switch is generated based on the system clock and system status.

[0052] Optionally, it also includes:

[0053] The device enters shutdown mode when all power channels are turned off after the switch.

[0054] Optionally, the start and end times of the set period both correspond to the low-level center point or the high-level center point of the pulse width modulation signal of the main power supply channel.

[0055] Optionally, it also includes:

[0056] The phase difference between the power channels that need to be turned on can be obtained using the following formula:

[0057]

[0058] in, Let m be the phase difference, and m be the number of power channels that need to be activated, where m is an integer greater than 1.

[0059] The switched pulse width modulation signal is phase-interval according to the phase difference.

[0060] The power supply device and its power modulation method provided by this invention, after receiving a channel change command, clears the duty cycle of the pulse width modulation signal of each power channel near the zero-crossing point of the input voltage, maintains it for a set period, and then restores the pulse width modulation signal of each power channel according to the changed pulse width modulation signal of each power channel. The channel is switched at the zero-crossing point of the input voltage, which can improve the smoothness of the input current before and after the switch, improve the overall power factor of the power supply device, and improve the utilization rate of the power grid.

[0061] The power supply device provided by this invention can improve the smoothness of the input voltage before and after switching, improve the overall power factor of the power supply device, and improve the utilization rate of the power grid by reliably switching multiple parallel power channels. Attached Figure Description

[0062] The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0063] Figure 1 A schematic diagram of the structure of an AC / DC converter according to the prior art is shown;

[0064] Figure 2 A schematic diagram of the power supply device according to an embodiment of the present invention is shown;

[0065] Figure 3A and Figure 3B A schematic flowchart of a power modulation method according to an embodiment of the present invention is shown;

[0066] Figure 4A , Figure 4B , Figure 4C , Figure 4D A schematic diagram illustrating the state changes of some signals during channel switching in a power modulation method according to an embodiment of the present invention is shown.

[0067] Figure 5A and Figure 5B A schematic diagram showing the state change times of some signals in the channel switching of the power modulation method according to an embodiment of the present invention is shown.

[0068] Figure 6A , Figure 6B , Figure 6C , Figure 6D A schematic diagram illustrating another state change of a portion of the signal during channel switching in a power modulation method according to an embodiment of the present invention is shown. Detailed Implementation

[0069] Various embodiments of the invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0070] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0071] Figure 2 A schematic diagram of a power supply device according to an embodiment of the present invention is shown. In this embodiment, the power supply device 20 and... Figure 1 The AC / DC converter 10 shown has a similar structure, and its common parts will not be described again here.

[0072] Reference Figure 2The power supply device 20 in this embodiment includes a second power supply channel and a third power supply channel connected in parallel with the first power supply channel. The second power supply channel includes a second inductor L2, a second diode D2, a second transistor M2, and a second resistor R2. The third power supply channel includes a third inductor L3, a third diode D3, a third transistor M3, and a third resistor R3.

[0073] In an optional embodiment, the main power circuit of each power channel of the power supply device 20 is any one of a ground-type Buck power circuit, a virtual-ground-type Buck power circuit, a flyback power circuit, a Buck-boost power circuit, or a Boost power circuit.

[0074] The control unit 22 also provides the second pulse width modulation signal PWM2 and the third pulse width modulation signal PWM3 to the second transistor M2 and the third transistor M3 respectively, based on the second sampling current signal ADC2 and the third sampling current signal ADC3.

[0075] When the duty cycle of the first pulse width modulation signal PWM1 to the third pulse width modulation signal PWM3 is not zero, the corresponding power supply channel is turned on. The control unit 22 controls the switching of the number of power supply channels turned on by controlling the phase difference of each pulse width modulation signal.

[0076] In this embodiment, the first transistor M1 to the third transistor M3 are all IGBTs (Insulated Gate Bipolar Transistors). In an optional embodiment, they are NMOS (N-Metal-Oxide-Semiconductor) transistors.

[0077] Figure 3A and Figure 3B A schematic flowchart of a power modulation method according to an embodiment of the present invention is shown.

[0078] Reference Figure 3A The power modulation method of this invention mainly includes:

[0079] Step S10: Clear the duty cycle of the pulse width modulation signal of the multiple power supply channels at the zero crossing point of the input voltage.

[0080] In step S10, when channel switching is required, the input voltage VIN is detected, channel switching is performed at the zero-crossing point of the input voltage, and the duty cycle of the pulse width modulation signal of the multi-power supply channel is cleared.

[0081] In step S10, the system status is also detected to determine whether channel switching is required. Specifically, this includes obtaining the total power, load power, and average on-time of each of the currently active power channels. If the load power changes and the total power of the currently active power channel does not match the load power, switching is performed; or if the average on-time of each of the multiple power channels differs significantly, channel switching is performed.

[0082] In channel switching due to load power changes, the power channel with the shorter average turn-on time is selected based on the average turn-on time of each of the multiple power channels.

[0083] In this embodiment, the threshold for zero-crossing detection is set at 5% of the maximum amplitude of the input voltage VIN. A zero-crossing is confirmed when the input voltage VIN is less than or equal to the threshold.

[0084] The channel switching operation is selected at the zero-crossing point of the input voltage VIN, which corresponds to the minimum point of the input voltage VIN and the input current. This avoids large jumps in input current and voltage during switching and ensures smooth switching of input current and voltage.

[0085] Step S20: Obtain the switched pulse width modulation signal of the switched multi-power channels.

[0086] In step S20, the phase difference of the pulse width modulation signal is mainly determined based on the number of power channels that need to be activated after the switch. The phase difference between the power channels that need to be activated satisfies the following:

[0087]

[0088] in, Let m be the phase difference, m be the number of power channels to be turned on, and m be an integer greater than 1. The pulse width modulation signals of the power channels to be turned on after the switch are equally spaced according to the phase difference (equally spaced in a certain order).

[0089] Generally, when two or more power channels are activated, their phase difference needs to be modulated to ensure the interoperability of multiple power channels and to guarantee power modulation efficiency. When two power channels are activated, their phase difference is 180°, and when three power channels are activated, their phase difference is 120°.

[0090] Step S30: After the duty cycle is cleared to zero and the set period is reached, output the switched pulse width modulation signal.

[0091] Reference Figure 3B The steps to obtain the pulse width modulation signals of each power channel after the change mainly include:

[0092] Step S21: Determine the number of power channels that need to be turned on, and obtain the phase difference between the power channels that need to be turned on based on the number.

[0093] Step S22: Determine the main power channel among the power channels that need to be turned on.

[0094] In this embodiment, the main power channel is the power channel that is active both before and after the channel change. When there are power channels that need to be active both before and after the switch, the main power channel is determined from these channels. Therefore, the timing information of the pulse width modulation signal for the main power channel is no longer required. If the number of power channels that need to be active after the change is zero or one, or if all the power channels that need to be active after the change are newly activated, then the main power channel confirmation process is not required. When the number of power channels that need to be active after the change is zero, it indicates that all power channels are turned off, and the system enters a shutdown state.

[0095] In an optional embodiment, if there are no power channels that need to be turned on before and after the channel change, the timing information of their pulse width modulation signals can be regenerated according to the system clock and system status. For example, if the channel 2 is turned on, the channel 1 and 3 are turned on to balance the average conduction time of each channel. If there are no power channels that need to be turned on before and after the change, the timing information of their pulse width modulation signals can be generated according to the system status and system clock.

[0096] Step S23: Perform a phase shift operation on the pulse width modulation signal of the main power channel according to the phase difference to obtain the pulse width modulation signal after switching of other power channels that need to be turned on.

[0097] In step S23, the switched pulse width modulation signals are obtained by phase shifting (shifting forward or backward) according to the pulse width modulation signal of the main power supply channel.

[0098] The power modulation method of this invention further includes: recording the average turn-on time of each power channel, so as to select the power channel to be turned on after switching according to the average turn-on time, so as to reduce the difference in the average turn-on time of each power modulation, thereby averaging the average working time of each power channel, balancing the working aging degree of the circuit and electronic devices, balancing the service life of each power channel, and reducing the impact of the short board effect on the overall service life of the power supply device.

[0099] Figure 4A , Figure 4B , Figure 4C , Figure 4D A schematic diagram illustrating the state changes of some signals during channel switching in a power modulation method according to an embodiment of the present invention is shown.

[0100] Reference Figure 4AThe channel change has been changed from one to two. Taking the currently activated power channel as the first power channel, the power channels to be activated include the first power channel and the second power channel.

[0101] Upon receiving the channel change instruction, since the first power channel is a power channel that is active both before and after the change, the first power channel is configured as the main power channel, and the duty cycle of each pulse width modulation signal is cleared to zero at the first moment T1, which is the center of a low-level time of the first pulse width modulation signal PWM1.

[0102] The period from the first time T1 to the second time T2 is a set period, which corresponds to one period of the first pulse width modulation signal PWM1. The second time T2 also corresponds to the center position of a low-level time of the first pulse width modulation signal PWM1.

[0103] Within a set period, the second pulse width modulation signal PWM2 is obtained by 180-degree phase shift based on the first pulse width modulation signal PWM1, and the duty cycle of the third pulse width modulation signal PWM3 is always zero.

[0104] In this embodiment, clearing the duty cycle to zero does not affect the timing information of the first pulse width modulation signal PWM1 of the main power supply channel, so as to perform a phase shift operation according to the first pulse width modulation signal to obtain the second pulse width modulation signal PWM2.

[0105] At the second time T2, the duty cycle is restored according to the modified first pulse width modulation signal PWM1 and second pulse width modulation signal PWM2, and the power modulation function of the first power channel and the second power channel is restored.

[0106] Reference Figure 4B The power channel has been changed from two to one. The currently activated power channel includes the first power channel and the second power channel. After the change, the power channel that needs to be activated will include the first power channel.

[0107] At the first time T1, the duty cycles of the first pulse width modulation signal PWM1 and the second pulse width modulation signal PWM2 are cleared. At the second time T2, the duty cycle of the first pulse width modulation signal PWM1 is restored, and the duty cycles of the second pulse width modulation signal PWM2 and the third pulse width modulation signal PWM3 are zero.

[0108] When the number of power channels that need to be activated after the change is one or zero, the main power channel does not need to be selected, which can save data processing volume and system power consumption.

[0109] Reference Figure 4C The number of power channels has been changed from two to three. The currently activated power channels include the first power channel and the second power channel. After the change, the power channels that need to be activated will include the first power channel, the second power channel, and the third power channel.

[0110] At the first moment T1, the duty cycle of the first pulse width modulation signal PWM1 and the second pulse width modulation signal PWM2 is cleared.

[0111] After the modification, three power channels need to be activated. Based on the phase difference requirement, the three pulse width modulation (PWM) signals must be 120° out of phase. Since the first and second power channels need to be activated both before and after the modification, either the first or second power channel can be selected as the main power channel. Taking the first power channel as the main power channel as an example, the timing of the first PWM signal PWM1 is shifted 120° backward to obtain the timing of the modified second PWM signal PWM2 and third PWM signal PWM3.

[0112] At the second time T2, the duty cycle is restored based on the timing information of the modified first pulse width modulation signal PWM1, second pulse width modulation signal PWM2 and third pulse width modulation signal PWM3.

[0113] Reference Figure 4D The number of power channels has been changed from three to two. Currently, there are three power channels in operation, and after the change, there are two power channels that need to be opened. In this embodiment, the power channels that need to be opened after the change are the first power channel and the second power channel.

[0114] At the first moment T1, the duty cycles of the first pulse width modulation signal PWM1 to the third pulse width modulation signal PWM3 are cleared to zero.

[0115] After the change, the power channels that need to be activated are the first power channel and the second power channel. According to the phase difference requirement, the two pulse width modulation signals must be 180° out of phase. Since both the first and second power channels need to be activated before and after the change, either the first or second power channel can be selected as the primary power channel. Taking the first power channel as the primary power channel as an example, the timing information of the changed second pulse width modulation signal PWM2 is obtained by shifting the timing of the first pulse width modulation signal PWM1 backward by 180°.

[0116] At the second time T2, the duty cycle of the first pulse width modulation signal PWM1 and the second pulse width modulation signal PWM2 is restored according to the timing of the changed signal, while the third pulse width modulation signal PWM3 remains in a zero state.

[0117] Figure 5A and Figure 5B A schematic diagram illustrating the state change times of some signals during channel switching in a power modulation method according to an embodiment of the present invention is shown.

[0118] Reference Figure 5A and Figure 5BThe power channel has been changed from one to two, and there are no channels that need to be activated before and after the change. In this embodiment, the power channel that was activated before the change is the first power channel, and the power channels that need to be activated after the change are the second power channel and the third power channel.

[0119] exist Figure 5A In the embodiment shown, the first time T1 for clearing the duty cycle of each pulse width modulation signal is the center point of the low-level time of the first pulse width modulation signal PWM1 of the first power channel, and the second time T2 for restoring the duty cycle of each pulse width modulation signal is the center point of the low-level time of the original timing of the first pulse width modulation signal PWM1 of the first power channel.

[0120] exist Figure 5B In the embodiment shown, the first time T1 for clearing the duty cycle of each pulse width modulation signal is the center point of the high-level time of the first pulse width modulation signal PWM1 of the first power channel, and the second time T2 for restoring the duty cycle of each pulse width modulation signal is the center point of the high-level time of the original timing of the first pulse width modulation signal PWM1 of the first power channel.

[0121] That is, the duty cycle clearing and recovery time in the power modulation method of the present invention is the low-level center point or the high-level center point of the pulse width modulation signal of the selected power channel.

[0122] Figure 6A , Figure 6B , Figure 6C , Figure 6D A schematic diagram illustrating another state change of a portion of the signal during channel switching in a power modulation method according to an embodiment of the present invention is shown.

[0123] in, Figure 6A The number of power channels that have been activated has changed from one to two. Figure 6B The number of power channels that have been activated has been reduced from two to one. Figure 6C The number of power channels that have been activated has been changed from two to three. Figure 6D The number of power channels that are activated has been changed from three to two, and is consistent with... Figures 4A to 4D The difference in the illustrated embodiment is that in this embodiment, the duty cycle clearing and recovery times of each pulse width modulation signal are located at the high-level center point of the pulse width modulation signal in the main power supply channel, and the phase difference processing of each pulse width modulation signal is different from that of the other embodiment. Figures 4A to 4D The embodiments shown are the same and will not be described again here.

[0124] In the above embodiments, only some channel changes are shown. The embodiments of the present invention also adjust the average on-time of each power channel to balance the working duration of each power channel, balance the aging rate, reduce the impact of the bottleneck effect, and thus improve the service life of the system hardware. Channels 1, 2, and 3 correspond to the first to third power channels respectively, with 1 representing on and 0 representing off. The on-time combinations of these channels are shown in Table 1.

[0125] Table 1

[0126] Channel 1 Channel 2 Channel 3 Number of channels opened 1 0 0 0 0 2 1 0 0 1 3 0 1 0 1 4 0 0 1 1 5 1 1 0 2 6 0 1 1 2 7 1 0 1 2 8 1 1 1 3

[0127] As shown in Table 1, there are eight activation combinations. The number of channels activated (one or two) each includes three cases. In the above embodiments, the activation of the first power channel is taken as an example when the number of channels activated is one, and the activation of the first and second power channels is taken as an example when the number of channels activated is two. In practice, the activation of each channel is flexibly adjusted according to the correspondence in Table 1 in order to balance the average working time of each channel.

[0128] Table 2 is derived from the current number of open channels and the number of channels that need to be opened after the change.

[0129] Table 2

[0130]

[0131]

[0132] As shown in Table 2, there are 12 types of channel number changes. The above embodiments use the 5th, 8th, 9th and 12th as examples for illustration. When the number of channels is changed to zero, all pulse width modulation signals are kept at zero. Other cases can be obtained by combining and modifying the above embodiments, which will not be described in detail here.

[0133] The power modulation method of the present invention, upon receiving a channel change command, clears the duty cycle of the pulse width modulation signal of each power channel near the zero-crossing point of the input voltage, maintains it for a set period, and then restores the pulse width modulation signal of each power channel according to the changed pulse width modulation signal of each power channel. The channel is switched near the zero-crossing point of the input voltage, which can improve the smoothness of the input current before and after the switch, improve the overall power factor of the power supply device, and improve the utilization rate of the power grid.

[0134] The power supply device provided by this invention controls the reliable switching of multiple parallel power channels according to the power modulation method of this invention, which can improve the smoothness of the input voltage before and after switching, improve the overall power factor of the power supply device, and improve the utilization rate of the power grid.

[0135] As described above, these embodiments of the present invention do not exhaustively cover all details, nor do they limit the invention to the specific embodiments described. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to effectively utilize the invention and its modifications. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A power supply device, comprising: A rectifier bridge is used to convert AC voltage into DC input voltage. Multiple power supply channels are connected in parallel, each power supply channel having an input terminal connected to the input voltage and an output terminal connected to the load to provide an output voltage, and the multiple power supply channels receive pulse width modulation signals for switching; as well as The control unit detects the system status to determine whether channel switching is required. Before the switching is performed on the multiple power supply channels, it determines whether the input voltage of the multiple power supply channels has reached a set threshold. If the input voltage is less than or equal to the set threshold, it clears the duty cycle of the pulse width modulation signal of the multiple power supply channels. After the duty cycle is cleared to zero for a set period, it generates the switched pulse width modulation signal and controls the multiple power supply channels to perform the switching.

2. The power supply device according to claim 1, wherein, The switching includes changing the power channel, increasing or decreasing the number of power channels that need to be turned on, turning on all or some of the power channels, or turning off all or some of the power channels.

3. The power supply device according to claim 2, wherein, The control unit is configured to perform the switching based on a comparison between the total power of the currently active power channel and the load power, and the average on-time of each of the multiple power channels.

4. The power supply device according to claim 3, wherein, The control unit is configured to obtain the load power based on the current sampling signal of the currently active power channel.

5. The power supply device according to any one of claims 1 to 4, wherein, The control unit is configured to acquire the pulse width modulation signal after the switching of the power channel to be activated through the following operations: Determine the number of power channels that need to be activated, and obtain the phase difference between the power channels that need to be activated based on the number; as well as The pulse width modulation signal of the power channel to be turned on is phase-shifted according to the phase difference to obtain the switched pulse width modulation signal.

6. The power supply device according to claim 5, wherein, The control unit is configured to perform the following phase-shifting operation: Identify the main power channel among the power channels that need to be activated; The pulse width modulation signal of the main power channel is phase-shifted according to the phase difference to obtain the pulse width modulation signal after switching of other power channels that need to be turned on.

7. The power supply device according to claim 6, wherein, The control unit is configured to determine the main power channel by performing the following operations: Obtain the power channels that need to be turned on before and after the switch, and identify the main power channel among them.

8. The power supply device according to claim 7, wherein, The control unit is also configured to: If there is no power channel that needs to be turned on before and after the switch, the pulse width modulation signal after the switch is generated according to the system clock and system status.

9. The power supply device according to claim 6, wherein, The control unit is also configured to enter a shutdown state if all power channels are turned off after the switch.

10. The power supply device according to claim 6, wherein, The start and end times of the set period both correspond to the low-level center point or the high-level center point of the pulse width modulation signal of the main power supply channel.

11. The power supply device according to claim 5, wherein, The control unit obtains the phase difference between the power channels that need to be turned on using the following formula: Where φ is the phase difference, m is the number of power channels that need to be activated, and m is an integer greater than 1. The switched pulse width modulation signal is spaced at equal phase intervals according to the phase difference φ.

12. The power supply device according to claim 1, wherein, Each of the multiple power supply channels includes: The main power circuit includes a power switch and a power element connected in series. The power switch is turned on or off under the control of the pulse width modulation signal. The main power circuit supplies power to the load.

13. The power supply device according to claim 12, wherein, The main power circuit can be any one of the following: a ground-type Buck power circuit, a virtual-ground-type Buck power circuit, a flyback power circuit, a Buck-boost power circuit, or a Boost power circuit.

14. A power modulation method for a power supply device, the power supply device including a rectifier bridge for converting AC voltage into an input voltage; Multiple power supply channels connected in parallel, each power supply channel having an input terminal connected to the input voltage and an output terminal connected to the load to provide an output voltage; The power modulation method of the power supply device includes: The system status is detected to determine whether channel switching is required. Based on the channel switching signal issued by the control unit, the input voltage of the multiple power supply channels is detected to see if it reaches a set threshold. If the input voltage is less than or equal to the set threshold, the duty cycle of the pulse width modulation signal of the multiple power supply channels is cleared. After the duty cycle of the multiple power supply channels reaches a set period, the pulse width modulation signal after the switching of the multiple power supply channels is obtained.

15. The power modulation method according to claim 14, wherein, The switching includes changing the power channel, increasing or decreasing the number of power channels that need to be turned on, turning on all or some of the power channels, or turning off all or some of the power channels.

16. The power modulation method according to claim 14, wherein, The control unit is configured to perform the switching based on a comparison between the total power of the currently active power channel and the load power, and the average on-time of each of the multiple power channels.

17. The power modulation method according to claim 16, wherein, Also includes: The load power is obtained based on the current sampling signal of the currently active power channel.

18. The power modulation method according to any one of claims 14 to 17, wherein, The steps for obtaining the pulse width modulation signal after switching of the activated power channels include: determining the number of power channels to be activated, and obtaining the phase difference between the power channels to be activated based on the number; and The pulse width modulation signal of the power channel to be turned on is phase-shifted according to the phase difference to obtain the switched pulse width modulation signal.

19. The power modulation method according to claim 18, wherein, Also includes: Identify the main power channel among the power channels that need to be activated; The pulse width modulation signal of the main power channel is phase-shifted according to the phase difference to obtain the pulse width modulation signal after switching of other power channels that need to be turned on.

20. The power modulation method according to claim 19, wherein, Also includes: Obtain the power channels that need to be turned on before and after the switch, and determine the main power channel among them.

21. The power modulation method according to claim 19, wherein, Also includes: In the absence of a power channel that needs to be turned on before and after the switch, the pulse width modulation signal after the switch is generated based on the system clock and system status.

22. The power modulation method according to claim 19, wherein, Also includes: The device enters shutdown mode when all power channels are turned off after the switch.

23. The power modulation method according to claim 19, wherein, The start and end times of the set period both correspond to the low-level center point or the high-level center point of the pulse width modulation signal of the main power supply channel.

24. The power modulation method according to claim 18, wherein, Also includes: The phase difference between the power channels that need to be turned on can be obtained using the following formula: Where φ is the phase difference, m is the number of power channels that need to be activated, and m is an integer greater than 1. The switched pulse width modulation signal is phase-interval according to the phase difference.

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