TWI863849B - Control method of power supply apparatus - Google Patents

Abstract

The present application provides a control method of a power supply apparatus. The method is applied to a power supply apparatus supplying energy to a load periodically changing between a heavy load and a light load. The working state of the power supply apparatus includes state 1 and state 2 of continuous switching. In the method, a switching time from the current working state to the next different working state is predicted according to the current working state. A control unit issues a control instruction for adjusting an output voltage of the power supply apparatus earlier than the next switching time predicted correspondingly. By enabling active control to intervene before the working state switching, dynamic performance of the power supply apparatus can be improved effectively and the fluctuation range of the output voltage can be reduced.

Description

Power supply device control method

This case involves the field of power electronics technology, and in particular, a method for controlling a power supply device.

Power supply devices, such as switching power supplies, are usually used as power sources for various types of electrical equipment to convert unregulated AC or DC input voltage into regulated AC or DC output voltage. Due to the need to adapt to different working conditions, the performance requirements for the dynamic response of power supplies are getting higher and higher. Good dynamic effects require power supply devices to have small voltage changes and voltage recovery time. When the power demand of the load suddenly increases or decreases significantly, the output voltage of the power supply device will be undervoltage or overvoltage, which can not only fail to meet the load demand, but also easily cause damage to the load.

In the prior art, in order to improve the dynamic performance of the power supply device in response to changing loads, the common control method is voltage loop or current loop. However, whether it is voltage loop control or current loop control, the control is only intervened after the output voltage changes suddenly. When the control signal acts on the switch unit, the amplitude of the output voltage has changed greatly, and the voltage peak has reached a relatively high level. Therefore, this control method has a certain lag and can only improve the dynamic performance of the power supply device to a limited extent.

As the load side's requirements for power quality continue to increase, how to improve the dynamic response capability of the power supply device and reduce the fluctuation range of the output voltage is an urgent problem to be solved.

Therefore, how to develop a power supply device control method that can improve the above-mentioned defects of the known technology is an urgent need at present.

This case provides a power supply device control method to solve at least one of the defects of the above-mentioned existing technology.

In the first aspect, the present invention provides a power supply device control method, providing a power supply device, the power supply device includes a control unit; the working state of the power supply device includes a state 1 and a state 2 that are switched continuously; the adjacent state 1 and state 2 form a cycle, and in each cycle, state 1 switches to state 2 in the current cycle at the first switching moment; in each cycle, state 2 switches to state 2 in the next cycle at the second switching moment; the control method includes the following steps: obtaining the current working state of the power supply device; predicting the switching moment from the current working state to the next different working state according to the current working state of the power supply device; the control unit issues an instruction earlier than the corresponding predicted next switching moment, and the instruction is used to adjust the output voltage of the power supply device.

In the above technical solution, the power supply device predicts the switching time between heavy load and light load in advance through the working state of the power supply device for loads with periodic changes in power demand, so as to control the power supply device in advance. Compared with the passive and lagging shortcomings of traditional control schemes, the control method disclosed in this case has the advantages of active and advance, which can greatly improve the dynamic performance of the power supply device and reduce the fluctuation range of the output voltage.

Optionally, the step of predicting the next switching time corresponding to the current working state of the power supply device includes: obtaining the starting time of the current working state; obtaining the duration of the working state of the power supply device that is the same as the current working state in the previous cycle; the next switching time corresponding to the current working state prediction is the sum of the starting time of the current working state and the duration of the working state that is the same as the current working state in the previous cycle.

Optionally, obtaining the starting time of the current working state includes: if the current working state is state one, the starting time of the current working state is the second switching time in the previous cycle; if the current working state is state two, the starting time of the current working state is the first switching time in the current cycle.

0，計數值x初始值為0；循環執行以下步驟，直至判斷相鄰兩次供電裝置工作狀態不同時，結束循環並獲取當前計數值X，其中X=x+n，n為循環執行次數；獲取相鄰兩次供電裝置工作狀態；判斷相鄰兩次供電裝置工作狀態是否相同； 若相鄰兩次供電裝置工作狀態相同，則計數值x累加，並返回重新獲取相鄰兩次供電裝置工作狀態；若第a+1次獲取供電裝置工作狀態為狀態一時，狀態一的持續時長等於當前計數值X與預設時間間隔的乘積；若第a+1次獲取供電裝置工作狀態為狀態二時，狀態二的持續時長等於當前計數值X與預設時間間隔的乘積。 Optionally, the step of obtaining the duration of state 1 and the duration of state 2 includes: the control unit obtains the working state of the power supply device multiple times at preset time intervals; the control unit determines whether the working state of the power supply device at the ath time and the a+1th time is the same; if the working state of the power supply device at the ath time and the a+1th time is different, a counting cycle is started, and the counting value is x, where x

0, the initial value of the count value x is 0; loop and execute the following steps until it is determined that the working states of the two adjacent power supply devices are different, then end the loop and obtain the current count value X, where X=x+n, n is the number of times the loop is executed; obtain the working states of the two adjacent power supply devices; determine whether the working states of the two adjacent power supply devices are the same; If the working status of two adjacent power supply devices is the same, the count value x is accumulated and returned to re-obtain the working status of the two adjacent power supply devices; if the working status of the power supply device obtained for the a+1th time is state 1, the duration of state 1 is equal to the product of the current count value X and the preset time interval; if the working status of the power supply device obtained for the a+1th time is state 2, the duration of state 2 is equal to the product of the current count value X and the preset time interval.

Optionally, the step of the control unit issuing an instruction earlier than the corresponding predicted next switching moment includes: if the current working state is state one, the control unit issues an instruction at a first instruction moment, and the first instruction moment is the predicted first switching moment minus the first time; if the current working state is state two, the control unit issues an instruction at a second instruction moment, and the second instruction moment is the predicted second switching moment minus the second time.

Optionally, the first time and the second time are both fixed values.

Optionally, the control unit issues a command at the first command moment including: the control unit issues a command at the first command moment including: obtaining the current time of the current working state; judging the size of the current time and the first command moment; if the current time is less than or equal to the first command moment, returning to re-obtain the current time of the current working state; if the current time is greater than the first command moment, the control unit issues a command; the control unit issues a second command at the second command moment including: obtaining the current time of the current working state; judging the size of the current time and the second command moment; if the current time is less than or equal to the second command moment, returning to re-obtain the current time of the current working state; if the current time is greater than the second command moment, the control unit issues a command.

Optionally, the absolute value of the difference between the output current when the power supply device is operating in state 1 and the output current when the power supply device is operating in state 2 is greater than a preset current threshold.

Optionally, the output current of the power supply device when operating in state 1 is less than the output current of the power supply device when operating in state 2.

Optionally, if the current working state of the power supply device is state one, the instruction is used to increase the output voltage of the power supply device; if the current working state of the power supply device is state two, the instruction is used to reduce the output voltage of the power supply device.

Optionally, a preset target voltage value is obtained in the power supply device; if the current working state of the power supply device is state one, the instruction is used to make the output voltage of the power supply device equal to the sum of the preset target voltage value and a first gain; if the current working state of the power supply device is state two, the instruction is used to make the output voltage of the power supply device equal to the difference between the preset target voltage value and a second gain.

Optionally, the first gain and the second gain are both fixed values.

Optionally, the first gain and the second gain are both set multipliers of the difference between the maximum output voltage of the power supply device and the minimum output voltage of the power supply device.

Optionally, the output current of the power supply device is direct current.

A power supply device control method provided in this case is applied to a power supply device. The working state of the power supply device includes a state 1 and a state 2 that are switched continuously. The adjacent state 1 and state 2 form a cycle. During the operation of the power supply device, the control unit obtains the current working state of the power supply device, predicts the switching moment from the current working state to the next different working state according to the current working state of the power supply device, and issues a command earlier than the corresponding predicted next switching moment to adjust the output voltage of the power supply device. By intervening in active control before the working state is switched, the dynamic performance of the power supply device can be effectively improved and the fluctuation range of the output voltage can be reduced.

Vo: output voltage

Va, Vmax, Vmin, V1, V2: voltage

PWM: Pulse Width Modulation drive signal

I_load: output current

m, n: time

X1, X2, Y1, Y2, Z1, Z2, C: time

T1, T2, t1, t2: time

S01, S02, S021, S022, S0221, S0222, S0223, S0224, S023, S03, S031, S032, S033, S131, S132, S133: Steps

The drawings herein are incorporated into and constitute a part of the specification, showing embodiments consistent with the present invention, and together with the specification, are used to explain the principles of the present invention.

Figure 1 is a waveform diagram of the output voltage generated by a power supply device using traditional control according to an exemplary embodiment of the present invention.

Figure 2 is a schematic diagram of the process of the power supply device control method provided in this case according to an exemplary embodiment.

Figure 3 is a schematic diagram of the process of the switching moment prediction method provided in this case according to an exemplary embodiment.

Figure 4 is a flowchart of a method for determining the duration of a state provided in this case according to an exemplary embodiment.

Figure 5A is a flowchart of a method for determining the first instruction time to send an instruction according to an exemplary embodiment of this case.

Figure 5B is a flowchart of a method for determining the second instruction time to send an instruction according to an exemplary embodiment of this case.

Figure 6 is a waveform diagram of the output voltage generated by a power supply device provided in this case according to an exemplary embodiment using a power supply device control method.

The above-mentioned figures have shown clear implementation examples of this case, which will be described in more detail later. These figures and text descriptions are not intended to limit the scope of the concept of this case in any way, but to explain the concept of this case to technical personnel in this field by referring to specific implementation examples.

Exemplary embodiments are described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the attached invention application patent scope.

The terms "first", "second", "third", "fourth", etc. in the description and scope of the invention application of this case and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or precedence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances. For example, without departing from the scope of this article, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information.

Depending on the context, the word "if" as used herein can be interpreted as "when" or "when" or "in response to a determination".

Furthermore, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context indicates otherwise.

It should be further understood that the terms "include", "comprises" and "includes" indicate the existence of features, steps, operations, elements, components, items, categories, and/or groups, but do not exclude the existence, occurrence or addition of one or more other features, steps, operations, elements, components, items, categories, and/or groups.

The terms "or" and "and/or" used herein are interpreted as inclusive, or mean any one or any combination. Thus, "A, B or C" or "A, B and/or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Exceptions to this definition occur only when the combination of elements, functions, steps or operations are inherently mutually exclusive in some manner.

In order to solve the technical problems mentioned in the background technology, this case discloses a new power supply device control method. The control method disclosed in this case is mainly applied to loads with periodic changes in power demand, hereinafter referred to as heavy load and light load. By predicting the moment of switching between heavy load and light load in advance, the power supply device is controlled in advance. Compared with the traditional control scheme that is passive and lagging, the control method disclosed in this case has the advantages of being active and advanced, which can greatly improve the dynamic performance of the power supply device and reduce the fluctuation range of the output voltage.

According to the different power requirements of the load under different working conditions, the output current of the power supply device also changes accordingly. Since the output current responds to load changes quickly, the size of the output current can be used to indicate the working state of the load. When the output current is small, it means that the load is working in light load mode, and when the output current is large, it means that the load is working in heavy load mode.

Figure 1 shows the waveform of the output voltage generated by the power supply device using traditional control. When the output voltage is stable, the magnitude is Vo. At time m, the output current I_load of the power supply device jumps from a small current to a large current, indicating that the load switches from a light load to a heavy load. At this time, the output voltage has begun to drop. Under traditional control methods, such as voltage loop control, the voltage loop will intervene in voltage control only when the output voltage drops by more than a certain threshold, for example, when the output voltage drops by more than Va. Until time n, the pulse width modulation drive signal (PWM) of the switching unit receives the control result of the voltage loop and changes. At this time, the output voltage has dropped to Vmin, and then gradually rises to Vo. As can be seen from Figure 1, when the load switches from light load to heavy load, the time required for the drive signal PWM to change is (m-n), and the amplitude of the output voltage drop is (Vo-Vmin). It can be seen that the traditional voltage loop control has inherent defects, such as long response time, large output voltage amplitude change, and dynamic performance that cannot meet the requirements. Similarly, when the output current I_load drops from a large current to a small current, it means that the load has switched from a heavy load to a light load. It can also be seen from Figure 1 that the drive signal PWM will not change until the output voltage rises to Vmax, such as frequency modulation control, and the output voltage will drop from Vmax to Vo. Therefore, it can be found from Figure 1 that the traditional control method has poor dynamic performance of the power supply device when dealing with loads that switch between heavy loads and light loads, which can easily affect the stability of the load and even damage the load.

The control method disclosed in this case predicts the switching time between heavy load and light load in advance, thereby controlling the power supply device in advance. Compared with the traditional control scheme, which is passive and lagging, the control method disclosed in this case has the advantages of being active and advanced, which can greatly improve the dynamic performance of the power supply device and reduce the fluctuation range of the output voltage.

When the load switches between heavy load and light load periodically and continuously, the power supply device that supplies energy to it will also have two continuously switched working states, such as continuously switched state 1 and state 2. State 1 and state 2 can correspond to light load and heavy load of the load, and state 1 and state 2 can also correspond to heavy load and light load of the load respectively. This case does not limit this. In the case, for the convenience of explanation, state 1 and state 2 correspond to light load and heavy load of the load, that is, when the power supply device works in state 1, it outputs a small current, and when the power supply device works in state 2, it outputs a large current, and the adjacent state 1 and state 2 form a cycle of the power supply device. In actual process, since it is difficult to achieve a constant output current, the output current will also have certain ripples under stable output conditions. Therefore, only when the output current change is greater than a preset current threshold value, it will be determined that the working state of the power supply device has switched.

In each cycle, there is a first switching moment and a second switching moment. At the first switching moment, the power supply device switches from state 1 to state 2. At the second switching moment, the power supply device switches from state 2 to state 1 of the next cycle.

Since the power demand of the load changes periodically, the switching moment between light load and heavy load can be predicted, so that the power supply device can make corresponding preparations in advance to deal with the output voltage jump or drop, thereby avoiding large fluctuations in the output voltage.

In actual operation, the periodic change of the load's power demand leads to the periodic change of the working state of the power supply device. Therefore, by directly predicting the switching moment of the power supply device in each cycle, the control unit in the power supply device can issue instructions earlier than the predicted switching moment and adjust the output voltage of the power supply device in advance.

In some embodiments, the control method includes the following steps, as shown in FIG. 2, wherein the numbers before the steps are only a preferred order and are not limited thereto: S01: obtaining the current working state of the power supply device; S02: predicting the switching moment to the next different working state according to the current working state of the power supply device; S03: according to the predicted switching moment, the control unit issues a control instruction earlier than the predicted switching moment to actively adjust the output voltage of the power supply device.

Regarding step S01: In some embodiments, the sampling unit in the power supply device continuously samples the output current of the power supply device at a certain sampling frequency. Once the difference between the output currents of two previous and subsequent samples is greater than the set current threshold, it is determined that the power supply device has switched the working state, and before the next switch, the control unit in the power supply device will continuously record the current working state. For example, when the difference between the output currents sampled twice is greater than the set current threshold, the current magnitudes of the two times are judged. If the output current sampled previously is less than the output current sampled later, it means that the working state of the power supply device has been switched from state one to state two. Before the next switch occurs, the control unit will always record the working state of the power supply device as state two. When step S02 is required, the current working state of the power supply device can be directly obtained from the control unit as state two.

In other embodiments, the working state of the power supply device can be obtained by real-time sampling of the output current of the power supply device. For example, a standard current value can be set. When the real-time output current obtained by sampling is less than the standard current value, it is judged that the current working state is state one, and the load is in a light-load working state. When the real-time output current obtained by sampling is greater than the standard current, it is judged that the current working state is state two, and the load is in a heavy-load working state.

For step S02: In some embodiments, after obtaining the current working state of the power supply device, the switching moment to the next different working state can be predicted according to the current working state. For example, if the current working state is state one, the first switching moment to switch to state two is predicted, and if the current working state is state two, the second switching moment to switch to state one is predicted.

For step S03: In some embodiments, the control unit will issue an action command in advance of the predicted switching moment to actively control the output voltage of the power supply device in advance. For example, if the current state is state 1, the predicted switching moment is the predicted first switching moment, which means that the load will jump from light load to heavy load at the predicted first switching moment, and the output voltage will drop at the predicted first switching moment. Therefore, the control unit will actively increase the output voltage in advance of the predicted first switching moment to avoid the output voltage dropping to a lower voltage value after the first switching moment actually arrives, such as Vmin shown in Figure 1. Similarly, if the current state is state 2, the control unit will proactively reduce the output voltage in advance of the predicted second switching moment to prevent the output voltage from rising to a higher voltage value, such as Vmax shown in Figure 1, after the second switching moment actually arrives.

By actively controlling the output voltage in advance, the output voltage fluctuation range of the power supply device can be significantly smaller than the traditional passive control method.

The specific execution method of the above step S02 is explained below in conjunction with Figure 3.

As for step S02, as shown in Figure 3, it specifically includes the following steps: S021: obtaining the starting time of the current working state; S022: obtaining the duration of the power supply device being in the same working state as the current working state last time; S023: calculating the predicted switching time corresponding to the current working state.

The above steps are explained below in conjunction with Figure 6: Figure 6 schematically shows two working cycles of the power supply device. For ease of explanation, 0-Y1 is the first cycle, and Y1-Y2 is the second cycle, where X1 represents the first switching moment in the first cycle, and Y1 represents the second switching moment in the first cycle. Similarly, X2 represents the first switching moment in the second cycle, and Y2 represents the second switching moment in the second cycle. Among them, 0, X1, Y1, X2, Y2 and C all represent moments, and T1, T2, t1 and t2 in Figure 6 all represent time.

After step S01, the current working state of the power supply device may be located at any position shown in FIG. 6. For the sake of explanation, it is assumed that after step S01, the current working state of the power supply device is state 1 corresponding to moment C, which is located in the second working cycle Y1-X2; then step S021 can confirm that the starting moment of the current working state is the second switching moment Y1 in the first cycle; step S022: according to FIG. 6 It can be seen that the last time the power supply device was in state 1, it was within the interval 0-X1 of the first cycle, and the figure shows that its duration is T1; step S023, according to the starting moment Y1 of the current working state and the duration of the last state 1 is T1, it can be predicted that the power supply device will switch to state 2 at the moment (Y1+T1), that is, the predicted first switching moment will occur at the moment (Y1+T1).

If after step S01, the current working state of the power supply device is state 2 and is in the second working cycle X2-Y2, then the corresponding current state start time is X2, and the duration of the last time it was in state 2 is the duration T2 of the interval X1-Y1 of the first cycle, then the corresponding predicted second switching time will occur at (X2+T2).

The following further explains how to obtain the duration of state 1 or state 2 in conjunction with Figure 4.

As mentioned above, the sampling unit in the power supply device will continuously sample the output current of the power supply device at a certain sampling frequency or a preset time interval m. Once the difference between the output currents of two previous samples is greater than the set current threshold, it is determined that the power supply device has switched its working state. If the difference between the output currents of two previous samples is less than or equal to the set current threshold, it means that the power supply device maintains the previous working state. Based on this scheme, a count value x is set in the control unit, and the initial value of the count value x is 0, which is used to obtain the duration of state 1 or state 2. The specific method is as follows: obtain the working status of the two adjacent power supply devices before and after. For the convenience of explanation, for example, if the difference between the output current of the ath time and the a+1th time is greater than the set current threshold, then the following steps are executed in a loop until the difference between the output currents of the two adjacent times is greater than the set current threshold. If the a+nth and a+n+1th currents are greater than the set current threshold again: S0221: obtain the working status of the two adjacent power supply devices; S0222: determine whether the working status of the two adjacent power supply devices is the same; S0223: if the function status of the two adjacent power supply devices is the same, the count value x is accumulated and the process returns to step S0221; for example, if the output current sampled a+1th and a+2th times is greater than the set current threshold again: S0221: obtain the working status of the two adjacent power supply devices; S0222: determine whether the working status of the two adjacent power supply devices is the same; S0223: if the function status of the two adjacent power supply devices is the same, the count value x is accumulated and the process returns to step S0221; for example, if the output current sampled a+1th and a+2th times is greater than the set current threshold again: If the difference is less than or equal to the set current threshold, that is, the working state of the power supply device for the a+1th time and the a+2th time is the same, then the value of x is increased by 1, and the difference between the output currents sampled for the a+2th time and the a+3th time is returned to determine whether the working state of the power supply device is the same, until the difference between the output currents sampled for the a+nth time and the a+n+1th time is greater than the set current threshold, the loop is determined to be terminated and the process goes to step S0. 224: Get the current count value X. At this time, n cycles have been experienced, so the current count value X=x+n. If the working state of the power supply device obtained for the a+1th time is state 1, the duration of state 1 is the product of X and the preset time interval m, X*m. If the working state of the power supply device obtained for the a+1th time is state 2, the duration of state 2 is the product of X and the preset time interval m, X*m.

In some embodiments, two count values p and q can be set to record the duration of state 1 and state 2 respectively.

Through the above method, the duration T1 of state 1 and the duration T2 of state 2 shown in Figure 6 can be obtained.

The specific execution method of the above step S03 is explained below in conjunction with Figure 6: As shown in Figure 6, assuming that the current working state is state 1 and is located in the Y1-X2 interval, and the first switching moment predicted by step S02 is located at X2, then step S03 will determine the first instruction moment Z1 in advance of the predicted first switching moment X2. As shown in Figure 6, the first instruction moment Z1 differs from the predicted first switching moment X2 by a first time t1.

Similarly, if the current working state is state 2 and is within the X2-Y2 interval, then the second switching moment predicted in step S02 is at Y2, and step S03 will determine the second instruction moment Z2 in advance of the predicted second switching moment Y2. As shown in FIG. 6, the second instruction moment Z2 differs from the predicted second switching moment Y2 by a second time t2.

In some embodiments, t1 and t2 are the same size.

In some embodiments, t1 and t2 may be preset fixed values.

At the first instruction moment Z1 and the second instruction moment Z2, the control unit will issue corresponding instructions to adjust the output voltage of the power supply device. By setting the first instruction moment Z1 and the second instruction moment Z2 before the corresponding predicted first switching moment X2 and the predicted second switching moment Y2, respectively, the power supply device can be more proactive in responding to sudden changes in output voltage, thereby improving the dynamic performance of the power supply device and controlling and reducing the fluctuation amplitude of the output voltage of the power supply device.

After determining the first instruction moment Z1 or the second instruction moment Z2, it is also necessary to determine in real time whether the current moment in the cycle reaches the first instruction moment Z1. Specifically, it includes: if the working state of the current moment is state 1, as shown in Figure 5A, execute the following steps: S031: obtain the current moment of the current working state; S032: determine the size of the current moment and the first instruction moment Z1; S033: if the current moment is less than or equal to the first instruction moment Z1, return to step S031; if the current moment is greater than the first instruction moment Z1, the control unit issues a corresponding instruction.

If the current working state is state 2, as shown in Figure 5B, the following steps are executed: S131: Get the current working state of the current moment; S132: Determine the size of the current moment and the second instruction moment Z2; S133: If the current moment is less than or equal to the second instruction moment Z2, return to step S131; if the current moment is greater than the second instruction moment Z2, the control unit issues a corresponding instruction.

Referring to Figure 6, if the current working state is state 1 and is within the Y1-X2 interval, it is necessary to determine the size of the current moment and the first instruction moment Z1. If the current moment is less than or equal to the first instruction moment Z1, it returns to re-obtain the current moment updated in real time. If the current moment is greater than the first instruction moment Z1, it means that the control unit needs to issue a corresponding instruction. If the current working state is state 2, it is necessary to determine the size of the current moment and the second instruction moment Z2. If the current moment is less than or equal to the second instruction moment Z2, it returns to re-obtain the current moment updated in real time. If the current moment is greater than the second instruction moment Z2, it means that the control unit needs to issue a corresponding instruction.

In other embodiments, the magnitude of the count value x can also be used directly to compare the time. The count value x multiplied by the same preset time interval m is the duration of the working state. Since the count value x is updated in real time, the real-time value of the count value x can also be used as a reference factor for determining the time.

Referring to Figure 6, if the current working state is state 1 and is within the interval Y1-X2, assuming that the count value x is used to time state 1 within the first cycle 0-X1, the size of T1 is K. Then, at the current moment, the predicted first switching moment is converted into the count value x, which is K, and then the first time t1 is subtracted to obtain the first instruction moment Z1. At this time, t1 can also be expressed in the unit of the count value x. For example, the first time t 1 is equivalent to a count value of 5, so when the first instruction moment Z1 is converted into the unit of count value x, its size is (K-5); then the current count value X of the current moment is compared with (K-5) in a loop. If the current count value X is less than (K-5), the count value x continues to accumulate. As the number of cycles increases, when the control unit determines that the current count value X is greater than (K-5), the control unit issues a corresponding instruction to actively increase the output voltage. Similarly, the method when the current working state is state 2 is similar to state 1, and will not be repeated here.

Please continue to refer to Figure 6 to explain the specific control method of the control unit at the first instruction moment Z1 and the second instruction moment Z2.

At the first instruction moment Z1, the control unit will control the output voltage of the power supply device to increase, such as increasing the output voltage of the power supply device to the sum of the preset target voltage value Vo plus the first gain; at the second instruction moment Z2, the control unit will control the output voltage of the power supply device to decrease, such as decreasing the output voltage of the power supply device to the preset target voltage value Vo minus the sum of the second gain.

Referring to Figure 6, the 0-Y1 interval is the output voltage when the control method disclosed in this case is not used for control. It can be seen from the PWM waveform that the control action is started only after the working state is switched, such as frequency modulation control, resulting in the maximum value of the output voltage being Vmax and the minimum value being Vmin; and in the Y1-Y2 interval, using the control method disclosed in this case, it can be seen from the PWM waveform that before the working state is switched, active control has been involved at the first instruction moment Z1 and the second instruction moment Z2, such as frequency modulation control, of course It can also be duty cycle adjustment. This case does not limit this. By intervening in active control in advance, the voltage fluctuation amplitude is only (V1-V2). Compared with (Vmax-Vmin), the voltage fluctuation range is significantly reduced, effectively increasing the dynamic performance of the power supply device.

In some embodiments, the first gain and the second gain are both fixed values; in some embodiments, the first gain and the second gain are both set multiples of the difference between the maximum output voltage and the minimum output voltage of the power supply device, for example, 30% of (Vmax-Vmin).

In some embodiments, the output current of the power supply device is direct current. The power supply device includes but is not limited to a direct current to direct current (DCDC) converter and an alternating current to direct current (ACDC) converter. The topology of the power supply device includes but is not limited to an LLC architecture.

It should be noted that since the control method disclosed in this case needs to use the relevant parameters of the previous cycle, such as the duration of the state, the empty built-in method of this case cannot intervene immediately in the first cycle after the power supply device is started, as shown in the 0-Y1 interval in Figure 6.

It should be noted that after the power supply device has been put into operation for a period of time, the load state changes further, for example, the power demand of the load becomes larger, the original heavy load becomes light load, and a heavy load state with a larger power demand is added, the control method is also applicable. In this state, the changed heavy load can be regarded as state one, and the heavy load with a larger power demand can be regarded as state two, which can match the control method.

The control method disclosed in this case is to make predictions and corresponding active control in the current cycle based on the status of the previous cycle. Therefore, this method can be used for various loads with cyclical changes in power demand and has wide applicability. After applying this control method, the circuit response time of the power supply device is greatly shortened to close to zero, and even if the cycle of the load's own power demand changes, it can be adjusted adaptively, which can realize full digital control of the power supply device and greatly improve the working performance of the power supply device.

After considering the specification and practicing the invention disclosed herein, the skilled person in the art will easily think of other implementation schemes of the present invention. The present invention is intended to cover any variation, use or adaptation of the present invention, which follows the general principles of the present invention and includes common knowledge or conventional technical means in the field of technology not disclosed in the present invention. The specification and embodiments are to be regarded as exemplary only, and the true scope and spirit of the present invention are indicated by the scope of the invention application below.

It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the scope of the attached invention application patent.

S01, S02, S03: Steps

Claims (14)

A power supply device control method, wherein, a power supply device is provided, the power supply device includes a control unit; the working state of the power supply device includes a state 1 and a state 2 that are switched continuously; adjacent states 1 and 2 form a cycle, and state 1 in each cycle switches to state 2 in the current cycle at the first switching moment; and state 2 in each cycle switches to the next state in the next cycle at the second switching moment; the control method includes the following steps: obtaining the current working state of the power supply device; predicting the switching moment of switching from the current working state to the next different working state according to the current working state of the power supply device; the control unit issues an instruction earlier than the corresponding predicted next switching moment, and the instruction is used to adjust the output voltage of the power supply device. The power supply device control method of claim 1, wherein, The step of predicting the next switching moment corresponding to the current working state of the power supply device includes: Obtaining the starting moment of the current working state; Obtaining the duration of the working state of the power supply device that is the same as the current working state in the previous cycle; The next switching moment corresponding to the current working state prediction is the sum of the starting moment of the current working state and the duration of the working state that is the same as the current working state in the previous cycle. As in claim 2, the power supply device control method, wherein, the starting time of obtaining the current working state includes: if the current working state is state 1, the starting time of the current working state is the second switching time in the previous cycle; if the current working state is state 2, the starting time of the current working state is the first switching time in the current cycle. As in claim 2, the power supply device control method, wherein, the step of obtaining the duration of state 1 and the duration of state 2 includes: the control unit obtains the working state of the power supply device multiple times at a preset time interval; the control unit determines whether the working state of the power supply device at the ath time and the a+1th time is the same; if the working state of the power supply device at the ath time and the a+1th time is different, start a counting loop, the counting value is x, where x≥0, and the initial value of the counting value x is 0; the following steps are executed in a loop until it is determined that the working state of the power supply device is different for two adjacent times, then the loop is terminated and the current counting value X is obtained, where X=x+n, and n is the number of times the loop is executed: Obtain the working status of the power supply device for two adjacent times; Determine whether the working status of the power supply device for two adjacent times is the same; If the working status of the power supply device for two adjacent times is the same, the count value x is accumulated, and the working status of the power supply device for two adjacent times is obtained again; If the working status of the power supply device obtained for the a+1th time is state 1, the duration of state 1 is equal to the product of the current count value X and the preset time interval; if the working status of the power supply device obtained for the a+1th time is state 2, the duration of state 2 is equal to the product of the current count value X and the preset time interval. The power supply device control method of claim 1, wherein, the control unit issues a command earlier than the predicted next switching moment, including: if the current working state is state 1, the control unit issues the command at a first command moment, the first command moment being the predicted first switching moment minus the first time; if the current working state is state 2, the control unit issues the command at a second command moment, the second command moment being the predicted second switching moment minus the second time. As in claim 5, the power supply device control method, wherein, the first time and the second time are both fixed values. As in claim 5, the power supply device control method, wherein, the control unit issues the command at the first command moment, including: obtaining the current moment of the current working state; judging the size of the current moment and the first command moment; if the current moment is less than or equal to the first command moment, returning to re-obtain the current moment of the current working state; if the current moment is greater than the first command moment, the control unit issues the command; the control unit issues the second command at the second command moment, including: obtaining the current moment of the current working state; judging the size of the current moment and the second command moment; if the current moment is less than or equal to the second command moment, returning to re-obtain the current moment of the current working state; if the current moment is greater than the second command moment, the control unit issues the command. A power supply device control method as claimed in any one of claims 1 to 7, wherein the absolute value of the difference between the output current when the power supply device is operating in state 1 and the output current when the power supply device is operating in state 2 is greater than a preset current threshold. A power supply device control method as claimed in claim 8, wherein, the output current of the power supply device when operating in state 1 is less than the output current of the power supply device when operating in state 2. A power supply device control method as claimed in claim 9, wherein, if the current working state of the power supply device is state 1, the instruction is used to increase the output voltage of the power supply device; if the current working state of the power supply device is state 2, the instruction is used to reduce the output voltage of the power supply device. A power supply device control method as claimed in claim 10, wherein: A preset target voltage value is obtained in the power supply device; If the current working state of the power supply device is state 1, the instruction is used to make the output voltage of the power supply device equal to the sum of the preset target voltage value and a first gain; If the current working state of the power supply device is state 2, the instruction is used to make the output voltage of the power supply device equal to the difference between the preset target voltage value and a second gain. As in claim 11, the power supply device control method, wherein, the first gain and the second gain are both fixed values. As in claim 11, the power supply device control method, wherein, the first gain and the second gain are both set multipliers of the difference between the maximum output voltage of the power supply device and the minimum output voltage of the power supply device. A power supply device control method as claimed in any one of claims 1 to 7, wherein the output current of the power supply device is direct current.

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