Multi-switch power supply selection method and device

Abstract

The invention discloses a multi-switching power supply selection method and device, and relates to the field of power management, and the method comprises the steps: at least providing two switching power supplies with different rated powers, switching the switching power supplies in sequence to power on, and obtaining the current efficiency and the output voltage ripple peak-to-peak value of each switching power supply; calculating an optional coefficient of each switching power supply according to the current efficiency and the output voltage ripple peak-to-peak value of each switching power supply; the selectable coefficients of all the switching power supplies are compared, and the switching power supply with the minimum selectable coefficient is switched to and connected to a load; wherein the smaller the selectable coefficient is, the more beneficial to energy conservation and / or stable power output is achieved when the selected switching power supply supplies power. According to the method and the device, the switching power supplies with different powers are tested and selected, and higher power supply conversion efficiency and more stable power supply are achieved by switching the switching power supplies with different powers.

Description

Technical Field

[0001] The present invention relates to the field of power management, and in particular to a method and device for selecting a multi-switch power supply, which achieves higher power conversion efficiency and more stable output through switching. Background Art

[0002] Commonly used switching power supplies have calibrated rated power and marked input and output voltage ranges. Switching power supplies from different manufacturers, different powers, and different implementation technologies all have different efficiency curves, and the efficiency of switching power supplies is also affected by input voltage, working environment temperature, etc. In addition, different switching power supplies also present different ripple size curves under different conditions. Manufacturers cannot provide all of these parameters, and users cannot conduct complete tests. In use, users generally choose switching power supplies based on the maximum power requirements of the application, leaving a certain margin.

[0003] For some special usage scenarios, the power demand varies greatly in different periods and modes, but most of the time it can be powered by a smaller switching power supply, and in rare cases a larger switching power supply is required. In this case, if a switching power supply with a larger rated power is simply selected, it will have a greater impact on the cumulative power consumption of the normal power supply scenario. For example, the overall efficiency curve of the switching power supply rated 800W and 300W is as follows: Figure 1 As shown, it can be seen that for a switching power supply with a certain rated power, the conversion efficiency is reduced when supplying power to low loads and high loads, that is, the conversion efficiency at both ends of the curve is lower than the conversion efficiency in the middle of the curve. Assuming that it is used in a 200W working scene most of the time, and occasionally exceeds 300W, an 800W switching power supply will be selected according to the normal selection process; the conversion efficiency of the 800W and 300W power supplies at 200W is now tested to be 85% and 91% respectively, and the cumulative power consumption in one year will differ by about 100 kWh.

[0004] Therefore, how to improve the conversion efficiency of switching power supplies in certain scenarios to achieve the purpose of energy saving is an issue that technical personnel in this field urgently need to solve. Summary of the invention

[0005] In view of the above problems and technical requirements, the inventors have proposed a method and device for selecting multiple switching power supplies, which can monitor and analyze the working environment and working status of the power supply, test and select switching power supplies of different powers, and achieve higher power conversion efficiency and more stable power supply by switching switching power supplies of different powers. At the same time, the present invention can perform specific tests on the working environment for any switching power supply (not affected by type and brand, etc.), and select a power supply that is more suitable for the environment. The technical solution of the present invention is as follows:

[0006] In a first aspect, the present application provides a method for selecting a multi-switch power supply, comprising the following steps:

[0007] At least two switching power supplies with different rated powers are provided, the switching power supplies are switched on in sequence, and the current efficiency and output voltage ripple peak-to-peak value of each switching power supply are obtained;

[0008] Calculate the optional coefficient of each switching power supply according to the current efficiency and the peak-to-peak value of the output voltage ripple of each switching power supply;

[0009] Compare the selectable coefficients of all switching power supplies, and switch to the switching power supply with the smallest selectable coefficient to connect it to the load;

[0010] Among them, the smaller the selectable coefficient is, the more conducive the selected switching power supply is to energy saving and / or outputting stable power supply when supplying power.

[0011] A further technical solution is to obtain the current efficiency of each switching power supply, including:

[0012] For each switching power supply,

[0013] Detect its input voltage V in 、Input current I in , calculate the input power;

[0014] Detect its output voltage V o , output current I o , calculate the output power;

[0015] According to the input power and output power, the current efficiency is calculated and expressed as:

[0016]

[0017] A further technical solution is that the optional coefficient is recorded as c, and its calculation expression is:

[0018]

[0019] Where: Er represents the rated efficiency or average efficiency given under a certain working environment, e represents the current efficiency of the switching power supply, V p-p Indicates the peak-to-peak value of the output voltage ripple of the switching power supply;

[0020] k v , k e There are two preset coefficients used to control the influence of efficiency and ripple when selecting a switching power supply; when energy saving is preferred, k is increased. v , when outputting a stable power supply, increase k e , the sum of the two is 1.

[0021] Its further technical solution is that the method further comprises:

[0022] Continuously detect the relevant parameters of the current switching power supply connected to the load to determine whether the external power supply and power receiving environment have changed;

[0023] When a change occurs, the detection value of the current switching power supply is matched with the historical detection value of each switching power supply. If the match is successful, the corresponding switching power supply is switched. Otherwise, the optional coefficient is recalculated based on the detection value of the current switching power supply, and the switching power supply is reselected.

[0024] A further technical solution is to continuously detect relevant parameters of the current switching power supply connected to the load to determine whether the external power supply and power receiving environment have changed, including:

[0025] The current switching power supply connected to the load continuously detects its input voltage V in , average input current I in , average output current I o , output voltage ripple peak-to-peak value V p-p , ambient temperature T;

[0026] The P value is calculated based on the above detection values. When the P value is greater than the threshold, it indicates that the external power supply and power receiving environment have changed;

[0027] The P value is expressed as:

[0028] P = k vin *W vin +k iin *W iin +k io *W io +k vpp *W vpp +k t *W t ;

[0029] Among them, k is the weight of each parameter, and the sum is 1; each parameter is expressed as:

[0030]

[0031] The superscript t-1 represents the previous sampling period, and the superscript t represents the current sampling period.

[0032] A further technical solution is to match the detection value of the current switching power supply with the historical detection value of each switching power supply, including:

[0033] Perform consistency check on the input voltage, output current, and ambient temperature of each switching power supply recorded after the switching power supplies were switched on in sequence before, and the input voltage, output current, and ambient temperature of the current switching power supply recorded at this time;

[0034] During the inspection, if the floating range of each detection value of a switching power supply and the corresponding detection value of the current switching power supply do not exceed the set threshold, it is considered that the relevant detection value of the switching power supply meets the current working environment and the match is considered successful.

[0035] Its further technical solution is that the method further comprises:

[0036] Switch the switching power supplies on in sequence and record at least the input voltage, output current, ambient temperature, and power supply number of each switching power supply to form a four-dimensional selection matrix. Continuously improve the matrix under the working environment to match when the external power supply and power receiving environment change.

[0037] Its further technical solution is that the method further comprises:

[0038] When switching the switching power supply, there will be a certain period of simultaneous power supply. At this time, the output voltage of the high-power switching power supply is controlled to be lower than the output voltage of the low-power switching power supply to achieve stable switching.

[0039] A further technical solution is to switch on the switch power supply in sequence, including:

[0040] The switching power supplies are switched on in order of rated power from large to small. If the rated power of the lower switching power supply is smaller than the load size of the current working environment, the circuit is temporarily disconnected and the upper switching power supply is returned.

[0041] In a second aspect, the present application also provides a multi-switch power supply selection device, comprising:

[0042] At least two switching power supplies with different power ratings;

[0043] The current and voltage detection circuit provided at the input end of the switching power supply is used to detect the input voltage and input current of the switching power supply;

[0044] A switching circuit provided at the output end of the switching power supply;

[0045] The current and voltage detection circuit provided at the output end of the switching circuit is used to detect the output voltage and output current of the switching power supply;

[0046] A temperature and humidity detection circuit is arranged near the switching power supply, and is used to detect the ambient temperature of the switching power supply;

[0047] The MCU is connected to the sampling ends of the current and voltage detection circuits and the temperature and humidity detection circuits and the control end of the switching circuit, and is used to implement the multi-switch power supply selection method as described in the first aspect.

[0048] The beneficial technical effects of the present invention are:

[0049] Compared with the prior art, the present method and device use a more complete power supply selection method, comprehensively considering the environmental conditions, power supply conditions, and power receiving conditions, and are suitable for the selection of multiple switching power supplies. The entire implementation process does not require the detailed parameters of each power supply to be selected to be input in advance, and calculations and analysis can be performed by the user to obtain the best choice.

[0050] It provides a fast matching method when the external power supply and power receiving environment change, so as to achieve faster and more accurate switching; after a period of use, the device can form a four-dimensional selection matrix suitable for the current working environment to achieve faster switching and reduce unnecessary testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic diagram of the efficiency curve of switching power supplies with different rated powers obtained through testing.

[0052] Figure 2 It is a schematic diagram of a multi-switch power supply selection device provided in this application.

[0053] Figure 3 It is a flowchart of the multi-switch power supply selection method provided by this application. DETAILED DESCRIPTION

[0054] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0055] In one embodiment of the present application, a multi-switch power supply selection device is provided, which can monitor and switch the output of multiple switch power supplies. The main monitoring contents include input and output voltage and current, ambient temperature and output power ripple. The device provides an AC input interface, multiple groups of switch power supply input and output interfaces, and an external DC output interface. The specific structure is as follows Figure 2 As shown, it includes an MCU, at least two switching power supplies A and B with different rated powers, and current and voltage detection circuits arranged at the input ends of the switching power supplies A and B, a switching circuit arranged at the output ends of the switching power supplies A and B, a current and voltage detection circuit arranged at the output end of the switching circuit, and a temperature and humidity detection circuit arranged near the switching power supplies A and B. The MCU is connected to the sampling ends of each current and voltage detection circuit, the sampling end of the temperature and humidity detection circuit, and the control end of the switching circuit. Among them, the current and voltage detection circuit at the input end is used to detect the input voltage and input current of the switching power supply, the current and voltage detection circuit at the output end is used to detect the output voltage and output current of the switching power supply, and the temperature and humidity detection circuit is used to detect the ambient temperature of the switching power supply. The above sampled detection values ​​are all transmitted to the MCU for record management and corresponding calculation.

[0056] The above circuit structures are all implemented by existing functional circuits. For example, the switching circuit is implemented by a relay combination circuit. The circuit structures are not described here. Among them, the voltage detection circuit at the output end is implemented by an ADC voltage detection circuit, which transmits the voltage sampling signal to the AD pin of the MCU, so that the MCU obtains the output voltage and its ripple peak value. The MCU also stores a multi-switch power supply selection method to realize the switching of the output power supply. The implementation steps of this method will be described in detail below.

[0057] Another embodiment of the present application provides a method for selecting a multi-switch power supply, which needs to be implemented in conjunction with the above device, such as Figure 3 As shown, the method specifically comprises the following steps:

[0058] Step 1: Provide at least two switching power supplies with different rated powers, switch the switching power supplies on in sequence and obtain the current efficiency and output voltage ripple peak-to-peak value of each switching power supply. When the device is working, first connect the switching power supply to be managed, the external power supply, and the powered load to the device. For the convenience of description, the switching power supplies to be managed are uniformly described as two in the subsequent description. This method can manage multiple switching power supplies, which are power supply A and power supply B respectively, and switch the switching power supplies on in order from large to small rated power. If the rated power of the lower-level switching power supply is less than the load size of the current working environment, it will temporarily not be connected to the circuit and return to the upper-level switching power supply. In this embodiment, power supply A is the default power supply.

[0059] After connecting to the external power supply, the default power supply A outputs power and supplies power to the MCU and other detection circuits of the device. The input voltage V of power supply A is detected. in 、Input current I ib , calculate the input power. Detect the output voltage V of power supply A o , output current I o , record the output voltage ripple peak value V p-p , calculate the output power. According to the input power and output power, calculate the current efficiency e, expressed as:

[0060]

[0061] At the same time, the ambient temperature of power supply A needs to be detected. Since the conversion efficiency of the switching power supply is mainly affected by the input voltage, output current, ambient temperature, etc., in this embodiment, at least the current input voltage, current output current, current ambient temperature, and current power supply number need to be recorded to form a four-dimensional selection matrix. Optionally, if the MCU memory is large enough, the current efficiency, current output voltage, and current ripple peak-to-peak value can also be recorded.

[0062] If power supply B meets the current working environment, the device switches the output power supply to power supply B, then detects the input voltage and input current of power supply B, and calculates the input power. Detect the output voltage and output current of power supply B, and record the output voltage ripple peak value V p-p , calculate the output power. According to the input power and output power, calculate the current efficiency e. At the same time, it is also necessary to detect the ambient temperature of power supply B, and at least record the current input voltage, current output current, current ambient temperature, and current power supply number, and update to the next row of the four-dimensional selection matrix.

[0063] Step 2: Calculate the optional coefficient c of each switching power supply based on the current efficiency and output voltage ripple peak-to-peak value of each switching power supply. The calculation expression is:

[0064]

[0065] Where: Er represents the rated efficiency or average efficiency given under a certain working environment.

[0066] k v , k e are two preset coefficients used to control the weight of efficiency and ripple when selecting a switching power supply. When the device is mainly used for power saving, k can be increased v , when the device is mainly used to output a stable power supply, k can be increased e The sum of the two is 1. According to the actual needs of users, the k v , k e Burn it into the MCU and readjust it later if the requirements change.

[0067] After calculation according to the above formula, the optional coefficients c of power supply A and power supply B are obtained respectively. a and c b , which is used to describe the selectable coefficient of each switching power supply under the current input voltage and the current output current. The smaller the selectable coefficient, the more conducive the selected switching power supply is to energy saving and / or outputting stable power supply when supplying power.

[0068] Step 3: Compare the selectable coefficients of all switching power supplies, and switch to the switching power supply with the smallest selectable coefficient to connect it to the load.

[0069] When it is necessary to perform specific tests on multiple switching power supplies in a certain application scenario and finally select a power supply that is more suitable for this scenario, the above-mentioned multi-switching power supply selection method and device can be used, that is, the power supplies to be selected are connected to this device, and power supply parameters are input according to possible scenarios. The c value of each power supply to be tested is calculated by this device, so as to select a switching power supply that is more suitable for this scenario.

[0070] In order to expand the use scenarios of the device, the present application expands the above-mentioned multi-switch power supply selection method, and also includes:

[0071] Step 4: After completing the above selection, the current switching power supply connected to the load is continuously tested for its relevant parameters to determine whether the external power supply and power receiving environment have changed. Specifically, the current switching power supply connected to the load is continuously tested for its input voltage V in , average input current I in , average output current I o , output voltage ripple peak-to-peak value V p-p , ambient temperature T. Based on the above detection values, the P value is calculated. When the P value is greater than the threshold, it indicates that the external power supply and power receiving environment have changed, and the switching power supply needs to be reselected. The P value is expressed as:

[0072] P = k vin *W vin +k iin *W iin +k io *W io +k vpp *W vpp +k t *W t ;

[0073] Among them, k is the weight of each parameter, and the sum is 1. Each parameter is expressed as:

[0074]

[0075] The superscript t-1 represents the previous sampling period, and the superscript t represents the current sampling period.

[0076] Step 5: When a change occurs, the detection value of the current switching power supply is matched with the historical detection value of each switching power supply. If the match is successful, switch to the corresponding switching power supply. Otherwise, recalculate its optional coefficient based on the detection value of the current switching power supply, and reselect the switching power supply, that is, re-execute steps 2 and 3.

[0077] The matching method specifically includes: performing consistency check on the input voltage, output current, and ambient temperature of each switching power supply previously recorded in step 1, and the input voltage, output current, and ambient temperature of the current switching power supply recorded at this time. During the check, if the floating range of each detection value of a switching power supply and the corresponding detection value of the current switching power supply does not exceed the set threshold, it is considered that the relevant detection value of the switching power supply meets the current working environment, and the corresponding switching power supply can be directly selected according to the record, and it is considered that the match is successful.

[0078] Optionally, when the matching is unsuccessful, the input voltage, output current and ambient temperature of the current switching power supply can be updated to the next row of the four-dimensional selection matrix, that is, the matrix is ​​continuously improved under the working environment to facilitate rapid matching when the external power supply and power receiving environment change.

[0079] Since it takes a certain amount of time to establish the output of the power supply, when the switching power supply needs to be switched during the execution of the above steps, there will be a certain period of simultaneous power supply. At this time, the output voltage of the high-power switching power supply controlled by the MCU is slightly lower than the output voltage of the low-power switching power supply to ensure the stability of the switching.

[0080] In addition to being applicable to specific test scenarios, the above method is also applicable to scenarios where the switch power supply is switched in real time according to actual working conditions. For example, the power consumption of a certain equipment system is 20W most of the time, and the power consumption is 100W in very rare cases. Now two power supplies of 30W and 150W are selected to drive the system. The device equipped with the above method switches the power supply when the system power consumption increases and decreases. While ensuring stable power supply, higher conversion efficiency and less cumulative power consumption can be achieved.

[0081] The above is only a preferred embodiment of the present application, and the present invention is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the protection scope of the present invention.

Claims

1. A method for selecting a multi-switch power supply, characterized in that: The method comprises: At least two switching power supplies with different rated powers are provided, the switching power supplies are switched on in sequence, and the current efficiency and output voltage ripple peak-to-peak value of each switching power supply are obtained; Calculating the optional coefficient of each switching power supply according to the current efficiency and the peak-to-peak value of the output voltage ripple of each switching power supply; Compare the selectable coefficients of all switching power supplies, and switch to the switching power supply with the smallest selectable coefficient to connect it to the load; The smaller the selectable coefficient is, the more conducive the selected switching power supply is to energy saving and / or outputting stable power when supplying power.

2. The method for selecting a multi-switch power supply according to claim 1, characterized in that: The method of obtaining the current efficiency of each switching power supply comprises: For each switching power supply, Detect its input voltage V in 、Input current I in , calculate the input power; Detect its output voltage V o , output current I o , calculate the output power; According to the input power and the output power, the current efficiency is calculated and expressed as:

3. The multi-switch power supply selection method according to claim 1, characterized in that: The optional coefficient is denoted as c, and its calculation expression is: Where: Er represents the rated efficiency or average efficiency given under a certain working environment, e represents the current efficiency of the switching power supply, V p-p represents the peak-to-peak value of the output voltage ripple of the switching power supply; k v , k e are two preset coefficients used to control the influence weight of efficiency and ripple when selecting a switching power supply; when energy saving is preferred, the k v , when biased towards outputting a stable power supply, increase the k e , the sum of the two is 1.

4. The method for selecting a multi-switch power supply according to claim 1, characterized in that: The method further comprises: Continuously detect the relevant parameters of the current switching power supply connected to the load to determine whether the external power supply and power receiving environment have changed; When a change occurs, the detection value of the current switching power supply is matched with the historical detection value of each switching power supply. If the match is successful, the corresponding switching power supply is switched. Otherwise, the optional coefficient is recalculated based on the detection value of the current switching power supply, and the switching power supply is reselected.

5. The method for selecting a multi-switch power supply according to claim 4, characterized in that: The method of continuously detecting relevant parameters of the current switching power supply connected to the load to determine whether the external power supply and power receiving environment have changed includes: The current switching power supply connected to the load continuously detects its input voltage V in , average input current I in , average output current I o , output voltage ripple peak-to-peak value V p-p , ambient temperature T; The P value is calculated based on the above detection values. When the P value is greater than a threshold value, it indicates that the external power supply and power receiving environment have changed. The P value is expressed as: P=k vun *W vin +k iin *W iin +k io *W io +k vpp *W vpp +k t *W t ; Among them, k is the weight of each parameter, and the sum is 1; each parameter is expressed as: The superscript t-1 represents the previous sampling period, and the superscript t represents the current sampling period.

6. The method for selecting a multi-switch power supply according to claim 4, characterized in that: The matching of the current detection value of the switching power supply with the historical detection value of each switching power supply includes: Perform consistency check on the input voltage, output current, and ambient temperature of each switching power supply recorded after the switching power supplies were switched on in sequence before, and the input voltage, output current, and ambient temperature of the current switching power supply recorded at this time; During the inspection, if the floating range of each detection value of a switching power supply and the corresponding detection value of the current switching power supply do not exceed the set threshold, it is considered that the relevant detection value of the switching power supply meets the current working environment and the match is considered successful.

7. The method for selecting a multi-switch power supply according to claim 4, characterized in that: The method further comprises: Switch the switching power supplies on in sequence and record at least the input voltage, output current, ambient temperature, and power supply number of each switching power supply to form a four-dimensional selection matrix. Continuously improve the matrix under the working environment to match when the external power supply and power receiving environment change.

8. The method for selecting multiple switching power supplies according to claim 1, characterized in that: The method further comprises: When switching the switching power supply, there will be a certain period of simultaneous power supply. At this time, the output voltage of the high-power switching power supply is controlled to be lower than the output voltage of the low-power switching power supply to achieve stable switching.

9. The method for selecting multiple switching power supplies according to claim 1, characterized in that: The step of switching on the switch power supply in sequence comprises: The switching power supplies are switched on in order of rated power from large to small. If the rated power of the lower switching power supply is smaller than the load size of the current working environment, the circuit is temporarily disconnected and the upper switching power supply is returned.

10. A multi-switch power supply selection device, characterized in that: include: At least two switching power supplies with different power ratings; The current and voltage detection circuit provided at the input end of the switching power supply is used to detect the input voltage and input current of the switching power supply; A switching circuit provided at the output end of the switching power supply; The current and voltage detection circuit provided at the output end of the switching circuit is used to detect the output voltage and output current of the switching power supply; A temperature and humidity detection circuit is arranged near the switching power supply, and is used to detect the ambient temperature of the switching power supply; MCU, connected to the sampling end of the current and voltage detection circuit, the temperature and humidity detection circuit and the control end of the switching circuit, is used to implement the multi-switch power supply selection method as described in any one of claims 1 to 9.

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