Intelligent power supply control method adaptive to different loads

Abstract

The invention discloses an intelligent power supply control method adaptive to different loads, and the method comprises the following steps: starting up a power supply, carrying out the output in a constant voltage source mode, and relaxing a voltage and current loop; when more than two times of rated current occurs, the output voltage is reduced according to the output current signal, whether an overload phenomenon occurs or not is judged, and a dynamic response mode or a peak power mode is entered; if the power supply stays in a dynamic response mode or a peak power mode for a long time or enters an accumulated continuous different-place time for multiple times in a short time, entering a constant-current protection mode; and after the output voltage signal and the output current signal of the power supply return to normal, the constant current protection mode is quitted, and the constant voltage source mode is re-entered. The output of the power supply is controlled through the micro control unit (MCU), and different types of loads are intelligently detected and responded, so that the purposes of timely identification, timely protection and rapid and stable output are achieved, and the reliability and applicability of the power supply are enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply control, and in particular to an intelligent power supply control method capable of adaptively controlling different loads. Background Art

[0002] When the power supply is used for inductive loads, its starting current often reaches 5-6 times, and conventional products cannot meet the required requirements. Currently, there are some products on the market that provide 2-3 times the peak power, but there are few products that can provide 6 times or higher peak power. Such high peak power products have slow dynamic response speeds under different load conditions, especially in some complex application scenarios, which are prone to trigger output protection.

[0003] Although the current power supplies that support high peak current can achieve effective current response when facing inductive loads, it is difficult to respond in time when facing loads such as constant voltage (battery), constant resistance (heating resistor), constant power (power IC management chip), etc. Most of them will directly trigger the corresponding protection and shut down directly.

[0004] In order to achieve the output of ultra-high peak current, when the power supply is in normal operation, it outputs a constant voltage source. When encountering ultra-high peak current, the overload protection (OLP) function on the front-end side is used to limit the constant power, thereby reducing the output voltage and maintaining the peak current. After a corresponding period of time, the output is turned off and the corresponding protection is performed. The above method is simple to implement and can be achieved using pure hardware, but it has the following disadvantages: (1) The hardware circuit is complex and requires countermeasures for various load conditions. For example, when facing a CV load, the output current is the peak current and needs to be shut down in time; (2) The OLP point on the front-end side is difficult to adjust, the MOS tube is under great stress, the cost is high, and it is easy to be damaged; (3) The power volume is large, and the transformer has problems such as uneven current, which make it impossible to carry load for a long time.

[0005] Therefore, it is necessary to study a high peak load control method that can adapt to different types of loads and has fast dynamic response, so as to solve the dynamic response problems of inductive loads and various complex application scenarios. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an intelligent power supply control method that is adaptive to different loads. The output of the power supply is controlled by a microcontroller unit (MCU), and different types of loads are intelligently detected and responded to, so as to achieve the purpose of timely identification, timely protection, and rapid and stable output, thereby enhancing the reliability and applicability of the power supply.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows: an intelligent power supply control method that is adaptive to different loads, comprising the following steps:

[0008] (1) The power supply is turned on to output in constant voltage source mode, and the voltage and current loops are relaxed to cope with load changes of motor loads;

[0009] (2) When the current is more than twice the rated current, the output voltage is reduced according to the output current signal to determine whether an overload occurs;

[0010] (3) When the output current signal decreases, the load is determined to be a constant voltage or constant resistance load, and the system enters the dynamic response mode to control the output voltage through current feedback to maintain the rated power.

[0011] (4) When the output current signal does not decrease, the load is determined to be a constant current or constant power load, and the peak power mode is entered to respond to the high peak current output;

[0012] (5) If the power supply is in dynamic response mode or peak power mode for a long period of time or enters the mode multiple times in a short period of time, the power supply enters constant current protection mode;

[0013] (6) When the power supply is in constant current protection mode, the reference voltage is the rated voltage, and the reference current varies with the input voltage, output voltage, and power supply temperature;

[0014] (7) After the output voltage and output current signals of the power supply return to normal, the constant current protection mode is exited and the constant voltage source mode is re-entered.

[0015] As a preferred solution, in the constant voltage source mode in step (1), the reference voltage is the rated voltage, and the reference current is 6 times the rated current.

[0016] As a preferred solution, the dynamic response mode in step (3) uses the output current signal as feedback to dynamically adjust the output voltage to maintain the output current signal at the rated current.

[0017] As a preferred solution, in step (4), the reference voltage in the peak power mode decreases as the current increases, and the reference current is 6 times the rated current.

[0018] As a preferred scheme, the power supply control method controls the output voltage and output current signal through a voltage-current loop, and the voltage-current loop includes a voltage control loop and a current control loop. The voltage control loop is used to adjust the reference voltage to control the output voltage, and the current control loop is used to adjust the reference current to control the output current signal.

[0019] As a preferred solution, the voltage control loop and the current control loop are connected in parallel with an optocoupler feedback circuit.

[0020] As a preferred solution, a unidirectional conduction circuit is provided between the optocoupler feedback circuit and the voltage control loop and the current control loop.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The microcontroller unit (MCU) detects load conditions and controls voltage and current references, thereby providing real-time and rapid response;

[0023] (2) Solved the output response problem of power supply equipment facing different loads such as motor, constant current, constant voltage, constant power, constant resistance, etc.;

[0024] (3) The problem of power supply equipment being triggered by the electromotive force of motor loads to protect it has been solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a control flow chart of the present invention;

[0026] Figure 2 is a circuit diagram of a voltage and current loop in the present invention;

[0027] Figure 3 It is a waveform diagram of the power supply in the present invention when facing a constant current type load or an inductive load;

[0028] Figure 4 It is a waveform diagram of the power supply in the present invention when facing a constant voltage type non-adaptive load;

[0029] Figure 5 It is a waveform diagram of the power supply in the present invention when facing a constant voltage type adaptive load;

[0030] Figure 6 It is a waveform diagram of the power supply in the present invention when facing the switching between constant voltage load and constant current load;

[0031] Figure 7 It is a waveform diagram of the power supply in the present invention when facing a constant power type load;

[0032] Figure 8 It is a waveform diagram of the power supply in the present invention when facing a constant resistance load. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with specific examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention.

[0034] Example:

[0035] like Figure 1 As shown, an intelligent power supply control method that is adaptive to different loads includes the following steps:

[0036] (1) The power supply is turned on to output in constant voltage source mode, and the voltage and current loops are relaxed to cope with load changes of motor loads;

[0037] (2) When the current is more than twice the rated current, the output voltage +V1 is reduced according to the output current signal I_MEAN to determine whether an overload occurs;

[0038] (3) When the output current signal I_MEAN decreases, the load is determined to be a constant voltage or constant resistance load, and the dynamic response mode is entered. The output voltage +V1 is controlled by current feedback to maintain the rated power.

[0039] (4) When the output current signal I_MEAN does not decrease, the load is determined to be a constant current or constant power load, and the peak power mode is entered to respond to the high peak current output;

[0040] (5) If the power supply is in dynamic response mode or peak power mode for a long period of time or enters the mode multiple times in a short period of time, the power supply enters constant current protection mode;

[0041] (6) When the power supply is in constant current protection mode, the reference voltage V_SET is the rated voltage, and the reference current I_SET varies with the input voltage, output voltage +V1, and power supply temperature;

[0042] (7) After the output voltage +V1 and the output current signal I_MEAN of the power supply return to normal, the constant current protection mode is exited and the constant voltage source mode is re-entered.

[0043] Preferably, in the constant voltage source mode in step (1), the reference voltage V_SET is the rated voltage, and the reference current I_SET is 6 times the rated current.

[0044] Preferably, in the step (3), the dynamic response mode uses the output current signal I_MEAN as feedback to dynamically adjust the output voltage +V1 to maintain the output current signal I_MEAN at the rated current.

[0045] Preferably, in the peak power mode in step (4), the reference voltage V_SET decreases as the current increases, and the reference current I_SET is 6 times the rated current.

[0046] In this embodiment, the present invention takes the 120W-24V model as an example, uses a microcontroller unit (MCU) to control the reference voltage V_SET and the reference current I_SET, and performs unidirectional conduction driving. By detecting the output voltage +V1 and the output current signal I_MEAN status, the load type is inferred to achieve regulation of the output voltage +V1 and the output current signal I_MEAN.

[0047] Preferably, Figure 2 As shown, the power supply control method controls the output voltage +V1 and the output current signal I_MEAN through a voltage-current loop. The voltage-current loop includes a voltage control loop and a current control loop. The voltage control loop is used to adjust the reference voltage V_SET to control the output voltage +V1, and the current control loop is used to adjust the reference current I_SET to control the output current signal I_MEAN.

[0048] Preferably, the current control loop includes a first operational amplifier U1, a first capacitor C1 is connected in series between the positive power supply and the negative power supply of the first operational amplifier U1, a second capacitor C2 is connected in series between the output end of the first operational amplifier U1 and the negative input end of the first operational amplifier U1, and a third capacitor C3 and a first resistor R1 are connected in parallel at both ends of the second capacitor C2, the positive power supply of the first operational amplifier U1 is connected to the DC voltage, and the negative power supply is grounded; the reference current I_SET is connected to the positive input end of the first operational amplifier U1 after passing through the second resistor R2, and the negative input end of the first operational amplifier U1 leads to the output current signal I_MEAN after passing through the third resistor R3.

[0049] Specifically, the first capacitor C1 is a capacitor for stabilizing the power supply voltage of the first operational amplifier U1, and plays a role in voltage stabilization and filtering; the second capacitor C2, the third capacitor C3, and the first resistor R1 play a feedback role; the DC voltage connected to the positive power supply of the first operational amplifier U1 is a +12V power supply voltage; the second resistor R2 and the third resistor R3 are both used for current limiting.

[0050] More preferably, a fourth resistor R4 is connected in series between the reference current I_SET and the second resistor R2 , and a node between the second resistor R2 and the fourth resistor R4 is connected in series with a fourth capacitor C4 and then grounded.

[0051] Specifically, the fourth resistor R4 and the fourth capacitor C4 are used to stabilize the reference current I_SET.

[0052] More preferably, a node between the third resistor R3 and the output current signal I_MEAN is connected in series with a fifth capacitor C5 and then grounded.

[0053] Specifically, the fifth capacitor C5 is used to stabilize the output current signal I_MEAN.

[0054] Preferably, the voltage control loop includes a second operational amplifier U2, the reference voltage V_SET is connected to the positive input terminal of the second operational amplifier U2 after passing through the sixth resistor R6, the negative input terminal of the second operational amplifier U2 leads to an output voltage +V1 after passing through the seventh resistor R7 and the sixth capacitor C6, a seventh capacitor C7 is connected in series between the output terminal of the second operational amplifier U2 and the negative input terminal of the second operational amplifier U2, and an eighth capacitor C8 and an eighth resistor R8 are connected in parallel at both ends of the seventh capacitor C7.

[0055] Specifically, the sixth resistor R6 is used for current limiting, the seventh resistor R7 and the sixth capacitor C6 form a high-pass filter, and the seventh capacitor C7, the eighth resistor R8, and the eighth capacitor C8 play a feedback role.

[0056] More preferably, the negative input terminal of the second operational amplifier U2 leads to a test node OVP, a ninth resistor R9 is arranged between the test node OVP and the output voltage +V1, the ninth resistor R9 is connected in parallel with the seventh resistor R7 and the second capacitor C6, the negative input terminal of the second operational amplifier U2 is grounded after passing through the tenth resistor R10, and the two ends of the tenth resistor R10 are connected in parallel with an eleventh resistor R11.

[0057] Specifically, the voltage of the test node OVP is less than the output voltage +V1. Since the reference voltage V_SET cannot reach the voltage value of the output voltage +V1, the ninth resistor R9, the tenth resistor R10, and the eleventh resistor R11 are set for voltage division, wherein the ninth resistor R9 is used for upper voltage division, and the tenth resistor R10 and the eleventh resistor R11 are used for lower voltage division.

[0058] More preferably, the voltage control loop and the current control loop are connected in parallel with an optocoupler feedback circuit.

[0059] Specifically, the optocoupler feedback circuit includes a twelfth resistor R12 and an optical isolator U5 connected in series, one end of the twelfth resistor R12 is connected to a DC voltage, the other end of the twelfth resistor R12 is connected to an input end of the optical isolator U5, and an output end of the optical isolator U5 is connected to an output end of the first operational amplifier U1 or the second operational amplifier U2.

[0060] More specifically, an optocoupler feedback circuit is used for feedback control to improve stability.

[0061] More preferably, a unidirectional conduction circuit is provided between the optocoupler feedback circuit and the voltage control loop and the current control loop.

[0062] Specifically, the unidirectional conduction circuit of the voltage control loop includes a first diode D1 and a thirteenth resistor R13, and the unidirectional conduction circuit of the current control loop includes a second diode D2 and a fourteenth resistor R14. The input end of the first diode D1 and the input end of the second diode D2 are connected to the output end of the optical isolator U5, the output end of the first diode D1 is connected in series with the thirteenth resistor R13 and then connected to the output end of the second operational amplifier U2, and the output end of the second diode D2 is connected in series with the fourteenth resistor R14 and then connected to the output end of the first operational amplifier U1.

[0063] More specifically, the first diode D1 and the second diode D2 play a unidirectional conduction role to prevent the voltage control loop and the current control loop from interfering with each other, and the thirteenth resistor R13 and the fourteenth resistor R14 are used for current limiting.

[0064] In this embodiment, the reference voltage V_SET is output by the micro control unit (MCU) through two voltage PWM signals VO_ADJ1 and VO_ADJ2, which are followed and output by the third operational amplifier U3 after low-pass filtering. The positive input terminal of the third operational amplifier U3 is connected in parallel with a fifteenth resistor R15, a sixteenth resistor R16, and a ninth capacitor C9. The fifteenth resistor R15 and the sixteenth resistor R16 are respectively connected to the two voltage PWM signals VO_ADJ1 and VO_ADJ2 of the micro control unit (MCU), the ninth capacitor C9 is grounded, the negative input terminal of the third operational amplifier U3 is connected to the output terminal of the third operational amplifier U3, and the output terminal of the third operational amplifier U3 leads to the reference voltage V_SET.

[0065] In this embodiment, the reference current I_SET is output by the micro control unit (MCU) through two current PWM signals IO_ADJ1 and IO_ADJ2, which are followed and output by the fourth operational amplifier U4 after low-pass filtering. The positive input terminal of the fourth operational amplifier U4 is connected in parallel with the seventeenth resistor R17, the eighteenth resistor R18, and the tenth capacitor C10. The seventeenth resistor R17 and the eighteenth resistor R18 are respectively connected to the two current PWM signals IO_ADJ1 and IO_ADJ2 of the micro control unit (MCU), the tenth capacitor C10 is grounded, the negative input terminal of the fourth operational amplifier U4 is connected to the output terminal of the fourth operational amplifier U4, and the output terminal of the fourth operational amplifier U4 leads to the reference current I_SET.

[0066] More specifically, the reference voltage V_SET is between 0V and 3.3V.

[0067] The intelligent power supply control method of the present invention has different output responses when facing different types of loads, as follows:

[0068] (1) When the power supply faces a constant current load or an inductive load, it needs to output an ultra-high peak current in a timely manner to avoid load startup failure. Under the test condition of CC = 30A (6 times the rated current): the power supply can adjust the output voltage +V1 in time, maintain the peak current for a period of time, and maintain full load constant current without shutting down. The waveform is as follows Figure 3 As shown;

[0069] (2) When the power supply faces a constant voltage load, it needs to respond in time to avoid shutdown protection due to excessive peak current. Under the test condition of output load CV = 23V (rated voltage - 1V): the power supply can avoid excessive peak current and maintain rated power output. When there is no adaptive load control, the output current I_OUT has large ripples, V P-P :13A (rated current 5A), the waveform is as follows Figure 4 As shown, when there is adaptive load control, the output current I_OUT has a small ripple and V P-P :1.03A (rated current 5A), the waveform is as follows Figure 5 As shown, CH2: output voltage +V1, CH4: output current I_OUT;

[0070] (3) The power supply can also respond to the switching between constant voltage load and constant current load in a timely manner. Under the test conditions of switching between output loads CV = 23V and CC = 30A, the power supply can respond to either load condition in a timely manner. The waveform is shown in the figure below. Figure 6 As shown;

[0071] (4) When the power supply faces a constant power load, it is necessary to timely control the output current I_OUT to avoid damage to the power supply due to excessive output current I_OUT. Under the test condition that the output load is CP = 720W (rated power is 120W): the power supply can timely control the output current I_OUT and perform short-circuit constant current protection. The waveform is shown in the figure. Figure 7 As shown;

[0072] (5) When the power supply faces a constant resistance load, it needs to switch the output voltage +V1 in time according to the change of the load resistance to avoid the occurrence of ultra-high peak current that damages the resistive load. Under the test condition that the output load is CR = 2Ω: the power supply can reduce the output voltage +V1 in time to avoid ultra-high peak current. The waveform is as follows: Figure 8 shown.

[0073] In summary, the present invention is suitable for a microcontroller unit (MCU) to detect load conditions, control a reference voltage V_SET and a reference current I_SET, and thus implement a quick response, thereby solving the output response problem of a power supply device facing different loads such as motors, constant current, constant voltage, constant power, and constant resistance, and also solves the problem of the power supply device being triggered by the electromotive force of a motor load to protect it.

[0074] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An intelligent power supply control method that is adaptive to different loads, characterized in that: The steps include: (1) The power supply is turned on to output in constant voltage source mode, and the voltage and current loops are relaxed to cope with load changes of motor loads; (2) When the current is more than twice the rated current, the output voltage is reduced according to the output current signal to determine whether an overload occurs; (3) When the output current signal decreases, the load is determined to be a constant voltage or constant resistance load, and the system enters the dynamic response mode to control the output voltage through current feedback to maintain the rated power. (4) When the output current signal does not decrease, the load is determined to be a constant current or constant power load, and the peak power mode is entered to respond to the high peak current output; (5) If the power supply is in dynamic response mode or peak power mode for a long period of time or enters the mode multiple times in a short period of time, the power supply enters constant current protection mode; (6) When the power supply is in constant current protection mode, the reference voltage is the rated voltage, and the reference current varies with the input voltage, output voltage, and power supply temperature; (7) After the output voltage and output current signals of the power supply return to normal, the constant current protection mode is exited and the constant voltage source mode is re-entered.

2. The intelligent power supply control method according to claim 1, characterized in that: In the constant voltage source mode in step (1), the reference voltage is the rated voltage, and the reference current is 6 times the rated current.

3. The intelligent power supply control method according to claim 1, characterized in that: In the step (3), the dynamic response mode uses the output current signal as feedback to dynamically adjust the output voltage to maintain the output current signal at the rated current.

4. The intelligent power supply control method according to claim 1, characterized in that: In step (4), the reference voltage in the peak power mode decreases as the current increases, and the reference current is 6 times the rated current.

5. The intelligent power supply control method according to claim 1, characterized in that: The power supply control method controls the output voltage and output current signal through a voltage-current loop, wherein the voltage-current loop includes a voltage control loop and a current control loop, wherein the voltage control loop is used to adjust a reference voltage to control the output voltage, and the current control loop is used to adjust a reference current to control the output current signal.

6. The intelligent power supply control method capable of adapting to different loads according to claim 5, characterized in that: The voltage control loop and the current control loop are connected in parallel with an optocoupler feedback circuit.

7. The intelligent power supply control method capable of self-adapting to different loads according to claim 6, characterized in that: A unidirectional conduction circuit is arranged between the optocoupler feedback circuit and the voltage control loop and the current control loop.

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