A power supply output load regulation rate compensation system

Abstract

The invention discloses an output load regulation rate compensation system for a power supply, relates to the technical field of power supply, and solves the technical problem in the prior art that the system stability is insufficient due to the fact that the buffering effect of the capacitor is not considered to be affected by the capacitor characteristics; the invention collects the output current, adjustment voltage and temperature change of the capacitor of the internal load of the power supply through a sensor; obtains the voltage difference based on the adjustment voltage and the reference voltage, and generates a pulse width modulation signal according to the voltage difference; calculates the temperature compensation coefficient of the capacitor based on the pulse width modulation signal and the temperature change of the capacitor, and obtains the adjusted adjustment duty cycle according to the temperature compensation coefficient; obtains the application duty cycle according to the signal type of the pulse width modulation signal; compares the application duty cycle with the duty cycle, obtains the conduction time according to the comparison result and applies it to the switch element; re-inputs the same output current, and re-measures the adjusted load voltage to complete the verification of the temperature compensation effect.

Description

Technical Field

[0001] The invention belongs to the technical field of power supply, and in particular is an output load regulation rate compensation system of a power supply. Background Art

[0002] With the continuous development of modern electronic equipment, the requirements for power supply systems are getting higher and higher; power supply systems not only need to provide stable and reliable power supply, but also need to maintain the stability of output voltage under various load conditions; load regulation is a key indicator to measure the performance of power supply systems. It indicates the stability of the output voltage of the power supply when the load changes; a low load regulation means that the power supply can maintain the stability of the output voltage when the load changes.

[0003] When the output current of the power supply changes from minimum to maximum, the ideal power supply should maintain a constant output voltage when the load changes. However, in practical applications, as the load increases or decreases, the output voltage of the power supply tends to fluctuate. The capacitor can smooth the voltage waveform and provide energy storage, acting as a buffer. However, as the output current changes, the capacitor will also heat up. Since the capacitance of the capacitor changes with the temperature, its buffering effect will also be affected, and ultimately the effect of maintaining a constant voltage will also be affected, resulting in an unstable voltage of the power supply, affecting the stability of the system.

[0004] The present invention provides an output load regulation rate compensation system for a power supply to solve the above technical problems. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art; to this end, the present invention proposes an output load regulation rate compensation system for a power supply, which is used to solve the technical problem in the prior art that the system stability is insufficient due to the failure to consider the impact of capacitor characteristics on the buffering effect of the capacitor.

[0006] To achieve the above-mentioned object, a first aspect of the present invention provides an output load regulation rate compensation system of a power supply, comprising: a state monitoring module, a state feedback module, a load compensation module and an effect verification module;

[0007] Status monitoring module: used to monitor the output current, adjust voltage and temperature changes inside the power supply;

[0008] State feedback module: used to obtain the voltage difference between the output current input power supply and the adjustment voltage and the reference voltage, and generate a pulse width modulation signal according to the voltage difference;

[0009] Load compensation module: used to perform temperature compensation on the capacitor according to the pulse width modulation signal and temperature changes;

[0010] Effect verification module: used to detect the adjusted load regulation rate, and compare the load voltage difference and voltage difference between the load voltage and the reference voltage based on the load regulation rate to obtain the temperature compensation effect.

[0011] The present invention collects the output current, adjustment voltage and temperature change of the internal load of the power supply, taking into account that the increase of the load output current causes the temperature change of the capacitor, which in turn causes the capacitance value of the capacitor to change, and the capacitance value of the capacitor will affect the buffering of the capacitor for the load voltage change. The capacitor is temperature compensated according to the pulse width modulation signal and the temperature change, and the conduction time of the switch element is adjusted to adjust the load voltage.

[0012] Preferably, generating a pulse width modulation signal according to the voltage difference includes:

[0013] A1: Extract the voltage difference; set the frequency of the sawtooth wave generator; input the sawtooth wave generated by the sawtooth wave generator into the comparator to obtain the sawtooth wave output;

[0014] A2: Determine whether the voltage difference is greater than the sawtooth wave output; if yes, mark the signal type of the pulse width modulation signal as a high level signal; if no, mark the signal type of the pulse width modulation signal as a low level signal;

[0015] A3: Determine whether the voltage difference is zero; if yes, mark the duty cycle of the pulse width modulation signal as 50%; if no, calculate the duty cycle ZKB of the pulse width modulation signal by the formula ZKB=Vc / (Vc+Vt)×100%; where Vc represents the reference voltage and Vt represents the adjustment voltage;

[0016] A4: Combine the signal type and duty cycle to obtain a pulse width modulated signal.

[0017] Preferably, the temperature compensation of the capacitor according to the pulse width modulation signal and the temperature change includes:

[0018] Extract pulse width modulation signal and temperature change; extract temperature characteristic curve of capacitor;

[0019] The temperature change is matched with the temperature characteristic curve to obtain the current capacitance value of the capacitor; the capacitance value before the capacitor changes is marked as the standard capacitance value, and the formula KD=log Cj / Cn α is used to calculate the temperature compensation coefficient KD of the capacitor; where Cj represents the current capacitance value, Cn represents the standard capacitance value, α is the influence coefficient, which is set according to the temperature characteristic curve of the capacitor, and α is greater than 0 and not equal to 1; when Cj=Cn, KD=1;

[0020] The adjusted duty cycle TKB is calculated by the formula TKB=ZKB×KD; wherein 0%≤TKB≤100%; and the adjusted duty cycle is applied to the system according to the signal type of the pulse width modulation signal.

[0021] Preferably, the step of applying the adjusted duty cycle to the system according to the signal type of the pulse width modulation signal comprises:

[0022] Extract the signal type of the pulse width modulation signal;

[0023] If the signal type of the pulse width modulation signal is high level, the applied duty cycle of the adjusted duty cycle is TKB;

[0024] If the signal type of the pulse width modulation signal is low level, the applied duty cycle of the adjusted duty cycle is 1-TKB;

[0025] The on-time of the switching element is adjusted according to the application duty cycle, and the high-frequency components of the pulse width modulation signal are filtered out by the LC filter.

[0026] Preferably, adjusting the on-time of the control switch element according to the application duty cycle includes:

[0027] Extract application duty cycle;

[0028] The applied duty cycle is compared with the duty cycle, and the adjusted high level time and adjusted low level time that need to be adjusted are obtained through the definition formula of the duty cycle according to the comparison result. The adjusted high level time and the adjusted low level time are combined to obtain the adjusted on-time and applied to the switching element.

[0029] Preferably, the step of comparing the load voltage difference and the voltage difference between the load voltage and the reference voltage based on the load regulation rate to obtain the temperature compensation effect includes:

[0030] B1: extract the adjusted load voltage, reference voltage and voltage difference;

[0031] B2: Mark the difference between the load voltage and the reference voltage as the load voltage difference; determine whether the load voltage difference is greater than or equal to the voltage difference; if yes, mark the corresponding adjustment state as invalid adjustment; if no, mark the corresponding adjustment state as valid adjustment and jump to B3;

[0032] B3: Set the adjustment rate threshold; calculate the load adjustment rate through the load adjustment rate definition formula; determine whether the load adjustment rate is less than or equal to the adjustment rate threshold; if yes, mark the temperature compensation effect as effective compensation; if no, mark the temperature compensation effect as incomplete compensation.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. The present invention collects the output current, adjustment voltage and temperature change of the internal load of the power supply through a sensor; obtains a voltage difference based on the adjustment voltage and the reference voltage, and generates a pulse width modulation signal according to the voltage difference, which can quickly obtain the signal type and duty cycle of the pulse width modulation signal, making the system more stable and smooth; calculates the temperature compensation coefficient of the capacitor based on the pulse width modulation signal and the temperature change of the capacitor, and obtains the adjusted adjustment duty cycle according to the temperature compensation coefficient, and applies the adjustment duty cycle to the system, which can ensure that the capacitance value of the capacitor remains relatively stable at different temperatures, improve the stability of the entire system, improve the overall performance and accuracy of the system, and can also perform temperature compensation in real time according to the temperature change of the capacitor; obtains the application duty cycle according to the signal type of the pulse width modulation signal; compares the application duty cycle with the duty cycle, obtains the conduction time according to the comparison result and applies it to the switching element, which can realize accurate control of the output voltage or current, enables the system to quickly adapt to load changes or other interferences, improves the dynamic performance of the system, and improves the reliability and maintainability of the system.

[0035] 2. After obtaining the conduction time, the present invention needs to verify the temperature compensation effect; re-input the same output current, and re-measure the adjusted load voltage, compare the load voltage difference with the voltage difference, and obtain the adjustment state. If the adjustment state is a valid adjustment, the adjusted load adjustment rate is calculated by the load adjustment rate definition formula, and the load adjustment rate is compared with the preset adjustment rate threshold to obtain the temperature compensation effect. This can verify the effect of temperature compensation, ensure the stability and availability of the system, improve the reliability and robustness of the system, and improve the overall cost-effectiveness of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 The following is a flowchart of an embodiment of the present invention.

[0038] Figure 2 It is a system composition diagram of the present invention.

[0039] Figure 3 A complete flow chart for obtaining temperature compensation effect in one embodiment of the present invention. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] See also Figure 1-Figure 3 , the first aspect of the present invention provides an output load regulation rate compensation system for a power supply, comprising: a state monitoring module, a state feedback module, a load compensation module and an effect verification module;

[0042] Status monitoring module: used to monitor the output current, adjust voltage and temperature changes inside the collection power supply.

[0043] Exemplarily, the current and voltage inside the power supply are collected by a Hall effect current sensor and a voltage sensor disposed inside the power supply, the temperature of the capacitor is collected by a temperature sensor, and a microcontroller is used to convert the data collected by the sensor into a digital signal through an analog-to-digital converter.

[0044] In this embodiment, the initial current of the power supply collected by the Hall effect current sensor is 5 amperes, and the output current of the power supply is 10 amperes after the current is increased. The initial voltage of the power supply is 10 volts, and the adjusted voltage of the power supply is 20 volts after the current is increased. The initial temperature of the capacitor is 25 degrees, and the temperature change of the capacitor is 45 degrees after the current is increased.

[0045] State feedback module: used to obtain the voltage difference between the output current input power supply and the adjustment voltage and the reference voltage, and generate a pulse width modulation signal according to the voltage difference.

[0046] Exemplarily, in this embodiment, the reference voltage of the power supply after the output current is set to 15 volts. The reference voltage is the voltage value reached after the load changes under ideal conditions. The voltage difference between the adjusted voltage and the reference voltage is 5 volts. The generation frequency of the sawtooth wave generator in this embodiment is 200 Hz. The sawtooth wave generated by the sawtooth wave generator is input into the comparator to obtain a sawtooth wave output of 2 volts.

[0047] Determine whether the voltage difference is greater than the sawtooth wave output; if the voltage difference is greater than the sawtooth wave output, mark the signal type of the pulse width modulation signal as a high-level signal; determine whether the voltage difference is zero; if the voltage difference is not equal to zero, calculate the duty cycle of the pulse width modulation signal ZKB=42.9% through the formula ZKB=Vc / (Vc+Vt)×100%, and combine the duty cycle with the signal type to obtain a high-level pulse width modulation signal with a duty cycle of 42.9%.

[0048] In another embodiment, if the voltage difference is zero, it means that the adjusted voltage meets the corresponding reference voltage, or an adjustment threshold is designed. When the voltage difference is less than or equal to the adjustment threshold, it means that the adjusted voltage of the power supply meets the normal fluctuation range and does not need to be adjusted, so the duty cycle of the pulse width modulation signal is marked as 50%.

[0049] Load compensation module: used to perform temperature compensation on the capacitor according to the pulse width modulation signal and temperature changes.

[0050] Exemplarily, a temperature characteristic curve of a capacitor of a corresponding model is extracted from a database, the temperature characteristic curve including a suitable operating temperature of the capacitor, a changing relationship between the capacitance value and temperature, and a temperature tolerance range; the temperature change of the capacitor must conform to the temperature tolerance range, if the temperature change of the capacitor exceeds the temperature tolerance range, the capacitor needs to be replaced; in this embodiment, a suitable operating temperature of the capacitor is selected as 5 to 45 degrees, a changing relationship between the capacitance value and temperature is ±5 millifarads per degree, a temperature tolerance range is -15 to 85 degrees, the temperature change of the capacitor conforms to the temperature tolerance range, the standard capacitance value of the capacitor is 200 millifarads, and the temperature change is matched with the temperature characteristic curve to obtain a current capacitance value of 300 millifarads.

[0051] In this embodiment, the influence coefficient α is set to 3, and the formula KD=log Cj / Cn α is calculated to obtain the temperature compensation coefficient of the capacitor KD=0.68; the adjusted duty cycle TKB=29.2% is calculated by the formula TKB=ZKB×KD; in this embodiment, the signal type of the pulse width modulation signal is high level, and the adjusted duty cycle is applied to the switch element as the applied duty cycle to control the on time of the switch element; in this embodiment, the pulse width modulation signal cycle of the switch element is 20 microseconds, and the definition formula of the duty cycle is ZKB=Ton / (Ton+Toff), where Ton represents the high level time in a pulse width modulation signal cycle, and T off represents the low level time in a pulse width modulation signal; the duty cycle definition formula is used to calculate the adjusted high level time to be 5.84 microseconds, the adjusted low level time to be 14.16 microseconds, the adjusted high level time and the adjusted low level time are combined to obtain the adjusted on time and applied to the switching element, and the high frequency component of the pulse width modulation signal is filtered out by the LC filter to help reduce the switching loss caused by high frequency switching, improve the overall efficiency, make the output voltage smoother, transfer energy more efficiently, reduce energy loss, and also reduce transient voltage fluctuations when the load changes.

[0052] The on-time of the switching element determines the time ratio of the high-level time and the low-level time. The signal type of the pulse width modulation signal will affect the load voltage. When the signal type of the pulse width modulation signal is a high-level signal, the switching element is turned on, the power supply voltage is directly applied to the load, and the average voltage on the load is higher. When the signal type of the pulse width modulation signal is a low-level signal, the switching element is turned off, the power supply voltage is disconnected from the load, and the average voltage on the load is lower. By controlling the on-time of the switching element, the voltage time that the power supply voltage is applied to the load can be controlled, thereby affecting the load voltage and making it closer to the reference voltage.

[0053] Effect verification module: used to detect the adjusted load regulation rate, and compare the load voltage difference and voltage difference between the load voltage and the reference voltage based on the load regulation rate to obtain the temperature compensation effect.

[0054] Exemplarily, after the on-time is adjusted, the same output current is re-input and the load voltage inside the power supply is re-collected. In this embodiment, the voltage before adjustment is 20 volts and the load voltage after adjustment is 21 volts. The load adjustment rate FZL=5% is calculated by the load adjustment rate definition formula FZL=ΔVf / Vc×100%. The lower the load adjustment rate, the more stable the output voltage of the power supply is when the load changes.

[0055] In this embodiment, the adjustment rate threshold is set to 10%. The adjustment rate threshold is determined by experts based on the temperature characteristic curve of the capacitor to meet the load adjustment rate of the actual working requirements of the power supply; the difference between the load voltage and the reference voltage is marked as the load voltage difference, and it is judged whether the load voltage difference is greater than or equal to the voltage difference; if it is judged that the load voltage difference is 1 volt, which is less than the voltage difference, it is further judged whether the load adjustment rate is less than or equal to the adjustment rate threshold; if it is judged that the load adjustment rate is less than the adjustment rate threshold, the temperature compensation coefficient is marked as effective compensation; it means that the adjustment of the conduction time of the switching element not only effectively buffers the reduction in buffering capacity caused by the change in capacitor temperature due to the current input, but also can meet the required load adjustment rate requirements.

[0056] Part of the data in the above formula is calculated by removing the dimension and taking its numerical value. The formula is a formula closest to the actual situation obtained by software simulation of a large amount of collected data; the preset parameters and preset thresholds in the formula are set by technical personnel in this field according to actual conditions or obtained through simulation of a large amount of data.

[0057] Working principle of the present invention:

[0058] The present invention collects the output current of the internal load of the power supply, the corresponding adjustment voltage and the temperature change of the capacitor through a sensor, obtains the signal type and duty cycle of the pulse width modulation signal based on the voltage difference obtained by the adjustment voltage and the reference voltage, and combines them to obtain the pulse width modulation signal; matches the temperature change with the temperature characteristic curve to obtain the current capacitance value of the capacitor, calculates the temperature compensation coefficient of the capacitor, obtains the adjustment duty cycle based on the temperature compensation coefficient and the duty cycle, obtains the application duty cycle according to the signal type of the pulse width modulation signal, obtains the on-time that needs to be adjusted according to the comparison result of the application duty cycle and the duty cycle through the definition formula of the duty cycle and applies it, and filters out the high-frequency components in the pulse width modulation signal through the LC filter; collects the adjusted load voltage after re-outputting the current, marks the difference between the load voltage and the reference voltage as the load voltage difference, compares the load voltage difference with the voltage difference to obtain the adjustment state, calculates the load adjustment rate through the load adjustment rate definition formula, and compares the load adjustment rate with the preset adjustment rate threshold to obtain the temperature compensation effect.

[0059] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A power supply output load regulation rate compensation system, characterized in that: include: State monitoring module, state feedback module, load compensation module and effect verification module; Status monitoring module: used to monitor the output current, adjust voltage and temperature changes inside the power supply; State feedback module: used to obtain the voltage difference between the output current input power supply and the adjustment voltage and the reference voltage, and generate a pulse width modulation signal according to the voltage difference; Load compensation module: used to perform temperature compensation on the capacitor according to the pulse width modulation signal and temperature changes; Effect verification module: used to detect the adjusted load regulation rate, and compare the load voltage difference and voltage difference between the load voltage and the reference voltage based on the load regulation rate to obtain the temperature compensation effect; The method of performing temperature compensation on the capacitor according to the pulse width modulation signal and the temperature change comprises: Extract pulse width modulation signal and temperature change; extract temperature characteristic curve of capacitor; The temperature change is matched with the temperature characteristic curve to obtain the current capacitance value of the capacitor; the capacitance value before the capacitor changes is marked as the standard capacitance value, and the formula KD=log Cj / Cn α is used to calculate the temperature compensation coefficient KD of the capacitor; where Cj represents the current capacitance value, Cn represents the standard capacitance value, α is the influence coefficient, which is set according to the temperature characteristic curve of the capacitor, and α is greater than 0 and not equal to 1; when Cj=Cn, KD=1; The adjusted duty cycle TKB is calculated by the formula TKB=ZKB×KD; wherein 0%≤TKB≤100%; the adjusted duty cycle is applied to the system according to the signal type of the pulse width modulation signal; The step of applying the adjusted duty cycle to the system according to the signal type of the pulse width modulation signal comprises: Extract the signal type of the pulse width modulation signal; If the signal type of the pulse width modulation signal is high level, the applied duty cycle of the adjusted duty cycle is TKB; If the signal type of the pulse width modulation signal is low level, the applied duty cycle of the adjusted duty cycle is 1-TKB; Adjust the on-time of the control switch element according to the application duty cycle, and filter out the high-frequency components of the pulse width modulation signal through the LC filter; The step of adjusting the on-time of the control switch element according to the application duty cycle comprises: Extract application duty cycle; The applied duty cycle is compared with the duty cycle, and the adjusted high level time and adjusted low level time that need to be adjusted are obtained through the definition formula of the duty cycle according to the comparison result. The adjusted high level time and the adjusted low level time are combined to obtain the adjusted on-time and applied to the switching element.

2. The output load regulation rate compensation system of a power supply according to claim 1, characterized in that: The step of generating a pulse width modulation signal according to the voltage difference comprises: A1: Extract the voltage difference; set the frequency of the sawtooth wave generator; input the sawtooth wave generated by the sawtooth wave generator into the comparator to obtain the sawtooth wave output; A2: Determine whether the voltage difference is greater than the sawtooth wave output; if yes, mark the signal type of the pulse width modulation signal as a high level signal; if no, mark the signal type of the pulse width modulation signal as a low level signal; A3: Determine whether the voltage difference is zero; if yes, mark the duty cycle of the pulse width modulation signal as 50%; if no, calculate the duty cycle ZKB of the pulse width modulation signal by the formula ZKB=Vc / (Vc+Vt)×100%; where Vc represents the reference voltage and Vt represents the adjustment voltage; A4: Combine the signal type and duty cycle to obtain a pulse width modulated signal.

3. The output load regulation rate compensation system of a power supply according to claim 1, characterized in that: The method of comparing the load voltage difference and the voltage difference between the load voltage and the reference voltage based on the load regulation rate to obtain the temperature compensation effect includes: B1: extract the adjusted load voltage, reference voltage and voltage difference; B2: Mark the difference between the load voltage and the reference voltage as the load voltage difference; determine whether the load voltage difference is greater than or equal to the voltage difference; if yes, mark the corresponding adjustment state as invalid adjustment; if no, mark the corresponding adjustment state as valid adjustment and jump to B3; B3: Set the adjustment rate threshold; calculate the load adjustment rate through the load adjustment rate definition formula; determine whether the load adjustment rate is less than or equal to the adjustment rate threshold; if yes, mark the temperature compensation effect as effective compensation; if no, mark the temperature compensation effect as incomplete compensation.

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