Method for dynamically balancing output power of power supplies in parallel power supplies

Abstract

The invention discloses a method for dynamically balancing the output power of each power supply in parallel power supplies. Each power supply in the parallel power supplies is in communication connection with an upper computer. According to the method, the output voltage and current of each power supply are calibrated in advance, an upper computer collects the output voltage and current data of each power supply in real time, and then the real-time output voltage of each power supply is adjusted through a power equalization algorithm, so that the equalization control of the output power of each power supply is realized. The number of the power equalization programmable power supplies can be adjusted at will, and the situation that the overall power equalization fails if a single power supply has a fault can be effectively avoided; moreover, the method mainly depends on upper computer software for control and adjustment, the whole power supply loop does not need to increase hardware cost, and the stability and safety of power supply are further improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power supply, and particularly relates to a method for dynamically balancing the output power of each power supply in a parallel power supply. Background Art

[0002] During the ground comprehensive test of large aircraft, multiple ground programmable power supplies are required to be connected in parallel for power supply. However, due to the imbalance of cable impedance and the change of load power, the power distribution among the power supply modules is unbalanced, which may lead to power overload or efficiency decline of the power supply. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for dynamically balancing the output power of each power supply in a parallel power supply, which dynamically balances the output power of each power supply through a control algorithm, promoting the continuous innovation and progress of power supply technology.

[0004] To solve the above problems, the technical solution of the present invention is as follows:[[]] A method for dynamically balancing the output power of each power supply in a parallel power supply, which is used in the power supply system of a large aircraft, includes:[[]] Each power supply in the parallel power supply is communicatively connected to the upper computer. The upper computer calibrates the output voltage and current of each power supply, real-time collects the voltage and current of each power supply, and dynamically adjusts the real-time output voltage of each power supply through a power balance algorithm to achieve the balance of the output power of each power supply;[[]] Among them, the power balance algorithm includes:[[]] Set initial parameters, including the power supply output voltage, allowable imbalance degree, and voltage adjustment step value;[[]] Real-time obtain the output voltage and current of each power supply, and calculate the average power value;[[]] Calculate the difference between the output power of each working power supply and the average power value, and adjust the output voltage of the power supply respectively according to different difference situations;[[]] After the output voltage is adjusted, synchronously adjust the output voltage of each power supply so that its highest output voltage does not exceed the set voltage;[[]] After several adjustments, control the difference between the output power of each power supply and the average power within the allowable imbalance degree range to achieve power balance.[[]]

[0005] According to an embodiment of the present invention, the power balance algorithm further includes:[[]] Obtain the collected voltage values x1, x2... xn and collected current values y1, y2... yn of each power supply;[[]] Set the current balance degree W, and compare the compliance of the output current of each power supply with it. If the output current y / (y1 + y2 +... + yn)*n > W, then reduce the voltage output value by 1 resolution; the resolution is the voltage adjustment step value;[[]] If the collected voltage values x1, x2... xn of all power supplies are all less than the voltage output value, the voltage output of each power supply is increased by one resolution; Through several voltage adjustments, the control of the current balance degree is realized, and finally the current balance degree is within the allowable range.

[0006] According to an embodiment of the present invention, before performing power balance control, the host computer calibrates the output voltage and current of each power supply.

[0007] According to an embodiment of the present invention, the host computer further includes the following steps when calibrating the output voltage and current of each power supply: The positive and negative electrodes of each power supply are connected to a calibration box, the output of the calibration box is connected to a digital multimeter, and the digital multimeter is connected to the host computer; When the calibration box switch is in the open position, the host computer performs voltage calibration, including output voltage and collected voltage; When the calibration box switch is in the closed state, it is equivalent to connecting a calibrated electronic load in the circuit, and the host computer performs collected current calibration.

[0008] According to an embodiment of the present invention, the host computer further includes the following steps when performing voltage calibration: Output known voltage values in sequence To each power supply, and use a digital multimeter to measure to obtain the corresponding output result ; According to the difference principle, construct an equation: Among them, ; Output through the corrected voltage values y2, y3 and obtain x2, x3, detect the deviation value between y2 and x2, if the deviation exceeds the standard, calculate the coefficients a2, a3 according to the above equation; And so on, continuously correct until the deviation between the corrected power supply input voltage and the digital multimeter measurement is less than the design value.

[0009] According to an embodiment of the present invention, when the host computer performs voltage calibration, it is also necessary to make the deviation between the power supply output voltage and the digital multimeter measurement less than the design value.

[0010] According to an embodiment of the present invention, the host computer calibrates one power supply each time.

[0011] According to an embodiment of the present invention, when any one of the parallel power supplies fails, the host computer identifies the power supply failure, corrects the number of power supplies participating in power balance, and at the same time closes the output of the faulty power supply.

[0012] Due to the above technical solutions adopted by the present invention, compared with the prior art, it has the following advantages and positive effects: In the method for output power of each power supply in the dynamic equalization parallel power supply according to an embodiment of the present invention, the number of equalization power programmable power supplies can be adjusted arbitrarily, effectively avoiding the situation where the overall power equalization fails if a single power supply fails; and this method mainly relies on the host computer software for control and adjustment, without increasing the hardware cost in the entire power supply loop, further improving the stability and safety of the power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a flowchart of the method for output power of each power supply in the dynamic equalization parallel power supply according to an embodiment of the present invention; Figure 2 is a calibration connection diagram of the host computer according to an embodiment of the present invention; Figure 3 is a schematic diagram of the power supply parallel power supply system according to an embodiment of the present invention; Figure 4 is a flowchart of the power equalization control according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] The following further describes in detail a method for output power of each power supply in a dynamic equalization parallel power supply proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. According to the following description and the claims, the advantages and features of the present invention will be clearer.

[0015] Please refer to Figure 1 , this embodiment provides a method for output power of each power supply in a dynamic equalization parallel power supply, including the following steps: Each power supply in the parallel power supply is communicatively connected to the host computer. The host computer first pre-calibrates the output voltage and current of each power supply, then real-time collects the voltage and current of each power supply, and adjusts the output voltage of each power supply in real time through a power equalization algorithm to achieve the equalization of the output power among the power supplies; Among them, the power equalization algorithm includes: Set initial parameters, including the power supply output voltage, allowable imbalance degree, and voltage adjustment step value; Real-time obtain the output voltage and current of each power supply, and calculate the average power value; Calculate the difference between the output power of each working power supply and the average power value, and adjust the output voltage of the power supply respectively according to different difference situations; After the output voltage is adjusted, synchronously adjust the output voltage of each power supply so that its highest output voltage does not exceed the set voltage; After several adjustments, control the difference between the output power of each power supply and the average power within the allowable imbalance degree range to achieve power equalization.

[0016] This method mainly relies on the host computer software for control and adjustment. There is no need to increase the hardware cost for the entire power supply circuit, which can improve the stability and safety of the power supply.

[0017] Specifically, before the formal parallel output, it is necessary to calibrate and record the output voltage value and current value of each power supply through the supporting software of the host computer. After calibration, the initial output accuracy of the power supply can be improved, and the equalization software can make the power reach equilibrium faster.

[0018] Please refer to Figure 2 , a calibration requires an external calibration box, a six and a half digit multimeter, and an electronic load. The positive and negative poles of each power supply are connected to the calibration box. The output of the calibration box is connected to the digital multimeter, the digital multimeter is connected to the host computer, and the host computer is communicatively connected to each power supply. The interactive information includes voltage acquisition, current acquisition, and power supply output voltage control. This embodiment is introduced by taking a programmable power supply as an example.

[0019] The channels of 4 programmable power supplies are all connected together in the calibration box: all the positive poles are connected together, and all the negative poles are connected together. Each power supply has independent control. The software controls the output and calibration of the programmable power supply, and only 1 power supply is calibrated each time. When the calibration box switch is in the open position, the software performs voltage calibration, including output voltage and acquired voltage; when the calibration box switch is in the closed state, it is equivalent to connecting a calibrated electronic load in the circuit, and the software performs acquired current calibration.

[0020] The calibration program will start with voltage calibration first. It will prompt the user to confirm that the switch on the calibration box is in the voltage position and continue after getting confirmation. Once the voltage calibration is completed, it will prompt the user to switch the switch to the current position and continue after getting confirmation.

[0021] After the calibration is completed, the calibration program will generate a record file, which can be saved and printed out. The deviation between the corrected power supply output voltage and the multimeter measurement is less than 20 mV; the deviation between the power supply acquired voltage value and the multimeter measurement value is less than 20 mV; the deviation between the power supply acquired current value and the multimeter measurement value is less than 40 mA.

[0022] Specifically, the voltage calibration by the host computer further includes: Sequentially output known voltage values to each power supply, and use the digital multimeter to measure to obtain the corresponding output results ; According to the difference principle, construct an equation: where ; Output using the corrected voltage values y2 and y3, and obtain x2 and x3. Detect the deviation value between y2 and x2. If the deviation exceeds the standard, calculate the coefficients a2 and a3 according to the above equation; and so on, continuously correct until the deviation between the corrected power input voltage and the digital multimeter measurement is less than the design value (such as 20 mV).

[0023] Similarly, calculate the deviation between the software voltage measurement value and the multimeter measurement value, with the target being less than 20 mV. And calculate the deviation between the software current measurement value and the shunt current of the multimeter measurement calibration box, with the target being less than 40 mA.

[0024] Please refer to Figure 4 , the power balance algorithm provided in this embodiment is as follows: Initial settings of the following parameters: the power supply output voltage Uon, the allowable imbalance degree A between power supplies, and the voltage adjustment step value △U (generally the program control resolution of the power supply). The software real-time collects the output voltage Ui and output current Ii of each power supply, and calculates the average power value P 均 . If the current working power supply voltage is within the adjustment range, calculate the difference between the output power Pi of this power supply and the average power value P. If , it indicates that the output voltage of this power supply is too high, then reduce the output voltage value to reduce its output power; if , it indicates that the output voltage of this power supply is too low, then increase the output voltage value to increase its output power; if , then keep the output voltage unchanged. After calculating the output voltage, it is necessary to synchronously adjust the output voltages of each power supply so that the highest output voltage does not exceed the set voltage. After several adjustments, the difference between the output power of each power supply and the average power will be controlled within the range of ±A, achieving power balance.

[0025] In addition, the power balance algorithm further includes: Obtain the collected voltage values x1, x2... xn and collected current values y1, y2... yn of each power supply; Set the current balance degree W, and compare the compliance of the output current of each power supply with it. If the output current y / (y1 + y2 +... + yn)*n > W, then reduce the voltage output value by 1 resolution; the resolution is the voltage adjustment step value; If the collected voltage values x1, x2... xn of all power supplies are less than the voltage output value, then increase the voltage output of each power supply by 1 resolution; Through several voltage adjustments, control the current balance degree, and finally make the current balance degree within the allowable range.

[0026] The following introduces the method for the output power of each power supply in this dynamic balanced parallel power supply through two examples: Please refer to Figure 3, equipped with a parallel power supply system of 4 programmable power supplies. The rated output voltage of a single programmable power supply is 0 - 150V, the rated output current is 0 - 50A, and the rated power is 7.5kW. The 4 power supplies jointly supply power to the load, and the measurement feedback point of the programmable power supply is short-circuited at the load input side.

[0027] The load requires an input voltage of 100V, a load power of 0W - 14kW. The lengths of the power supply cables for power supplies 1 - 3 are the same, and the power supply cable of power supply 4 is longer than those of the other 3 groups of power supplies.

[0028] Implementation example 1: 4 power supplies are connected in parallel to supply power to the load. Set the output voltage of the programmable power supply to 100V, the output voltage adjustment step of the programmable power supply to 0.01V, and the allowable power imbalance degree between the power supplies to 5%, and output the voltage of the programmable power supply.

[0029] When the load power is 10kW, the host computer collects the total output power of the 4 programmable power supplies, and calculates that the expected output power of each is 2.5kW. According to the comparison between the real-time collected power supply output power and the expected power, calculate the adjusted power supply output voltage, and ensure that the maximum value of the power supply output voltage is equal to the set programmable power supply output setting value of 100V. For example Figure 4 , after several cycles, the power output imbalance degree of each programmable power supply is less than 5%, and the output voltage of each power supply is maintained. When the change in load power causes the power output imbalance degree of the programmable power supply to be greater than 5%, recalculate the output voltage of each power supply to achieve a real-time power balance state.

[0030] Implementation example 2: When 4 power supplies are connected in parallel to supply power to the load, any one of the power supplies fails.

[0031] After the host computer software recognizes the power supply failure information, correct the number of power supplies participating in power balance, and at the same time turn off the output of the faulty power supply.

[0032] When the load power is 10kW, the host computer collects the total output power of the 4 programmable power supplies, and 1 of the power supplies fails. The expected output power of each power supply is 3.3kW. According to the comparison between the real-time collected output power of the 3 power supplies and the expected power, calculate the adjusted output voltage of the 3 power supplies, and ensure that the maximum value of the power supply output voltage is equal to the set programmable power supply output setting value of 100V. For example Figure 4 , after several cycles, the power output imbalance degree of each programmable power supply is less than 5%, and the output voltage of the 3 power supplies is maintained. When the change in load power causes the power output imbalance degree of the programmable power supply to be greater than 5%, recalculate the output voltage of the 3 power supplies to achieve a real-time power balance state.

[0033] The present invention is applicable to various models of programmed power supplies, with no restrictions on the impedance requirements between the sampling points and the load. It adopts software programming to achieve automatic closed-loop control of power balance, and is used to support the ground power supply system during the ground comprehensive testing of large aircraft, providing the power required for testing the on-board platform and payloads.

[0034] The embodiments of the present invention have been described in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, provided that these changes fall within the scope of the claims of the present invention and its equivalent technologies, they still fall within the protection scope of the present invention.

Claims

1. A method for dynamically balancing the output powers of power supplies in a parallel power supply system, which is used in the power supply system of a large aircraft, is characterized in that Including: Each power supply in the parallel power supply is communicatively connected to the host computer. The host computer calibrates the output voltage and current of each power supply, real-time collects the voltage and current of each power supply, and adjusts the real-time output voltage of each power supply through a power balance algorithm to achieve the balance of output power among the power supplies; Among them, the power balance algorithm includes: Set initial parameters, including power supply output voltage, allowable imbalance degree, and voltage adjustment step value; Real-time obtain the output voltage and current of each power supply, and calculate the average power; Calculate the difference between the output power of each working power supply and the average power, and adjust the power supply output voltage respectively according to different difference situations; After the output voltage is adjusted, synchronously adjust the output voltage of each power supply so that its highest output voltage does not exceed the set voltage; After several adjustments, control the difference between the output power of each power supply and the average power within the allowable imbalance degree range to achieve power balance.

2. The method for equalizing the output powers of power supplies in the dynamic equalizing parallel power supply according to claim 1, wherein The power balance algorithm further includes: Obtain the collected voltage values x1, x2…xn and collected current values y1, y2…yn of each power supply; Set the current balance degree W, and compare the compliance of the output current of each power supply with it. If the output current y / (y1 + y2 + … + yn)*n > W, then reduce the voltage output value by 1 resolution; the resolution is the voltage adjustment step value; If the collected voltage values x1, x2…xn of all power supplies are less than the voltage output value, then increase the voltage output of each power supply by 1 resolution; Through several voltage adjustments, control the current balance degree, and finally make the current balance degree within the allowable range.

3. The method for equalizing the output powers of power supplies in a dynamic equalization parallel power supply according to claim 1, characterized in that, Before performing power balance control, the host computer calibrates the output voltage and current of each power supply.

4. The method for output power of each power supply in the dynamic equalization parallel power supply according to claim 3, wherein The host computer's further calibration of the output voltage and current of each power supply includes: The positive and negative poles of each power supply are connected to the calibration box. The output of the calibration box is connected to a digital multimeter, and the digital multimeter is connected to the host computer; When the calibration box switch is in the open position, the host computer performs voltage calibration, including output voltage and collected voltage; When the calibration box switch is in the closed state, it is equivalent to connecting a calibrated electronic load in the circuit, and the host computer performs collected current calibration.

5. The method for equalizing the output powers of power supplies in the dynamic equalizing parallel power supply according to claim 4, wherein The host computer's further voltage calibration includes: Output known voltage values in sequence For each power supply, measure using a digital multimeter to obtain the corresponding output result ; According to the difference principle, construct an equation: Among them, ; Output through the corrected voltage values y2, y3 and obtain x2, x3, detect the deviation value between y2 and x2. If the deviation exceeds the standard, then calculate the coefficients a2, a3 according to the above equation; And so on, continuously correct until the deviation between the corrected power supply input voltage and the digital multimeter measurement is less than the design value.

6. The method for equalizing the output powers of power supplies in a dynamic equalizing parallel power supply according to claim 5, characterized in that, When the host computer performs voltage calibration, it is also necessary to make the deviation between the power supply output voltage and the digital multimeter measurement less than the design value.

7. The method for equalizing the output powers of power supplies in a dynamic equalizing parallel power supply according to claim 4, characterized in that, The host computer calibrates one power supply each time, and each power supply needs to complete voltage and current calibration.

8. The method for equalizing the output powers of power supplies in the dynamic equalizing parallel power supply according to claim 1, wherein, When any power supply in the parallel power supply fails, the host computer identifies the power supply failure, corrects the number of power supplies participating in power balance, and simultaneously shuts down the output of the faulty power supply.

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