Hydrogen production power supply low-voltage ride-through control method, computer device and hydrogen production power supply circuit

Abstract

The invention relates to a hydrogen production power supply low-voltage ride-through control method, a computer device and a hydrogen production power supply circuit, and belongs to the field of water electrolysis hydrogen production. The method comprises the following steps of: performing upper deviation amplitude limiting processing on a difference value obtained by subtracting a reference voltage of an upper deviation controller from a direct current bus voltage through the upper deviation controller; performing lower deviation amplitude limiting processing on a difference value obtained by subtracting the reference voltage of the lower deviation controller from the direct current bus voltage through the lower deviation controller; summing a result of the upper deviation amplitude limiting processing and a result of the lower deviation amplitude limiting processing to obtain a deviation total output; and a difference value obtained by subtracting the deviation total output from the reference current of the step-down circuit of the hydrogen production power supply circuit is used as a new reference current, the new reference current is used for performing current loop regulation control on the actual output current of the step-down circuit, and a driving signal for controlling the step-down circuit is generated. The complexity of the low-voltage ride-through control method of the hydrogen production power supply can be reduced.

Description

Technical Field

[0001] The present invention relates to a low-voltage ride-through control method for a hydrogen production power supply, a computer device, and a hydrogen production power supply circuit, and belongs to the field of hydrogen production by electrolyzing water. Background Art

[0002] In the field of hydrogen production by electrolyzing water, generally, a hydrogen production power supply circuit supplies power to an electrolyzer, and the electrolyzer electrolyzes water to obtain hydrogen. Figure 1 The following is a schematic structural diagram of a conventional hydrogen production power supply circuit. As Figure 1 shown, the hydrogen production power supply circuit generally includes a rectifier circuit and a buck circuit. The input end of the rectifier circuit is connected to the power grid, the output end of the rectifier circuit is connected to the input end of the buck circuit through a DC bus, and the output end of the buck circuit is connected to the electrolyzer of the hydrogen production device. The power grid voltage is rectified and transformed into an appropriate DC voltage by the hydrogen production power supply circuit to supply power to the electrolyzer. Among them, the rectifier circuit is any one of a neutral point clamped three-level circuit, an active neutral point clamped three-level circuit, and a two-level rectifier circuit; the buck circuit is a BUCK circuit.

[0003] To ensure the safe operation of the system, the hydrogen production power supply circuit must still be able to supply power stably when the power grid voltage drops abnormally. According to industry standards, when the input voltage is lower than the rated value but not lower than 20%, the rectifier circuit of the hydrogen production power supply circuit needs to maintain stable power supply to ensure the safe operation of the electrolyzer. Therefore, it is necessary to formulate a low-voltage ride-through control method to maintain the power supply power of the electrolyzer as much as possible while ensuring the safety of the hydrogen production power supply circuit.

[0004] The published text of the Chinese patent application with the application publication number CN119276133A discloses a hydrogen production power supply and its low-voltage ride-through control method and device. The method includes the following steps: if the power grid voltage drops below the power grid voltage drop threshold but the drop degree does not reach the point where the DC bus voltage is less than the DC bus voltage drop threshold, a first duty ratio calculated on the principle that the output power of the buck circuit remains unchanged before and after the power grid voltage drop is used to generate the drive pulse signal of the buck circuit of the hydrogen production power supply; if the drop degree of the power grid voltage reaches the point where the DC bus voltage is less than the DC bus voltage drop threshold, a second duty ratio calculated according to the minimum power percentage allowed by the electrolyzer is used to generate the drive pulse signal of the buck circuit.

[0005] Although this invention can maintain the power supply power of the electrolyzer to the greatest extent while ensuring the safe and stable operation of the hydrogen production power supply, before calculating the first duty ratio, it is necessary to first judge whether the rectifier circuit in the hydrogen production power supply circuit is overloaded, and then determine the first duty ratio according to the judgment result. Therefore, there is a problem of complex control method. Summary of the Invention

[0006] The object of the present invention is to provide a low-voltage ride-through control method for a hydrogen production power supply, a computer device, and a hydrogen production power supply circuit, so as to solve the problem that in the existing low-voltage ride-through control method for a hydrogen production power supply, it is necessary to consider whether the rectifier circuit in the hydrogen production power supply circuit is overloaded, resulting in a complex control method.

[0007] To achieve the above object, the solution of the present invention includes:

[0008] A low-voltage ride-through control method for a hydrogen production power supply of the present invention includes the following steps: subtracting the DC bus voltage from the reference voltage of the upper deviation controller, and then performing upper deviation limit processing after passing through the upper deviation controller;

[0009] Subtracting the DC bus voltage from the reference voltage of the lower deviation controller, and then performing lower deviation limit processing after passing through the lower deviation controller;

[0010] Adding the result of the upper deviation limit processing and the result of the lower deviation limit processing to obtain the total deviation output;

[0011] Taking the difference obtained by subtracting the total deviation output from the reference current of the buck circuit of the hydrogen production power supply circuit as the new reference current, and using the new reference current to perform current loop regulation control on the actual output current of the buck circuit to generate a drive signal for controlling the buck circuit;

[0012] The upper deviation limit processing has at least an upper limit amplitude of 0; the lower deviation limit processing has at least a lower limit amplitude of 0;

[0013] The reference voltage of the upper deviation controller is greater than the reference voltage of the lower deviation controller.

[0014] Further, the lower deviation limit processing also has an upper limit amplitude, and the upper limit amplitude in the lower deviation limit processing depends on the voltage sag degree of the power grid;

[0015] When the voltage sag degree of the power grid cannot enable the rectifier circuit in the hydrogen production power supply circuit to stably control the DC bus voltage, the upper limit amplitude in the lower deviation limit processing is the reference current of the buck circuit of the hydrogen production power supply circuit;

[0016] When the voltage sag degree of the power grid can enable the rectifier circuit in the hydrogen production power supply circuit to stably control the DC bus voltage, the upper limit amplitude in the lower deviation limit processing is the quotient obtained by dividing the minimum power of the electrolyzer by the reference voltage of the lower deviation controller.

[0017] Further, when the power grid voltage is less than the power grid voltage sag threshold value, it is considered that the voltage sag degree of the power grid cannot enable the rectifier circuit in the hydrogen production power supply circuit to stably control the DC bus voltage;

[0018] When the grid voltage is greater than the first preset threshold value, it is considered that the degree of grid voltage drop can enable the rectifier circuit in the hydrogen production power supply circuit to stably control the DC bus voltage;

[0019] The first preset threshold value is the sum value obtained by adding the grid voltage drop threshold value and the grid voltage drop callback offset value.

[0020] Further, the method further includes: calculating a DC power feedforward value according to the electrolyzer power value and the positive sequence active component of the grid voltage;

[0021] Superimpose the DC power feedforward value on the output for voltage outer loop control of the DC voltage on the output side of the rectifier circuit of the hydrogen production power supply circuit to obtain the given value of the active current on the output side of the rectifier circuit of the hydrogen production power supply circuit;

[0022] Use the given value of the active current as the input for active current inner loop control of the active current on the output side of the rectifier circuit;

[0023] Perform reactive current inner loop control on the reactive current on the output side of the rectifier circuit;

[0024] Generate a drive signal for controlling the rectifier circuit according to the output result of the active current inner loop control and the output result of the reactive current inner loop control.

[0025] Further, both the upper deviation controller and the lower deviation controller are PI controllers.

[0026] A computer device of the present invention includes a processor, and the processor executes a computer program to implement the steps of the hydrogen production power supply low voltage ride-through control method as described above.

[0027] A hydrogen production power supply circuit of the present invention includes a rectifier circuit, a buck circuit, and a hydrogen production power supply circuit control module. The hydrogen production power supply circuit control module includes a processor. The input end of the rectifier circuit is used to connect to the grid. The output end of the rectifier circuit is connected to the high voltage end of the buck circuit through a DC bus. The low voltage end of the buck circuit is used to connect to the electrolyzer of the hydrogen production equipment. The processor is used to execute the steps of the hydrogen production power supply low voltage ride-through control method as described above.

[0028] The beneficial effects of the present invention are as follows: As a pioneering invention, a low-voltage ride-through control method for a hydrogen production power supply, a computer device, and a hydrogen production power supply circuit provided by the present invention perform upper deviation limit processing on the difference after subtracting the DC bus voltage from the reference voltage of the upper deviation controller through the upper deviation controller; perform lower deviation limit processing on the difference after subtracting the DC bus voltage from the reference voltage of the lower deviation controller through the lower deviation controller; sum the results of the upper deviation limit processing and the lower deviation limit processing to obtain the total deviation output; use the difference obtained by subtracting the total deviation output from the reference current of the buck circuit of the hydrogen production power supply circuit as the new reference current, and use the new reference current to perform current loop regulation control on the actual output current of the buck circuit to generate a drive signal for controlling the buck circuit; the upper deviation limit processing has at least an upper limit amplitude, and the upper limit amplitude is 0; the lower deviation limit processing has at least a lower limit amplitude, and the lower limit amplitude is 0; the reference voltage of the upper deviation controller is greater than the reference voltage of the lower deviation controller. A voltage-current double closed-loop control method with bus voltage deviation control is used to control the buck circuit in the hydrogen production power supply circuit. The reference current of the buck circuit of the hydrogen production power supply circuit is compensated by using the total deviation output to obtain a new reference current, and the reference current of the buck circuit of the hydrogen production power supply circuit can be adjusted in real time. Then, using the new reference current, current loop regulation control is performed on the actual output current of the buck circuit to generate a drive signal for controlling the buck circuit. Since the reference current of the buck circuit of the hydrogen production power supply circuit can be adjusted in real time by using the new reference current, the output current can be quickly reduced in the case of unstable bus voltage to avoid the occurrence of overload. Compared with the prior art, since the control of the hydrogen production power supply circuit can be realized without judging the overload situation, the complexity of the control method can be reduced. Also, since the use of this control method can directly avoid the occurrence of overload, the safety of the hydrogen production system can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of an existing hydrogen production power supply circuit;

[0030] Figure 2 is a control block diagram for controlling the buck circuit in the hydrogen production power supply circuit provided by an embodiment of the present invention;

[0031] Figure 3 is a control block diagram for controlling the rectifier circuit in the hydrogen production power supply circuit provided by an embodiment of the present invention;

[0032] Figure 4 is a schematic flow diagram for judging the drop degree of the grid voltage provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0034] The inventive concept of the present invention lies in: controlling the buck circuit in the hydrogen production power supply circuit by using a voltage-current double closed-loop control method with bus voltage deviation control, and controlling the rectifier circuit in the hydrogen production power supply circuit by using a voltage-current double closed-loop control method.

[0035] Specifically, the difference obtained by subtracting the DC bus voltage from the reference voltage of the upper deviation controller is subjected to upper deviation limit processing after passing through the upper deviation controller; the difference obtained by subtracting the DC bus voltage from the reference voltage of the lower deviation controller is subjected to lower deviation limit processing after passing through the lower deviation controller; the results of the upper deviation limit processing and the lower deviation limit processing are summed to obtain the total deviation output; the difference obtained by subtracting the total deviation output from the reference current of the buck circuit of the hydrogen production power supply circuit is used as the new reference current, and the new reference current is used to perform current loop regulation control on the actual output current of the buck circuit to generate a drive signal for controlling the buck circuit; the upper deviation limit processing has at least an upper limit amplitude, and the upper limit amplitude is 0; the lower deviation limit processing has at least a lower limit amplitude, and the lower limit amplitude is 0; the reference voltage of the upper deviation controller is greater than the reference voltage of the lower deviation controller.

[0036] An embodiment of a low voltage ride-through control method for a hydrogen production power supply:

[0037] The low voltage ride-through control method for a hydrogen production power supply provided by the embodiment of the present invention can be applied to any hydrogen production power supply circuit including a rectifier circuit and a buck circuit in the art. This embodiment takes Figure 1 the shown hydrogen production power supply circuit as an example for illustrative description.

[0038] The low voltage ride-through control method for a hydrogen production power supply provided by the embodiment of the present invention is divided into a control method for the rectifier circuit in the hydrogen production power supply circuit and a control method for the buck circuit in the hydrogen production power supply circuit. Since the voltage drop of the power grid will affect the DC bus voltage, and the magnitude of the DC bus voltage has a great impact on the buck circuit in the hydrogen production power supply circuit and will affect the working condition of the electrolytic cell, therefore, first, in combination with Figure 2 , the control method for the buck circuit in the hydrogen production power supply circuit will be specifically introduced first, and then, in combination with Figure 3 , the control method for the rectifier circuit in the hydrogen production power supply circuit will be specifically introduced.

[0039] Figure 2 is a control block diagram for controlling the buck circuit in the hydrogen production power supply circuit provided by the embodiment of the present invention. As Figure 2 shown, a voltage-current double closed-loop control method with bus voltage deviation control is used to control the buck circuit in the hydrogen production power supply circuit.

[0040] The reference voltage U of the upper deviation controller dc_ref_H+ With DC bus voltage U dc The difference after the difference is processed by the upper deviation controller and then the upper deviation is limited; the reference voltage U dc_ref_L+ With DC bus voltage U dc The difference after the difference is processed by the lower deviation controller and then the lower deviation is limited. The result of the upper deviation limit processing △I1 and the result of the lower deviation limit processing △I2 are summed to obtain the total deviation output △I. The reference current I of the step-down circuit of the hydrogen production power supply circuit is used. ref The difference obtained by subtracting the deviation total output △I is used as the new reference current, and the new reference current is used to adjust the actual output current I of the buck circuit. fdb Perform current loop regulation control to generate a drive signal DR for controlling the buck circuit.

[0041] Among them, the upper deviation limit processing has at least an upper limit amplitude, and the upper limit amplitude is 0; the lower deviation limit processing has at least a lower limit amplitude, and the lower limit amplitude is 0; the reference voltage U of the upper deviation controller dc_ref_H+ Greater than the reference voltage U of the lower deviation controller dc_ref_L+ .

[0042] In order to prevent the controller from over-deviation, the reference voltage U dc_ref_H+ With DC bus voltage U dc The difference after the subtraction is too small, resulting in the inability to subsequently adjust the output current I of the step-down circuit. fdb As an optional implementation, the upper deviation limit processing also has a lower limit value -I N .

[0043] To prevent the controller from under-deviation, the reference voltage U dc_ref_L+ With DC bus voltage U dc The difference after the subtraction is too large, resulting in the inability to subsequently adjust the output current I of the step-down circuit. fdb As an optional implementation, the lower deviation limit processing also has an upper limit amplitude I N .

[0044] Among them, the upper deviation controller and the lower deviation controller can be a PI controller, or a PID controller, etc. The present invention does not make any special limitation on this. The following explanation is given by taking the upper deviation controller and the lower deviation controller both as PI controllers as an example.

[0045] As the grid voltage continues to drop, the DC bus voltage continues to decrease. dc The reference voltage U of the upper deviation controller dc_ref_H+and the reference voltage U of the lower deviation controller dc_ref_L+ When it is between them, it indicates that the voltage dip of the power grid is relatively light. At this time, the buck circuit needs to ensure that the output current value remains unchanged to ensure that the electrolyzer can operate at the normal power.

[0046] Specifically, when the DC bus voltage U dc is between the reference voltage U of the upper deviation controller dc_ref_H+ and the reference voltage U of the lower deviation controller dc_ref_L+ The difference between the reference voltage U of the upper deviation controller dc_ref_H+ and the DC bus voltage U dc is greater than 0. After the upper deviation limiting process of the upper deviation controller (i.e., under the cumulative effect of error integration), the upper deviation controller outputs the upper limit amplitude value of 0 amperes (A) of the upper deviation controller, that is, at this time, △I1 = 0A; the difference between the reference voltage U of the lower deviation controller dc_ref_L+ and the DC bus voltage U dc is less than 0. After the lower deviation limiting process of the lower deviation controller (i.e., under the cumulative effect of error integration), the lower deviation controller outputs the lower limit amplitude value of 0A of the lower deviation controller, that is, △I2 = 0A.

[0047] Among them, the upper limit amplitude value of the upper deviation controller is also called the upper limit amplitude value in the upper deviation limiting process; the lower limit amplitude value of the lower deviation controller is also called the lower limit amplitude value in the lower deviation limiting process.

[0048] Sum △I1 and △I2 to obtain the total deviation output △I. At this time, the total deviation output △I is 0A; since △I is 0A, the reference current I of the buck circuit of the hydrogen production power supply circuit ref minus △I to get the new reference current still being I ref ; then subtract the output current I of the buck circuit from the new reference current fdb to perform PI control to generate a drive signal DR for controlling the buck circuit.

[0049] Among them, the drive signal DR is a duty cycle signal.

[0050] Since both △I1 and △I2 are 0A, it indicates that the influence of the deviation of the DC bus voltage is eliminated. At this time, the control method for the buck circuit of the hydrogen production power supply circuit is essentially in the current single closed-loop state, which can ensure that the output current of the buck circuit of the hydrogen production power supply circuit remains unchanged, so that the electrolyzer can operate at the normal power.

[0051] When the DC bus voltage U dc is less than the reference voltage U of the lower deviation controller dc_ref_L+When it indicates that the grid voltage has entered the sag state, the current value output by the buck circuit at this time depends on the degree of grid voltage sag, and it is necessary to ensure that the electrolytic cell can operate at the minimum power.

[0052] Specifically, when the DC bus voltage U dc is less than the reference voltage U dc_ref_L+ of the lower deviation controller, the difference between the reference voltage U dc_ref_H+ of the upper deviation controller and the DC bus voltage U dc is greater than 0. After the upper deviation limiting process of the upper deviation controller, the upper deviation controller outputs the upper limit amplitude 0A of the upper deviation controller, that is, △I1 = 0A at this time; the difference between the reference voltage U dc_ref_L+ of the lower deviation controller and the DC bus voltage U dc is greater than 0. After the lower deviation limiting process of the lower deviation controller (i.e., under the cumulative effect of error integration), the value output by the lower deviation controller is between the lower limit value 0A (including 0A) and the upper limit value I N (including I N ). Subsequently, taking the upper limit value I N output by the lower deviation controller as an example for illustrative description, that is, △I2 = I N .

[0053] Sum △I1 and △I2 to obtain the total deviation output △I. The total deviation output △I at this time is I N ; since △I is I N , the reference current I ref of the buck circuit of the hydrogen production power supply circuit minus △I to obtain a new reference current of I ref - I N ; then use the new reference current I ref - I N minus the actual output current I fdb of the buck circuit to perform PI control to generate a drive signal DR for controlling the buck circuit.

[0054] Among them, the upper limit value of the lower deviation controller is also called the upper limit amplitude of the lower deviation controller; the magnitude of the upper limit value I N of the lower deviation controller depends on the degree of grid voltage sag.

[0055] Among them, the value of the upper limit value I N of the lower deviation controller can refer to the following formula (1):

[0056]

[0057] Among them, V_Flag represents the voltage dip flag of the power grid voltage. V_Flag = 0 indicates that the degree of voltage dip of the power grid voltage is not serious, and V_Flag = 1 indicates that the degree of voltage dip of the power grid voltage is more serious. I N1 represents the upper limit value of the lower deviation controller when the degree of voltage dip of the power grid voltage is not serious. I N The value of; I N2 represents the upper limit value of the lower deviation controller when the degree of voltage dip of the power grid voltage is serious. The value of IN.

[0058] Among them, I N1 The expression of can refer to the following formula (2):

[0059]

[0060] Among them, R elzer represents the minimum power of the electrolytic cell.

[0061] Among them, I N2 The expression of can refer to the following formula (3):

[0062] I N2 = I re f (3)

[0063] Among them, I ref represents the preset current value.

[0064] Among them, the degree of voltage dip of the power grid voltage is more serious, indicating that the degree of voltage dip of the power grid voltage cannot make the rectifier circuit in the hydrogen production power supply circuit stably control the DC bus voltage; the degree of voltage dip of the power grid voltage is not serious, indicating that the degree of voltage dip of the power grid voltage can make the rectifier circuit in the hydrogen production power supply circuit stably control the DC bus voltage.

[0065] Among them, for the judgment of the degree of voltage dip of the power grid voltage, reference can be made to Figure 4 .

[0066] Figure 4 is a schematic flow chart for judging the degree of voltage dip of the power grid voltage provided by an embodiment of the present invention. As Figure 4 shown, first judge whether the power grid voltage U dp1 is less than the power grid voltage dip threshold U Lvit . If the power grid voltage U dp1 is less than the power grid voltage dip threshold U Lvit , then set the voltage drop flag bit V_Flag of the power grid voltage to 1, indicating that the degree of voltage dip of the power grid voltage is relatively serious, and the rectifier circuit in the hydrogen production power supply circuit cannot stably control the DC bus voltage; if the power grid voltage U dp1 is greater than or equal to the power grid voltage dip threshold U Lvit , then continue to judge the power grid voltage U dp1Is it greater than the first preset threshold value? If the grid voltage U dp1 is greater than the first preset threshold value, the voltage drop flag bit V_Flag of the grid voltage is set to 0, indicating that the voltage drop of the grid voltage is relatively small, and the rectifier circuit in the hydrogen production power supply circuit can still stably control the DC bus voltage; if the grid voltage U dp1 is less than or equal to the first preset threshold value, the voltage drop flag bit of the grid voltage maintains the voltage drop flag bit of the previous time state.

[0067] Among them, the first preset threshold value is the sum of the grid voltage drop threshold value U Lvit and the grid voltage drop callback offset value U Bias . The grid voltage drop callback offset value U Bias is a parameter greater than 0.

[0068] As an alternative implementation, it is also possible to first determine whether the grid voltage U dp1 is greater than the first preset threshold value. When the grid voltage U dp1 is greater than the first preset threshold value, the voltage drop flag bit V_Flag of the grid voltage is set to 0. When the grid voltage U dp1 is less than or equal to the first preset threshold value, then determine whether the grid voltage U dp1 is less than the grid voltage drop threshold value U Lvit ; when the grid voltage U dp1 is less than the grid voltage drop threshold value U Lvit , the voltage drop flag bit V_Flag of the grid voltage is set to 1. When the grid voltage U dp1 is greater than or equal to the grid voltage drop threshold value U Lvit , the voltage drop flag bit of the grid voltage maintains the voltage drop flag bit of the previous time state.

[0069] As the grid voltage continues to drop, the DC bus voltage output by the rectifier circuit will also continue to decrease. When the grid voltage drops severely, the DC bus voltage output by the rectifier circuit will be equal to or less than the reference voltage U dc_ref_L+ of the lower deviation controller. At this time, the upper deviation controller does not work, and the upper deviation controller always outputs the upper limit value of 0A, while the lower deviation controller starts to work, and the output of the lower deviation controller changes from the lower limit value of 0A to the upper limit value I N . Using the total deviation output △I to compensate the reference current I ref of the buck circuit of the hydrogen production power supply circuit can adjust the reference current I ref of the buck circuit of the hydrogen production power supply circuit in real time. At this time, the control method for the buck circuit of the hydrogen production power supply circuit is essentially in a voltage loop regulation with a DC bus voltage deviation, which can ensure that the electrolyzer can operate at the lowest power or reduce the current to 0.

[0070] The following will specifically introduce the control method for the rectifier circuit in the hydrogen production power supply circuit in conjunction with Figure 3 ...

[0071] Figure 3 is a control block diagram provided by an embodiment of the present invention for controlling the rectifier circuit in the hydrogen production power supply circuit. As Figure 3 shown, the DC power feedforward value is calculated according to the electrolyzer power value P dc and the positive-sequence active component U of the grid voltage dp ; the DC power feedforward value is superimposed on the output of the voltage outer loop control for the DC voltage U dc (i.e., the DC bus voltage) on the output side of the rectifier circuit of the hydrogen production power supply circuit to obtain the given value I d_ref of the active current on the output side of the rectifier circuit of the hydrogen production power supply circuit; the given value I d_ref of the active current is used as the input for the active current inner loop control of the active current on the output side of the rectifier circuit; the reactive current inner loop control is performed on the reactive current on the output side of the rectifier circuit; and the drive signal for controlling the rectifier circuit is generated according to the output results of the active current inner loop control and the reactive current inner loop control.

[0072] Among them, the DC power feedforward value is the quotient obtained by dividing the electrolyzer power value P dc by the positive-sequence active component U of the grid voltage dp .

[0073] Specifically, in the DC bus voltage outer loop, the difference is taken between the DC bus voltage reference U dc_ref and the DC bus voltage U dc . After the difference is calculated by PI, it is added to the DC power feedforward value P dc / U dP to obtain the given value I d_ref of the active current; in the grid-connected current inner loop, the difference is taken between the given value I d_ref of the active current and the active current feedback I d_fdb . After the difference is calculated by PI, it is added to the grid voltage active component feedforward value U d to obtain the active control quantity; in the grid-connected current inner loop, the difference is taken between the given value I q_ref of the reactive current and the reactive current feedback I q_fdb . After the difference is calculated by PI, it is added to the grid voltage reactive component feedforward value U qThey are added to obtain the reactive power control quantity; finally, the active power control quantity and the reactive power control quantity are used to generate the Pulse Width Modulation (PWM) drive signal of the rectifier circuit through the Space Vector Pulse Width Modulation (SVPWM) link.

[0074] A low-voltage ride-through control method for a hydrogen production power supply provided by an embodiment of the present invention performs upper deviation limit processing on the difference after subtracting the DC bus voltage from the reference voltage of the upper deviation controller through the upper deviation controller; performs lower deviation limit processing on the difference after subtracting the DC bus voltage from the reference voltage of the lower deviation controller through the lower deviation controller; sums the results of the upper deviation limit processing and the lower deviation limit processing to obtain the total deviation output; uses the difference obtained by subtracting the total deviation output from the reference current of the buck circuit of the hydrogen production power supply circuit as the new reference current, and uses the new reference current to perform current loop regulation control on the actual output current of the buck circuit to generate a drive signal for controlling the buck circuit; the upper deviation limit processing has at least an upper limit amplitude, and the upper limit amplitude is 0; the lower deviation limit processing has at least a lower limit amplitude, and the lower limit amplitude is 0; the reference voltage of the upper deviation controller is greater than the reference voltage of the lower deviation controller. The buck circuit in the hydrogen production power supply circuit is controlled by using a voltage-current double closed-loop control method with bus voltage deviation control. The reference current of the buck circuit of the hydrogen production power supply circuit is compensated by using the total deviation output to obtain a new reference current, and the reference current of the buck circuit of the hydrogen production power supply circuit can be adjusted in real time. Then, by using the new reference current, current loop regulation control is performed on the actual output current of the buck circuit to generate a drive signal for controlling the buck circuit. Since the reference current of the buck circuit of the hydrogen production power supply circuit can be adjusted in real time by using the new reference current, the output current can be quickly reduced in the case of unstable bus voltage to avoid the occurrence of overload. Compared with the prior art, since the control of the hydrogen production power supply circuit can be realized without judging the overload situation, the complexity of the control method can be reduced, and since the occurrence of overload can be directly avoided by using this control method, the safety of the hydrogen production system can also be ensured.

[0075] An implementation manner of a computer device:

[0076] A computer device provided by an embodiment of the present invention includes a processor, and the processor executes a computer program to implement the steps of the low-voltage ride-through control method for a hydrogen production power supply.

[0077] Among them, the low-voltage ride-through control method for a hydrogen production power supply can refer to the relevant descriptions in the foregoing "Embodiment of a Low-voltage Ride-through Control Method for a Hydrogen Production Power Supply", which will not be elaborated here.

[0078] An embodiment of the computer device provided by the present invention can achieve the same beneficial effects as the hydrogen production power supply crossing control method in the foregoing "Embodiment of a Low-Voltage Ride-Through Control Method for Hydrogen Production Power Supply", which will not be elaborated here.

[0079] An embodiment of a hydrogen production power supply circuit:

[0080] A hydrogen production power supply circuit of the present invention includes a rectification circuit, a step-down circuit, and a hydrogen production power supply circuit control module. The hydrogen production power supply circuit control module includes a processor. The input end of the rectification circuit of the hydrogen production power supply circuit is used to connect to the power grid. The output end of the rectification circuit of the hydrogen production power supply circuit is connected to the high-voltage end of the step-down circuit of the hydrogen production power supply circuit through a DC bus. The low-voltage end of the step-down circuit of the hydrogen production power supply circuit is used to connect to the electrolytic cell of the hydrogen production device. The processor is used for the steps of the low-voltage ride-through control method of the hydrogen production power supply.

[0081] Among them, the steps of the low-voltage ride-through control method of the hydrogen production power supply can refer to the relevant expressions in the foregoing "Embodiment of a Low-Voltage Ride-Through Control Method for Hydrogen Production Power Supply", which will not be elaborated here.

[0082] An embodiment of the hydrogen production power supply circuit provided by the present invention can achieve the same beneficial effects as the hydrogen production power supply crossing control method in the foregoing "Embodiment of a Low-Voltage Ride-Through Control Method for Hydrogen Production Power Supply", which will not be elaborated here.

Claims

1. A low-voltage ride-through control method for a hydrogen production power source, characterized in that, It includes the following steps: The difference between the reference voltage of the upper deviation controller and the DC bus voltage is processed by the upper deviation controller and then subjected to upper deviation limit processing; The difference between the reference voltage of the lower deviation controller and the DC bus voltage is processed by the lower deviation controller and then subjected to lower deviation limit processing; The results of the upper deviation limit processing and the lower deviation limit processing are summed to obtain the total deviation output; The difference obtained by subtracting the total deviation output from the reference current of the buck circuit of the hydrogen production power supply circuit is used as the new reference current, and the new reference current is used to perform current loop regulation control on the actual output current of the buck circuit to generate a drive signal for controlling the buck circuit; The upper deviation limit processing has at least an upper limit amplitude of 0; The lower deviation limit processing has at least a lower limit amplitude of 0; The reference voltage of the upper deviation controller is greater than the reference voltage of the lower deviation controller.

2. The low-voltage ride-through control method for a hydrogen production power supply according to claim 1, wherein The lower deviation limit processing also has an upper limit amplitude, and the upper limit amplitude in the lower deviation limit processing depends on the degree of grid voltage drop; When the degree of grid voltage drop cannot enable the rectifier circuit in the hydrogen production power supply circuit to stably control the DC bus voltage, the upper limit amplitude in the lower deviation limit processing is the reference current of the buck circuit of the hydrogen production power supply circuit; When the degree of grid voltage drop can enable the rectifier circuit in the hydrogen production power supply circuit to stably control the DC bus voltage, the upper limit amplitude in the lower deviation limit processing is the quotient obtained by dividing the minimum power of the electrolyzer by the reference voltage of the lower deviation controller.

3. The low-voltage ride-through control method for a hydrogen production power source according to claim 2, characterized in that When the grid voltage is less than the grid voltage drop threshold value, it is considered that the degree of grid voltage drop cannot enable the rectifier circuit in the hydrogen production power supply circuit to stably control the DC bus voltage; When the grid voltage is greater than the first preset threshold value, it is considered that the degree of grid voltage drop can enable the rectifier circuit in the hydrogen production power supply circuit to stably control the DC bus voltage; The first preset threshold value is the sum value obtained by adding the grid voltage drop threshold value and the grid voltage drop callback offset value.

4. The low-voltage ride-through control method for a hydrogen production power supply according to any one of claims 1 to 3, characterized in that This method further includes: calculating a DC power feedforward value according to the electrolyzer power value and the positive sequence active component of the grid voltage; The DC power feedforward value is superimposed on the output for voltage outer loop control of the DC voltage on the output side of the rectifier circuit of the hydrogen production power supply circuit to obtain the given value of the active current on the output side of the rectifier circuit of the hydrogen production power supply circuit; The given value of the active current is used as the input for active current inner loop control of the active current on the output side of the rectifier circuit; Perform reactive current inner loop control on the reactive current on the output side of the rectifier circuit; Generate a drive signal for controlling the rectifier circuit according to the output result of the active current inner loop control and the output result of the reactive current inner loop control.

5. The low-voltage ride-through control method for a hydrogen production power source according to claim 1, characterized in that, Both the upper deviation controller and the lower deviation controller are PI controllers.

6. A computer device, comprising a processor, characterized in that, The processor executes a computer program to implement the steps of the hydrogen production power supply low voltage ride-through control method as described in any one of claims 1-5.

7. A hydrogen production power supply circuit, comprising a rectification circuit, a buck circuit and a control module for the hydrogen production power supply circuit. The control module for the hydrogen production power supply circuit includes a processor. The input end of the rectification circuit is used to connect to the power grid. The output end of the rectification circuit is connected to the high-voltage end of the buck circuit through a DC bus. The low-voltage end of the buck circuit is used to connect to the electrolytic cell of the hydrogen production equipment, and is characterized in that, The processor is used to execute the steps of the hydrogen production power supply low voltage ride-through control method as described in any one of claims 1-5.

Images