Voltage stabilizing circuit control method, control device and power supply equipment

Abstract

The invention relates to the technical field of voltage stabilizing circuit control, in particular to a voltage stabilizing circuit control method and device and power supply equipment. The steady-state circuit control method comprises the steps of monitoring load current of the output end of the voltage stabilizing circuit in real time, judging whether the load current is suddenly changed or not, and when the load current is not suddenly changed, controlling the voltage stabilizing circuit to operate based on a steady-state control strategy; and when the load current suddenly changes, the voltage stabilizing circuit is controlled to operate based on a transient control strategy, that is, the on-off moment of the switch is calculated according to the output capacitor charge balance principle, and the main phase switching circuit and the auxiliary phase switching circuit are synchronously switched on and off in time. According to the voltage stabilizing circuit control method, the control device and the power supply equipment, quick response can be realized when the load current suddenly changes, so that the output current quickly adapts to the suddenly changes of the load current, the long-time fluctuation of the output voltage during transient operation is reduced, and the reliability and the stability of electric energy supply are improved.

Description

Technical Field

[0001] The present application relates to the technical field of voltage stabilizing circuit control, and in particular to a voltage stabilizing circuit control method, a control device and a power supply device. Background Art

[0002] In the field of power electronics, asymmetric multiphase Buck converter is an important voltage stabilizer, mainly used to output low voltage and high current. In the complex and diverse power system of microgrid, various distributed power sources, energy storage devices and various loads are intertwined, which puts higher requirements on the stable conversion and efficient distribution of electric energy. Asymmetric multiphase Buck converter plays a key role in microgrid power system. It realizes low voltage and high current DC-DC conversion by coupling multiple Buck circuits in parallel and turning them on in sequence according to a specific conduction order. This unique working mode can not only effectively improve the efficiency of power conversion, but also better cope with the variable load requirements in microgrid.

[0003] In the microgrid architecture, the grid-type inverter is the key interface connecting the distributed power source and the microgrid. As the output device of the previous asymmetric multiphase Buck converter, the grid-type inverter has strict requirements on its previous voltage regulator. In the actual application of the microgrid power system, the load often jumps, the load current will change instantly, and the voltage across the output capacitor will also change, causing the voltage on the load to change. The load will be in a voltage fluctuation state for a long time, which is easy to cause equipment failure and affect the reliability and stability of the power supply. Summary of the invention

[0004] Based on this, it is necessary to provide a voltage stabilizing circuit control method, control device and power supply equipment that can solve the above-mentioned technical problems, which can respond quickly when the load current suddenly changes, reduce the long-term fluctuation of the output voltage during transient operation, and improve the reliability and stability of the power supply.

[0005] The above-mentioned purpose of the present application is achieved through the following technical solutions.

[0006] In a first aspect of the present application, a voltage stabilizing circuit control method is provided, wherein the voltage stabilizing circuit comprises a main phase switch circuit, an auxiliary phase switch circuit and an output capacitor, wherein the main phase switch circuit and the auxiliary phase switch circuit are connected in parallel with each other; the output capacitor is connected in parallel to the rear ends of the main phase switch circuit and the auxiliary phase switch circuit;

[0007] The control method of the voltage stabilizing circuit is as follows: real-time monitoring of the load current at the output end of the voltage stabilizing circuit, obtaining the load current value and determining whether a mutation occurs; when the load current does not mutate, controlling the operation of the voltage stabilizing circuit based on a steady-state control strategy; when the load current mutates, controlling the operation of the voltage stabilizing circuit based on a transient control strategy; the transient control strategy is: obtaining the total inductance current value of the voltage stabilizing circuit before and after the load current mutates, and comparing the load current values ​​before and after the mutation; if the load current increases, determining the load current after the load current increases based on the circuit parameters of the voltage stabilizing circuit and the total inductance current value; At the moment, and The main phase switch circuit and the auxiliary phase switch circuit are controlled to be turned on at the same time. The main phase switch circuit and the auxiliary phase switch circuit are controlled to be turned off at the same time; if the load current decreases, the load current after the load current decreases is determined based on the circuit parameters of the voltage stabilizing circuit and the total inductor current value. At the moment, and The main phase switch circuit and the auxiliary phase switch circuit are controlled to be turned off at the same time. The main phase switch circuit and the auxiliary phase switch circuit are controlled to be turned on at the same time.

[0008] In one embodiment, after the load current increases, The time is determined by:

[0009] Determine the output capacitor charge calculation equation: ,in, is the moment when the load current suddenly changes. It is the moment when the total inductor current value is equal to the load current value after the load current changes suddenly. It is the moment when all the switch circuits of the voltage stabilizing circuit are turned on at the same time. is the moment when the load current mutation ends, is the total inductor current value when all switch circuits of the voltage regulator circuit are turned off at the same time, is the load current value after the load current suddenly changes;

[0010] Determine the discharge charge of the output capacitor using the equation: ,in, is the total inductor current value when the load current changes suddenly;

[0011] The calculation equation for determining the slope of the total inductor current rise of the voltage stabilizing circuit is: ,in, is the slope of the total inductor current rise, is the main phase inductance of the voltage stabilizing circuit, is the auxiliary phase inductance value of the voltage stabilizing circuit, is the DC input voltage value of the voltage stabilizing circuit, is the DC output voltage value of the voltage stabilizing circuit;

[0012] The calculation equation for determining the slope of the total inductor current drop of the voltage stabilizing circuit is: ,in, is the slope of the total inductor current decrease;

[0013] Based on the condition that the charging charge and the discharging charge of the output capacitor are equal, the above equations are combined to determine : , , .

[0014] In one embodiment, after the load current decreases, The time is determined as follows:

[0015] Determine the output capacitor charge calculation equation: ,in, is the moment when the load current suddenly changes. It is the moment when the total inductor current value is equal to the load current value after the load current changes suddenly. is the total inductor current value when the load current changes suddenly, is the load current value after the load current suddenly changes;

[0016] The calculation equation for determining the discharge charge of the output capacitor is: ,in, It is the moment when all the switch circuits of the voltage stabilizing circuit are turned on at the same time. is the moment when the load current mutation ends. is the total inductor current value when all switch circuits of the voltage stabilizing circuit are turned off at the same time;

[0017] The calculation equation for determining the slope of the total inductor current rise of the voltage stabilizing circuit is: ,in, is the slope of the total inductor current rise, is the auxiliary phase inductance value of the voltage stabilizing circuit, is the main phase inductance of the voltage stabilizing circuit, is the DC input voltage value of the voltage stabilizing circuit, is the DC output voltage value of the voltage stabilizing circuit;

[0018] The calculation equation for determining the slope of the total inductor current drop of the voltage stabilizing circuit is: ,in, is the slope of the total inductor current decrease;

[0019] Based on the condition that the charging charge amount and the discharging charge amount of the output capacitor of the voltage stabilizing circuit are equal, the above equations are combined to determine : , , .

[0020] In one embodiment, the steady-state control strategy is: control the phase circuits of the main phase switch circuit to operate alternately in sequence, and control the auxiliary phase switch circuit to operate later than the main phase switch circuit, wherein the preset duty cycle of each phase switch circuit of the main phase switch circuit is , the phase of the auxiliary phase switch circuit is .

[0021] In one embodiment, the main phase switch circuit includes a three-phase switch circuit, each phase switch circuit is respectively connected in series with a first main phase inductor, a second main phase inductor and a third main phase inductor, and the inductance values ​​of the first main phase inductor, the second main phase inductor and the third main phase inductor are the same; the auxiliary phase switch circuit is connected in series with an auxiliary phase inductor, and the inductance value of the auxiliary phase inductor is smaller than the inductance value of each main phase inductor of the main phase switch circuit.

[0022] In a second aspect of the present application, a control device is provided, comprising an inductor current sampling module, a load current sampling module and a control module; the inductor current sampling module is used to obtain the total inductor current value of the voltage stabilizing circuit; the load current sampling module is used to obtain the load current value at the output end of the voltage stabilizing circuit; the control module controls the voltage stabilizing circuit based on the total inductor current value and the load current value using the voltage stabilizing circuit control method described in the above embodiment.

[0023] In a third aspect of the present application, a power supply device is provided, comprising a control device, a voltage stabilizing circuit, and an inverter connected to the output end of the voltage stabilizing circuit; the control device obtains the total inductance current value and the load current value of the voltage stabilizing circuit, and based on the total inductance current value and the load current value, uses the voltage stabilizing circuit control method described in the above embodiment to control the voltage stabilizing circuit.

[0024] The voltage stabilizing circuit control method of the embodiment of the present application is used to control the front-stage voltage stabilizing circuit of the inverter, collects the load current in real time, and determines whether the load current mutates. When the load current mutates, the on-off time of each operating state is determined according to the mutation direction of the load current and the output capacitor charge balance principle, and then the on-off of the main phase switch circuit and the auxiliary phase switch circuit is accurately controlled based on the on-off time. The method has a faster transient response speed, so that the output current adapts to the mutation of the load current, reduces the output capacitor voltage fluctuation ripple and recovery time during transient operation, avoids the load being in a voltage fluctuation state for a long time, improves the reliability and stability of the power supply, and is more conducive to the promotion and application of microgrid power systems.

[0025] Furthermore, when the voltage stabilizing circuit is running stably, the phase of the auxiliary phase switch circuit is adjusted so that the peak value of the auxiliary phase inductor current and the valley value of the main phase inductor current cancel each other out, thereby reducing the output current ripple. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the structure of a voltage stabilizing circuit provided in one embodiment of the present application.

[0027] Figure 2 A schematic diagram of the steps of a voltage stabilizing circuit control method provided in one embodiment of the present application.

[0028] Figure 3 This is a timing diagram of the steady-state operation of the voltage stabilizing circuit provided in one embodiment of the present application.

[0029] Figure 4 A timing diagram of a voltage stabilizing circuit provided in an embodiment of the present application when the load current transiently increases.

[0030] Figure 5 This is a timing diagram of a voltage stabilizing circuit provided by an embodiment of the present application when the load current decreases transiently.

[0031] Figure 6 This is a structural block diagram of a control device provided in one embodiment of the present application.

[0032] Figure 7 A control schematic diagram of a voltage stabilizing circuit control method provided in one embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0036] The embodiment of the present application provides a voltage stabilizing circuit control method for controlling the voltage stabilizing circuit of the front stage of the inverter to provide the inverter with a stable output voltage and output current to ensure that the inverter can invert direct current into alternating current with high quality and incorporate it into the microgrid.

[0037] In order to facilitate the understanding of the technical solution, the voltage stabilizing circuit is first introduced below.

[0038] like Figure 1 As shown, the front-stage voltage stabilizing circuit 20 of the inverter 30 is an asymmetric voltage stabilizer composed of a three-phase switching circuit as a main phase and a single-phase switching circuit as an auxiliary phase.

[0039] In this embodiment, the voltage stabilizing circuit 20 includes a main phase switch circuit, an auxiliary phase switch circuit and an output capacitor C o , the main phase switch circuit and the auxiliary phase switch circuit are connected in parallel; the output capacitor C o The output capacitor C is connected in parallel to the rear end of the main phase switch circuit and the auxiliary phase switch circuit. The difference between the load current and the equivalent inductor current generated after the load jump is calculated by the output capacitor C o To bear, that is, by the output capacitor C o Discharge replenishment.

[0040] The main phase switch circuit includes three-phase switch circuits, each of which includes a switch tube, an inductor, and a diode. The first main phase switch circuit includes a first switch S N1 , a first diode D1, and a first main phase inductor L N1 The second main phase switch circuit includes a second switch S N2 , the second diode D2, and the second main phase inductor L N2 The third main phase switch circuit includes a third switch S N3, a third diode D3, and a third main phase inductor L N3 .

[0041] The following takes the first main phase switch circuit as an example for connection description, and the connections of other main phase switch circuits are consistent with the first main phase switch circuit. N1 The first end of the first switch S is used to connect to the positive electrode of the DC input power supply. N1 The second end of the first main phase inductor L N1 The first end of the first main phase inductor L is connected to the cathode of the first diode D1. N1 The second terminal of the output capacitor C o The anode of the first diode D1 is connected to the negative electrode of the DC input power supply, and the output capacitor C o The second end of each main phase inductor is connected to the second end of the main phase inductor. The second end of each main phase inductor is a main phase current sampling end, which can be used to collect the main phase inductor current.

[0042] The auxiliary phase switch circuit includes a fourth switch S A , the fourth diode D4, and the auxiliary phase inductor L A , the fourth switch S A The first end of the fourth switch S is connected to the first end of the other main phase switch and to the positive electrode of the DC input power supply. A The second end of the fourth diode D4 is connected to the cathode of the fourth diode D4 and to the auxiliary phase inductor L A The first end of the auxiliary phase inductor L A The second end of the inductor is connected to the second end of the other main phase inductor and to the output capacitor C o The anode of the fourth diode D4 is connected to the anode of the other main phase diodes, connected to the negative electrode of the DC input power supply, and connected to the output capacitor C o The second end of the voltage regulator circuit 20 is connected to form the negative electrode of the output end.

[0043] It should be noted that in the voltage stabilizing circuit 20, the first main phase inductor L N1 , the second main phase inductance L N2 and the third main phase inductance L N3 The inductance value of the auxiliary phase is the same; the auxiliary phase inductance L A The inductance value of is smaller than the inductance value of each main phase inductor of the main phase switching circuit.

[0044] On the basis of the above connection structure, the second end of each main phase inductor is a main phase current sampling end for collecting the main phase inductor current; the second end of the auxiliary phase inductor is an auxiliary phase current sampling end for collecting the auxiliary phase inductor current; each main phase inductor and the auxiliary phase inductor are connected to form a total inductor current sampling end A for collecting the total inductor current; the total inductor current sampling end A is connected to the output capacitor Co After connection, an output current sampling terminal is formed, which is also a load current sampling terminal B.

[0045] The output end of the voltage stabilizing circuit 20 is used to connect to the inverter 30 to output high-quality DC power to the inverter 30. The inverter 30 may be a grid-type inverter. The output end of the inverter 30 is used to connect to the load to provide the load with converted AC power.

[0046] like Figure 2 , Figure 7 As shown, the control method of the voltage stabilizing circuit includes:

[0047] S1: monitor the load current at the output end of the voltage stabilization circuit in real time, obtain the load current value and determine whether a sudden change occurs;

[0048] S2: When the load current does not suddenly change, the voltage stabilization circuit is controlled based on the steady-state control strategy;

[0049] S3: When the load current changes suddenly, the voltage stabilization circuit is controlled based on the transient control strategy.

[0050] Transient control strategies, including:

[0051] Obtain the total inductor current value of the voltage stabilizing circuit before and after the load current suddenly changes, and compare the load current values ​​before and after the sudden change;

[0052] If the load current increases, the voltage regulator circuit parameters and the total inductor current value are used to determine the load current after the load current increases. At the moment, and The main phase switch circuit and the auxiliary phase switch circuit are controlled to be turned on at the same time. Always control the main phase switch circuit and the auxiliary phase switch circuit to be turned off at the same time;

[0053] If the load current decreases, the voltage after the load current decreases is determined based on the circuit parameters of the voltage regulator circuit and the total inductor current value. At the moment, and The main phase switch circuit and the auxiliary phase switch circuit are controlled to be turned off at the same time. The main phase switch circuit and the auxiliary phase switch circuit are controlled to be turned on at the same time at all times.

[0054] Combination Figure 4 and Figure 5 Come and see, is the moment when the load current suddenly changes. It is the moment when the total inductor current value is equal to the load current value (output current value) after the load current suddenly changes. It is the moment when all the switch circuits of the voltage stabilizing circuit are turned on at the same time. The moment when the load current mutation ends. The circuit parameters of the voltage stabilization circuit include the inductance value of each main phase , Auxiliary phase inductance , DC input voltage value of voltage stabilizing circuit 20 , and the DC output voltage value of the voltage stabilizing circuit 20 .

[0055] The voltage stabilizing circuit control method of the embodiment of the present application collects the load current in real time and determines whether the load current mutates. When the load current mutates, the on-off time of each operating state is determined according to the mutation direction of the load current, combined with the circuit parameters and operating state of the voltage stabilizing circuit, and then the on-off of the main phase switch circuit and the auxiliary phase switch circuit are accurately controlled based on the on-off time. The method has a faster transient response speed, so that the output current adapts to the sudden change of the load current, reduces the output capacitor voltage fluctuation ripple and recovery time during transient operation, avoids the load being in a voltage fluctuation state for a long time, improves the reliability and stability of the power supply, and is more conducive to the promotion and application of microgrid power systems.

[0056] Combination Figure 3 From the perspective of FIG. 1 , when the microgrid load does not change, the load current of the voltage stabilizing circuit 20 does not change suddenly, and the voltage stabilizing circuit 20 can operate stably, but there will also be ripples in the output current. Therefore, a corresponding steady-state control strategy is also required to control the voltage stabilizing circuit 20.

[0057] Optionally, the steady-state control strategy is: control the phase circuits of the main phase switch circuit to operate alternately in sequence, and control the auxiliary phase switch circuit to operate later than the main phase switch circuit. In this way, by adjusting the phase of the auxiliary phase switch circuit, the auxiliary phase inductor current The peak value of the main phase inductor current The valley value of the main phase inductor current can be cancelled, thereby reducing the output current ripple and obtaining a higher quality DC power supply output. and auxiliary phase inductor current Real-time sampling is performed to facilitate observation of the auxiliary phase inductor current The peak value of the main phase inductor current Optionally, the total inductor current value at the total inductor current sampling terminal A can also be Real-time sampling is performed to facilitate observation of changes in the total inductor current output after the main phase switch circuit and the auxiliary phase switch circuit are connected in parallel, thereby assisting in achieving steady-state control.

[0058] The preset duty cycle of each phase switch circuit of the main phase switch circuit is , the phase of the auxiliary phase switching circuit is The auxiliary phase switch circuit lags behind any phase switch circuit of the main phase switch circuit in phase. In this embodiment, the auxiliary phase switch circuit lags behind the first main phase switch circuit in phase.

[0059] Generally, since the microgrid load changes frequently, when the microgrid load jumps, the load current will change instantly. However, the switch circuit inductor connected in series with the load has the characteristic of hindering the sudden change of current, and the output current cannot immediately follow the change of load current. At this time, the difference between the load current generated after the load jump and the equivalent inductor current is generated by the output capacitor. To bear, according to the output capacitor Due to the characteristics of the load, the voltage at both ends will change accordingly, which in turn causes the voltage on the load to change, causing the load to not operate normally. In order to make the output current of the voltage stabilization circuit adapt to the sudden load change and avoid long-term voltage fluctuations on the load, it is necessary to determine the on and off time of each switch circuit according to the change of the load current.

[0060] In an optional embodiment, in combination Figure 4 From the perspective of load current, when the load current increases, it is necessary to determine the operating state of the voltage stabilization circuit. time, in order to control the voltage stabilizing circuit.

[0061] After the load current increases The time is determined as follows:

[0062] Determine the output capacitor charge calculation equation:

[0063] ,in, is the moment when the load current suddenly changes. It is the moment when the total inductor current value is equal to the load current value (output current value) after the load current suddenly changes. It is the moment when all the switch circuits of the voltage stabilizing circuit are turned on at the same time. is the moment when the load current mutation ends. is the total inductor current value when all switch circuits of the voltage regulator circuit are turned off at the same time, It is the load current value after the load current changes suddenly (the output current value of the voltage stabilizing circuit).

[0064] Determine the discharge charge of the output capacitor using the equation: ,in, It is the total inductor current value when the load current changes suddenly.

[0065] The above calculation equations for the charging charge amount and the discharging charge amount of the output capacitor are determined by the circuit connection mode of the voltage stabilizing circuit.

[0066] Determine the calculation equation for the slope of the total inductor current rise in the voltage regulator circuit: ,in, is the slope of the total inductor current rise, is the auxiliary phase inductance value of the voltage stabilizing circuit, is the main phase inductance of the voltage stabilizing circuit, is the DC input voltage value of the voltage stabilizing circuit, is the DC output voltage value of the voltage stabilizing circuit.

[0067] Determine the calculation equation for the slope of the total inductor current drop in the voltage regulator circuit: ,in, is the slope of the total inductor current decrease.

[0068] The calculation equation for the slope of the total inductor current rise and the calculation equation for the slope of the total inductor current fall are determined according to the parallel relationship between the main phase inductance and the auxiliary phase inductance of the voltage stabilizing circuit.

[0069] Based on the condition that the charging charge and discharging charge of the output capacitor are equal, the above equations are combined to determine .

[0070] Combination Figure 4 From the perspective of the output capacitor charging charge is equal to the output capacitor discharging charge, the output capacitor discharging charge is equal to Time to The area of ​​the triangle formed by the total inductor current and the load current at the moment, the output capacitor charge is equal to Time to The area of ​​the triangle formed by the total inductor current and the load current at the moment is .

[0071] Combining the above equations, we can get , and The calculation formula is: , , .

[0072] In an optional embodiment, in combination Figure 5 From the perspective of load current, when the load current decreases, it is necessary to redetermine the voltage according to the operating status of the voltage stabilization circuit. time, in order to control the voltage stabilizing circuit.

[0073] After the load current decreases The time is determined as follows:

[0074] Determine the output capacitor charge calculation equation: ,in, is the moment when the load current suddenly changes. It is the moment when the total inductor current value is equal to the load current value after the load current changes suddenly. is the total inductor current value when the load current changes suddenly, It is the load current value (output current value) after the load current changes suddenly.

[0075] The calculation equation to determine the discharge charge of the output capacitor is: ,in, It is the moment when all the switch circuits of the voltage stabilizing circuit are turned on at the same time. is the moment when the load current mutation ends, It is the total inductor current value when all switch circuits of the voltage regulator circuit are turned off at the same time.

[0076] Determine the calculation equation for the slope of the total inductor current rise in the voltage regulator circuit: ,in, is the slope of the total inductor current rise, is the auxiliary phase inductance value of the voltage stabilizing circuit, is the main phase inductance of the voltage stabilizing circuit, is the DC input voltage value of the voltage stabilizing circuit, is the DC output voltage value of the voltage stabilizing circuit.

[0077] Determine the calculation equation for the slope of the total inductor current drop in the voltage regulator circuit: ,in, is the slope of the total inductor current decrease.

[0078] Based on the condition that the charging charge and discharging charge of the output capacitor of the voltage regulator circuit are equal, the above equations are combined to determine .

[0079] Combination Figure 5 From the perspective of the output capacitor, the charge amount of the output capacitor is equal to the discharge charge amount of the output capacitor, and the charge amount of the output capacitor is equal to Time to The area of ​​the triangle formed by the total inductor current and the load current at the moment, the output capacitor discharge charge is equal to Time to The area of ​​the triangle formed by the total inductor current and the load current at the moment is .

[0080] Combining the above equations, we can get , and The calculation formula is: , , .

[0081] It can be seen from the above embodiments that: during transient operation, no matter whether the load current increases or decreases, the on-off time can be calculated according to the output capacitor charge balance principle, and the main phase switch circuit and the auxiliary phase switch circuit can be turned on and off at the same time, so that the output current adapts to the sudden change of the load current, reducing the output capacitor voltage fluctuation ripple and recovery time during transient operation.

[0082] The voltage stabilizing circuit control method divides the working state of the asymmetric voltage stabilizing circuit into steady-state operation and transient operation. During steady-state operation, the phase of the auxiliary phase switch circuit is changed to reduce the total output inductor current ripple; during transient operation, the load change is judged by sampling the load current, and the on-off time of the main phase switch circuit and the auxiliary phase switch circuit is calculated, thereby realizing transient minimum time control and effectively suppressing the output capacitor voltage fluctuation, thereby providing a stable output voltage and a fast-response output current for the inverter.

[0083] In the specific control process, the load current is collected in real time and it is determined whether the load current mutates. When the load current mutates, the on-off time of each operating state is determined according to the direction of the load current mutation and the output capacitor charge balance principle. Then, the on-off of the main phase switch circuit and the auxiliary phase switch circuit is accurately controlled based on the on-off time. It has a faster transient response speed, so that the output current can quickly adapt to the sudden change of the load current, reduce the output capacitor voltage fluctuation ripple and recovery time during transient operation, avoid the load being in a voltage fluctuation state for a long time, improve the reliability and stability of the power supply, and be more conducive to the promotion and application of microgrid power systems.

[0084] Furthermore, when the voltage stabilizing circuit is running stably, the phase of the auxiliary phase switch circuit is adjusted so that the peak value of the auxiliary phase inductor current and the valley value of the main phase inductor current cancel each other out, thereby reducing the output current ripple.

[0085] The present application also provides a control device, such as Figure 6 As shown, the control device includes an inductor current sampling module 101 , a load current sampling module 102 and a control module 103 .

[0086] The inductor current sampling module 101 is used to obtain the total inductor current value obtained by adding the main phase inductor current and the auxiliary phase inductor current of the voltage stabilizing circuit; the load current sampling module 102 is used to obtain the load current value of the output end of the voltage stabilizing circuit.

[0087] The control module 103 controls the voltage stabilizing circuit based on the total inductor current value and the load current value by using the voltage stabilizing circuit control method of the above embodiment.

[0088] The control module 103 generates an on-off control signal and transmits it to the on-off signal distribution module 104, and then the on-off signal distribution module 104 controls each pulse width modulation module 105 to generate corresponding pulse modulation signals PWM1~PWMn. Among them, the pulse modulation signal PWM1 is output to the first switch of the first main phase switch circuit, the pulse modulation signal PWM2 is output to the second switch of the second main phase switch circuit, the pulse modulation signal PWM3 is output to the third switch of the third main phase switch circuit, and the pulse modulation signal PWM4 is output to the fourth switch of the auxiliary phase switch circuit.

[0089] The present application also provides a power supply device, such as Figure 1 As shown, the power supply device includes a control device 10, a voltage stabilizing circuit 20, and an inverter 30 connected to the output end of the voltage stabilizing circuit 20; the control device 10 obtains the total inductance current value and the load current value of the voltage stabilizing circuit 20, and based on the total inductance current value and the load current value, uses the voltage stabilizing circuit control method of the above embodiment to control the voltage stabilizing circuit 20.

[0090] The control device and power supply equipment can control the front-stage voltage regulator to provide a stable voltage and a fast-response current; in steady-state operation, the peak value of the auxiliary phase inductor current and the valley value of the main phase inductor current are offset by adjusting the phase of the auxiliary phase switch circuit, thereby reducing the output current ripple; in transient operation, the on-off time is calculated according to the output capacitor charge balance principle, and the main phase switch circuit and the auxiliary phase switch circuit are turned on and off at the same time, so that the output current quickly adapts to the sudden change of the load current, reducing the output capacitor voltage fluctuation ripple and recovery time in transient operation.

[0091] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0092] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims, and the description may be used to interpret the contents of the claims.

Claims

1. A voltage stabilizing circuit control method, characterized in that: The voltage stabilizing circuit comprises a main phase switch circuit, an auxiliary phase switch circuit and an output capacitor, wherein the main phase switch circuit and the auxiliary phase switch circuit are connected in parallel with each other; the output capacitor is connected in parallel to the rear ends of the main phase switch circuit and the auxiliary phase switch circuit; The control method of the voltage stabilizing circuit is: Monitor the load current at the output end of the voltage stabilizing circuit in real time, obtain the load current value and determine whether a sudden change occurs; When the load current does not suddenly change, the voltage stabilization circuit is controlled to operate based on a steady-state control strategy; When a sudden change occurs in the load current, the voltage stabilization circuit is controlled to operate based on a transient control strategy; The transient control strategy is: obtaining the total inductance current value of the voltage stabilizing circuit before and after the load current suddenly changes, and comparing the load current values ​​before and after the sudden change; If the load current increases, the load current after the load current increases is determined based on the circuit parameters of the voltage stabilizing circuit and the total inductor current value. At the moment, and The main phase switch circuit and the auxiliary phase switch circuit are controlled to be turned on at the same time. Controlling the main phase switch circuit and the auxiliary phase switch circuit to be turned off at the same time; If the load current decreases, the load current after the load current decreases is determined based on the circuit parameters of the voltage stabilizing circuit and the total inductor current value. At the moment, and The main phase switch circuit and the auxiliary phase switch circuit are controlled to be turned off at the same time. The main phase switch circuit and the auxiliary phase switch circuit are controlled to be turned on at the same time.

2. The voltage stabilizing circuit control method according to claim 1, characterized in that: After the load current increases The time is determined by: Determine the output capacitor charge calculation equation: ， in, is the moment when the load current suddenly changes. It is the moment when the total inductor current value is equal to the load current value after the load current changes suddenly. It is the moment when all the switch circuits of the voltage stabilizing circuit are turned on at the same time. is the moment when the load current mutation ends, is the total inductor current value when all switch circuits of the voltage regulator circuit are turned off at the same time, is the load current value after the load current suddenly changes; Determine the discharge charge of the output capacitor using the equation: ， in, is the total inductor current value when the load current changes suddenly; The calculation equation for determining the slope of the total inductor current rise of the voltage stabilizing circuit is: ， in, is the slope of the total inductor current rise, is the main phase inductance of the voltage stabilizing circuit, is the auxiliary phase inductance value of the voltage stabilizing circuit, is the DC input voltage value of the voltage stabilizing circuit, is the DC output voltage value of the voltage stabilizing circuit; The calculation equation for determining the slope of the total inductor current drop of the voltage stabilizing circuit is: ， in, is the slope of the total inductor current decrease; Based on the condition that the charging charge and the discharging charge of the output capacitor are equal, the above equations are combined to determine : ， ， 。 3. The voltage stabilizing circuit control method according to claim 1, characterized in that: After the load current decreases The time is determined by: Determine the output capacitor charge calculation equation: ， in, is the moment when the load current suddenly changes. It is the moment when the total inductor current value is equal to the load current value after the load current changes suddenly. is the total inductor current value when the load current changes suddenly, is the load current value after the load current suddenly changes; The calculation equation for determining the discharge charge of the output capacitor is: ， in, It is the moment when all the switch circuits of the voltage stabilizing circuit are turned on at the same time. is the moment when the load current mutation ends, is the total inductor current value when all switch circuits of the voltage stabilizing circuit are turned off at the same time; The calculation equation for determining the slope of the total inductor current rise of the voltage stabilizing circuit is: ， in, is the slope of the total inductor current rise, is the auxiliary phase inductance value of the voltage stabilizing circuit, is the main phase inductance of the voltage stabilizing circuit, is the DC input voltage value of the voltage stabilizing circuit, is the DC output voltage value of the voltage stabilizing circuit; The calculation equation for determining the slope of the total inductor current drop of the voltage stabilizing circuit is: ， in, is the slope of the total inductor current decrease; Based on the condition that the charging charge and the discharging charge of the output capacitor are equal, the above equations are combined to determine : ， ， 。 4. The voltage stabilizing circuit control method according to claim 1, characterized in that: The steady-state control strategy is: The phase circuits of the main phase switch circuit are controlled to operate alternately in sequence, and the auxiliary phase switch circuit is controlled to operate after the main phase switch circuit, wherein the preset duty ratio of each phase switch circuit of the main phase switch circuit is , the phase of the auxiliary phase switch circuit is .

5. The voltage stabilizing circuit control method according to claim 1, characterized in that: The main phase switch circuit includes a three-phase switch circuit, each phase switch circuit is respectively connected in series with a first main phase inductor, a second main phase inductor and a third main phase inductor, and the first main phase inductor, the second main phase inductor and the third main phase inductor have the same inductance value; An auxiliary phase inductor is connected in series in the auxiliary phase switch circuit, and the inductance value of the auxiliary phase inductor is smaller than the inductance value of each main phase inductor of the main phase switch circuit.

6. A control device, characterized in that: It includes an inductor current sampling module, a load current sampling module and a control module; The inductor current sampling module is used to obtain the total inductor current value of the voltage stabilization circuit; The load current sampling module is used to obtain the load current value of the output end of the voltage stabilization circuit; The control module controls the voltage stabilizing circuit based on the total inductor current value and the load current value by using the voltage stabilizing circuit control method according to any one of claims 1 to 5.

7. A power supply device, characterized in that: It includes a control device, a voltage stabilizing circuit, and an inverter connected to the output end of the voltage stabilizing circuit; The control device obtains the total inductance current value and the load current value of the voltage stabilizing circuit, and based on the total inductance current value and the load current value, controls the voltage stabilizing circuit using the voltage stabilizing circuit control method according to any one of claims 1 to 5.

8. The power supply device according to claim 7, characterized in that: The inverter is a grid-type inverter.

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