WO2023000297A1

WO2023000297A1 - Bus voltage control method and system for uninterruptible power supply system, and related component

Info

Publication number: WO2023000297A1
Application number: PCT/CN2021/108112
Authority: WO
Inventors: 刘琴
Original assignee: 深圳市英威腾电源有限公司
Priority date: 2021-07-23
Filing date: 2021-07-23
Publication date: 2023-01-26
Also published as: CN113785467B; CN113785467A

Abstract

A bus voltage control method and system for an uninterruptible power supply system, and a related component, comprising: detecting a main circuit input voltage; determining a current bus voltage target value on the basis of the main circuit input voltage; and controlling bus voltage target values of uninterruptible power supplies connected in parallel in the uninterruptible power supply system to be the currently determined bus voltage target value, wherein the uninterruptible power supply system at least comprises two uninterruptible power supplies connected in parallel. By means of the solution of the present application, good dynamic response and overall efficiency can be ensured, and a situation that a direct current bus voltage rises due to uncontrollability is avoided.

Description

Bus voltage control method, system and related components of uninterruptible power supply system

technical field

The invention relates to the technical field of AC power supply, in particular to a bus voltage control method, system and related components of an uninterruptible power supply system.

Background technique

In medium and high power on-line uninterruptible power supply systems, the main circuit usually includes devices such as bypass/rectifier/inverter. Wherein, the rectifier can rectify the AC mains voltage into a DC bus voltage, and the inverter can convert the DC bus voltage into an AC voltage and then output it to the load.

Generally speaking, the control target value of the DC bus voltage is selected in advance according to the demand specification, and is generally set to be higher than the peak voltage of the AC input, taking into account factors such as bus capacitor cost, dynamic response, and efficiency.

However, if the bus voltage target value is fixed, it often happens that good dynamic response and efficiency indicators cannot be achieved. Therefore, some current solutions are to set the target value of the bus voltage to change dynamically according to the load. Usually, the bus voltage is higher at no-load and lower at full load, so as to balance dynamic response and overall machine efficiency. However, in practical applications of this method, it often occurs that the DC bus voltage rises without the control of the rectifier, causing overvoltage protection or even device damage.

To sum up, how to avoid the occurrence of uncontrolled DC bus voltage while taking into account the dynamic response and overall machine efficiency is a technical problem urgently needed to be solved by those skilled in the art.

Contents of the invention

The purpose of the present invention is to provide a bus voltage control method, system and related components of an uninterruptible power supply system, so as to avoid uncontrolled DC bus voltage while taking into account dynamic response and overall machine efficiency.

In order to solve the above technical problems, the present invention provides the following technical solutions:

A bus voltage control method for an uninterruptible power supply system, comprising:

Detect the main circuit input voltage;

determining a current bus voltage target value based on the main circuit input voltage;

Controlling the busbar voltage target value of each parallel uninterruptible power supply in the uninterruptible power supply system is the currently determined busbar voltage target value;

Wherein, the uninterruptible power supply system includes at least two parallel uninterruptible power supplies.

Preferably, it also includes:

judging whether at least one uninterruptible power supply is in a state of preparation for bypass switching;

If yes, detect the bypass input voltage;

Correspondingly, the determining the current bus voltage target value based on the main circuit input voltage includes:

Based on the main circuit input voltage and the bypass input voltage, a current bus voltage target value is determined.

Preferably, the determining the current bus voltage target value based on the main circuit input voltage and the bypass input voltage includes:

Determine a first bus voltage target value corresponding to the main circuit input voltage according to a preset first correspondence relationship;

determining a second bus voltage target value corresponding to the bypass input voltage according to a preset second corresponding relationship;

using the maximum value of the first bus voltage target value and the second bus voltage target value as the determined current bus voltage target value;

Wherein, in the first corresponding relationship, the main circuit input voltage is positively correlated with the first bus voltage target value, and in the second corresponding relationship, the bypass input voltage and the second bus The voltage target value is positively correlated.

Preferably, the first correspondence includes:

When the input voltage of the main circuit is less than or equal to the preset first input threshold, the value of the corresponding first bus voltage target value is a preset first value;

When the main circuit input voltage is greater than the first input threshold, the value of the corresponding first bus voltage target value is a preset second value, and the second value is greater than the first value;

The second correspondence includes:

When the bypass input voltage is less than or equal to the preset second input threshold, the value of the corresponding second bus voltage target value is the first value;

When the bypass input voltage is greater than the second input threshold, the corresponding second bus voltage target value is the second value.

Preferably, each uninterruptible power supply has its own rectification controller and an inverter controller communicatively connected with its own rectifier controller, and the inverter controllers of each uninterruptible power supply are all communicatively connected to each other;

Correspondingly, the detection of the input voltage of the main circuit includes:

The rectification controllers of each uninterruptible power supply receive the detected input voltage of the main circuit;

The determining the current bus voltage target value based on the main circuit input voltage includes:

Each rectifier controller determines the current bus voltage target value based on the input voltage of the main circuit and sends it to the inverter controller connected to itself through communication;

The busbar voltage target value of each parallel uninterruptible power supply in the control uninterruptible power supply system is the currently determined busbar voltage target value, including:

Any one of the inverter controllers sends the bus voltage target value sent by the rectification controller connected with itself to other inverter controllers, and receives the bus voltage target value sent by the other inverter controllers;

Any one of the inverter controllers takes the bus voltage target value sent by the rectifier controller connected to itself and the maximum value of the bus voltage target values sent by the other inverter controllers as the determined bus voltage target value , and feed back to the rectification controller connected with itself in communication, so that each rectification controller controls the bus voltage target value of the corresponding uninterruptible power supply to the bus voltage target value received by the rectification controller.

A bus voltage control system for an uninterruptible power supply system, comprising:

The main circuit input voltage detection module is used to detect the main circuit input voltage;

A bus voltage target value determining module, configured to determine the current bus voltage target value based on the main circuit input voltage;

The bus voltage target value synchronization control module is used to control the bus voltage target value of each parallel uninterruptible power supply in the uninterruptible power supply system to be the currently determined bus voltage target value;

Preferably, it also includes:

A bypass switching preparation state judging module, used to judge whether at least one uninterruptible power supply is in a bypass switching preparation state;

If so, trigger the bypass input voltage detection module for detecting the bypass input voltage;

Correspondingly, the bus voltage target value determination module is specifically used for:

Preferably, the bus voltage target value determination module is specifically used for:

A busbar voltage control device for an uninterruptible power supply system, comprising:

memory for storing computer programs;

A processor, configured to execute the computer program to implement the steps of the bus voltage control method for an uninterruptible power supply system described in any one of the above.

A computer-readable storage medium, where a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the steps of the bus voltage control method for an uninterruptible power supply system described in any one of the above are implemented.

Applying the technical solutions provided by the embodiments of the present invention, the applicant considers that, in a parallel system, when the target values of the bus voltages of the two uninterruptible power supplies are inconsistent, high-frequency circulating currents are likely to occur, thus causing the DC bus voltage to be unaffected. The control of the rectifier increases, causing overvoltage protection and even device damage. Therefore, the solution of the present application synchronizes the busbar voltage target values of each parallel uninterruptible power supply. Specifically, in order to take into account the dynamic response and overall machine efficiency, the solution of this application does not set a fixed bus voltage target value, but detects the main circuit input voltage, and determines the current bus voltage target value based on the main circuit input voltage, that is, Therefore, the determined current bus voltage target value can guarantee good dynamic response and overall machine efficiency. After determining the current bus voltage target value, the application will control the bus voltage target value of each parallel uninterruptible power supply in the uninterruptible power supply system to be the currently determined bus voltage target value, that is, to realize each parallel connection The synchronization of the bus voltage target value of the uninterruptible power supply, so that there will be no high-frequency circulating current, which will cause the DC bus voltage to rise uncontrollably.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the implementation flowchart of the busbar voltage control method of a kind of uninterruptible power supply system in the present invention;

Fig. 2 is a schematic structural view of an uninterruptible power supply system equipped with a bypass loop in a specific embodiment of the present invention;

Fig. 3 is a schematic diagram of the communication structure of the respective rectifier controllers and inverter controllers of two parallel uninterruptible power supplies in a specific embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a bus voltage control system of an uninterruptible power supply system in the present invention.

detailed description

The core of the present invention is to provide a bus voltage control method for an uninterruptible power supply system, which can ensure good dynamic response and overall machine efficiency, and will not cause the DC bus voltage to rise uncontrollably.

In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Please refer to Fig. 1, Fig. 1 is the implementation flowchart of a bus voltage control method of an uninterruptible power supply system in the present invention, the bus voltage control method of this uninterruptible power supply system may include the following steps:

Step S101: Detect the input voltage of the main circuit.

In practical applications, the input voltage of the main circuit may change due to changes in the power environment. In the present application, the detection of the input voltage of the main circuit can be realized through devices such as voltage sensors, which can be detected in real time or according to a preset detection cycle.

Step S102: Determine the current bus voltage target value based on the main circuit input voltage.

This application can preset the corresponding relationship between the input voltage of the main circuit and the target value of the bus voltage. The specific content can be set and adjusted according to actual needs. For example, it can be a linear corresponding relationship, which is conducive to accurately determining the required bus voltage. The target value, for example, can be a segmented corresponding relationship, so that when the input voltage of the main circuit fluctuates little, there is no need to adjust the target value of the bus voltage, which can avoid excessively frequent and meaningless adjustments.

However, it can be understood that the determined current bus voltage target value should be positively correlated with the detected input voltage of the main circuit, so as to ensure system efficiency and stability.

Step S103: Control the busbar voltage target value of each parallel-connected uninterruptible power supply in the uninterruptible power supply system to be the currently determined busbar voltage target value.

This application is aimed at a parallel system, that is, an uninterruptible power supply system includes at least two parallel uninterruptible power supplies. After determining the current bus voltage target value, this application will synchronize the bus voltage target value, namely This application will control the busbar voltage target value of each parallel-connected uninterruptible power supply in the uninterruptible power supply system to be the currently determined busbar voltage target value.

Due to the synchronization of the busbar voltage target value, the present application takes both efficiency and stability into account, and at the same time, the problem caused by the inconsistency of the busbar voltage target value does not occur.

In a specific embodiment of the present invention, it may also include:

If yes, detect the bypass input voltage;

Correspondingly, step S102 may specifically include: determining the current bus voltage target value based on the input voltage of the main circuit and the input voltage of the bypass.

In the foregoing embodiments, the current bus voltage target value is determined based on the input voltage of the main circuit, thereby effectively ensuring the efficiency and stability of the system. In this embodiment, it is further considered that there are Bypass loop, for example, FIG. 2 is a schematic structural diagram of an uninterruptible power supply system equipped with a bypass loop in a specific occasion. If an uninterruptible power supply needs to be switched from the bypass to the inverter, or from the inverter to the bypass, in order to ensure that the output voltage is uninterrupted during the switching, it is necessary to adjust the output voltage and phase of the inverter. , making it completely trace bypassed. However, if the bypass input voltage is high and the bus voltage target value is low, the output voltage of the inverter may be clipped, that is, the output voltage of the inverter cannot track the bypass well, which is not conducive to Ensure the stability of the system.

In this implementation manner, it will be judged whether at least one uninterruptible power supply is in a bypass switching preparation state. For any uninterruptible power supply, if the uninterruptible power supply is about to switch from the bypass to the inverter, or is about to switch from the inverter to the bypass, it is considered to be in a state of preparation for bypass switching.

When at least one uninterruptible power supply is in the bypass switching preparation state, the application will detect the bypass input voltage, and determine the current bus voltage target value based on the main circuit input voltage and the bypass input voltage.

That is to say, in this embodiment, when determining the current bus voltage target value, not only the factor of the input voltage of the main circuit, but also the factor of the input voltage of the bypass is taken into consideration, so that the bypass switching can be effectively ensure the stability of the system.

In practical applications, when the bypass switching is completed, that is, when any uninterruptible power supply is not in the state of bypass switching preparation, it can be judged whether there is at least one bypass working at present, and if it exists, it can continue based on the main circuit input voltage And the bypass input voltage to determine the current bus voltage target value. If it does not exist, that is, each uninterruptible power supply uses an inverter to output voltage, it can return to determine the current bus voltage target value based on the input voltage of the main circuit.

Based on the input voltage of the main circuit and the bypass input voltage, the specific operation of determining the current bus voltage target value can be set according to the actual situation. A relatively simple and convenient solution is to set the bus voltage target value according to the maximum value required. Set, so that the determined bus voltage target value can be applied to the current main circuit input voltage and bypass input voltage.

That is, in a specific embodiment of the present invention, based on the main circuit input voltage and the bypass input voltage, determining the current bus voltage target value may specifically include the following steps:

Step 1: Determine the first bus voltage target value corresponding to the input voltage of the main circuit according to the preset first corresponding relationship;

Step 2: According to the preset second corresponding relationship, determine the second bus voltage target value corresponding to the bypass input voltage;

Step 3: use the maximum value of the first bus voltage target value and the second bus voltage target value as the determined current bus voltage target value;

Wherein, in the first corresponding relationship, the main circuit input voltage is positively correlated with the first bus voltage target value, and in the second corresponding relationship, the bypass input voltage is positively correlated with the second bus voltage target value.

It can be understood that the first bus voltage target value corresponding to the main circuit input voltage determined according to the preset first correspondence relationship can be applied to the current main circuit input voltage, that is, the bus voltage target finally determined in step 3 Value, usually should not be lower than the first bus voltage target value, in order to avoid the situation that the bus voltage target value is lower than the peak value of the main circuit input voltage.

Similarly, according to the preset second corresponding relationship, the second bus voltage target value corresponding to the bypass input voltage is determined, which can be applied to the current bypass input voltage, that is, the bus voltage target value finally determined in step 3, Generally, it should not be lower than the target value of the second bus voltage, so as to avoid the occurrence of output voltage clipping during bypass switching.

Therefore, in this embodiment, the maximum value of the first bus voltage target value and the second bus voltage target value is directly used as the determined current bus voltage target value, the solution is simple and convenient, and there will be no bus voltage target If the value is lower than the peak value of the input voltage of the main circuit, there will be no clipping of the output voltage during bypass switching.

The specific content of the first correspondence and the second correspondence can be set according to actual needs. For example, in combination with the above description, the first correspondence can be a linear correspondence or a segmented correspondence, but due to The higher the input voltage of the main circuit, the higher the required bus voltage target value. Therefore, in the first corresponding relationship, the main circuit input voltage and the first bus voltage target value need to be positively correlated. Similarly, the higher the bypass input voltage is, the higher the required bus voltage target value is. Therefore, in the second corresponding relationship, the bypass input voltage needs to be positively correlated with the second bus voltage target value.

In a specific implementation manner of the present invention, the first correspondence includes:

When the main circuit input voltage is less than or equal to the preset first input threshold, the value of the corresponding first bus voltage target value is the preset first value;

The second correspondence includes:

When the bypass input voltage is greater than the second input threshold, the corresponding second bus voltage target value is a second value.

The specific values of the first input threshold and the second input threshold can be set and adjusted according to actual needs. In this embodiment, both the first correspondence and the second correspondence are segmented correspondences, and in this embodiment, there are only two possibilities for the value of the first bus voltage target value: the first Similarly, there are only two possibilities for the value of the second bus voltage target value: the first value or the second value, so that the finally determined bus voltage target value also has only these two possibilities: the first The numerical value or the second numerical value, that is, the target value of the bus voltage has only 2 gears for selection.

Such an embodiment, on the one hand, makes the content of the first correspondence and the second correspondence simple and convenient to set, and on the other hand, makes data transmission very easy. Specifically, when implementing the scheme of this application, each step of this application can be realized by a single controller, but the requirements for this single controller will be very high. In practical applications, it is more commonly used that each continuous Each power supply has its own rectifier controller and an inverter controller communicatively connected with its own rectifier controller. At this time, in order to realize the synchronization of the bus voltage target values among the uninterruptible power supplies, it is necessary to set the current bus voltage target For example, when the first correspondence and the second correspondence are linear correspondences, it is necessary to transmit the specific value of the bus voltage target value, which has a large amount of data and is easily disturbed. However, in this implementation mode, there are only 2 gears for the bus voltage target value, and the information of which gear needs to be selected at present is transmitted. The transmission process will be very convenient and will not be easily disturbed.

In a specific embodiment of the present invention, each uninterruptible power supply has its own rectification controller and an inverter controller communicatively connected with its own rectification controller, and the inverter controllers of each uninterruptible power supply are connected to each other communication connection;

Correspondingly, step S101 may specifically include:

Step S102 may specifically include:

Step S103 may specifically include:

In this embodiment, each uninterruptible power supply has its own rectification controller and an inverter controller communicatively connected with its own rectifier controller, and the inverter controllers of each uninterruptible power supply are connected to each other by communication, which is also Currently, the commonly used solution, for example, FIG. 3 is a schematic diagram of the communication structure of the respective rectifier controllers and inverter controllers of two parallel uninterruptible power supplies in a specific situation.

Specifically, the input voltage of the main circuit can be detected by a single sensor, and the detection result can be sent to the rectifier controllers of each uninterruptible power supply, or the rectifier controllers of each uninterruptible power supply can respectively detect the input voltage of the main circuit, and Does not affect the implementation of the present invention. Of course, in practical applications, if the rectification controllers of each uninterruptible power supply detect the input voltage of the main circuit separately, if there is a large difference between the detected values, measures such as alarm prompts can be implemented.

Each rectifier controller determines the current bus voltage target value based on the input voltage of the main circuit, and sends it to the inverter controller communicated with itself.

For example, in a specific situation, when the main circuit input voltage is less than or equal to the preset first input threshold 250V, the rectifier controller may determine that the current bus voltage target value is the preset first value 360V. When the input voltage of the main circuit is greater than 250V, the rectification controller may determine that the current bus voltage target value is a preset second value of 400V. Taking the rectifier controller 1 in FIG. 3 as an example, for example, the rectifier controller 1 determines that the current bus voltage target value is 400V, and can send this information to the inverter controller 1 communicated with itself.

It should be noted that when there are only a few gears available for the bus voltage target value, several electrical signals can replace the specific value of the bus voltage target value to realize information transmission. For example, in the above example, if the rectifier controller 1 determines that the current bus voltage target value is 360V, it can send an electrical signal 0 to the inverter controller 1 to indicate that the rectifier controller 1 determines that the current bus voltage target value is 360V. And if the rectifier controller 1 determines that the current bus voltage target value is 400V, it can send an electrical signal 1 to the inverter controller 1 to indicate that the rectifier controller 1 determines that the current bus voltage target value is 400V.

Any inverter controller sends the bus voltage target value sent by the rectifier controller connected with itself to other inverter controllers, and receives the bus voltage target value sent by the other inverter controllers, for example, in Fig. In 3, the inverter controller 1 will send the electrical signal 1 to the inverter controller 2, and receive the bus voltage target value sent by the inverter controller 2, for example, the inverter controller 2 sends the electrical signal 0, indicating that the rectification The controller 2 determines that the current bus voltage target value is 360V.

Afterwards, the inverter controller 1 will determine the maximum value of the bus voltage target value 400V sent by the rectifier controller 1 and the received bus voltage target value 360V sent by the inverter controller 2, which is 400V, and use it as the determined The target value of the bus voltage is fed back to the rectifier controller 1. In this example, the electric signal 1 is fed back to the rectification controller 1 , so that the rectification controller 1 controls the corresponding bus voltage target value of the uninterruptible power supply 1 to be 400V.

Similarly, the inverter controller 2 will determine the maximum value of the bus voltage target value 360V sent by the rectifier controller 2 and the bus voltage target value 400V sent by the inverter controller 1, which is 400V, and take it as the determination The output bus voltage target value is fed back to the rectifier controller 2. In this example, the electric signal 1 is fed back to the rectification controller 2, so that the rectification controller 2 controls the corresponding bus voltage target value of the uninterruptible power supply 2 to be 400V.

In addition, in one of the foregoing embodiments, it is described that when determining the target value of the bus voltage, not only the main circuit input voltage but also the bypass input voltage will be taken into consideration, and it is applied to this embodiment, Each inverter controller can determine the current bus voltage target value based on the main circuit input voltage and the bypass input voltage. When each inverter controller has determined the current bus voltage target value, then through the communication connection with other inverter controllers, determine the maximum value, so that each uninterruptible power supply The specific implementation of the control of the bus voltage target value is the same as that of this embodiment, that is, the inverter controller can feed back to the rectifier controller for execution.

Corresponding to the above method embodiments, the embodiments of the present invention also provide a bus voltage control system of an uninterruptible power supply system, which can be referred to above.

Referring to Fig. 4, it is a schematic structural diagram of a bus voltage control system of an uninterruptible power supply system in the present invention, including:

The main circuit input voltage detection module 401 is used to detect the main circuit input voltage;

The bus voltage target value determination module 402 is used to determine the current bus voltage target value based on the main circuit input voltage;

The bus voltage target value synchronization control module 403 is used to control the bus voltage target value of each parallel uninterruptible power supply in the uninterruptible power supply system to be the currently determined bus voltage target value;

In a specific embodiment of the present invention, it also includes:

Correspondingly, the bus voltage target value determining module 402 is specifically used for:

Based on the main circuit input voltage and the bypass input voltage, the current bus voltage target value is determined.

In a specific implementation manner of the present invention, the bus voltage target value determining module 402 is specifically used for:

According to the preset first corresponding relationship, determine the first bus voltage target value corresponding to the main circuit input voltage;

According to the preset second corresponding relationship, a second bus voltage target value corresponding to the bypass input voltage is determined;

Taking the maximum value of the first bus voltage target value and the second bus voltage target value as the determined current bus voltage target value;

The second correspondence includes:

Correspondingly, detecting the input voltage of the main circuit includes:

Determine the current bus voltage target value based on the input voltage of the main circuit, including:

Corresponding to the above method and system embodiments, the embodiment of the present invention also provides a bus voltage control device for an uninterruptible power supply system and a computer-readable storage medium, where a computer program is stored on the computer-readable storage medium. When the program is executed by the processor, the steps of the bus voltage control method of the uninterruptible power supply system in any of the above-mentioned embodiments are realized. The computer-readable storage medium mentioned here includes random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, Or any other form of storage medium known in the technical field.

The bus voltage control equipment of the UPS system may include:

memory for storing computer programs;

A processor, configured to execute a computer program to implement the steps of the bus voltage control method for an uninterruptible power supply system in any of the above embodiments.

It should also be noted that in this article, relational terms such as first and second etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or operations Any such actual relationship or order exists between. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

Professionals can further realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software or a combination of the two. In order to clearly illustrate the possible For interchangeability, in the above description, the composition and steps of each example have been generally described according to their functions. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present invention.

In this paper, specific examples are used to illustrate the principles and implementation methods of the present invention, and the descriptions of the above embodiments are only used to help understand the technical solutions and core ideas of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

A bus voltage control method for an uninterruptible power supply system, characterized in that it comprises:

Detect the main circuit input voltage;

determining a current bus voltage target value based on the main circuit input voltage;

Controlling the busbar voltage target value of each parallel uninterruptible power supply in the uninterruptible power supply system is the currently determined busbar voltage target value;

Wherein, the uninterruptible power supply system includes at least two parallel uninterruptible power supplies.
The bus voltage control method of an uninterruptible power supply system according to claim 1, further comprising:

judging whether at least one uninterruptible power supply is in a state of preparation for bypass switching;

If yes, detect the bypass input voltage;

Correspondingly, the determining the current bus voltage target value based on the main circuit input voltage includes:

Based on the main circuit input voltage and the bypass input voltage, a current bus voltage target value is determined.
The bus voltage control method of an uninterruptible power supply system according to claim 2, wherein said determining the current bus voltage target value based on said main circuit input voltage and said bypass input voltage comprises:

Determine a first bus voltage target value corresponding to the main circuit input voltage according to a preset first correspondence relationship;

determining a second bus voltage target value corresponding to the bypass input voltage according to a preset second corresponding relationship;

using the maximum value of the first bus voltage target value and the second bus voltage target value as the determined current bus voltage target value;

Wherein, in the first corresponding relationship, the main circuit input voltage is positively correlated with the first bus voltage target value, and in the second corresponding relationship, the bypass input voltage and the second bus The voltage target value is positively correlated.
The bus voltage control method of an uninterruptible power supply system according to claim 3, wherein the first correspondence includes:

When the input voltage of the main circuit is less than or equal to the preset first input threshold, the value of the corresponding first bus voltage target value is a preset first value;

When the main circuit input voltage is greater than the first input threshold, the value of the corresponding first bus voltage target value is a preset second value, and the second value is greater than the first value;

The second correspondence includes:

When the bypass input voltage is less than or equal to a preset second input threshold, the corresponding second bus voltage target value is the first value;

When the bypass input voltage is greater than the second input threshold, the corresponding second bus voltage target value is the second value.
The bus voltage control method of an uninterruptible power supply system according to any one of claims 1 to 4, wherein each uninterruptible power supply has its own rectification controller and an inverter communicatively connected with its own rectification controller controllers, and the inverter controllers of each uninterruptible power supply are connected to each other by communication;

Correspondingly, the detection of the input voltage of the main circuit includes:

The rectification controllers of each uninterruptible power supply receive the detected input voltage of the main circuit;

The determining the current bus voltage target value based on the main circuit input voltage includes:

Each rectifier controller determines the current bus voltage target value based on the input voltage of the main circuit and sends it to the inverter controller connected to itself through communication;

The busbar voltage target value of each parallel uninterruptible power supply in the control uninterruptible power supply system is the currently determined busbar voltage target value, including:

Any one of the inverter controllers sends the bus voltage target value sent by the rectification controller connected with itself to other inverter controllers, and receives the bus voltage target value sent by the other inverter controllers;

Any one of the inverter controllers takes the bus voltage target value sent by the rectifier controller connected to itself and the maximum value of the bus voltage target values sent by the other inverter controllers as the determined bus voltage target value , and feed back to the rectification controller connected with itself in communication, so that each rectification controller controls the bus voltage target value of the corresponding uninterruptible power supply to the bus voltage target value received by the rectification controller.
A bus voltage control system for an uninterruptible power supply system, characterized in that it includes:

The main circuit input voltage detection module is used to detect the main circuit input voltage;

A bus voltage target value determining module, configured to determine the current bus voltage target value based on the main circuit input voltage;

The bus voltage target value synchronization control module is used to control the bus voltage target value of each parallel uninterruptible power supply in the uninterruptible power supply system to be the currently determined bus voltage target value;

Wherein, the uninterruptible power supply system includes at least two parallel uninterruptible power supplies.
The bus voltage control system of an uninterruptible power supply system according to claim 6, further comprising:

A bypass switching preparation state judging module, used to judge whether at least one uninterruptible power supply is in a bypass switching preparation state;

If so, trigger the bypass input voltage detection module for detecting the bypass input voltage;

Correspondingly, the bus voltage target value determination module is specifically used for:

Based on the main circuit input voltage and the bypass input voltage, a current bus voltage target value is determined.
The bus voltage control system of an uninterruptible power supply system according to claim 7, wherein the bus voltage target value determination module is specifically used for:

Determine a first bus voltage target value corresponding to the main circuit input voltage according to a preset first correspondence relationship;

determining a second bus voltage target value corresponding to the bypass input voltage according to a preset second corresponding relationship;

using the maximum value of the first bus voltage target value and the second bus voltage target value as the determined current bus voltage target value;

Wherein, in the first corresponding relationship, the main circuit input voltage is positively correlated with the first bus voltage target value, and in the second corresponding relationship, the bypass input voltage and the second bus The voltage target value is positively correlated.
A busbar voltage control device for an uninterruptible power supply system, characterized in that it includes:

memory for storing computer programs;

The processor is used to execute the computer program to realize the steps of the bus voltage control method of the uninterruptible power supply system according to any one of claims 1 to 5.
A computer-readable storage medium, characterized in that a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the uninterruptible power supply according to any one of claims 1 to 5 is realized The steps of the bus voltage control method of the system.