Array type combination method and system of uninterruptible power supply module

Abstract

The invention discloses an array type combination method and system for uninterruptible power supply modules, and the method comprises the steps: S1, configuring an input DC bus, an output AC bus and a current sharing control bus which are used for the connection between the uninterruptible power supply modules; s2, verifying the load current of the online module by collecting the total load current, controlling the current output of the to-be-input module according to the verification result, and enabling the load current to be close to a current sharing value through closed-loop control; s3, acquiring bypass voltage frequency and inversion output voltage frequency, performing phase comparison judgment on the bypass voltage frequency and the inversion output voltage frequency, and controlling synchronous operation of the inverter according to a judgment result; and step S4, setting a backward flowing prevention diode, and carrying out backward flowing prevention loop self-inspection so as to prevent backward flowing of voltage or current. The problems that in the prior art, the whole machine configuration maintenance and operation maintenance cost is high, equipment is not compatible, expansion is not suitable, and the comprehensive input cost is high are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to an array combination method and system of uninterruptible power supply modules. Background Art

[0002] In the power system, the high-frequency uninterruptible power supply (UPS) of the substation is a key device that bears the important responsibility of providing stable and reliable power supply for the load that cannot be interrupted. With the rapid evolution of substations towards programming and digitalization, the role of high-frequency uninterruptible power supply in ensuring the stable operation of the power system has become increasingly prominent. It has put forward higher requirements on the reliability and stability of the operating status and the convenience of daily operation and maintenance.

[0003] However, there are many challenges in the process of technical transformation of substation systems. On the one hand, technical transformation work often does not allow long-term power outages, and involves a large number of equipment and a large workload; on the other hand, in actual applications, there is a mismatch in functional compatibility between temporary power supply equipment and online equipment, which undoubtedly increases the difficulty and complexity of technical transformation work.

[0004] Traditional high-frequency uninterruptible power supply solutions have many limitations. First, the equipment needs to be configured as a whole machine, resulting in high maintenance and operation costs; second, there is a lack of compatibility between different equipment and different configurations, making it difficult to achieve flexible expansion and upgrades; finally, the comprehensive investment cost is high, which brings a heavy burden to the construction and operation and maintenance of the power system. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an array combination method and system for uninterruptible power supply modules to achieve efficient and flexible combination of uninterruptible power supply modules and improve the economy and reliability of the system.

[0006] In order to solve the above technical problems, the present invention provides an array assembly method of uninterruptible power supply modules, comprising:

[0007] Step S1, configuring an input DC bus, an output AC bus, and a current sharing control bus for connecting between uninterruptible power supply modules;

[0008] Step S2, verifying the load current of the online module by collecting the total load current, and controlling the current output of the module to be put into use according to the verification result, and making the load current close to the current sharing value through closed-loop control;

[0009] Step S3, collecting the bypass voltage frequency and the inverter output voltage frequency, performing phase comparison and judgment on the two, and controlling the synchronous operation of the inverter according to the judgment result;

[0010] Step S4, setting an anti-backflow diode and performing a self-check on the anti-backflow circuit to prevent voltage or current backflow.

[0011] Preferably, the step S1 specifically includes:

[0012] The free combination between modules is realized through the input DC bus, output AC bus and current sharing control bus, where the input DC bus is used for DC power input, the output AC bus is used for AC power output, and the current sharing control bus is used to balance the load between modules;

[0013] In the module's internal control program, the relevant electrical parameters of the output AC bus to be incorporated into the module are collected and analyzed to provide a basis for the hot-swap permission logic judgment;

[0014] When a new module is connected, it is first soft-started by the input DC bus, and the hot plug permission logic is judged based on the relevant parameters. When the conditions are met, the new module is connected to the output AC bus.

[0015] Preferably, the hot-plug permission logic judgment specifically includes:

[0016] Prepare the input DC bus interface and output AC bus interface;

[0017] The controller collects the input status of the DC bus to obtain the start command and perform soft start;

[0018] Collect the voltage and frequency data of the output AC bus through the controller;

[0019] The controller performs a comprehensive logical judgment based on the collected input DC bus input status, output AC bus voltage and frequency data; if it is determined that the new module meets the integration conditions, the controller controls the corresponding output switch action to successfully integrate the new module into the output AC bus.

[0020] Preferably, the step S2 specifically includes:

[0021] Step S21, before the module is connected to the DC and before being incorporated into the output AC bus, the total load current is collected through the controller for synchronous control of the output current during the soft start process;

[0022] Step S22, after the soft start is completed, the controller verifies the load current of the online module again;

[0023] Step S23, during the verification process, the controller optimizes the control strategy according to the load characteristics, and the load current of the closed-loop control module approximates the calculated current value.

[0024] Preferably, the step S3 specifically includes:

[0025] Step S31, converting the bypass voltage AC quantity into a square wave signal and then collecting the frequency by the CPU to obtain basic bypass voltage frequency data;

[0026] Step S32, converting the inverter output voltage AC quantity into a square wave signal and then collecting the frequency by the CPU to obtain inverter output voltage frequency basic data;

[0027] Step S33, the CPU performs an “AND” process detection on the square wave after the bypass voltage and the inverter output voltage are converted to obtain the basic phase difference data;

[0028] Step S34, performing inverter synchronization control according to the phase difference basic data to make the phase comparison judgment result approach zero.

[0029] Preferably, the method further comprises: using an ultra-wide range power supply circuit unit for power supply, which specifically comprises:

[0030] Perform pre-stage rectification and filtering operations on the input power to convert AC power into DC power;

[0031] Adopt high-voltage DCDC chip with ultra-wide voltage input range to convert and regulate the voltage of DC power after front-stage rectification and filtering;

[0032] A non-isolated DCDC chip is used to convert the processed voltage from 5V to 3.3V.

[0033] The present invention also provides an array combination system of uninterruptible power supply modules, comprising:

[0034] A module connection unit, which is configured with an input DC bus, an output AC bus and a current sharing control bus for connecting between uninterruptible power supply modules;

[0035] The load balancing unit is used to verify the load current of the online module by collecting the total load current, and control the current output of the module to be put into use according to the verification result, and make the load current close to the average current value through closed-loop control;

[0036] The bypass voltage tracking unit is used to collect the bypass voltage frequency and the inverter output voltage frequency, compare and judge the phase between the two, and control the synchronous operation of the inverter according to the judgment result;

[0037] The anti-backflow protection unit is used to prevent the backflow of voltage or current through the anti-backflow diode and the anti-backflow circuit self-check.

[0038] Preferably, the module connection unit further includes:

[0039] A parameter evaluation module, used to collect and analyze the electrical parameters of the output AC busbar of the module to be incorporated;

[0040] The hot-swap logic judgment module is used to combine the electrical parameters and the system operation status information to judge whether the connection conditions are met when the new module is connected to the input DC bus for soft start, and control the output switch to connect the new module to the output AC bus when the conditions are met.

[0041] Preferably, the load balancing unit includes:

[0042] A total load current acquisition module is used to collect the total load current when the module is connected to the DC and is not fully integrated into the output AC bus;

[0043] A load current verification module is used to verify the load current of the online module after the soft start is completed;

[0044] The current control module is used to control the module load current to approach the average current value according to the load characteristics during the verification process.

[0045] Preferably, the bypass voltage tracking unit comprises:

[0046] The bypass voltage frequency acquisition module is used to convert the bypass voltage AC quantity into a square wave signal and then acquire the frequency;

[0047] The inverter output voltage frequency acquisition module is used to convert the inverter output voltage AC quantity into a square wave signal and then acquire the frequency;

[0048] A phase comparison module, used for performing phase comparison detection on the two square wave signals;

[0049] The inverter synchronization control module is used to control the inverter output voltage to be synchronized with the bypass voltage according to the phase comparison result.

[0050] Preferably, the anti-backflow circuit self-check is specifically to perform temperature, open circuit and breakdown state detection on the anti-backflow diode input and output circuits.

[0051] Preferably, the array combination system of the uninterruptible power supply modules also includes an ultra-wide range power supply unit for powering the internal chips of the system, and the ultra-wide range power supply unit includes a pre-stage rectifier and filter unit for performing AC-to-DC operations, an ultra-wide range power-specific chip, and a low-voltage power supply stabilization unit for converting 5V voltage to 3.3V voltage.

[0052] The implementation of the present invention has the following beneficial effects: the present invention realizes free and efficient combination of modules through array interface technology, thereby improving system efficiency and reliability; active load balancing technology ensures module load balance and enhances system stability; bypass voltage tracking technology ensures precise control of inverter and bypass switching, and ensures power supply continuity; DC voltage dual anti-reverse injection technology effectively prevents voltage and current reverse injection and protects system equipment. These technologies, combined with ultra-wide range power supply technology, not only solve the problems of high cost of whole machine configuration maintenance and operation and maintenance, incompatibility between equipment, unsuitability for expansion and high comprehensive investment cost in the prior art, but are also suitable for a variety of power applications, and can quickly configure arrays for free combination as required, significantly reducing operation and maintenance costs, improving system compatibility and scalability, and bringing efficient, stable, flexible and economical system solutions to uninterruptible power supply systems for power, with significant economic benefits and practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 The present invention is a flowchart of an array combination method of uninterruptible power supply modules according to an embodiment of the present invention.

[0055] Figure 2 It is a principle block diagram of an array interface constructed according to an embodiment of the present invention.

[0056] Figure 3 It is a schematic diagram of the hot-plug permission logic judgment process in an embodiment of the present invention.

[0057] Figure 4 It is a schematic diagram of the active load balancing process in an embodiment of the present invention.

[0058] Figure 5 It is a schematic diagram of the bypass voltage tracking process in an embodiment of the present invention. DETAILED DESCRIPTION

[0059] The following descriptions of the embodiments refer to the accompanying drawings to illustrate specific embodiments in which the present invention may be implemented.

[0060] Please refer to Figure 1 As shown, an embodiment of the present invention provides an array combination method of uninterruptible power supply modules, comprising:

[0061] Step S1, configuring an input DC bus, an output AC bus, and a current sharing control bus for connecting between uninterruptible power supply modules;

[0062] Step S2, verifying the load current of the online module by collecting the total load current, and controlling the current output of the module to be put into use according to the verification result, and making the load current close to the current sharing value through closed-loop control;

[0063] Step S3, collecting the bypass voltage frequency and the inverter output voltage frequency, performing phase comparison and judgment on the two, and controlling the synchronous operation of the inverter according to the judgment result;

[0064] Step S4, setting an anti-backflow diode and performing a self-check on the anti-backflow circuit to prevent voltage or current backflow.

[0065] It can be seen from the above steps that the embodiments of the present invention improve the performance, efficiency and reliability of the high-frequency uninterruptible power supply system, and provide a more stable, efficient and flexible solution for power supply: by configuring the input DC bus, the output AC bus and the current sharing control bus, the free combination and flexible expansion of the modules are realized, and the scalability and adaptability of the system are improved; the active load balancing technology ensures the load balance among the modules, avoids the situation where some modules are overloaded and some modules are idle, and improves the overall efficiency and reliability of the system; the bypass voltage tracking control technology realizes the synchronous tracking and control of the voltage, ensures the stability and consistency of the system voltage, and improves the power supply quality; at the same time, the setting of the dual anti-reverse injection measures of the DC voltage effectively prevents the reverse injection of voltage or current, and ensures the safety and reliability of the system.

[0066] Specifically, in the embodiment of the present invention, step S1 realizes an efficient and flexible module free combination system by constructing an array interface, so as to ensure that the maximum performance and reliability can be provided when the array system is integrated.

[0067] like Figure 2 As shown in the figure, the interconnection interface design between modules includes three key components: input DC bus, output AC bus and current sharing control bus. The input DC bus is mainly responsible for introducing external DC power into each module and is the channel for module power input; the output AC bus is used to output processed AC power to meet the power demand of external equipment; the role of the current sharing control bus is to coordinate the current distribution between each module to ensure that each module bears a relatively balanced load when working, thereby avoiding failure of a module due to overload or uneven load, and also improving the reliability and stability of the entire system. Through the collaborative work of these three buses, the free combination of modules without distinction between master and slave is realized, so that the system can flexibly configure the number and layout of modules according to actual needs, improving the adaptability and scalability of the system.

[0068] The key design parameter evaluation optimization control is designed into the module's internal control program, which realizes precise control of the module combination process by collecting and analyzing specific data. Specifically, the voltage and frequency data on the output AC bus of the module to be incorporated can reflect the electrical characteristics and operating status of the module to be incorporated. Through real-time monitoring and analysis of these data, it can be determined whether the module to be incorporated is compatible with the existing array system, and under what conditions the integration can achieve the best performance and stability, thereby providing a key basis for the subsequent hot-swap permission logic judgment.

[0069] Hot-swap permission logic judgment is one of the key links to achieve free combination of modules. When a new module needs to be incorporated into the array system, the module will first be put into the input DC bus for soft start. The soft start process can prevent the module from generating excessive impact current at the moment of connection, thereby protecting the module and the electrical components of the entire system from damage. At the same time as the soft start, the hot-swap permission logic judgment mechanism starts to work. It will comprehensively consider multiple factors, including the voltage and frequency data provided by the key design parameter evaluation optimization control, as well as the current load status and operating temperature of the system, to determine whether the module meets the conditions for incorporation. If the judgment result is that the conditions are met, the system will control the corresponding output switch action to successfully incorporate the new module into the output AC bus, making it officially part of the array system and starting to assume the task of power supply.

[0070] Please refer to Figure 3 As shown, the hot-plug permission logic judgment process specifically includes:

[0071] Step S11, interface preparation;

[0072] (1) Prepare the input DC bus interface: Ensure that the input DC bus interconnection interface between modules is ready to meet the DC input conditions of the array combination of high-frequency uninterruptible power supply modules.

[0073] (2) Prepare the output AC bus interface: Ensure that the output AC bus interconnection interface between modules is ready to meet the AC output conditions of the array combination of high-frequency uninterruptible power supply modules.

[0074] Step S12, data collection;

[0075] (1) Collecting the input DC bus status: The controller collects the input DC bus status to obtain the start command and soft start. That is, the controller first detects the status of the input DC bus. When a new module needs to be connected, this step is used to determine when to start soft starting the new module.

[0076] (2) Collecting output AC bus data: The controller collects the voltage and frequency data of the output AC bus to provide conditions for the hot plug permission logic judgment. While the new module is soft-starting, the controller collects the voltage and frequency data on the output AC bus to determine whether the new module can be safely integrated into the system.

[0077] Step S13, logical judgment;

[0078] The controller performs comprehensive logical judgment based on the collected information such as the input DC bus input status, output AC bus voltage and frequency data. If the judgment result shows that the new module meets the conditions for incorporation (such as voltage and frequency matching, system load permission, etc.), the controller will control the corresponding output switch action to successfully incorporate the new module into the output AC bus, making it part of the system and start working.

[0079] Through the above process, the embodiment of the present invention realizes the hot-swap operation during the array combination process of the uninterruptible power supply module, ensuring that the modules can be freely combined safely and reliably, improving the flexibility and maintainability of the system, significantly reducing the maintenance cost and downtime of the system, and improving the continuity and reliability of the power supply.

[0080] Step S2 involves the active load balancing process, please refer to Figure 4 As shown in the figure, the active load balancing process specifically includes:

[0081] Step S21, before the module is connected to the DC and before being connected to the output AC bus, the total load current is collected through the controller for synchronous control of the output current during the soft start process.

[0082] After the module is connected to the DC, it is operated before being connected to the output AC bus 112 to obtain the total load current of the current system.

[0083] The acquisition of the existing total load current is used for synchronous control of the output current during the soft start process. By understanding the current total load current of the system, the controller can better coordinate and control the output current during the module soft start, ensure the smooth progress of the soft start process, and avoid the impact on the system caused by the sudden change of current.

[0084] Step S22: After the soft start is completed, the controller verifies the load current of the online module again.

[0085] After the soft start is completed, the load current of the online module is verified. At this time, the module has completed the initial connection and startup process.

[0086] The module performs a load current re-verification process online to ensure that the active current sharing process of the module is completed. It should be noted that the total load current collected in step S21 is a basic data for soft start control. After the soft start is completed, the actual operating state of the module may change, and it is necessary to check the load current of the module again to ensure that the load current borne by each module meets expectations and prepare for subsequent precise load control. By re-verifying the load current of the module online, the load situation actually borne by each module can be more accurately understood, ensuring that the active current sharing process of the module is successfully completed.

[0087] Step S23, during the verification process, the controller optimizes the control strategy according to the load characteristics, and the load current of the closed-loop control module approximates the calculated current value.

[0088] By optimizing the control strategy according to the load characteristics, the controller continuously closes the loop to control the module's load current to approach the calculated current value. During the verification process, the controller will use the optimized control strategy according to the system's load characteristics to continuously adjust and control the module's load current so that it gradually approaches the calculated current value, thereby achieving balanced load sharing for all modules, ensuring that the entire array system is load balanced for each module during operation, and improving the stability and reliability of the system.

[0089] Through the active load balancing process, automatic adaptation and balanced distribution of loads of modules during access and operation are achieved.

[0090] Step S3 involves bypass voltage tracking, which is used to synchronously track and control the phase and frequency of the bypass input voltage and the output voltage of the high-frequency uninterruptible power supply module, and complete the optimal switching time control when switching between the inverter output and the bypass input output. It specifically includes:

[0091] Step S31, converting the bypass voltage AC quantity into a square wave signal and then collecting the frequency by the CPU to obtain bypass voltage frequency basic data.

[0092] The basic frequency data of the bypass voltage is obtained, which will be used for subsequent phase comparison and synchronous control.

[0093] Step S32, converting the inverter output voltage AC quantity into a square wave signal and then collecting the frequency by the CPU to obtain inverter output voltage frequency basic data.

[0094] The frequency basic data of the inverter output voltage is obtained for comparison with the bypass voltage frequency and subsequent processing.

[0095] Step S33, the CPU performs an “AND” process detection on the square wave after the bypass voltage and the inverter output voltage are converted to obtain the basic phase difference data;

[0096] Step S34, performing inverter synchronization control according to the phase difference basic data to make the phase comparison judgment result approach zero.

[0097] According to the phase difference basic data result obtained by the phase comparison judgment in step S33, an inverter synchronization control command is output to control the result of the phase comparison judgment to approach 0, thereby realizing synchronous tracking and control of the phase and frequency of the bypass input voltage and the output voltage of the high-frequency uninterruptible power supply module, ensuring that the optimal switching time control can be achieved when switching between the two modes of inverter output and bypass input output, thereby ensuring the continuity and stability of the power supply.

[0098] Step S4 involves a dual DC voltage anti-reverse injection mechanism. The dual DC voltage anti-reverse injection mechanism is mainly used in the DC bus side loop control, aiming to solve two reverse injection problems: one is to prevent the voltage of the internal rectifier unit from being reversed to the external battery, and the other is to prevent the external DC system charging device from reversely injecting current into the local rectifier unit output loop. Through these two aspects of protection design, the safe and stable operation of the DC bus side loop is ensured.

[0099] The anti-backflow diode used in the embodiment of the present invention adopts a high-voltage and high-current common cathode double-tube structure. This structure of the diode can withstand higher voltage and larger current, and is suitable for the environment where high voltage and large current may exist on the DC bus side.

[0100] In the DC bus side circuit, when there is a situation that may cause voltage or current backflow, the anti-backflow diode can play a unidirectional conduction role. It only allows current to flow in the normal direction and prevents the flow of reverse current. For example, when the internal rectifier unit has a voltage that may be backflowed to the external battery, the diode will prevent the transmission of this reverse voltage and protect the external battery from the impact of reverse voltage; similarly, when the external DC system charging equipment may generate reverse current to the local rectifier unit output circuit, the diode can also play a blocking role.

[0101] The DC voltage dual anti-reverse injection mechanism also includes an anti-reverse injection circuit self-test process. This self-test process is the process of testing and verifying the high-voltage and high-current common cathode dual-tube input and output circuit. The test content includes:

[0102] (1) Temperature detection: Detect the temperature of the anti-backflow diode during operation. When the anti-backflow diode is working, if the current is too large or there is an abnormal situation, the temperature may rise. Through temperature detection, it is possible to find out whether the anti-backflow diode is in an abnormal working state in time. For example, if the temperature of the anti-backflow diode exceeds the normal range, it may indicate that there is an overload or short circuit in the circuit.

[0103] (2) Open circuit detection: Check whether the anti-backflow diode has an open circuit fault. If the anti-backflow diode is open, it will not be able to prevent backflow, which may cause voltage or current backflow. Through open circuit detection, it can be ensured that the anti-backflow diode is in a normal conduction state, ensuring the normal implementation of the anti-backflow function.

[0104] (3) Breakdown detection: Check whether the anti-backflow diode is broken down. When the anti-backflow diode is broken down, it will lose its unidirectional conduction characteristics and cannot prevent reverse current or voltage, thus making the anti-backflow protection invalid. Through breakdown detection, the fault of the anti-backflow diode can be discovered in time, and appropriate measures can be taken to repair or replace it.

[0105] Through the synergistic effect of the anti-backflow diode and the anti-backflow circuit self-test process, the DC voltage dual anti-backflow mechanism of the embodiment of the present invention can effectively protect the equipment in the DC bus side loop, prevent damage caused by voltage or current backflow, and ensure the stable and reliable operation of the entire DC system.

[0106] The embodiment of the present invention provides a stable power supply for all internal chips through an ultra-wide range power supply circuit unit to ensure that the chips can work normally. The circuit unit is suitable for industrial products and other fields, and has the advantages of a small number of peripheral components and easy implementation of a low-power power supply solution. The specific composition and principle of the ultra-wide range power supply circuit unit are described as follows:

[0107] (1) Pre-stage rectification and filtering

[0108] The pre-stage rectifier and filter is located in the front stage of the power supply. Its main function is to convert the input AC power into DC power. In actual operation, the rectifier diode is usually used to flip the negative half cycle of the AC power to the positive half cycle to achieve rectification. After that, the rectified voltage is smoothed by filter elements such as capacitors and inductors to filter out the ripple components and obtain a more stable DC voltage.

[0109] (2) Ultra-wide range of power-specific chips

[0110] The chip adopts high-voltage DCDC chip design. It can work normally in the ultra-wide voltage input range of 12-380VAC, can adapt to a variety of different input voltage conditions, and has strong versatility.

[0111] The chip is integrated with comprehensive protection functions, including short circuit protection, overload protection, output overvoltage protection, output undervoltage protection and overheat protection. These protection functions can ensure that the chip will not be damaged under various abnormal conditions. For example, when a short circuit occurs at the output end, the short circuit protection function will start quickly to limit the current inside the chip to prevent the chip from burning due to excessive current; when the load is too heavy and causes overload, the overload protection function will work to prevent the chip from being damaged due to long-term overload operation.

[0112] The chip can also provide a power supply capability of up to 500mA continuous output current, and has no audio noise and low heat during operation. It can provide stable current while reducing electromagnetic interference to the surrounding environment and its own heat generation.

[0113] Through the ultra-wide range power-specific chip, the DC voltage after the front-stage rectification and filtering can be converted and adjusted to provide a suitable input voltage for the subsequent low-voltage power supply stabilization circuit, ensuring that the entire power supply system can work stably within the ultra-wide voltage input range.

[0114] (3) Low voltage power supply stabilizing circuit

[0115] The low-voltage power supply voltage regulator circuit uses a non-isolated DCDC chip to achieve voltage conversion from 5V to 3.3V. The non-isolated DCDC chip steps down the input 5V voltage through the internal switching circuit and control logic to obtain a stable 3.3V output voltage.

[0116] The ultra-wide range power supply circuit unit realizes the whole process from AC input to providing stable low-voltage DC power supply for the internal chip of the product through the coordinated work of three parts: the front-stage rectification and filtering, the ultra-wide range power-specific chip and the low-voltage power supply stabilization circuit. It has the advantages of adapting to a wide voltage range, complete protection functions, and stable performance, and is suitable for industrial products and other fields.

[0117] Corresponding to the array assembly method of the uninterruptible power supply modules described in the first embodiment of the present invention, the second embodiment of the present invention further provides an array assembly system of uninterruptible power supply modules, including:

[0118] A module connection unit, which is configured with an input DC bus, an output AC bus and a current sharing control bus for connecting between uninterruptible power supply modules;

[0119] The load balancing unit is used to verify the load current of the online module by collecting the total load current, and control the current output of the module to be put into use according to the verification result, and make the load current close to the average current value through closed-loop control;

[0120] The bypass voltage tracking unit is used to collect the bypass voltage frequency and the inverter output voltage frequency, compare and judge the phase between the two, and control the synchronous operation of the inverter according to the judgment result;

[0121] The anti-backflow protection unit is used to prevent the backflow of voltage or current through the anti-backflow diode and the anti-backflow circuit self-check.

[0122] Preferably, the module connection unit further includes:

[0123] A parameter evaluation module, used to collect and analyze the electrical parameters of the output AC busbar of the module to be incorporated;

[0124] The hot-swap logic judgment module is used to combine the electrical parameters and the system operation status information to judge whether the connection conditions are met when the new module is connected to the input DC bus for soft start, and control the output switch to connect the new module to the output AC bus when the conditions are met.

[0125] Preferably, the load balancing unit includes:

[0126] A total load current acquisition module is used to collect the total load current when the module is connected to the DC and is not fully integrated into the output AC bus;

[0127] A load current verification module is used to verify the load current of the online module after the soft start is completed;

[0128] The current control module is used to control the module load current to approach the average current value according to the load characteristics during the verification process.

[0129] Preferably, the bypass voltage tracking unit comprises:

[0130] The bypass voltage frequency acquisition module is used to convert the bypass voltage AC quantity into a square wave signal and then acquire the frequency;

[0131] The inverter output voltage frequency acquisition module is used to convert the inverter output voltage AC quantity into a square wave signal and then acquire the frequency;

[0132] A phase comparison module, used for performing phase comparison detection on the two square wave signals;

[0133] The inverter synchronization control module is used to control the inverter output voltage to be synchronized with the bypass voltage according to the phase comparison result.

[0134] Preferably, the anti-backflow circuit self-check is specifically to perform temperature, open circuit and breakdown state detection on the anti-backflow diode input and output circuits.

[0135] Preferably, the array combination system of the uninterruptible power supply modules also includes an ultra-wide range power supply unit for powering the internal chips of the system, and the ultra-wide range power supply unit includes a pre-stage rectifier and filter unit for performing AC-to-DC operations, an ultra-wide range power-specific chip, and a low-voltage power supply stabilization unit for converting 5V voltage to 3.3V voltage.

[0136] For the working principle and process of this embodiment, please refer to the description of the aforementioned embodiment 1 of the present invention, which will not be repeated here.

[0137] Compared with the prior art, the beneficial effects brought by the embodiments of the present invention are that the present invention realizes the free and efficient combination of modules through array interface technology, thereby improving the system efficiency and reliability; the active load balancing technology ensures the load balance of the modules and enhances the system stability; the bypass voltage tracking technology ensures the precise control of the inverter and bypass switching, and ensures the continuity of power supply; the DC voltage dual anti-reverse injection technology effectively prevents voltage and current reverse injection and protects the system equipment. These technologies, combined with the ultra-wide range power supply technology, not only solve the problems of high cost of whole machine configuration maintenance and operation and maintenance, incompatibility between equipment, unsuitability for expansion and high comprehensive investment cost in the prior art, but also are suitable for a variety of power application occasions, can quickly configure the array for free combination according to demand, significantly reduce the operation and maintenance cost, improve the system compatibility and scalability, and bring efficient, stable, flexible and economical system solutions to the uninterruptible power supply system for power, with significant economic benefits and practical value.

[0138] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for combining uninterruptible power supply modules in an array, characterized in that: include: Step S1, configuring an input DC bus, an output AC bus, and a current sharing control bus for connecting between uninterruptible power supply modules; Step S2, verifying the load current of the online module by collecting the total load current, and controlling the current output of the module to be put into use according to the verification result, and making the load current close to the current sharing value through closed-loop control; Step S3, collecting the bypass voltage frequency and the inverter output voltage frequency, performing phase comparison and judgment on the two, and controlling the synchronous operation of the inverter according to the judgment result; Step S4, setting an anti-backflow diode and performing a self-check on the anti-backflow circuit to prevent voltage or current backflow.

2. The method according to claim 1, characterized in that The step S1 specifically includes: The free combination between modules is realized through the input DC bus, output AC bus and current sharing control bus, where the input DC bus is used for DC power input, the output AC bus is used for AC power output, and the current sharing control bus is used to balance the load between modules; In the module's internal control program, the relevant electrical parameters of the output AC bus to be incorporated into the module are collected and analyzed to provide a basis for the hot-swap permission logic judgment; When a new module is connected, it is first soft-started by the input DC bus, and the hot plug permission logic is judged based on the relevant parameters. When the conditions are met, the new module is connected to the output AC bus.

3. The method according to claim 2, characterized in that The hot-plug permission logic judgment specifically includes: Prepare the input DC bus interface and output AC bus interface; The controller collects the input status of the DC bus to obtain the start command and perform soft start; Collect the voltage and frequency data of the output AC bus through the controller; The controller performs a comprehensive logical judgment based on the collected input DC bus input status, output AC bus voltage and frequency data; if it is determined that the new module meets the integration conditions, the controller controls the corresponding output switch action to successfully integrate the new module into the output AC bus.

4. The method according to claim 1, characterized in that: The step S2 specifically includes: Step S21, before the module is connected to the DC and before being incorporated into the output AC bus, the total load current is collected through the controller for synchronous control of the output current during the soft start process; Step S22, after the soft start is completed, the controller verifies the load current of the online module again; Step S23, during the verification process, the controller optimizes the control strategy according to the load characteristics, and the load current of the closed-loop control module approximates the calculated current value.

5. The method according to claim 1, characterized in that The step S3 specifically includes: Step S31, converting the bypass voltage AC quantity into a square wave signal and then collecting the frequency by the CPU to obtain basic bypass voltage frequency data; Step S32, converting the inverter output voltage AC quantity into a square wave signal and then collecting the frequency by the CPU to obtain inverter output voltage frequency basic data; Step S33, the CPU performs an AND process detection on the square wave after the bypass voltage and the inverter output voltage are converted to obtain the basic phase difference data; Step S34, performing inverter synchronization control according to the phase difference basic data to make the phase comparison judgment result approach zero.

6. The method according to claim 1, characterized in that Also includes: An ultra-wide range power supply circuit unit is used for power supply, which specifically includes: Perform pre-stage rectification and filtering operations on the input power to convert AC power into DC power; Adopt high-voltage DCDC chip with ultra-wide voltage input range to convert and regulate the voltage of DC power after front-stage rectification and filtering; A non-isolated DCDC chip is used to convert the processed voltage from 5V to 3.3V.

7. An array combination system of uninterruptible power supply modules, characterized in that: include: A module connection unit, which is configured with an input DC bus, an output AC bus and a current sharing control bus for connecting between uninterruptible power supply modules; The load balancing unit is used to verify the load current of the online module by collecting the total load current, and control the current output of the module to be put into use according to the verification result, and make the load current close to the average current value through closed-loop control; The bypass voltage tracking unit is used to collect the bypass voltage frequency and the inverter output voltage frequency, compare and judge the phase between the two, and control the synchronous operation of the inverter according to the judgment result; The anti-backflow protection unit is used to prevent the backflow of voltage or current through the anti-backflow diode and the anti-backflow circuit self-check.

8. The system according to claim 7, characterized in that The module connection unit also includes: A parameter evaluation module, used to collect and analyze the electrical parameters of the output AC busbar of the module to be incorporated; The hot-swap logic judgment module is used to combine the electrical parameters and the system operation status information to judge whether the connection conditions are met when the new module is connected to the input DC bus for soft start, and control the output switch to connect the new module to the output AC bus when the conditions are met.

9. The system according to claim 7, characterized in that The load balancing unit comprises: A total load current acquisition module is used to collect the total load current when the module is connected to the DC and is not fully integrated into the output AC bus; A load current verification module is used to verify the load current of the online module after the soft start is completed; The current control module is used to control the module load current to approach the average current value according to the load characteristics during the verification process.

10. The system according to claim 7, characterized in that The bypass voltage tracking unit comprises: The bypass voltage frequency acquisition module is used to convert the bypass voltage AC quantity into a square wave signal and then acquire the frequency; The inverter output voltage frequency acquisition module is used to convert the inverter output voltage AC quantity into a square wave signal and then acquire the frequency; A phase comparison module, used for performing phase comparison detection on the two square wave signals; The inverter synchronization control module is used to control the inverter output voltage to be synchronized with the bypass voltage according to the phase comparison result.

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