A method and system for parallel operation of UPS modules

Abstract

The present application relates to a kind of UPS module parallel operation method, comprising: when the UPS system of multiple UPS modules is parallelly constructed, based on system load rate, a certain number of the UPS module is put to sleep to maintain the UPS system at a certain efficiency level operation;Control the UPS module that is not put to sleep in the UPS system enters main road inverter power supply or main road bypass common mode to carry out reactive power and harmonic compensation;When load suddenly increases and causes the system load rate to drop by a certain value, wake up the UPS module that is put to sleep.The present application also relates to a kind of UPS module parallel operation method.The present application can intelligently put to sleep or wake up UPS module according to system load rate in dynamic online mode, and ensure that output voltage meets Class1 curve, so it can improve the overall operation efficiency of system, also has high reliability, can keep UPS system in the highest efficiency point around operation at any time.

Description

Technical Field

[0001] This invention relates to the field of UPS, and more specifically, to a method and system for parallel operation of UPS modules. Background Technology

[0002] Current UPS systems can comprise one or more racks. Each rack can contain multiple UPS modules. During UPS system operation, the goal is to achieve the highest possible system efficiency while ensuring high reliability. However, various known operating modes in existing technologies have different drawbacks. For example, while ECO energy-saving mode improves the UPS system's operating efficiency, the power factor of the bypass current is not guaranteed, and the addition of different loads may pollute the power grid. Another example is intelligent parallel sleep mode, which, while improving system efficiency, reduces reliability. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method and system for parallel operation of UPS modules that can improve the overall operating efficiency of the system and has high reliability, in order to address the above-mentioned deficiencies of the prior art.

[0004] The technical solution adopted by this invention to solve its technical problem is: constructing a method for parallel operation of UPS modules, including:

[0005] S1. In a UPS system constructed by multiple UPS modules in parallel, the number of UPS modules to be put into sleep mode is set based on the system load rate to maintain the UPS system at a set efficiency level; the UPS modules that are not in sleep mode are controlled to enter the main circuit inverter power supply mode or the main circuit bypass common mode to perform reactive power and harmonic compensation.

[0006] S2. When a sudden increase in load causes the system load rate to drop by a set value, wake up the dormant UPS module.

[0007] In the UPS module parallel operation method of the present invention, step S1 further includes:

[0008] S11. The UPS system is constructed by connecting multiple UPS modules in parallel, and the UPS modules are operated in the main circuit inverter power supply mode.

[0009] S12. Determine whether the UPS module needs to go into hibernation based on the system load rate. If yes, proceed to step S13; otherwise, keep the UPS module in the main inverter power supply mode.

[0010] S13. A set number of UPS modules are put into hibernation mode to maintain the UPS system at a first efficiency level or a second efficiency level.

[0011] S14. Control the non-dormant UPS module to enter the main-bypass common mode for reactive power and harmonic compensation.

[0012] S15. Based on the relationship between bypass current and bypass voltage, maintain the non-dormant UPS module in dynamic online mode or return it to main circuit inverter power supply mode.

[0013] In the UPS module parallel operation method of the present invention, step S13 further includes:

[0014] S131. Put the first set number of UPS modules into hibernation according to a preset order and obtain the current efficiency level;

[0015] S132. Calculate the estimated efficiency level after the second set number of UPS modules are put into hibernation according to the preset order;

[0016] S133. Determine whether the current efficiency level is greater than the estimated efficiency level. If yes, return to step S131; otherwise, maintain the current operating state.

[0017] In the UPS module parallel operation method of the present invention, the first set number of UPS modules includes one UPS module or all UPS modules contained in a tower crane frame.

[0018] In the UPS module parallel operation method described in this invention, when the system load percentage is less than 20%, the efficiency level of the UPS system is the eighth efficiency level; when 20% ≤ system load percentage < 30%, the efficiency level of the UPS system is the seventh efficiency level; when 30% ≤ system load percentage < 40%, the efficiency level of the UPS system is the fourth efficiency level; when 40% ≤ system load percentage < 50%, the efficiency level of the UPS system is the first efficiency level; when 50% ≤ system load percentage < 60%, the efficiency level of the UPS system is the second efficiency level; when 60% ≤ system load percentage < 70%, the efficiency level of the UPS system is the third efficiency level; when 70% ≤ system load percentage < 80%, the efficiency level of the UPS system is the fifth efficiency level; when 80% ≤ system load percentage < 90%, the efficiency level of the UPS system is the sixth efficiency level; and when 90% ≤ system load percentage, the efficiency level of the UPS system is the ninth efficiency level.

[0019] In the UPS module parallel operation method of the present invention, step S14 further includes:

[0020] S14a. Control the non-dormant UPS module to enter the main-bypass common mode and simultaneously perform bypass current sharing and harmonic compensation.

[0021] In the UPS module parallel operation method of the present invention, step S14 further includes:

[0022] S141. Control the non-dormant UPS module to enter the main-bypass common mode, control the main power unit of the UPS module to invert and compensate reactive power and harmonics and make the bypass current sinusoidal, and force the bypass current to lead the bypass voltage, and continue to run for a first set time.

[0023] S142. The bypass power transistor of the UPS module is driven by the bypass power equalization to equalize the bypass current of the UPS module, and the operation continues for a second set time.

[0024] In the UPS module parallel operation method of the present invention, step S15 further includes maintaining the non-dormant UPS module in dynamic online mode or returning it to the main circuit inverter power supply mode when the bypass current of the UPS module leads the bypass voltage by a set angle and the input power factor is greater than the set value.

[0025] In the UPS module parallel operation method of the present invention, step S2 further includes:

[0026] S21. When a sudden increase in load causes the system load rate to drop by at least two efficiency levels, wake up the dormant UPS module and control all UPS modules to enter the main inverter power supply mode and repeatedly execute step S1; or

[0027] S2a. When a sudden increase in load causes the system load rate to drop by at least two efficiency levels, wake up the dormant UPS module and control the woken UPS module to directly enter the dynamic online mode.

[0028] Another technical solution adopted by the present invention to solve its technical problem is to construct a UPS module parallel operation system, including multiple UPS modules and a processor, wherein the processor stores a computer program, and when the computer program is executed by the processor, it implements the UPS module parallel operation method.

[0029] Another technical solution adopted by the present invention to solve its technical problem is to construct a UPS module parallel operation system, including multiple UPS modules, and further including:

[0030] The hibernation module is used to put a set number of UPS modules into hibernation based on the system load rate in a UPS system with multiple UPS modules connected in parallel, so as to maintain the UPS system at a set efficiency level; and to control the UPS modules that are not in hibernation to enter the main circuit inverter power supply mode or the main circuit bypass common mode for reactive power and harmonic compensation.

[0031] The wake-up module is used to wake up the dormant UPS module when the load suddenly increases, causing the system load rate to drop by a set value.

[0032] In the UPS module parallel operation system described in this invention, the hibernation module further includes:

[0033] The first mode control unit is used to construct the UPS system using multiple UPS modules connected in parallel, and to enable the UPS modules to operate in the main circuit inverter power supply mode.

[0034] The hibernation unit is used to determine whether the UPS module needs to be hibernated based on the system load rate. If so, a set number of UPS modules are hibernated to keep the UPS system running at the first efficiency level or the second efficiency level. Otherwise, the UPS module is kept in the main circuit inverter power supply mode.

[0035] The second mode control unit is used to control the non-dormant UPS module to enter the main-bypass common mode for reactive power and harmonic compensation.

[0036] The third mode control unit is used to maintain the non-dormant UPS module in dynamic online mode or return it to main inverter power supply mode based on the relationship between bypass current and bypass voltage.

[0037] In the UPS module parallel operation system of the present invention, the hibernation unit is further used to hibernate a first set number of UPS modules in a preset order and obtain the current efficiency level; calculate the estimated efficiency level after hibernating a second set number of UPS modules in the preset order; and determine whether the current efficiency level is greater than the estimated efficiency level. If so, the aforementioned steps are repeated; otherwise, the current operating state is maintained.

[0038] In the UPS module parallel operation system described in this invention, the first predetermined number of UPS modules includes one UPS module or all UPS modules contained in a tower crane frame.

[0039] In the UPS module parallel operation system described in this invention, when the system load percentage is less than 20%, the efficiency level of the UPS system is the eighth efficiency level; when 20% ≤ system load percentage < 30%, the efficiency level of the UPS system is the seventh efficiency level; when 30% ≤ system load percentage < 40%, the efficiency level of the UPS system is the fourth efficiency level; when 40% ≤ system load percentage < 50%, the efficiency level of the UPS system is the first efficiency level; when 50% ≤ system load percentage < 60%, the efficiency level of the UPS system is the second efficiency level; when 60% ≤ system load percentage < 70%, the efficiency level of the UPS system is the third efficiency level; when 70% ≤ system load percentage < 80%, the efficiency level of the UPS system is the fifth efficiency level; when 80% ≤ system load percentage < 90%, the efficiency level of the UPS system is the sixth efficiency level; and when 90% ≤ system load percentage, the efficiency level of the UPS system is the ninth efficiency level.

[0040] In the UPS module parallel operation system described in this invention, the second mode control unit further includes a first compensation subunit, used to control the non-dormant UPS module to enter the main-bypass common mode and simultaneously perform bypass current sharing and harmonic compensation.

[0041] In the UPS module parallel operation system described in this invention, the second mode control unit further includes:

[0042] The second compensation subunit is used to control the non-dormant UPS module to enter the main-bypass common mode, control the main power unit of the UPS module to invert and compensate reactive power and harmonics and make the bypass current sinusoidal, and force the bypass current to lead the bypass voltage, and continue to run for a first set time.

[0043] The current sharing subunit is used to adjust the bypass power transistor drive of the UPS module to share the bypass current of the UPS module through bypass power equalization, and to run continuously for a second set time.

[0044] In the UPS module parallel operation system described in this invention, the third mode control unit is further configured to maintain the non-dormant UPS module in dynamic online mode or return it to the main circuit inverter power supply mode when the bypass current of the UPS module leads the bypass voltage by a set angle and the input power factor is greater than a set value.

[0045] In the UPS module parallel operation system described in this invention, the wake-up module further includes:

[0046] The first wake-up unit is used to wake up the dormant UPS module when a sudden increase in load causes the system load rate to drop by at least two efficiency levels, and to control all UPS modules to enter the main inverter power supply mode and cycle through the dormant modules; or

[0047] The second wake-up unit is used to wake up the dormant UPS module when the load suddenly increases, causing the system load rate to drop by at least two efficiency levels, and to control the woken UPS module to directly enter the dynamic online mode.

[0048] The UPS module parallel operation method and system of this invention can intelligently put the UPS modules into hibernation or wake them up according to the system load rate. Therefore, it can improve the overall system operating efficiency and has high reliability, keeping the UPS system operating near its peak efficiency at all times. Furthermore, reactive power and harmonic compensation can be performed on the bypass current to improve the input power factor and reduce harmonic pollution to the power grid. In the event of abnormal input voltage or short circuit, the UPS system can quickly exit the main-bypass common mode and enter the main inverter power supply, with the output voltage meeting the Class 1 curve. Even further, the transient transition of the UPS module from the main inverter power supply mode to the main-bypass common mode is controlled in two stages, reducing the mutual coupling effect of bypass current sharing and dynamic online compensation, resulting in a higher power factor for the bypass input circuit. Attached Figure Description

[0049] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0050] Figure 1 This is a flowchart of a first preferred embodiment of the UPS module parallel operation method of the present invention;

[0051] Figure 2 This is a flowchart of a second preferred embodiment of the UPS module parallel operation method of the present invention;

[0052] Figure 3 yes Figure 2 The diagram shows the principle of parallel operation of UPS modules.

[0053] Figure 4 This is a schematic block diagram of the first preferred embodiment of the UPS module parallel operation system of the present invention;

[0054] Figure 5 This is a schematic diagram of the second preferred embodiment of the UPS module parallel operation system of the present invention. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0056] This invention relates to a method for parallel operation of UPS modules, comprising: in a UPS system constructed by multiple UPS modules connected in parallel, putting a predetermined number of UPS modules into sleep mode based on the system load rate to maintain the UPS system at a predetermined efficiency level; controlling the UPS modules not in sleep mode to enter either the main circuit inverter power supply mode or the main circuit bypass common mode for reactive power and harmonic compensation; and waking up the sleep-bound UPS modules when a sudden increase in load causes the system load rate to drop by a predetermined value. This invention can intelligently put UPS modules into sleep mode or wake them up based on the system load rate, thus improving the overall system operating efficiency and providing high reliability, ensuring the UPS system always operates near its peak efficiency.

[0057] Figure 1 This is a flowchart of a first preferred embodiment of the parallel operation method for UPS modules of the present invention. Figure 1 As shown, in step S1, when a UPS system is constructed by connecting multiple UPS modules in parallel, a set number of the UPS modules are put into sleep mode based on the system load rate to maintain the UPS system at a set efficiency level; the UPS modules that are not in sleep mode are controlled to enter the main circuit inverter power supply or the main circuit bypass common mode to perform reactive power and harmonic compensation.

[0058] After constructing a UPS system using multiple racks in parallel or multiple UPS modules in parallel, it enters the main inverter power supply mode to supply power to the load. At this time, due to the light load, a set number of UPS modules can be put into sleep mode based on the system load rate to maintain the UPS system at a set efficiency level.

[0059] In a preferred embodiment of the present invention, the UPS system may include multiple racks connected in parallel, each rack including multiple UPS modules, and all UPS modules in each rack simultaneously enter sleep mode. In another preferred embodiment of the present invention, the UPS system may include multiple UPS modules connected in parallel, each UPS module entering sleep mode individually.

[0060] In a preferred embodiment of the invention, the load can be divided into multiple levels from 0% to 100% according to the system load rate, for example, into 9 levels. To maintain the UPS system at a set efficiency level, such as a first efficiency level or a second efficiency level, a set number of UPS modules can be put into hibernation, for example, all UPS modules in one or several racks, or one or several UPS modules. This maintains the overall system efficiency of the UPS system at its highest point. The UPS modules that are not in hibernation are controlled to enter the main circuit inverter power supply mode or the main circuit bypass common mode (i.e., VI mode), where the bypass outputs active power, performs reactive power and harmonic compensation, and charges the batteries in the UPS modules, making the power factor of the bypass input current close to 1.

[0061] In step S2, when a sudden increase in load causes the system load rate to drop below a set value, the dormant UPS module is awakened. The dormant UPS module can be awakened in a very short time, such as within 3ms, to quickly join the inverter power supply, ensuring high reliability of the power supply. Furthermore, even if the input voltage is abnormal or there is a short circuit, it can quickly exit the current mode and enter the main inverter power supply mode.

[0062] In a preferred embodiment of the present invention, when the load suddenly increases, for example, when the load suddenly increases and causes the system load rate to drop by at least two efficiency levels, the dormant UPS module is awakened, and the awakened UPS module is controlled to directly enter the dynamic online mode. In a preferred embodiment of the present invention, the dynamic online mode refers to the mode in which the UPS system output voltage meets a specific type of curve, such as a class 1 curve.

[0063] Because waking up a UPS module directly enters the dynamic online mode, it involves a dynamic process of bypass current sharing and harmonic extraction compensation, resulting in some instability in the overall stability of the UPS system. Therefore, in a further preferred embodiment of the invention, when a sudden increase in load causes the system load rate to drop by at least two efficiency levels, the dormant UPS module is woken up, and all UPS modules are controlled to enter the main inverter power supply mode and repeatedly execute step S1. In this way, all UPS modules exit their current operating mode and then enter the main inverter power supply mode together, subsequently repeating step S1 again, which further improves the reliability of the entire UPS system.

[0064] This invention can intelligently put the UPS module into hibernation or wake it up according to the system load rate, thus improving the overall operating efficiency of the system and ensuring high reliability, keeping the UPS system running near its highest efficiency point at all times.

[0065] Figure 2This is a flowchart of a second preferred embodiment of the UPS module parallel operation method of the present invention. Figure 3 yes Figure 2 The diagram illustrates the principle of parallel operation of UPS modules. Figure 2-3 As shown, in step S1, the UPS system is constructed by connecting multiple UPS modules in parallel, and the UPS modules are operated in the main circuit inverter power supply mode.

[0066] After constructing a UPS system using multiple racks in parallel or multiple UPS modules in parallel, it enters the main inverter power supply mode to supply power to the load. At this time, due to the light load, a set number of UPS modules can be put into sleep mode based on the system load rate to maintain the UPS system at a set efficiency level.

[0067] In a preferred embodiment of the present invention, the UPS system may include multiple racks connected in parallel, each rack including multiple UPS modules, and all UPS modules in each rack simultaneously enter sleep mode. In another preferred embodiment of the present invention, the UPS system may include multiple UPS modules connected in parallel, each UPS module entering sleep mode individually.

[0068] In step S2, it is determined whether the UPS module needs to go into hibernation based on the system load rate. If yes, step S3 is executed; otherwise, step S6 is executed to keep the UPS module in the main inverter power supply mode.

[0069] In a preferred embodiment of the present invention, the load from 0% to 100% can be divided into multiple levels, for example, nine levels, based on the system load rate. When the system load percentage is less than 20%, the efficiency level of the UPS system is the eighth efficiency level; when 20% ≤ system load percentage < 30%, the efficiency level of the UPS system is the seventh efficiency level; when 30% ≤ system load percentage < 40%, the efficiency level of the UPS system is the fourth efficiency level; when 40% ≤ system load percentage < 50%, the efficiency level of the UPS system is the first efficiency level; when 50% ≤ system load percentage < 60%, the efficiency level of the UPS system is the second efficiency level; when 60% ≤ system load percentage < 70%, the efficiency level of the UPS system is the third efficiency level; when 70% ≤ system load percentage < 80%, the efficiency level of the UPS system is the fifth efficiency level; when 80% ≤ system load percentage < 90%, the efficiency level of the UPS system is the sixth efficiency level; and when 90% ≤ system load percentage, the efficiency level of the UPS system is the ninth efficiency level. A lower efficiency level indicates higher UPS system efficiency. Therefore, to maintain system efficiency, the UPS system's efficiency level needs to be kept at a lower level. For example, if the UPS system's efficiency level is determined to be higher than the second efficiency level (i.e., the third efficiency level or above) based on the system load rate, the UPS module will be put into hibernation mode.

[0070] In step S3, a set number of UPS modules are put into hibernation to maintain the UPS system at either a first efficiency level or a second efficiency level.

[0071] In a preferred embodiment of the present invention, when the UPS system includes multiple racks connected in parallel, and each rack includes multiple UPS modules, it is possible to select all UPS modules in each rack to enter hibernation simultaneously, or to select one UPS module to enter hibernation. In another preferred embodiment of the present invention, when the UPS system includes multiple UPS modules connected in parallel, one UPS module can be selected for hibernation at a time.

[0072] In a further preferred embodiment of the present invention, firstly, a first set number of UPS modules are put into hibernation according to a preset order and the current efficiency level is obtained; then, the estimated efficiency level is calculated after a second set number of UPS modules are put into hibernation according to the preset order; finally, it is determined whether the current efficiency level is greater than the estimated efficiency level. If so, the first set number of UPS modules are put into hibernation again and the current efficiency level is obtained, and the aforementioned steps are repeated until the current efficiency level is equal to the estimated efficiency level, that is, the efficiency level cannot be reduced by hibernating the UPS modules.

[0073] In a further preferred embodiment of the present invention, the first predetermined quantity and the second predetermined quantity can be a single UPS module, or all UPS modules in a rack. The predetermined order can be to number the UPS modules and then poll them in descending or ascending order of their numbers.

[0074] For example, in a UPS system, there are five racks, each containing five UPS modules. In a preferred embodiment of the invention, they can be numbered as follows:

[0075] serial number Rack 1 Rack 2 Rack 3 Rack 4 Rack 5 UPS Module No. 1 1 6 11 16 21 UPS module No. 2 2 6 12 17 22 UPS module No. 3 3 8 13 18 23 UPS module No. 4 4 8 14 19 24 UPS module No. 5 5 10 15 20 25

[0076] When it is determined that the UPS module needs to be put into hibernation based on the system load rate, UPS module 1 is put into hibernation in ascending order of its numbers (1-25), and the current efficiency level is calculated. Since the system load rate changes with each UPS module put into hibernation, the corresponding current efficiency level also changes. Next, the estimated efficiency level obtained by putting UPS module 2 into hibernation is calculated. Then, it is compared whether the current efficiency level is greater than the estimated efficiency level; that is, whether putting the UPS module into hibernation will cause the efficiency level to decrease. If so, UPS module 2 is put into hibernation, and the estimated efficiency level obtained by putting UPS module 3 into hibernation is calculated. The current efficiency level and the estimated efficiency level are then compared again. This process is repeated until putting UPS modules into hibernation no longer causes the estimated efficiency level to decrease. At this point, the system can be maintained at its highest efficiency, that is, the UPS system maintains operation at either the first or second efficiency level.

[0077] In other preferred embodiments of the present invention, all UPS modules in each rack can be put into hibernation each time. The principle and method are the same, so they will not be described again.

[0078] In step S4, the UPS module that is not in sleep mode is controlled to enter the main-bypass common mode for reactive power and harmonic compensation. In a preferred embodiment of the present invention, the UPS module that is not in sleep mode is controlled to enter the main-bypass common mode (i.e., VI mode) and simultaneously perform bypass current sharing and harmonic compensation.

[0079] For a UPS system consisting of multiple racks in parallel, current sharing and compensation occur simultaneously after entering VI mode. Because the bypass current becomes distorted, the reactive power and harmonics of the bypass current extracted by the bypass DSP also become distorted with the bypass current sharing adjustment, resulting in insufficient inverter compensation for reactive power and harmonics. Therefore, in a further embodiment of the present invention, the transient state of the UPS module transitioning from the main inverter mode (VFI mode) to the main-bypass common mode (VI mode) is adjusted in stages:

[0080] Phase 1 involves controlling the non-dormant UPS module to enter the main-bypass common mode (VI mode). The main power unit of the UPS module is controlled to invert and compensate for reactive power and harmonics, resulting in a sinusoidal bypass current. This bypass current is forced to lead the bypass voltage and continues for a first set time. For example, the non-dormant UPS module is controlled to enter the main-bypass common mode and performs reactive power and harmonic compensation within the first set time (e.g., 40 seconds), resulting in a sinusoidal bypass current that is essentially in phase with the bypass voltage. However, the bypass current phase is forced to lead the bypass voltage by 5-10 degrees, i.e., a capacitive load is forcibly added to make the bypass current lead the voltage. This allows the bypass SCR to turn off prematurely during an input short circuit, preventing a drop in the UPS system's output voltage and ensuring the output voltage meets the Class 1 curve, i.e., entering dynamic online mode. Prematurely turning off the bypass SCR also prepares for subsequent bypass current sharing adjustments. Those skilled in the art will understand that this first set time and lead angle can be adjusted according to actual needs.

[0081] Phase 2: By adjusting the bypass power transistor drive of the UPS module through bypass power balancing to equalize the bypass current of the UPS module, and continuing to run for a second set time. For example, during the second set time (e.g., 20s) after Phase 1 has been completed, the bypass power transistor drive of the UPS module in each rack is adjusted through bypass power balancing to equalize the bypass current of the UPS module, thereby ensuring that the bypass current of each rack is equalized and that reactive power and harmonic compensation are stabilized, thus making the UPS system more stable.

[0082] In this preferred embodiment, the transient state of the UPS system after entering VI mode from VFI mode is divided into two stages for control, which reduces the mutual coupling effect of bypass current sharing and dynamic online compensation when rack paralleling, resulting in a higher power factor of the bypass input current.

[0083] In step S5, based on the relationship between bypass current and bypass voltage, the UPS module that is not in sleep mode is maintained in dynamic online mode or returned to main circuit inverter power supply mode. In a preferred embodiment of the present invention, when the bypass current of the UPS module leads the bypass voltage by a set angle and the input power factor is greater than a set value, the UPS module that is not in sleep mode is maintained in dynamic online mode or returned to main circuit inverter power supply mode. For example, the relationship between bypass current and voltage of each rack or each UPS module is determined to see if it should exit dynamic online mode. If the conditions are met, it remains in dynamic online mode for efficient operation; if not, it exits this mode and returns to main circuit inverter power supply mode. The process continues until the conditions are met again to determine whether to enter this mode. For example, in a preferred embodiment of the present invention, after bypass current sharing and reactive power and harmonic compensation to steady state, if the bypass current leads the bypass voltage by more than 5 degrees and the input power is greater than 0.975, it remains in dynamic online mode; otherwise, it exits dynamic online mode. Here, dynamic online mode is the mode where the output voltage satisfies the class1 curve.

[0084] In step S6, when a sudden increase in load causes the system load rate to drop by a set value, the dormant UPS module is awakened. In a preferred embodiment of the invention, when the load suddenly increases, for example, when the load suddenly increases and causes the system load rate to drop by at least two efficiency levels, the dormant UPS module is awakened, and the awakened UPS module is controlled to directly enter dynamic online mode. In a preferred embodiment of the invention, dynamic online mode refers to a mode in which the UPS system output voltage meets a specific type of curve, such as a class 1 curve.

[0085] Because waking up a UPS module directly enters the dynamic online mode, it involves a dynamic process of bypass current sharing and harmonic extraction compensation, resulting in some instability in the overall stability of the UPS system. Therefore, in a further preferred embodiment of the invention, when a sudden increase in load causes the system load rate to drop by at least two efficiency levels (e.g., efficiency level changes from 1 to 3), the dormant UPS module is woken up, and all UPS modules are controlled to enter the main inverter power supply mode and cyclically execute steps S1-S5. In this way, all UPS modules exit the current operating mode and then enter the main inverter power supply mode together, subsequently cyclically executing steps S1-S5 again, which further improves the reliability of the entire UPS system.

[0086] The parallel operation method for UPS modules implemented in this invention can intelligently put UPS modules into sleep mode or wake them up based on the system load rate. Therefore, it improves the overall system operating efficiency and provides high reliability, ensuring the UPS system always operates near its peak efficiency. Furthermore, reactive power and harmonic compensation can be applied to the bypass current, improving the input power factor and reducing harmonic pollution to the power grid. Even further, the transient transition of the UPS module from the main inverter power supply mode to the main-bypass common mode is controlled in two stages, reducing the mutual coupling effect of bypass current sharing and dynamic online compensation, resulting in a higher power factor for the bypass input circuit.

[0087] A further preferred embodiment of the present invention includes a UPS module parallel operation system, comprising multiple UPS modules and a processor, wherein the processor stores a computer program containing all the features capable of implementing the method of the present invention, and when installed in the processor, can implement the method of the present invention. The computer program referred to in this document means any expression of a set of instructions that can be written in any programming language, code, or symbol, which enables the system to have information processing capabilities to directly implement a specific function, or to implement a specific function after performing one or both of the following steps: a) converting it into another language, code, or symbol; b) reproducing it in a different format.

[0088] Figure 4 This is a schematic block diagram of a first preferred embodiment of the UPS module parallel operation system of the present invention. Figure 4 As shown, the UPS module parallel operation system of the present invention includes multiple UPS modules 310, 320 and 330...3N0, a hibernation module 100 and a wake-up module 200.

[0089] The plurality of UPS modules 310, 320, and 330…3N0 can be UPS modules in multiple racks connected in parallel, or they can be different UPS modules. Therefore, as mentioned above, the UPS system can include multiple racks connected in parallel, each rack including multiple UPS modules, and all UPS modules in each rack simultaneously enter sleep mode. In another preferred embodiment of the invention, the UPS system can include multiple UPS modules connected in parallel, each UPS module entering sleep mode individually.

[0090] The hibernation module 100 is used to put a predetermined number of UPS modules into hibernation based on the system load rate in a UPS system composed of multiple UPS modules connected in parallel, so as to maintain the UPS system at a predetermined efficiency level; and to control the UPS modules that are not in hibernation to enter the main circuit inverter power supply mode or the main circuit bypass common mode for reactive power and harmonic compensation. The wake-up module 200 is used to wake up the hibernating UPS modules when the load suddenly increases, causing the system load rate to drop by a predetermined value.

[0091] Here, the hibernation module 100 and the wake-up module 200 can be referred to Figure 1 The construction of the embodiment shown will not be described again here.

[0092] Figure 5 This is a schematic block diagram of a second preferred embodiment of the UPS module parallel operation system of the present invention. Figure 5 As shown, the UPS module parallel operation system of the present invention includes multiple UPS modules 310, 320 and 330...3N0, a hibernation module 100 and a wake-up module 200.

[0093] like Figure 5 As shown, the hibernation module 100 further includes: a first mode control unit 110, a hibernation unit 120, a second mode control unit 130, and a third mode control unit 140.

[0094] The first mode control unit 110 is used to construct the UPS system using multiple UPS modules 310, 320 and 330...3N0 connected in parallel, and to make the UPS modules 310, 320 and 330...3N0 operate in the main circuit inverter power supply mode.

[0095] The hibernation unit 120 is used to determine whether the UPS modules 310, 320, and 330…3N0 need to be put into hibernation based on the system load rate. If so, a set number of UPS modules are put into hibernation to maintain the UPS system at a first efficiency level or a second efficiency level; otherwise, the UPS modules are kept in the main inverter power supply mode. The first set number of UPS modules includes one UPS module or all UPS modules contained in a tower crane frame. When the system load percentage is less than 20%, the UPS system efficiency level is the eighth efficiency level; when 20% ≤ system load percentage < 30%, the UPS system efficiency level is the seventh efficiency level; when 30% ≤ system load percentage < 40%, the UPS system efficiency level is the fourth efficiency level; when 40% ≤ system load percentage < 50%, the UPS system efficiency level is the first efficiency level; when 50% ≤ system load percentage < 60%, the UPS system efficiency level is the second efficiency level; when 60% ≤ system load percentage < 70%, the UPS system efficiency level is the third efficiency level; when 70% ≤ system load percentage < 80%, the UPS system efficiency level is the fifth efficiency level; when 80% ≤ system load percentage < 90%, the UPS system efficiency level is the sixth efficiency level; and when 90% ≤ system load percentage, the UPS system efficiency level is the ninth efficiency level. In a preferred embodiment of the present invention, the hibernation unit 120 is further configured to hibernate a first set number of UPS modules in a preset order and obtain the current efficiency level; calculate the estimated efficiency level after hibernating a second set number of UPS modules in the preset order; and determine whether the current efficiency level is greater than the estimated efficiency level. If so, the aforementioned steps are repeated; otherwise, the current operating state is maintained.

[0096] The second mode control unit 130 is used to control the non-dormant UPS module to enter the main-bypass common mode for reactive power and harmonic compensation. Figure 5 In the preferred embodiment shown, the second mode control unit 130 may include a second compensation subunit 131 and a current sharing subunit 132. The second compensation subunit 131 controls the UPS module that is not in sleep mode to enter a main-bypass common mode, controls the main power unit of the UPS module to invert and compensate for reactive power and harmonics, and makes the bypass current sinusoidal, forcing the bypass current to lead the bypass voltage, and continuously operates for a first set time. The current sharing subunit 132 is used to adjust the bypass power transistor drive of the UPS module through bypass power equalization to share the bypass current of the UPS module, and continuously operates for a second set time.

[0097] In another preferred embodiment of the present invention, the second mode control unit 130 may employ a different control method, namely, performing bypass current sharing and harmonic compensation. In this case, the second mode control unit 130 may include a first compensation subunit, used to control the non-dormant UPS module to enter the main-bypass common mode and simultaneously perform bypass current sharing and harmonic compensation.

[0098] The third mode control unit 140 is used to maintain the non-dormant UPS module in dynamic online mode or return it to main circuit inverter power supply mode based on the relationship between bypass current and bypass voltage. In a further preferred embodiment of the present invention, the third mode control unit 140 may be further used to maintain the non-dormant UPS module in dynamic online mode or return it to main circuit inverter power supply mode when the bypass current of the UPS module leads the bypass voltage by a set angle and the input power factor is greater than a set value.

[0099] Further as Figure 5 As shown, the wake-up module 200 may include a first wake-up unit 210 or a second wake-up unit 220 to implement different wake-up methods respectively. The first wake-up unit 210 is used to wake up the hibernating UPS module when the load suddenly increases, causing the system load rate to drop by at least two efficiency levels, and to control all the UPS modules to enter the main circuit inverter power supply mode and cyclically run the hibernating module 100.

[0100] The second wake-up unit 220 is used to wake up the dormant UPS module when the load suddenly increases, causing the system load rate to drop by at least two efficiency levels, and to control the woken UPS module to directly enter the dynamic online mode.

[0101] Those skilled in the art will understand that the first mode control unit 110, the sleep unit 120, the second mode control unit 130 and the third mode control unit 140, the first compensation subunit, the second compensation subunit 13, the current sharing subunit 132, the first wake-up unit 210 or the second wake-up unit 220 can all be referred to herein. Figure 2-4 The embodiments shown are constructed on the same principle, and will not be described again here.

[0102] The UPS module parallel operation system implementing this invention can intelligently put the UPS modules into hibernation or wake them up according to the system load rate. Therefore, it can improve the overall system operating efficiency and has high reliability, keeping the UPS system operating near its peak efficiency at all times. Furthermore, reactive power and harmonic compensation can be performed on the bypass current, improving the input power factor and reducing harmonic pollution to the power grid. Even further, the transient transition of the UPS module from the main inverter power supply mode to the main-bypass common mode is controlled in two stages, reducing the mutual coupling effect of bypass current sharing and dynamic online compensation, resulting in a higher power factor for the bypass input circuit. Therefore, this invention can be implemented through hardware, software, or a combination of both. This invention can be implemented centrally in at least one computer system, or distributed in a decentralized manner by different parts distributed across several interconnected computer systems. Any computer system or other device capable of implementing the method of this invention is applicable. A common hardware and software combination is a general-purpose computer system with computer programs installed, controlling the computer system to operate according to the method of this invention by installing and executing the programs.

[0103] Although the present invention has been described through specific embodiments, those skilled in the art will understand that various modifications and equivalent substitutions can be made to the invention without departing from its scope. Furthermore, various modifications can be made to the invention for specific situations or materials without departing from its scope. Therefore, the present invention is not limited to the specific embodiments disclosed, but should include all embodiments falling within the scope of the claims.

[0104] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for parallel operation of UPS modules, characterized in that, include: S1. In a UPS system constructed by multiple UPS modules in parallel, the number of UPS modules to be put into sleep mode is set based on the system load rate to maintain the UPS system at a set efficiency level; the UPS modules that are not in sleep mode are controlled to enter the main circuit inverter power supply mode or the main circuit bypass common mode to perform reactive power and harmonic compensation. S2. When a sudden increase in load causes the system load rate to drop by a set value, wake up the hibernation UPS module; Step S1 further includes: S11. The UPS system is constructed by connecting multiple UPS modules in parallel, and the UPS modules are operated in the main circuit inverter power supply mode. S12. Determine whether the UPS module needs to go into hibernation based on the system load rate. If yes, proceed to step S13; otherwise, keep the UPS module in the main inverter power supply mode. S13. A set number of UPS modules are put into hibernation mode to maintain the UPS system at a first efficiency level or a second efficiency level. S14. Control the non-dormant UPS module to enter the main-bypass common mode for reactive power and harmonic compensation. S15. Based on the relationship between bypass current and bypass voltage, maintain the non-dormant UPS module in dynamic online mode or return it to main circuit inverter power supply mode; Step S14 further includes: S141. Control the non-dormant UPS module to enter the main-bypass common mode, control the main power unit of the UPS module to invert and compensate reactive power and harmonics and make the bypass current sinusoidal, and force the bypass current to lead the bypass voltage, and continue to run for a first set time. S142. The bypass power transistor of the UPS module is driven by the bypass power equalization to equalize the bypass current of the UPS module, and the operation continues for a second set time.

2. The UPS module parallel operation method according to claim 1, characterized in that, Step S13 further includes: S131. Put the first set number of UPS modules into hibernation according to a preset order and obtain the current efficiency level; S132. Calculate the estimated efficiency level after the second set number of UPS modules are put into hibernation according to the preset order; S133. Determine whether the current efficiency level is greater than the estimated efficiency level. If yes, return to step S131; otherwise, maintain the current operating state.

3. The UPS module parallel operation method according to claim 2, characterized in that, The first set number of UPS modules includes one UPS module or all UPS modules contained in a tower crane frame.

4. The UPS module parallel operation method according to claim 2, characterized in that, When the system load rate is less than 20%, the UPS system efficiency level is the eighth efficiency level; when 20% ≤ system load rate < 30%, the UPS system efficiency level is the seventh efficiency level; when 30% ≤ system load rate < 40%, the UPS system efficiency level is the fourth efficiency level; when 40% ≤ system load rate < 50%, the UPS system efficiency level is the first efficiency level; when 50% ≤ system load rate < 60%, the UPS system efficiency level is the second efficiency level; when 60% ≤ system load rate < 70%, the UPS system efficiency level is the third efficiency level; when 70% ≤ system load rate < 80%, the UPS system efficiency level is the fifth efficiency level; when 80% ≤ system load rate < 90%, the UPS system efficiency level is the sixth efficiency level; and when 90% ≤ system load rate, the UPS system efficiency level is the ninth efficiency level.

5. The UPS module parallel operation method according to claim 2, characterized in that, Step S15 further includes maintaining the non-dormant UPS module in dynamic online mode or returning it to main circuit inverter power supply mode when the bypass current of the UPS module leads the bypass voltage by a set angle and the input power factor is greater than the set value.

6. The UPS module parallel operation method according to claim 2, characterized in that, Step S2 further includes: S21. When a sudden increase in load causes the system load rate to drop by at least two efficiency levels, wake up the dormant UPS module and control all UPS modules to enter the main inverter power supply mode and repeatedly execute step S1; or S2a. When a sudden increase in load causes the system load rate to drop by at least two efficiency levels, wake up the dormant UPS module and control the woken UPS module to directly enter the dynamic online mode.

7. A UPS module parallel operation system, comprising multiple UPS modules and a processor, wherein the processor stores a computer program, characterized in that, When the computer program is executed by the processor, it implements the UPS module parallel operation method according to any one of claims 1-6.

8. A UPS module parallel operation system, comprising multiple UPS modules, characterized in that, Further includes: A hibernation module is used to put a set number of UPS modules into hibernation based on the system load rate in a UPS system with multiple UPS modules connected in parallel, so as to maintain the UPS system at a set efficiency level; and to control the UPS modules that are not in hibernation to enter the main circuit inverter power supply mode or the main circuit bypass common mode for reactive power and harmonic compensation. A wake-up module is used to wake up the dormant UPS module when a sudden increase in load causes the system load rate to drop by a set value; The hibernation module further includes: The first mode control unit is used to construct the UPS system using multiple UPS modules connected in parallel, and to enable the UPS modules to operate in the main circuit inverter power supply mode. The hibernation unit is used to determine whether the UPS module needs to be hibernated based on the system load rate. If so, a set number of UPS modules are hibernated to keep the UPS system running at the first efficiency level or the second efficiency level. Otherwise, the UPS module is kept in the main circuit inverter power supply mode. The second mode control unit is used to control the non-dormant UPS module to enter the main-bypass common mode for reactive power and harmonic compensation. The third mode control unit is used to maintain the non-dormant UPS module in dynamic online mode or return it to main inverter power supply mode based on the relationship between bypass current and bypass voltage. The second mode control unit further includes: The second compensation subunit is used to control the non-dormant UPS module to enter the main-bypass common mode, control the main power unit of the UPS module to invert and compensate reactive power and harmonics and make the bypass current sinusoidal, and force the bypass current to lead the bypass voltage, and continue to run for a first set time. The current sharing subunit is used to adjust the bypass power transistor drive of the UPS module to share the bypass current of the UPS module through bypass power equalization, and to run continuously for a second set time.

9. The UPS module parallel operation system according to claim 8, characterized in that, The hibernation unit is further used to hibernate a first set number of UPS modules in a preset order and obtain the current efficiency level; calculate the estimated efficiency level after hibernating a second set number of UPS modules in the preset order; and determine whether the current efficiency level is greater than the estimated efficiency level. If so, the aforementioned steps are repeated; otherwise, the current operating state is maintained.

10. The UPS module parallel operation system according to claim 9, characterized in that, The first set number of UPS modules includes one UPS module or all UPS modules contained in a tower crane frame.

11. The UPS module parallel operation system according to claim 9, characterized in that, When the system load rate is less than 20%, the UPS system efficiency level is the eighth efficiency level; when 20% ≤ system load rate < 30%, the UPS system efficiency level is the seventh efficiency level; when 30% ≤ system load rate < 40%, the UPS system efficiency level is the fourth efficiency level; when 40% ≤ system load rate < 50%, the UPS system efficiency level is the first efficiency level; when 50% ≤ system load rate < 60%, the UPS system efficiency level is the second efficiency level; when 60% ≤ system load rate < 70%, the UPS system efficiency level is the third efficiency level; when 70% ≤ system load rate < 80%, the UPS system efficiency level is the fifth efficiency level; when 80% ≤ system load rate < 90%, the UPS system efficiency level is the sixth efficiency level; and when 90% ≤ system load rate, the UPS system efficiency level is the ninth efficiency level.

12. The UPS module parallel operation system according to claim 9, characterized in that, The third mode control unit is further configured to maintain the non-dormant UPS module in dynamic online mode or return it to main circuit inverter power supply mode when the bypass current of the UPS module leads the bypass voltage by a set angle and the input power factor is greater than a set value.

13. The UPS module parallel operation system according to claim 9, characterized in that, The wake-up module further includes: The first wake-up unit is used to wake up the dormant UPS module when a sudden increase in load causes the system load rate to drop by at least two efficiency levels, and to control all UPS modules to enter the main inverter power supply mode and cycle through the dormant modules; or The second wake-up unit is used to wake up the dormant UPS module when the load suddenly increases, causing the system load rate to drop by at least two efficiency levels, and to control the woken UPS module to directly enter the dynamic online mode.

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