UPS current sharing control method and UPS

Abstract

The present invention discloses a UPS current sharing control method and UPS, which relates to the technical field of UPS, and includes the following steps: Step 1, obtaining current data; obtaining the instantaneous value of the inverter output voltage in the UPS in real time; Step 2, protection device: if the instantaneous value of the inverter output voltage in the UPS is greater than the first preset voltage value and lasts for the first preset time, then turning off the output of the inverter in the UPS; Step 3, input voltage judgment module; arranging the three-phase current values ​​in descending order. The UPS current sharing control method and UPS described in the present invention can effectively protect against faults caused by Hall sampling failure in a timely manner by turning off the output of the inverter in the UPS, prevent the duty cycle of the switch tube drive pulse and the drastic change of the inverter output voltage from causing the isolation transformer to generate a large excitation current, thereby preventing the damage of the inverter switch tube in the UPS, greatly reducing the failure rate of the UPS and improving the reliability of the UPS.

Description

Technical Field

[0001] The present invention relates to the technical field of UPS, and in particular to a UPS current sharing control method and a UPS. Background Art

[0002] UPS (Uninterruptible Power Supply) is an energy supply device used to provide uninterruptible power supply to power electronic equipment. When the AC input power is abnormal or power off, it can continue to supply power to the load to ensure normal power supply to the load.

[0003] The existing technology has the following problems:

[0004] The UPS current equalization control method and the UPS cannot effectively protect against inverter failures when in use, and thus the use is easily affected by the failures. At the same time, the UPS current equalization control method and the UPS cannot effectively improve the performance of the UPS when in use. Moreover, if a load of one phase fails when the UPS current equalization control method and the UPS are in use, the current of one phase cannot be shared, thus causing the current values ​​of the other two phases to be too large. Summary of the invention

[0005] The present invention provides a UPS current sharing control method and a UPS to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A UPS current sharing control method comprises the following steps: step 1, obtaining current data; obtaining the instantaneous value of the inverter output voltage in the UPS in real time; step 2, a protection device: if the instantaneous value of the inverter output voltage in the UPS is greater than a first preset voltage value and lasts for a first preset time, the output of the inverter in the UPS is turned off; step 3, an input voltage judgment module; arranging the three-phase current values ​​in descending order; step 4, data processing; the current data loaded on three items of the UPS are detected by a current detection instrument, and then the current data are processed by a server; step 5, current regulation; the DSP of the UPS shared DC input source is used to average the DC input current I_bat and the DC current reference I_share of the current sharing bus, and the operation is performed every 20 milliseconds, and then the results of multiple operations are averaged to obtain the DC input current average value I avg_bat and the DC current average value I avg_share of the current sharing bus.

[0008] Preferably, the step 2 can prevent the inverter output voltage from being overvoltage by setting a first-level overvoltage protection and detecting the effective value of the inverter output voltage, thereby affecting the output performance of the inverter and preventing the inverter from being damaged by long-term overvoltage.

[0009] Preferably, in step three, a current difference value is obtained according to a difference between a numerical value corresponding to the highest digit after sorting and a numerical value corresponding to the lowest digit, and the current difference value is compared with a preset current difference value.

[0010] Preferably, the step four, clearing the integral, is used to clear the integral of the current equalizing ring of each UPS module if the output of the current equalizing ring of each UPS module is greater than zero, or the output of the current equalizing ring of each UPS module is less than zero.

[0011] Preferably, in step four, a loop jump is performed; the difference between the mean of the effective values ​​of the output currents of the UPS modules and the effective values ​​of the output currents of the UPS modules is calculated to obtain the error of the current equalizing loop of the UPS module; if the outputs of the current equalizing loops of the UPS modules are greater than zero, or the outputs of the current equalizing loops of the UPS modules are less than zero, the integrals of the current equalizing loops of the UPS modules are cleared respectively, and step four is repeated for each loop adjustment.

[0012] Preferably, in step five, the average value of the DC input current I avg_bat is subtracted from the average value of the DC current of the current-sharing bus to obtain the average value of the current difference I avg_deta.

[0013] Preferably, in step five, the current difference average value I avg_deta is multiplied by a proportional coefficient and then superimposed on the effective value loop as a reference, and then the output of the effective value loop is multiplied by S i nWt as a reference for the voltage instantaneous value loop.

[0014] Preferably, in step five, the DSP of the UPS shared DC input source is used to subtract the collected local DC input current I_bat and the current sharing bus DC current reference I_share to obtain the current difference I_deta, and then the current difference I_deta is multiplied by a proportional coefficient and S i nWt, and then superimposed on the output of the voltage instantaneous value loop as a reference for the inductor current loop.

[0015] Preferably, in step five, the insulated gate bipolar transistor of the inverter bridge is finally driven by the output of the inductor current loop, and the output of the inverter bridge is connected in parallel after being filtered by the inductor and capacitor to supply power to the load. When the load changes, the input current of the shared DC input source of each UPS changes accordingly to achieve current sharing, thereby achieving load balance of the load cabinets loaded on the three items of the UPS.

[0016] A UPS includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and is implemented when the processor executes the computer program.

[0017] Due to the adoption of the above technical solution, the present invention has the following technical advances compared with the prior art:

[0018] 1. The present invention provides a UPS current sharing control method and a UPS. By shutting down the output of the inverter in the UPS, effective protection can be provided in time against faults caused by Hall sampling failure, thereby preventing the duty cycle of the switch tube driving pulse and the drastic change of the inverter output voltage from causing the isolation transformer to generate a large excitation current, thereby preventing the inverter switch tube in the UPS from being damaged, greatly reducing the failure rate of the UPS and improving the reliability of the UPS.

[0019] 2. The present invention provides a UPS current equalization control method and UPS. When the current equalization loop errors are greater than zero or less than zero, the integrals of the current equalization loops of each UPS module are cleared to prevent the current equalization loop integrals from continuously accumulating and causing output current distortion of each UPS module, thereby improving the THDI index and UPS performance.

[0020] 3. The present invention provides a UPS current sharing control method and UPS, which achieves the purpose of current sharing of the common DC input source of each UPS in the system by controlling the DC input current of the common DC input source of all UPS in the system. The parallel current sharing control process of the common DC input source of UPS with a common DC bus is simple and convenient to operate, and the process is no longer cumbersome, thereby making the three-phase input current sharing, avoiding UPS damage due to uneven input current, and extending the service life of the UPS. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the current sharing control process of the present invention;

[0022] Figure 2 It is a schematic diagram of the UPS structure of the present invention. DETAILED DESCRIPTION

[0023] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0024] like Figure 1As shown, a UPS current sharing control method includes the following steps: step 1, obtaining current data; obtaining the instantaneous value of the inverter output voltage in the UPS in real time; step 2, protection device: if the instantaneous value of the inverter output voltage in the UPS is greater than the first preset voltage value and lasts for the first preset time, then turning off the output of the inverter in the UPS; step 3, input voltage judgment module; arranging the three-phase current values ​​in descending order; step 4, data processing; the current data loaded on the three items of the UPS detected by the current detection instrument are then processed by the server; step 5, current regulation; the DSP of the UPS shared DC input source is used to average the DC input current I_bat and the DC current reference I_share of the current sharing bus, and the operation is performed every 20 milliseconds, and then the results of multiple operations are averaged to obtain the DC input current average value Iavg_bat and the DC current average value Iavg_share of the current sharing bus;

[0025] By shutting down the output of the inverter in the UPS, effective protection can be provided in time against faults caused by Hall sampling failure, and the duty cycle of the switch tube drive pulse and the drastic changes in the inverter output voltage can be prevented from causing the isolation transformer to generate a large excitation current. When the current balancing loop errors are greater than zero or less than zero, the integral of the current balancing loop of each UPS module is cleared to prevent the current balancing loop integral from continuously accumulating and causing output current distortion of each UPS module. By controlling the DC input current of the common DC input source of all UPS in the system, the purpose of current balancing of the common DC input source of each UPS in the system is achieved. The parallel current balancing control process of the common DC input source of UPS with a common DC bus is simple and convenient to operate, and the process is no longer cumbersome, thereby making the three-phase input current balancing, avoiding UPS damage due to uneven input current, and extending the service life of the UPS.

[0026] like Figure 1 As shown, the first-level overvoltage protection can be set to detect the effective value of the inverter output voltage to prevent the inverter output voltage from overvoltage, which affects the inverter output performance and prevents the inverter from being damaged by long-term overvoltage.

[0027] By shutting down the output of the inverter in the UPS, effective protection can be provided in time against faults caused by Hall sampling failure, preventing the duty cycle of the switch tube drive pulse and the drastic changes in the inverter output voltage from causing the isolation transformer to generate a large excitation current, thereby preventing damage to the inverter switch tube in the UPS, greatly reducing the failure rate of the UPS and improving the reliability of the UPS.

[0028] like Figure 1As shown, a current difference is obtained according to the difference between the numerical value corresponding to the highest bit and the numerical value corresponding to the lowest bit after sorting, and the current difference is compared with a preset current difference; integral clearing is used to clear the integral of the current equalizing ring of each UPS module if the output of the current equalizing ring of each UPS module is greater than zero, or the output of the current equalizing ring of each UPS module is less than zero; loop jump, calculate the difference between the average of the effective value of the output current of each UPS module and the effective value of the output current of the UPS module, and obtain the error of the current equalizing ring of the UPS module; if the output of the current equalizing ring of each UPS module is greater than zero, or the output of the current equalizing ring of each UPS module is less than zero, clear the integral of the current equalizing ring of each UPS module, and repeat step 4 for each loop adjustment;

[0029] When the current balancing loop errors are greater than zero or less than zero, the integral of the current balancing loop of each UPS module is cleared to prevent the current balancing loop integral from continuously accumulating and causing output current distortion of each UPS module, thereby improving the THD I index and UPS performance.

[0030] like Figure 1 As shown in the figure, the average value of the DC input current I avg_bat and the average value of the DC current of the current-sharing bus are subtracted to obtain the average value of the current difference I avg_deta; the average value of the current difference I avg_deta is multiplied by a proportional coefficient and then superimposed on the effective value loop as a reference, and then the output of the effective value loop is multiplied by S i nWt as a reference for the voltage instantaneous value loop; the DSP of the UPS shared DC input source is used to subtract the collected local DC input current I_bat and the DC current reference I_share of the current-sharing bus to obtain the current difference I_deta, and then the current difference I_deta is multiplied by a proportional coefficient and S i nWt. inWt, and then superimposed on the output of the voltage instantaneous value loop as a reference for the inductor current loop; finally, the output of the inductor current loop drives the insulated gate bipolar transistor of the inverter bridge, and the inverter bridge output is connected in parallel after being filtered by the inductor and capacitor to supply power to the load. When the load changes, the input current of the shared DC input source of each UPS changes accordingly to achieve current sharing, thereby achieving load balance of the load cabinets loaded on the three items of the UPS;

[0031] By controlling the DC input current of the common DC input source of all UPS in the system, the purpose of current balancing of the common DC input source of each UPS in the system is achieved. The parallel current balancing control process of the common DC input source of UPS with a common DC bus is simple and convenient to operate, and the process is no longer cumbersome, thereby making the three-phase input current balanced, avoiding UPS damage due to uneven input current, and extending the service life of the UPS.

[0032] like Figure 2As shown, a UPS comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein: when the processor executes the computer program, the computer program is implemented;

[0033] When the processor executes the computer program, the functions of the modules and units in the above-mentioned UPS current sharing control device embodiment are realized.

[0034] The working principle of the present invention includes the following steps: step 1, obtaining current data; obtaining the instantaneous value of the inverter output voltage in the UPS in real time; step 2, protection device: if the instantaneous value of the inverter output voltage in the UPS is greater than the first preset voltage value and lasts for the first preset time, the output of the inverter in the UPS is turned off, and the first-level overvoltage protection can be set to prevent the inverter output voltage from being over-voltage by detecting the effective value of the inverter output voltage, thereby affecting the output performance of the inverter and preventing the inverter from being damaged by long-term overvoltage; step 3, input voltage judgment module; arrange the three-phase current values ​​in descending order, obtain the current difference value according to the difference between the value corresponding to the highest bit after sorting and the value corresponding to the lowest bit, and compare the current difference value with the preset current difference; step 4, data processing; through The current detection instrument detects the current data loaded on the three items of the UPS, and then processes these current data through the server, and the integral is reset to zero. If the output of the current equalizing ring of each UPS module is greater than zero, or the output of the current equalizing ring of each UPS module is less than zero, then the integral of the current equalizing ring of each UPS module is reset to zero, and the loop jumps to calculate the difference between the average of the effective value of the output current of each UPS module and the effective value of the output current of the UPS module to obtain the error of the current equalizing ring of the UPS module. If the output of the current equalizing ring of each UPS module is greater than zero, or the output of the current equalizing ring of each UPS module is less than zero, then the integral of the current equalizing ring of each UPS module is reset to zero, and step four is repeated for each loop adjustment; step five, current adjustment;The DSP of the UPS shared DC input source is used to average the DC input current I_bat and the DC current reference I_share of the current-sharing bus. The operation is performed every 20 milliseconds, and then the results of multiple operations are averaged to obtain the DC input current average I avg_bat and the DC current average I avg_share of the current-sharing bus. The DC input current average I avg_bat and the DC current average of the current-sharing bus are subtracted to obtain the current difference average I avg_deta. The current difference average I avg_deta is multiplied by a proportional coefficient and then superimposed on the effective value loop as a reference. The output of the effective value loop is then multiplied by S i nWt as a reference for the voltage instantaneous value loop. The DSP of the UPS shared DC input source is used to subtract the collected local DC input current I_bat from the DC current reference I_share of the current-sharing bus to obtain the current difference I_deta. The current difference I_deta is then multiplied by a proportional coefficient and S i nWt, and then superimposed on the output of the voltage instantaneous value loop, as a reference for the inductor current loop, and finally the output of the inductor current loop drives the insulated gate bipolar transistor of the inverter bridge. The inverter bridge output is connected in parallel after being filtered by the inductor and capacitor to supply power to the load. When the load changes, the input current of each UPS shared DC input source changes accordingly to achieve current sharing, thereby achieving load balance of the load cabinets loaded on the three items of the UPS. ;

[0035] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A UPS current sharing control method, characterized in that: The steps include: Step 1, obtaining current data; Get the instantaneous value of the inverter output voltage in UPS in real time; Step 2, protection device: if the instantaneous value of the output voltage of the inverter in the UPS is greater than the first preset voltage value and lasts for the first preset time, then turn off the output of the inverter in the UPS; Step 3: Input voltage judgment module; arrange the three-phase current values ​​in descending order; Step 4: Data processing: The current data loaded on the three items of the UPS are detected by the current detection instrument, and then the current data are processed by the server; Step 5: Current regulation: Use the DSP of the UPS shared DC input source to average the DC input current I_bat and the DC current reference I_share of the current-sharing bus. Perform the operation once every 20 milliseconds, and then average the results of multiple operations to obtain the average DC input current Iavg_bat and the average DC current of the current-sharing bus Iavg_share.

2. A UPS current sharing control method according to claim 1, characterized in that: In the step 2, the first-level overvoltage protection can be set to prevent the inverter output voltage from being overvoltage by detecting the effective value of the inverter output voltage, thereby affecting the output performance of the inverter and preventing the inverter from being damaged by long-term overvoltage.

3. A UPS current sharing control method according to claim 1, characterized in that: The step three is to obtain a current difference value according to the difference between the numerical value corresponding to the highest bit and the numerical value corresponding to the lowest bit after sorting, and compare the current difference value with a preset current difference value.

4. A UPS current sharing control method according to claim 1, characterized in that: The step four, clearing the integral, is used to clear the integral of the current equalizing ring of each UPS module if the output of the current equalizing ring of each UPS module is greater than zero, or the output of the current equalizing ring of each UPS module is less than zero.

5. A UPS current sharing control method according to claim 4, characterized in that: The step four is a loop jump; the difference between the mean of the effective values ​​of the output currents of the UPS modules and the effective values ​​of the output currents of the UPS modules is calculated to obtain the error of the current equalizing loop of the UPS module; if the outputs of the current equalizing loops of the UPS modules are greater than zero, or the outputs of the current equalizing loops of the UPS modules are less than zero, the integrals of the current equalizing loops of the UPS modules are cleared respectively, and step four is repeated for each loop adjustment.

6. A UPS current sharing control method according to claim 1, characterized in that: In the step five, the average value of the DC input current Iavg_bat is subtracted from the average value of the DC current of the current-sharing bus to obtain the average value of the current difference Iavg_deta.

7. A UPS current sharing control method according to claim 6, characterized in that: In the step five, the current difference average value Iavg_deta is multiplied by a proportional coefficient, and then superimposed on the effective value loop as a reference, and then the output of the effective value loop is multiplied by SinWt as a reference for the voltage instantaneous value loop.

8. A UPS current sharing control method according to claim 7, characterized in that: In step five, the DSP of the UPS shared DC input source is used to subtract the collected local DC input current I_bat and the current sharing bus DC current reference I_share to obtain the current difference I_deta, and then the current difference I_deta is multiplied by a proportional coefficient and SinWt, and then superimposed on the output of the voltage instantaneous value loop as a reference for the inductor current loop.

9. A UPS current sharing control method according to claim 8, characterized in that: In step five, the output of the inductor current loop is finally used to drive the insulated gate bipolar transistor of the inverter bridge. The output of the inverter bridge is connected in parallel after being filtered by the inductor and capacitor to supply power to the load. When the load changes, the input current of the shared DC input source of each UPS changes accordingly to achieve current sharing, thereby achieving load balance of the load cabinets loaded on the three items of the UPS.

10. A UPS, based on any one of claims 1 to 9, implemented by the steps of a UPS current sharing control method, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: This is achieved when the processor executes the computer program.

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