A three-phase power dynamic distribution method and a three-phase inverter

Abstract

The present invention relates to a three-phase power dynamic distribution method and a three-phase inverter, which are used for a control unit of the three-phase inverter. The method includes: S1, obtaining the inverter power parameter values of each phase, obtaining the meter power parameter values of each phase, and obtaining the rated power parameter value of the inverter; S2, calculating the overload power of each phase according to the inverter power parameter values, the meter power parameter values, and the rated power parameter value, and then generating the overload state of each phase according to the overload power of each phase; S3, obtaining the power limit value of the current overload state according to the inverter power parameter values of each phase, the rated power parameter value of the inverter, and the overload state of each phase. The solution of the present application calculates a distribution result with lower overload power and higher power balance degree for each phase on the premise of meeting the maximum utilization of power, and can significantly reduce the negative impact caused by long-term overload of a certain phase.

Description

Technical Field

[0001] The present invention relates to the field of energy storage electric meters, and particularly to a three-phase power dynamic distribution method and a three-phase inverter. Background Art

[0002] With the advancement of globalization and the rapid development of renewable energy technologies, the market demand for inverters is increasing day by day. In overseas operations, the application scenarios and requirements of inverters show diverse characteristics. For example, in a photovoltaic energy storage system deployed overseas, a three-phase inverter is provided, and the utilization rate of the inverter power is not high, which not only affects the customer experience at the demand side but also poses higher requirements for the after-sales work of R & D manufacturers.

[0003] Therefore, there is a need in the industry to design a technical solution applicable to three-phase inverters to face the diversification of application scenarios and requirements, especially to improve the utilization rate of inverter power. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: how to design a three-phase power dynamic distribution method that can effectively solve the above problems.

[0005] The inventors found in the process of serving overseas customers that three-phase inverters in our country serve power-consuming entities such as large factories (with relatively stable loads and relatively balanced loads in each phase), and the inverters usually have three-phase balanced output; however, in overseas markets, especially in the European market, in the household electricity environment (or small commercial electricity environments of the same level), there are situations where single-phase loads and three-phase loads are used in a mixed manner. In such application scenarios, the loads in each phase vary greatly, and occasional load increases and temporary load peaks make it necessary for R & D personnel to refer to the peak load when designing inverter products. To cope with the temporary load peak in a certain phase, increasing the overall power of the inverter will affect the utilization rate of the inverter power. A strategy that can effectively distribute according to the load conditions in each phase while keeping the overall power of the inverter unchanged is needed; on the other hand, single-phase inverters are used in domestic household scenarios, and there is no such power distribution problem for single-phase inverters. Based on this, the present application proposes a three-phase power dynamic distribution method and a three-phase inverter, which calculate a distribution result with lower overload power and higher power balance degree in each phase on the premise of maximizing power utilization, and can significantly reduce the negative impact brought by long-term overload in a certain phase.

[0006] In a first aspect, the present invention provides a three-phase power dynamic distribution method for a control unit of a three-phase inverter. Each phase of the three-phase inverter includes an R phase, an S phase, and a T phase. The method includes: S1, obtaining the inverter power parameter values of each phase, obtaining the power meter power parameter values of each phase, and obtaining the rated power parameter value of the inverter; S2, calculating the overload power of each phase based on the inverter power parameter values, the power meter power parameter values, and the rated power parameter value, and then generating the overload state of each phase according to the overload power of each phase; S3, obtaining the power limit value of the current overload state based on the inverter power parameter values of each phase, the rated power parameter value of the inverter, and the overload state of each phase.

[0007] A further technical solution thereof is that S3, obtaining the power limit value of the current overload state based on the inverter power parameter values of each phase, the rated power parameter value of the inverter, and the overload state of each phase, includes: S31, judging the magnitude relationship between the sum of the effective load powers of each phase and the rated power parameter value; S32, if the sum of the effective load powers of each phase is less than the rated power parameter value, obtaining the power limit value of the current overload state through the first distribution mode; S33, if the sum of the effective load powers of each phase is not less than the rated power parameter value, obtaining the power limit value of the current overload state through the second distribution mode.

[0008] A further technical solution thereof is that S1, obtaining the inverter power parameter values of each phase, obtaining the power meter power parameter values of each phase, and obtaining the rated power parameter value of the inverter, includes: obtaining the inverter power parameter values of each phase, where the inverter power parameter values include the R-phase inverter power InvR, the S-phase inverter power InvS, and the T-phase inverter power InvT; obtaining the power meter power parameter values of each phase, where the power meter power parameter values include the R-phase power meter power MeterR, the S-phase power meter power MeterS, and the T-phase power meter power MeterT; obtaining the rated power parameter value of the inverter, and the rated power parameter value is the rated power Pn.

[0009] A further technical solution is that the rated power Pn multiplied by the coefficient K equals the clipped power, where the coefficient K is a preset maximum power coefficient per phase; it is defined that the inverter discharge power is positive and the meter power flowing from the grid side to the inverter side is positive. Based on the above direction definition, the effective load power is the inverter power plus the meter power, and the R-phase effective load power LR, S-phase effective load power LS, and T-phase effective load power LT are all not less than zero; the R-phase effective load power LR equals the R-phase inverter power InvR plus the R-phase meter power MeterR and does not exceed the clipped power, the S-phase effective load power LS equals the S-phase inverter power InvS plus the S-phase meter power MeterS and does not exceed the clipped power, and the T-phase effective load power LT equals the T-phase inverter power InvT plus the T-phase meter power MeterT and does not exceed the clipped power; in step S2, according to the inverter power parameter value, the meter power parameter value, and the rated power parameter value, calculate the overload power of each phase, and then generate the overload status of each phase based on the overload power of each phase, including: according to the inverter power parameter value, the meter power parameter value, and the rated power parameter value, calculate the overload power of the R phase, that is, the R-phase overload power PolR equals the R-phase inverter power InvR plus the R-phase meter power MeterR minus 1 / 3 of the rated power Pn, and then determine that if the R-phase overload power PolR is greater than zero, the R phase is overloaded, otherwise it is not overloaded, and thus obtain the R-phase judgment result; according to the inverter power parameter value, the meter power parameter value, and the rated power parameter value, calculate the overload power of the S phase, that is, the S-phase overload power PolS equals the S-phase inverter power InvS plus the S-phase meter power MeterS minus 1 / 3 of the rated power Pn, and then determine that if the S-phase overload power PolS is greater than zero, the S phase is overloaded, otherwise it is not overloaded, and thus obtain the S-phase judgment result; according to the inverter power parameter value, the meter power parameter value, and the rated power parameter value, calculate the overload power of the T phase, that is, the T-phase overload power PolT equals the T-phase inverter power InvT plus the T-phase meter power MeterT minus 1 / 3 of the rated power Pn, and then determine that if the T-phase overload power PolT is greater than zero, the T phase is overloaded, otherwise it is not overloaded, and thus obtain the T-phase judgment result. Among them, the coefficient K is a preset maximum power coefficient per phase, and its value range is [1 / 3, 1], which can be understood by engineers in this field.

[0010] A further technical solution is that the loads connected to the three-phase inverter include single-phase loads and three-phase loads; in step S31, determine the magnitude relationship between the sum of the effective load powers of each phase and the rated power parameter value, including: calculate the magnitude relationship between the sum of the R-phase effective load power LR, the S-phase effective load power LS, and the T-phase effective load power LT and the rated power Pn to obtain a comparison result.

[0011] A further technical solution thereof is that for S32, if the sum of the active load powers of each phase is less than the rated power parameter value, the power limit value of the current overload state is obtained through the first distribution mode, including: if the sum of the R-phase active load power LR, the S-phase active load power LS, and the T-phase active load power LT is less than the rated power parameter value, judge the overload conditions of the R phase, the S phase, and the T phase; in the case where none of the phases is overloaded, the power limit value PR1 is equal to 1 / 3 * the rated power Pn; the power limit value PS1 is equal to 1 / 3 * the rated power Pn; the power limit value PT1 is equal to 1 / 3 * the rated power Pn; in the case where the R phase is overloaded and the others are not, the power limit value PR1 is equal to the R-phase active load power LR; the power limit value PS1 is equal to the S-phase active load power LS plus the power parameter value TMP1; the power limit value PT1 is equal to the T-phase active load power LT plus the power parameter value TMP1; in the case where the S phase is overloaded and the others are not, the power limit value PR1 is equal to the R-phase active load power LR plus the power parameter value TMP1; the power limit value PS1 is equal to the S-phase active load power LS; the power limit value PT1 is equal to the T-phase active load power LT plus the power parameter value TMP1; in the case where the T phase is overloaded and the others are not, the power limit value PR1 is equal to the R-phase active load power LR plus the power parameter value TMP1; the power limit value PS1 is equal to the S-phase active load power LS plus the power parameter value TMP1; the power limit value PT1 is equal to the T-phase active load power LT; the power parameter value TMP1 is equal to half of the result of subtracting the R-phase active load power LR, the S-phase active load power LS, and the T-phase active load power LT from the rated power Pn; in the case where the R phase and the S phase are overloaded and the others are not, the power limit value PR1 is equal to the R-phase active load power LR; the power limit value PS1 is equal to the S-phase active load power LS; the power limit value PT1 is equal to the power parameter value TMP21; the power parameter value TMP21 is equal to the result of subtracting the R-phase active load power LR and the S-phase active load power LS from the rated power Pn; in the case where the R phase and the T phase are overloaded and the others are not, the power limit value PR1 is equal to the R-phase active load power LR; the power limit value PS1 is equal to the power parameter value TMP22; the power limit value PT1 is equal to the T-phase active load power LT; the power parameter value TMP22 is equal to the result of subtracting the R-phase active load power LR and the T-phase active load power LT from the rated power Pn; in the case where the S phase and the T phase are overloaded and the others are not, the power limit value PR1 is equal to the power parameter value TMP23; the power limit value PS1 is equal to the S-phase active load power LS; the power limit value PT1 is equal to the T-phase active load power LT; the power parameter value TMP23 is equal to the result of subtracting the S-phase active load power LS and the T-phase active load power LT from the rated power Pn;Obtain the results of the power limit values of the current overload state through the first distribution mode, namely the power limit value PR1, the power limit value PS1, and the power limit value PT1.;

[0012] Its further technical solution is that for S33, if the sum of the payload powers of each phase is not less than the rated power parameter value, obtaining the power limit value of the current overload state through the second distribution mode includes: if the sum of the R-phase payload power LR, the S-phase payload power LS, and the T-phase payload power LT is not less than the rated power parameter value, determining the overload conditions of the R phase, the S phase, and the T phase; in the case where all phases are overloaded, the power limit value PR2 is equal to 1 / 3 * the rated power Pn; the power limit value PS2 is equal to 1 / 3 * the rated power Pn; the power limit value PT2 is equal to 1 / 3 * the rated power Pn; in the case where the R phase is overloaded and the others are not, the power limit value PR2 is equal to the power parameter value TMP31; the power limit value PS2 is equal to the S-phase payload power LS; the power limit value PT2 is equal to the T-phase payload power LT; the power parameter value TMP31 is equal to the result of subtracting the S-phase payload power LS and the T-phase payload power LT from the rated power Pn; in the case where the S phase is overloaded and the others are not, the power limit value PR2 is equal to the R-phase payload power LR; the power limit value PS2 is equal to the power parameter value TMP32; the power limit value PT2 is equal to the T-phase payload power LT; the power parameter value TMP32 is equal to the result of subtracting the payload power LoadR and the payload power LoadT from the rated power Pn; in the case where the T phase is overloaded and the others are not, the power limit value PR2 is equal to the R-phase payload power LR; the power limit value PS2 is equal to the S-phase payload power LS; the power limit value PT2 is equal to the power parameter value TMP33; the power parameter value TMP33 is equal to the result of subtracting the payload power LoadR and the payload power LoadS from the rated power Pn; in the case where the R phase and the S phase are overloaded and the others are not, if the R-phase overload power PolR is less than the power parameter value TMP4, the judgment of the S-phase overload power PolS is omitted, the power limit value PR2 is equal to the R-phase payload power LR; the power limit value PS2 is equal to the rated power Pn minus the R-phase payload power LR minus the T-phase payload power LT; the power limit value PT2 is equal to the T-phase payload power LT; if the R-phase overload power PolR is not less than the power parameter value TMP4 and the S-phase overload power PolS is less than the power parameter value TMP4, the power limit value PR2 is equal to the rated power Pn minus the S-phase payload power LS minus the T-phase payload power LT; the power limit value PS2 is equal to the S-phase payload power LS; the power limit value PT2 is equal to the T-phase payload power LT; if the R-phase overload power PolR is not less than the power parameter value TMP4 and the S-phase overload power PolS is not less than the power parameter value TMP4, the power limit value PR2 is equal to 1 / 3 * the rated power Pn plus the power parameter value TMP4; the power limit value PS2 is equal to 1 / 3 * the rated power Pn plus the power parameter value TMP4; the power limit value PT2 is equal to the T-phase payload power LT;The power parameter value TMP4 is equal to one-half of the result of subtracting the T-phase effective load power LT from one-third of the rated power Pn. In the case of overload in the R phase and T phase while other phases are not overloaded, if the R-phase overload power PolR is less than the power parameter value TMP5, the judgment of the T-phase overload power PolT is omitted, and the power limit value PR2 is equal to the R-phase effective load power LR; the power limit value PS2 is equal to the S-phase effective load power LS; the power limit value PT2 is equal to the rated power Pn minus the R-phase effective load power LR minus the S-phase effective load power LS. If the R-phase overload power PolR is not less than the power parameter value TMP5 and the T-phase overload power PolT is less than the power parameter value TMP5, the power limit value PR2 is equal to the rated power Pn minus the S-phase effective load power LS minus the T-phase effective load power LT; the power limit value PS2 is equal to the S-phase effective load power LS; the power limit value PT2 is equal to the T-phase effective load power LT. If the R-phase overload power PolR is not less than the power parameter value TMP5 and the T-phase overload power PolT is not less than the power parameter value TMP5, the power limit value PR2 is equal to one-third of the rated power Pn plus the power parameter value TMP5; the power limit value PS2 is equal to the S-phase effective load power LS; the power limit value PT2 is equal to one-third of the rated power Pn plus the power parameter value TMP5. The power parameter value TMP5 is equal to one-half of the result of subtracting the S-phase effective load power LS from one-third of the rated power Pn. In the case of overload in the S phase and T phase while other phases are not overloaded, if the S-phase overload power PolS is less than the power parameter value TMP6, the judgment of the T-phase overload power PolT is omitted, and the power limit value PR2 is equal to the R-phase effective load power LR; the power limit value PS2 is equal to the S-phase effective load power LS; the power limit value PT2 is equal to the rated power Pn minus the R-phase effective load power LR minus the S-phase effective load power LS. If the S-phase overload power PolS is not less than the power parameter value TMP6 and the T-phase overload power PolT is less than the power parameter value TMP6, the power limit value PR2 is equal to the R-phase effective load power LR; the power limit value PS2 is equal to the rated power Pn minus the R-phase effective load power LR minus the T-phase effective load power LT; the power limit value PT2 is equal to the T-phase effective load power LT. If the S-phase overload power PolS is not less than the power parameter value TMP6 and the T-phase overload power PolT is not less than the power parameter value TMP6, the power limit value PR2 is equal to the R-phase effective load power LR; the power limit value PS2 is equal to one-third of the rated power Pn plus the power parameter value TMP6; the power limit value PT2 is equal to one-third of the rated power Pn plus the power parameter value TMP6. The power parameter value TMP6 is equal to one-half of the result of subtracting the R-phase effective load power LR from one-third of the rated power Pn.The result of obtaining the power limit amplitude value of the current overload state through the second distribution mode, namely the power limit amplitude value PR2, the power limit amplitude value PS2, and the power limit amplitude value PT2.

[0013] With the development of the new energy power generation field, three-phase four-wire inverters that support unbalanced three-phase output have emerged in the industry. Such inverters can support different powers for the three-phase outputs at the same time, improving the flexibility of power output. The maximum power of each phase of such inverters is also one-third of the rated power of the inverter; for three-phase inverters that support unbalanced output, when operating in parallel with a single-phase load and the load is greater than one-third of the rated power, due to the maximum output power limit of each phase, the power exceeding one-third of the rated power is provided by the power grid. At this time, since the other two phases have no load and the power cannot be output to the loaded phase, the power utilization rate is low. Since the other two phases have no load, the unused power can be considered to be added to the loaded phase. Usually, the hardware design considers that the rated power of each phase is one-third of the total power, and not all the power can be added to the same phase, but generally has a small overload output capacity. For example, for a 10KW machine, the maximum output of each phase is 5KW, but the total three-phase power does not exceed 10KW.

[0014] This application proposes a power dynamic distribution method for three-phase inverters to improve the power utilization rate of three-phase inverters that support unbalanced power output. Specifically: First, dynamically distribute the maximum power of each phase according to the load conditions to meet the load requirements to the greatest extent (distribution principle 1). Compared with the scheme where the maximum power of each phase is fixed at 1 / 3 of the rated power, the power utilization is improved; Second, on the premise of meeting distribution principle 1, the overload power of each phase is preferentially reduced (distribution principle 2). Selecting the distribution result with the lowest single-phase overload power reduces the situation of long-term overload of a certain phase; Finally, after the above two distribution principles, the three-phase reverse output balance of the inverter is preferentially ensured (distribution principle 3). Distribution principles 2 and 3 can reduce the difference in device life caused by the excessive long-term power difference of each phase, and make the inverter operate in a better working condition.

[0015] In summary, in overseas operations, the application scenarios and requirements of inverters exhibit diverse characteristics. For example, in a photovoltaic energy storage system deployed overseas, a three-phase inverter is installed, but the utilization rate of its inverter power is not high, which not only affects the customer experience at the demand side but also poses higher requirements for the after-sales work of R & D manufacturers. The three-phase inverters in our country serve power-consuming entities such as large factories (where the load is relatively stable and the three-phase loads are relatively balanced), and the inverters usually have a three-phase balanced output. However, in overseas markets, especially in the European market, in the household electricity environment (or a small commercial electricity environment of the same level), there is a situation where single-phase and three-phase loads are used in a mixed manner. In such application scenarios, the differences in the three-phase loads are large, and accidental load increases and temporary load peaks make it necessary for R & D personnel to use the peak load as a reference when designing inverter products. To cope with the temporary load peak of a certain phase, increasing the overall power of the inverter will affect the utilization rate of the inverter power. There is a need for a strategy that can effectively allocate power according to the load conditions of each phase while keeping the overall inverter power unchanged. On the other hand, single-phase inverters are used in domestic household scenarios, and there is no such power distribution problem. Based on this, the present application proposes a three-phase power dynamic distribution method and a three-phase inverter, which calculate a distribution result with lower overload power and higher power balance for each phase on the premise of maximizing power utilization, and can significantly reduce the negative impact caused by long-term overload of a certain phase. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings herein are incorporated into and constitute a part of this specification, showing embodiments consistent with the present invention, and are used together with the specification to explain the principles of the present invention.

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or in the prior art, the following will briefly introduce the accompanying drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a schematic flowchart of the three-phase power dynamic distribution method provided by an embodiment of the present invention.

[0019] Figure 2 It is another schematic flowchart of the three-phase power dynamic distribution method provided by an embodiment of the present invention.

[0020] Figure 3 It is a framework diagram of the energy storage system corresponding to the three-phase inverter provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] It should be understood that when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or other features, wholes, steps, operations, elements, components, and / or their combinations.

[0023] It should also be understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms.

[0024] It should be further understood that the term " / and" used in the specification of the present invention and the appended claims refers to any one or any combination of the related listed items and all possible combinations, and includes these combinations.

[0025] As used in this specification and the appended claims, the term "if" can be interpreted as "when...", "once", "in response to determining", or "in response to detecting" according to the context. Similarly, the phrase "if determined" or "if [the described condition or event] is detected" can be interpreted as meaning "once determined", "in response to determining", "once [the described condition or event] is detected", or "in response to detecting [the described condition or event]" according to the context.

[0026] In this specification and the appended claims, there may be multiple ways of expressing the same technical feature or professional term, such as using upper-level generalization, lower-level limitation, or synonymous substitution and other different expression forms; those skilled in the art can clearly understand the substantially same technical meaning pointed to by different expression forms based on their professional knowledge and in combination with the overall content of the specification and the accompanying drawings; the differences in different expression forms only lie in the diversity at the literal level, do not constitute a substantial modification or limitation to the technical solution, and will not affect the certainty of the protection scope of the patent claim and the full disclosure of the technical content of the specification.

[0027] Embodiment

[0028] Please refer to Figures 1 to 3 , wherein Figures 1 to 2Schematic flow chart of a three-phase power dynamic distribution method provided by an embodiment of the present invention. An embodiment of the present invention proposes a three-phase power dynamic distribution method for a control unit of a three-phase inverter. Each phase of the three-phase inverter includes an R phase, an S phase, and a T phase. In the following embodiments of the present application, the inverter power discharge is positive and the charging is negative; the meter power is positive when taking power from the power grid and negative when discharging to the power grid. The method includes: S1, obtaining the inverter power parameter values of each phase, obtaining the meter power parameter values of each phase, and obtaining the rated power parameter value of the inverter; S2, calculating the overload power of each phase according to the inverter power parameter values, the meter power parameter values, and the rated power parameter value, and then generating the overload state of each phase according to the overload power of each phase; S3, obtaining the power limit value of the current overload state according to the inverter power parameter values of each phase, the rated power parameter value of the inverter, and the overload state of each phase.

[0029] In one embodiment, in S3, obtaining the power limit value of the current overload state according to the inverter power parameter values of each phase, the rated power parameter value of the inverter, and the overload state of each phase includes: S31, judging the magnitude relationship between the sum of the effective load powers of each phase and the rated power parameter value; S32, if the sum of the effective load powers of each phase is less than the rated power parameter value, obtaining the power limit value of the current overload state through the first distribution mode; S33, if the sum of the effective load powers of each phase is not less than the rated power parameter value, obtaining the power limit value of the current overload state through the second distribution mode.

[0030] In one embodiment, in S1, obtaining the inverter power parameter values of each phase, obtaining the meter power parameter values of each phase, and obtaining the rated power parameter value of the inverter includes: obtaining the inverter power parameter values of each phase, where the inverter power parameter values include the R-phase inverter power InvR, the S-phase inverter power InvS, and the T-phase inverter power InvT; obtaining the meter power parameter values of each phase, where the meter power parameter values include the R-phase meter power MeterR, the S-phase meter power MeterS, and the T-phase meter power MeterT; obtaining the rated power parameter value of the inverter, where the rated power parameter value is the rated power Pn.

[0031] In one embodiment, the rated power Pn multiplied by the coefficient K equals the clipped power, where the coefficient K is a preset maximum power coefficient per phase; the inverter discharge power is defined as positive, and the power meter power flowing from the grid side to the inverter side is defined as positive. Based on the above direction definitions, the effective load power is the inverter power plus the power meter power, and the R-phase effective load power LR, S-phase effective load power LS, and T-phase effective load power LT are all not less than zero; the R-phase effective load power LR equals the R-phase inverter power InvR plus the R-phase power meter power MeterR and does not exceed the clipped power, the S-phase effective load power LS equals the S-phase inverter power InvS plus the S-phase power meter power MeterS and does not exceed the clipped power, and the T-phase effective load power LT equals the T-phase inverter power InvT plus the T-phase power meter power MeterT and does not exceed the clipped power; for S2, according to the inverter power parameter values, power meter power parameter values, and rated power parameter values, calculate the overload power of each phase, and then generate the overload status of each phase based on the overload power of each phase, including: according to the inverter power parameter values, power meter power parameter values, and rated power parameter values, calculate the overload power of the R phase, that is, the R-phase overload power PolR equals the R-phase inverter power InvR plus the R-phase power meter power MeterR minus 1 / 3 of the rated power Pn. Then, if the R-phase overload power PolR is greater than zero, the R phase is overloaded; otherwise, it is not overloaded, and thus the R-phase judgment result is obtained; according to the inverter power parameter values, power meter power parameter values, and rated power parameter values, calculate the overload power of the S phase, that is, the S-phase overload power PolS equals the S-phase inverter power InvS plus the S-phase power meter power MeterS minus 1 / 3 of the rated power Pn. Then, if the S-phase overload power PolS is greater than zero, the S phase is overloaded; otherwise, it is not overloaded, and thus the S-phase judgment result is obtained; according to the inverter power parameter values, power meter power parameter values, and rated power parameter values, calculate the overload power of the T phase, that is, the T-phase overload power PolT equals the T-phase inverter power InvT plus the T-phase power meter power MeterT minus 1 / 3 of the rated power Pn. Then, if the T-phase overload power PolT is greater than zero, the T phase is overloaded; otherwise, it is not overloaded, and thus the T-phase judgment result is obtained. Among them, the coefficient K is a preset maximum power coefficient per phase, and its value range is [1 / 3, 1], which can be understood by engineers in this field.

[0032] In one embodiment, the loads connected to the three-phase inverter include single-phase loads and three-phase loads; for S31, determine the magnitude relationship between the sum of the effective load powers of each phase and the rated power parameter value, including: calculate the magnitude relationship between the sum of the R-phase effective load power LR, S-phase effective load power LS, and T-phase effective load power LT and the rated power Pn to obtain a comparison result.

[0033] In one embodiment, for S32, if the sum of the payload powers of each phase is less than the rated power parameter value, obtaining the power limit value of the current overload state through the first distribution mode includes: if the sum of the R-phase payload power LR, the S-phase payload power LS, and the T-phase payload power LT is less than the rated power parameter value, determining the overload conditions of the R phase, the S phase, and the T phase; when none of the phases is overloaded, the power limit value PR1 is equal to 1 / 3 * the rated power Pn; the power limit value PS1 is equal to 1 / 3 * the rated power Pn; the power limit value PT1 is equal to 1 / 3 * the rated power Pn; when the R phase is overloaded and the others are not, the power limit value PR1 is equal to the R-phase payload power LR; the power limit value PS1 is equal to the S-phase payload power LS plus the power parameter value TMP1; the power limit value PT1 is equal to the T-phase payload power LT plus the power parameter value TMP1; when the S phase is overloaded and the others are not, the power limit value PR1 is equal to the R-phase payload power LR plus the power parameter value TMP1; the power limit value PS1 is equal to the S-phase payload power LS; the power limit value PT1 is equal to the T-phase payload power LT plus the power parameter value TMP1; when the T phase is overloaded and the others are not, the power limit value PR1 is equal to the R-phase payload power LR plus the power parameter value TMP1; the power limit value PS1 is equal to the S-phase payload power LS plus the power parameter value TMP1; the power limit value PT1 is equal to the T-phase payload power LT; the power parameter value TMP1 is equal to the result of multiplying (the rated power Pn minus the R-phase payload power LR minus the S-phase payload power LS minus the T-phase payload power LT) by one-half; when the R phase and the S phase are overloaded and the others are not, the power limit value PR1 is equal to the R-phase payload power LR; the power limit value PS1 is equal to the S-phase payload power LS; the power limit value PT1 is equal to the power parameter value TMP21; the power parameter value TMP21 is equal to the rated power Pn minus the R-phase payload power LR minus the S-phase payload power LS; when the R phase and the T phase are overloaded and the others are not, the power limit value PR1 is equal to the R-phase payload power LR; the power limit value PS1 is equal to the power parameter value TMP22; the power limit value PT1 is equal to the T-phase payload power LT; the power parameter value TMP22 is equal to the rated power Pn minus the R-phase payload power LR minus the T-phase payload power LT; when the S phase and the T phase are overloaded and the others are not, the power limit value PR1 is equal to the power parameter value TMP23; the power limit value PS1 is equal to the S-phase payload power LS; the power limit value PT1 is equal to the T-phase payload power LT; the power parameter value TMP23 is equal to the rated power Pn minus the S-phase payload power LS minus the T-phase payload power LT;Obtain the results of the power limit amplitude values of the current overload status through the first distribution mode, namely the power limit amplitude value PR1, the power limit amplitude value PS1, and the power limit amplitude value PT1.;

[0034] In one embodiment, for S33, if the sum of the payload powers of all phases is not less than the rated power parameter value, obtaining the power limit value of the current overload state through the second distribution mode includes: if the sum of the R-phase payload power LR, the S-phase payload power LS, and the T-phase payload power LT is not less than the rated power parameter value, determining the overload conditions of the R phase, the S phase, and the T phase; in the case where all phases are overloaded, the power limit value PR2 is equal to 1 / 3 * the rated power Pn; the power limit value PS2 is equal to 1 / 3 * the rated power Pn; the power limit value PT2 is equal to 1 / 3 * the rated power Pn; in the case where the R phase is overloaded and the others are not, the power limit value PR2 is equal to the power parameter value TMP31; the power limit value PS2 is equal to the S-phase payload power LS; the power limit value PT2 is equal to the T-phase payload power LT; the power parameter value TMP31 is equal to the result of subtracting the S-phase payload power LS and the T-phase payload power LT from the rated power Pn; in the case where the S phase is overloaded and the others are not, the power limit value PR2 is equal to the R-phase payload power LR; the power limit value PS2 is equal to the power parameter value TMP32; the power limit value PT2 is equal to the T-phase payload power LT; the power parameter value TMP32 is equal to the result of subtracting the payload power LoadR and the payload power LoadT from the rated power Pn; in the case where the T phase is overloaded and the others are not, the power limit value PR2 is equal to the R-phase payload power LR; the power limit value PS2 is equal to the S-phase payload power LS; the power limit value PT2 is equal to the power parameter value TMP33; the power parameter value TMP33 is equal to the result of subtracting the payload power LoadR and the payload power LoadS from the rated power Pn; in the case where the R phase and the S phase are overloaded and the others are not, if the R-phase overload power PolR is less than the power parameter value TMP4, the determination of the S-phase overload power PolS is omitted, the power limit value PR2 is equal to the R-phase payload power LR; the power limit value PS2 is equal to the rated power Pn minus the R-phase payload power LR minus the T-phase payload power LT; the power limit value PT2 is equal to the T-phase payload power LT; if the R-phase overload power PolR is not less than the power parameter value TMP4 and the S-phase overload power PolS is less than the power parameter value TMP4, the power limit value PR2 is equal to the rated power Pn minus the S-phase payload power LS minus the T-phase payload power LT; the power limit value PS2 is equal to the S-phase payload power LS; the power limit value PT2 is equal to the T-phase payload power LT; if the R-phase overload power PolR is not less than the power parameter value TMP4 and the S-phase overload power PolS is not less than the power parameter value TMP4, the power limit value PR2 is equal to 1 / 3 * the rated power Pn plus the power parameter value TMP4; the power limit value PS2 is equal to 1 / 3 * the rated power Pn plus the power parameter value TMP4; the power limit value PT2 is equal to the T-phase payload power LT;The power parameter value TMP4 is equal to one-half of the result of subtracting the T-phase effective load power LT from 1 / 3 of the rated power Pn; in the case of overload in the R-phase and T-phase while other phases are not overloaded, if the R-phase overload power PolR is less than the power parameter value TMP5, the judgment of the T-phase overload power PolT is omitted, and the power limit value PR2 is equal to the R-phase effective load power LR; the power limit value PS2 is equal to the S-phase effective load power LS; the power limit value PT2 is equal to the rated power Pn minus the R-phase effective load power LR minus the S-phase effective load power LS; if the R-phase overload power PolR is not less than the power parameter value TMP5 and the T-phase overload power PolT is less than the power parameter value TMP5, the power limit value PR2 is equal to the rated power Pn minus the S-phase effective load power LS minus the T-phase effective load power LT; the power limit value PS2 is equal to the S-phase effective load power LS; the power limit value PT2 is equal to the T-phase effective load power LT; if the R-phase overload power PolR is not less than the power parameter value TMP5 and the T-phase overload power PolT is not less than the power parameter value TMP5, the power limit value PR2 is equal to 1 / 3 of the rated power Pn plus the power parameter value TMP5; the power limit value PS2 is equal to the S-phase effective load power LS; the power limit value PT2 is equal to 1 / 3 of the rated power Pn plus the power parameter value TMP5; the power parameter value TMP5 is equal to one-half of the result of subtracting the S-phase effective load power LS from 1 / 3 of the rated power Pn; in the case of overload in the S-phase and T-phase while other phases are not overloaded, if the S-phase overload power PolS is less than the power parameter value TMP6, the judgment of the T-phase overload power PolT is omitted, and the power limit value PR2 is equal to the R-phase effective load power LR; the power limit value PS2 is equal to the S-phase effective load power LS; the power limit value PT2 is equal to the rated power Pn minus the R-phase effective load power LR minus the S-phase effective load power LS; if the S-phase overload power PolS is not less than the power parameter value TMP6 and the T-phase overload power PolT is less than the power parameter value TMP6, the power limit value PR2 is equal to the R-phase effective load power LR; the power limit value PS2 is equal to the rated power Pn minus the R-phase effective load power LR minus the T-phase effective load power LT; the power limit value PT2 is equal to the T-phase effective load power LT; if the S-phase overload power PolS is not less than the power parameter value TMP6 and the T-phase overload power PolT is not less than the power parameter value TMP6, the power limit value PR2 is equal to the R-phase effective load power LR; the power limit value PS2 is equal to 1 / 3 of the rated power Pn plus the power parameter value TMP6; the power limit value PT2 is equal to 1 / 3 of the rated power Pn plus the power parameter value TMP6; the power parameter value TMP6 is equal to one-half of the result of subtracting the R-phase effective load power LR from 1 / 3 of the rated power Pn;The result of obtaining the power limit amplitude of the current overload state through the second distribution mode, that is, the power limit amplitude PR2, the power limit amplitude PS2, and the power limit amplitude PT2. In the above solution, similar to the values of the power limit amplitude PR1 and the power limit amplitude PR2, there are changing situations, and the same is true for other similar values. Their specific reference relationships are known to engineers in this field.;

[0035] In one embodiment, refer to Figure 3 the framework diagram of the energy storage system shown in. The energy storage system includes a three-phase inverter. The loads connected to the three-phase inverter include single-phase loads and three-phase loads. The three-phase inverter is used to execute the three-phase power dynamic distribution method described in any of the above embodiments. To sum up, domestic inverters in our country need to be connected to single-phase output to adapt to the domestic household electricity environment. However, this design has limitations when going overseas; specifically, the limitation is that there is no power distribution problem for single-phase inverters in our country when serving households, nor will the efficiency be low due to power distribution. However, this problem may emerge after our technical solutions go overseas, sometimes resulting in an inadaptable situation, thus bringing after-sales problems; our three-phase inverters serve electricity consumers such as large factories (loads are relatively stable). However, in overseas markets, especially in the European market, in the household electricity environment (or a small commercial electricity environment of the same level), there are situations where single-phase loads and three-phase loads are used in a mixed manner. Occasional load increases and temporary load peaks make it necessary for R & D personnel to use the peak load as a reference when designing inverter products, which will affect the utilization rate of inverter power. Based on this, the present application proposes a three-phase power dynamic distribution method and a three-phase inverter, which can allocate the power limit amplitude of phase R (power limit amplitude PR), the power limit amplitude of phase S (power limit amplitude PS), and the power limit amplitude of phase T (power limit amplitude PT) on the premise of maximizing power utilization, preferentially reducing the overload power of each phase and significantly reducing the negative impact brought by long-term overload of a certain phase.

[0036] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions, but such implementation should not be considered to exceed the scope of the present invention.

[0037] In several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of each unit is only a logical function division, and there can be other division methods in actual implementation. For example, a unit or component can be combined or integrated into another system, or some features can be ignored or not executed.

[0038] The steps in the method embodiments of the present invention can be adjusted, combined, and deleted according to actual needs. The units in the device embodiments of the present invention can be combined, divided, and deleted according to actual needs. In addition, the functional units in each embodiment of the present invention can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

[0039] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a terminal, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention.

[0040] In the above embodiments, the descriptions of the various embodiments have their own focuses. For the parts not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0041] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, provided that these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these changes and modifications.

[0042] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A three-phase power dynamic distribution method, characterized in that: A control unit for a three-phase inverter, wherein each phase of the three-phase inverter includes an R phase, an S phase, and a T phase, and the method comprises: S1, obtaining the inverter power parameter value of each phase, obtaining the meter power parameter value of each phase, and obtaining the rated power parameter value of the inverter; S2, calculating the overload power of each phase according to the inverter power parameter value, the meter power parameter value, and the rated power parameter value, and then generating the overload state of each phase according to the overload power of each phase; S3, obtaining a power limit value of a current overload state according to the inverter power parameter value of each phase, the rated power parameter value of the inverter, and the overload state of each phase; The S3 includes: S31, determining the magnitude relationship between the sum of the effective load powers of each phase and the rated power parameter value; S32, if the sum of the effective load powers of each phase is less than the rated power parameter value, obtaining the power limit value of the current overload state through the first allocation mode; S33, if the sum of the effective load powers of each phase is not less than the rated power parameter value, obtaining the power limit value of the current overload state through the second allocation mode; The S1 includes: obtaining an inverter power parameter value of each phase, the inverter power parameter value includes R phase inverter power InvR, S phase inverter power InvS, T phase inverter power InvT; obtaining an electric meter power parameter value of each phase, the electric meter power parameter value includes R phase electric meter power MeterR, S phase electric meter power MeterS, T phase electric meter power MeterT; obtaining a rated power parameter value of the inverter, the rated power parameter value is the rated power Pn; The S2 includes: calculating the overload power of the R phase according to the inverter power parameter value, the meter power parameter value, and the rated power parameter value, that is, the R phase overload power PolR is equal to the R phase inverter power InvR plus the R phase meter power MeterR minus 1 / 3*rated power Pn, and then judging that if the R phase overload power PolR is greater than zero, the R phase is overloaded, otherwise it is not loaded, and then obtaining the R phase judgment result; According to the inverter power parameter value, the meter power parameter value, and the rated power parameter value, the overload power of the S phase is calculated, that is, the S phase overload power PolS is equal to the S phase inverter power InvS plus the S phase meter power MeterS minus 1 / 3*rated power Pn. Then, if the S phase overload power PolS is greater than zero, the S phase is overloaded, otherwise it is not overloaded, and then the S phase judgment result is obtained; The overload power of phase T is calculated according to the inverter power parameter value, the meter power parameter value, and the rated power parameter value, that is, the overload power of phase T PolT is equal to the inverter power InvT of phase T plus the meter power MeterT of phase T minus 1 / 3*rated power Pn. Then, if the overload power PolT of phase T is greater than zero, then phase T is overloaded, otherwise it is not overloaded, thereby obtaining the judgment result of phase T.

2. The three-phase power dynamic distribution method according to claim 1, characterized in that: The load connected to the three-phase inverter includes a single-phase load and a three-phase load; the S31, determining the sum of the effective load powers of each phase, and comparing the sum with the rated power parameter value, the magnitude relationship between the two includes: The sum of the R phase effective load power LR plus the S phase effective load power LS plus the T phase effective load power LT is calculated, and compared with the rated power Pn, the magnitude relationship between the two is obtained to obtain a comparison result.

3. The three-phase power dynamic distribution method according to claim 2, characterized in that: The S32, if the sum of the effective load powers of each phase is less than the rated power parameter value, obtaining the power limit value of the current overload state through the first allocation mode, includes: If the sum of the effective load power LR of the R phase plus the effective load power LS of the S phase plus the effective load power LT of the T phase is less than the rated power parameter value, the overload condition of the R phase, the S phase and the T phase is determined; when each phase is not overloaded, the power limit value PR1 is equal to 1 / 3*rated power Pn; the power limit value PS1 is equal to 1 / 3*rated power Pn; the power limit value PT1 is equal to 1 / 3*rated power Pn; When the R phase is overloaded and the other phases are not overloaded, the power limit value PR1 is equal to the R phase effective load power LR; the power limit value PS1 is equal to the S phase effective load power LS plus the power parameter value TMP1; the power limit value PT1 is equal to the T phase effective load power LT plus the power parameter value TMP1; when the S phase is overloaded and the other phases are not overloaded, the power limit value PR1 is equal to the R phase effective load power LR plus the power parameter value TMP1; the power limit value PS1 is equal to the S phase effective load power LS; the power limit value PT1 is equal to the T phase effective load power LT plus the power parameter value TMP1; when the T phase is overloaded and the other phases are not overloaded, the power limit value PR1 is equal to the R phase effective load power LR plus the power parameter value TMP1; the power limit value PS1 is equal to the S phase effective load power LS plus the power parameter value TMP1; the power limit value PT1 is equal to the T phase effective load power LT; the power parameter value TMP1 is equal to the result of the rated power Pn minus the R phase effective load power LR minus the S phase effective load power LS minus the T phase effective load power LT, multiplied by one half; When the R phase and the S phase are overloaded and the other phases are not overloaded, the power limit value PR1 is equal to the R phase effective load power LR; the power limit value PS1 is equal to the S phase effective load power LS; the power limit value PT1 is equal to the power parameter value TMP21; the power parameter value TMP21 is equal to the rated power Pn minus the R phase effective load power LR minus the S phase effective load power LS; When the R phase and the T phase are overloaded and the other phases are not overloaded, the power limit value PR1 is equal to the R phase effective load power LR; the power limit value PS1 is equal to the power parameter value TMP22; the power limit value PT1 is equal to the T phase effective load power LT; the power parameter value TMP22 is equal to the rated power Pn minus the R phase effective load power LR minus the T phase effective load power LT; When the S phase and the T phase are overloaded and the other phases are not overloaded, the power limit value PR1 is equal to the power parameter value TMP23; the power limit value PS1 is equal to the S phase effective load power LS; the power limit value PT1 is equal to the T phase effective load power LT; the power parameter value TMP23 is equal to the rated power Pn minus the S phase effective load power LS minus the T phase effective load power LT; The power limit value results of the current overload state are obtained through the first allocation mode, namely, the power limit value PR1, the power limit value PS1, and the power limit value PT1.

4. The three-phase power dynamic distribution method according to claim 3, characterized in that: The step S33, if the sum of the effective load powers of each phase is not less than the rated power parameter value, obtaining the power limit value of the current overload state through the second allocation mode, includes: If the sum of the effective load power LR of the R phase plus the effective load power LS of the S phase plus the effective load power LT of the T phase is not less than the rated power parameter value, the overload conditions of the R phase, the S phase and the T phase are judged; when all phases are overloaded, the power limit value PR2 is equal to 1 / 3*rated power Pn; the power limit value PS2 is equal to 1 / 3*rated power Pn; the power limit value PT2 is equal to 1 / 3*rated power Pn; When the R phase is overloaded and the others are not overloaded, the power limit value PR2 is equal to the power parameter value TMP31; the power limit value PS2 is equal to the S phase effective load power LS; the power limit value PT2 is equal to the T phase effective load power LT; the power parameter value TMP31 is equal to the result of the rated power Pn minus the S phase effective load power LS minus the T phase effective load power LT; When the S phase is overloaded and the others are not overloaded, the power limit value PR2 is equal to the R phase effective load power LR; the power limit value PS2 is equal to the power parameter value TMP32; the power limit value PT2 is equal to the T phase effective load power LT; the power parameter value TMP32 is equal to the result of the rated power Pn minus the effective load power LoadR minus the effective load power LoadT; When the T phase is overloaded and the others are not overloaded, the power limit value PR2 is equal to the R phase effective load power LR; the power limit value PS2 is equal to the S phase effective load power LS; the power limit value PT2 is equal to the power parameter value TMP33; the power parameter value TMP33 is equal to the result of the rated power Pn minus the effective load power LoadR minus the effective load power LoadS; When the R phase and S phase are overloaded and the other phases are not overloaded, if the R phase overload power PolR is less than the power parameter value TMP4, the judgment of the S phase overload power PolS is omitted, and the power limit value PR2 is equal to the R phase effective load power LR; the power limit value PS2 is equal to the rated power Pn minus the R phase effective load power LR minus the T phase effective load power LT; the power limit value PT2 is equal to the T phase effective load power LT; if the R phase overload power PolR is not less than the power parameter value TMP4, and the S phase overload power PolS is less than the power parameter value TMP4, the power limit value PR2 is equal to the rated power Pn minus the S phase effective load power LS minus the T phase effective load power LT; power limit value PS2 is equal to S phase effective load power LS; power limit value PT2 is equal to T phase effective load power LT; if R phase overload power PolR is not less than power parameter value TMP4, and S phase overload power PolS is not less than power parameter value TMP4, power limit value PR2 is equal to 1 / 3*rated power Pn plus power parameter value TMP4; power limit value PS2 is equal to 1 / 3*rated power Pn plus power parameter value TMP4; power limit value PT2 is equal to T phase effective load power LT; power parameter value TMP4 is equal to the result of 1 / 3*rated power Pn minus T phase effective load power LT, multiplied by one half; In the case where the R phase and the T phase are overloaded and the other phases are not overloaded, if the R phase overload power PolR is less than the power parameter value TMP5, the judgment of the T phase overload power PolT is omitted, and the power limit value PR2 is equal to the R phase effective load power LR; the power limit value PS2 is equal to the S phase effective load power LS; the power limit value PT2 is equal to the rated power Pn minus the R phase effective load power LR minus the S phase effective load power LS; if the R phase overload power PolR is not less than the power parameter value TMP5, and the T phase overload power PolT is less than the power parameter value TMP5, the power limit value PR2 is equal to the rated power Pn minus the S phase effective load power LS minus the T phase effective load power LT; the power limit value PS2 is equal to the S phase effective load power LS; The power limit value PT2 is equal to the effective load power LT of the T phase; if the overload power PolR of the R phase is not less than the power parameter value TMP5, and the overload power PolT of the T phase is not less than the power parameter value TMP5, the power limit value PR2 is equal to 1 / 3*rated power Pn plus the power parameter value TMP5; the power limit value PS2 is equal to the effective load power LS of the S phase; the power limit value PT2 is equal to 1 / 3*rated power Pn plus the power parameter value TMP5; the power parameter value TMP5 is equal to the result of subtracting the effective load power LS of the S phase from 1 / 3*rated power Pn, multiplied by one half; When the S phase and the T phase are overloaded and the other phases are not overloaded, if the S phase overload power PolS is less than the power parameter value TMP6, the judgment of the T phase overload power PolT is omitted, and the power limit value PR2 is equal to the R phase effective load power LR; the power limit value PS2 is equal to the S phase effective load power LS; the power limit value PT2 is equal to the rated power Pn minus the R phase effective load power LR minus the S phase effective load power LS; if the S phase overload power PolS is not less than the power parameter value TMP6, and the T phase overload power PolT is less than the power parameter value TMP6, the power limit value PR2 is equal to the R phase effective load power LR; the power limit value PS2 is equal to the rated power P n minus the R phase effective load power LR minus the T phase effective load power LT; the power limit value PT2 is equal to the T phase effective load power LT; if the S phase overload power PolS is not less than the power parameter value TMP6, and the T phase overload power PolT is not less than the power parameter value TMP6, the power limit value PR2 is equal to the R phase effective load power LR; the power limit value PS2 is equal to 1 / 3*rated power Pn plus the power parameter value TMP6; the power limit value PT2 is equal to 1 / 3*rated power Pn plus the power parameter value TMP6; the power parameter value TMP6 is equal to the result of 1 / 3*rated power Pn minus the R phase effective load power LR, multiplied by one half; The power limit value results of the current overload state are obtained through the second allocation mode, namely, the power limit value PR2, the power limit value PS2, and the power limit value PT2.

5. A three-phase inverter, characterized in that: The loads connected to the three-phase inverter include single-phase loads and three-phase loads, and the three-phase inverter is used to execute the three-phase power dynamic allocation method according to any one of claims 1 to 4.

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