Control method, controller and inverter system for an inverter

Abstract

The present disclosure relates to a control method of an inverter, a controller and an inverter system, and relates to the field of electric energy conversion. The method comprises: obtaining a target output power of an inverter. A target control power corresponding to the target output power is determined through a preset power correspondence relationship. The power correspondence relationship comprises a correspondence relationship between the target output power and the target control power. The power correspondence relationship is determined according to a sample output power and a sample control power, and the sample output power is obtained by controlling a sample inverter output according to the sample control power. According to the target control power, an inverter bridge of the inverter is controlled to make the inverter bridge output the target output power. The present disclosure corrects the target control power of the inverter according to the preset power correspondence relationship and the target output power, so that the output power of the inverter controlled by the target control power is the same as the target output power, thereby improving the control accuracy of the inverter.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of electric energy conversion, in particular, to a control method of an inverter, a controller and an inverter system. BACKGROUND

[0002] At present, the inverter control system usually adopts current loop PI control and grid voltage feedforward control to control the output target power. First, the instruction current and the real-time sampled inverter side current DC component are subtracted to input the current loop PI controller, the output values of the PI controller are added with the inductance feedforward decoupling amount and the grid voltage feedforward amount respectively to obtain the output reference voltage DC component, then the output reference voltage is obtained through Park inversion and Clark inversion, and then the PWM (English: Pulse Width Modulation, Chinese: Pulse Width Modulation) modulated output square wave signal is obtained to drive the three-phase inverter bridge to output the target power. Due to the inaccurate parameters of the inductance feedforward decoupling amount, and the line resistance voltage drop and filter capacitor current ignored in the control process, the actual output power of the inverter is greatly different from the target output power. SUMMARY

[0003] The purpose of the present disclosure is to provide a control method of an inverter, a controller and an inverter system for improving the accuracy of the output power of the inverter.

[0004] According to a first aspect of the embodiments of the present disclosure, a control method of an inverter is provided, the method comprising:

[0005] obtaining a target output power of the inverter;

[0006] determining a target control power corresponding to the target output power through a preset power corresponding relationship, the power corresponding relationship comprising a corresponding relationship between the target output power and the target control power, the power corresponding relationship being determined according to a corresponding relationship between a sample output power and a sample control power, the sample output power being obtained by controlling a sample inverter to output according to the sample control power;

[0007] controlling an inverter bridge of the inverter according to the target control power, so that the inverter bridge outputs the target output power.

[0008] Optionally, the target output power comprises a target active output power and a target reactive output power; the target control power comprises a target active control power and a target reactive control power; the power corresponding relationship comprises a relationship between the target active control power and the target active output power and the target reactive output power, and a relationship between the target reactive control power and the target active output power and the target reactive output power;

[0009] The target control power corresponding to the target output power is determined by a preset power correspondence relationship.

[0010] According to the target active output power, the target reactive output power, and the preset power correspondence relationship, the target active control power is determined.

[0011] According to the target active output power, the target reactive output power, and the preset power correspondence relationship, the target reactive control power is determined.

[0012] Optionally, the method further comprises:

[0013] The preset power correspondence relationship matched with the inverter is determined from a plurality of preset power correspondence relationships, each of which is matched with at least one preset inverter.

[0014] Optionally, the preset power correspondence relationship is generated in advance by:

[0015] A sample control power is obtained.

[0016] According to the sample control power, an inverter bridge of the sample inverter is controlled to obtain an output power of the sample inverter, and the output power of the sample inverter is taken as the sample output power.

[0017] According to the sample control power and the sample output power, the preset power correspondence relationship is generated.

[0018] Optionally, the sample control power includes a plurality of sample control powers, and the generation of the preset power correspondence relationship according to the sample control power and the sample output power comprises:

[0019] A plurality of sample control powers and sample output powers corresponding to each sample control power are fitted to obtain the preset power correspondence relationship.

[0020] Optionally, the sample control power includes a sample active control power and a sample reactive control power, and the sample output power includes a sample active output power and a sample reactive output power; and the control of the inverter bridge of the sample inverter according to the sample control power to obtain the output power of the sample inverter, and the taking of the output power of the sample inverter as the sample output power comprises:

[0021] According to the plurality of sample active control powers and the preset reactive control power, the inverter bridge of the sample inverter is controlled to obtain a plurality of active output powers and a plurality of reactive output powers output by the sample inverter, and the plurality of active output powers are taken as first sample active output powers, and the plurality of reactive output powers are taken as first sample reactive output powers.

[0022] According to the plurality of sample active control powers and the preset reactive control power, the inverter bridge of the sample inverter is controlled to obtain a plurality of active output powers and a plurality of reactive output powers output by the sample inverter, and the plurality of active output powers are taken as first sample active output powers, and the plurality of reactive output powers are taken as first sample reactive output powers.

[0023] Optionally, the step of controlling the inverter bridge of the sample inverter according to the plurality of sample active control powers and the preset reactive control power to obtain a plurality of active output powers and a plurality of reactive output powers output by the sample inverter comprises:

[0024] For each sample active control power, the inverter bridge of the sample inverter is controlled according to the sample active control power and the preset reactive control power multiple times to obtain a plurality of active output powers and a plurality of reactive output powers corresponding to the sample active control power, and the plurality of active output powers are taken as first sub-sample active output powers, and the plurality of reactive output powers are taken as first sub-sample reactive output powers.

[0025] The average of the plurality of first sub-sample active output powers is taken as the first sample active output power corresponding to the sample active control power, and the average of the plurality of first sub-sample reactive output powers is taken as the first sample reactive output power corresponding to the sample active control power.

[0026] Optionally, the step of controlling the inverter bridge of the sample inverter according to the plurality of sample active control powers and the preset reactive control power to obtain a plurality of active output powers and a plurality of reactive output powers output by the sample inverter comprises:

[0027] For each sample active control power, the inverter bridge of the sample inverter is controlled according to the sample active control power and the preset reactive control power multiple times to obtain a plurality of active output powers and a plurality of reactive output powers corresponding to the sample active control power, and the plurality of active output powers are taken as first sub-sample active output powers, and the plurality of reactive output powers are taken as first sub-sample reactive output powers.

[0028] The average of the plurality of second sub-sample active output powers is taken as the second sample active output power corresponding to the sample reactive control power, and the average of the plurality of second sub-sample reactive output powers is taken as the second sample reactive output power corresponding to the sample reactive control power.

[0029] Optionally, the fitting of the plurality of sample control powers and the sample output power corresponding to each sample control power to obtain the preset power correspondence relationship comprises:

[0030] According to the plurality of first sample active output powers, the plurality of sample active control powers, and the preset reactive control power, a first corresponding relationship between a first target active output power and the target active control power is fitted;

[0031] According to the plurality of first sample reactive output powers, the plurality of sample active control powers, and the preset reactive control power, a second corresponding relationship between a first target reactive output power and the target active control power is fitted;

[0032] According to the plurality of second sample reactive output powers, the plurality of sample reactive control powers, and the preset active control power, a third corresponding relationship between a second target reactive output power and the target reactive control power is fitted;

[0033] According to the plurality of second sample active output powers, the plurality of sample reactive control powers, and the preset active control power, a fourth corresponding relationship between a second target active output power and the target reactive control power is fitted;

[0034] The preset power correspondence relationship is determined according to the first corresponding relationship, the second corresponding relationship, the third corresponding relationship, the fourth corresponding relationship, and a preset equivalence relationship.

[0035] Optionally, the preset equivalence relationship comprises: the target active output power is a sum of the first target active output power and the second target active output power, and the target reactive output power is a sum of the first target reactive output power and the second target reactive output power.

[0036] According to a second aspect of the embodiments of the present disclosure, a controller of an inverter is provided, which is configured to execute the control method of the inverter as described in the first aspect of the present disclosure.

[0037] According to a third aspect of the embodiments of the present disclosure, an inverter system is provided, which comprises an inverter and the controller of the inverter as described in the second aspect of the present disclosure.

[0038] By the technical solution, the target output power of the inverter is acquired first, the target control power corresponding to the target output power is determined through the preset power corresponding relationship, and then the target control power is used to control the inverter bridge so that the inverter bridge outputs the target output power. The power corresponding relationship represents the corresponding relationship between the target output power and the target control power, and the power corresponding relationship is a corresponding relationship determined according to sample output power and sample control power, and the sample output power is obtained according to the sample control power. The power corresponding relationship and the target output power are used to correct the target control power of the inverter, so that the actual output power of the inverter controlled by the target control power is the same as the target output power, and the control accuracy of the inverter is improved.

[0039] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0040] The accompanying drawings are included to provide a further understanding of the present disclosure and constitute a part of the specification, and are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation on the present disclosure. In the drawings:

[0041] Figure 1 is a schematic diagram of a control process of an inverter according to an exemplary embodiment;

[0042] Figure 2 is a flowchart of a control method of an inverter according to an exemplary embodiment;

[0043] Figure 3 is a schematic diagram of another control process of an inverter according to an exemplary embodiment; Figure 1

[0044] Figure 4 is a flowchart of a control method of an inverter according to an exemplary embodiment;

[0045] Figure 5 is a flowchart of another control method of an inverter according to an exemplary embodiment;

[0046] Figure 6 is a flowchart of a generation method of a power corresponding relationship according to an exemplary embodiment;

[0047] Figure 7 is a flowchart of another generation method of a power corresponding relationship according to an exemplary embodiment;

[0048] Figure 8 is a flowchart of another generation method of a power corresponding relationship according to an exemplary embodiment;

[0049] ​Figure 9 is a block diagram of a control device of an inverter according to an exemplary embodiment;

[0050] Figure 10 is a block diagram of another control device of an inverter according to an exemplary embodiment. DETAILED DESCRIPTION

[0051] The specific embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present disclosure, and are not intended to limit the present disclosure.

[0052] Before introducing the control method, controller and inverter system of the inverter shown in the embodiments of the present disclosure, the application scenario of the embodiments of the present disclosure is introduced first. As shown in Figure 1 In the prior art, the control system of the inverter obtains the grid-side voltage (u g , abc) through a sampling circuit, calculates the current phase (θ = ωt) of the grid voltage through a phase-locked loop (PLL), and performs Clark transformation and Park transformation on the grid-side voltage to obtain the direct current component (U, dq) of the grid-side voltage in the rotating coordinate system. And the inverter-side current (i inv , abc) is obtained through a sampling circuit, and the inverter-side current is subjected to Clark transformation and Park transformation to obtain the direct current component (I, dq) of the inverter-side current in the rotating coordinate system. Then, according to the target power (P * , Q * ) and the direct current component (U, dq) of the grid-side voltage, the command current (I * , dq) is calculated through formula 1.

[0053]

[0054] The control system adopts current loop PI control and grid voltage feedforward control to control the output target power. Specifically, the command current (I * , dq) and the real-time sampling direct current component (I, dq) of the inverter-side current are input to two current loop PI controllers respectively, and the output values of the two current loop PI controllers are added to the inductance feedforward decoupling quantity (-ωL×i q , ωL×i d ) and the grid voltage feedforward quantity (U, dq) respectively, and the obtained output reference voltage direct current component (V ref , dq) is subjected to Park inverse transformation and Clark inverse transformation to obtain the output reference voltage (V ref , abc), which is subjected to PWM (SPWM or SVPWM) modulation to output square wave signals T1-T6, abc, and the square wave signals drive the inverter bridge to output the target power (P* , Q * ). Since the inductance feed-forward decoupling parameter L is not accurate, and the line resistance voltage drop and filter capacitor current are ignored in the control process, the actual output power of the inverter bridge is greatly different from the target power.

[0055] Figure 2 is a flow chart of a control method of an inverter according to an exemplary embodiment, as shown in Figure 2 , the method comprises:

[0056] Step 101, obtaining the target output power of the inverter.

[0057] Step 102, determining the target control power corresponding to the target output power through a preset power correspondence relationship, the power correspondence relationship includes the correspondence relationship between the target output power and the target control power, the power correspondence relationship is determined according to the sample output power and the sample control power, and the sample output power is obtained by controlling the sample inverter output according to the sample control power.

[0058] Step 103, controlling the inverter bridge of the inverter according to the target control power, so that the inverter bridge outputs the target output power.

[0059] For example, the inverter in the present disclosure includes a control system, an inverter bridge and a filter system, and the execution subject of the present disclosure can be the controller of the inverter. As shown in Figure 3 , first, the target output power of the inverter is obtained, wherein the target output power can be understood as the target value of the power expected to be output by the inverter, and then the target output power (P obj_m , Q obj_m ) is corrected through a preset power correspondence relationship to obtain the corresponding target control power (P obj , Q obj ), and the target control power (P obj , Q obj ) and the grid-side voltage DC component (U * , dq) are calculated through formula 1 to obtain the command current (I * , dq). Then, the command current (I q , dq) and the real-time sampling inverter-side current DC component (I d , dq) are subtracted and input to two current loop PI controllers, and the output values of the two current loop PI controllers are added to the inductance feed-forward decoupling amount (-ωL×i ef， , ωL×i refThe inverter bridge outputs square wave signals T1 to T6, which are modulated by PWM (SPWM or SVPWM). These square wave signals control the output current of the inverter bridge, thereby outputting the target output power (Po). bj_m Q obj_m In this way, the target control power of the inverter is first corrected by a preset power correspondence to obtain the corrected target control power. The output current of the inverter bridge is then controlled according to the corrected target control power, so that the inverter can accurately output the target output power and improve the accuracy of the inverter output power.

[0060] The preset power correspondence can be used to characterize the correspondence between the target output power and the target control power. Multiple sample control powers can be preset, and corresponding sample output powers can be obtained experimentally on sample inverters. In some embodiments, for each sample control power, a command current can be obtained based on the sample control power and the DC component of the grid-side voltage, and then... Figure 1 The control process shown outputs a square wave signal, which controls the output current of the inverter bridge of the sample inverter, thereby obtaining the output power of the sample inverter. This output power is then used as the sample output power corresponding to the sample control power. A power correspondence can then be determined based on the sample output power and the sample control power. There can be one sample inverter, i.e., the inverter in this embodiment. The power correspondence obtained through experiments on the sample inverter is the preset power correspondence. Alternatively, there can be multiple sample inverters. Multiple power correspondences can be obtained by conducting experiments on multiple sample inverters, and the power correspondence matching the inverter in this embodiment is used as the preset power correspondence. This disclosure does not specifically limit this approach.

[0061] In summary, this disclosure first obtains the target output power of the inverter, determines the target control power corresponding to the target output power through a pre-generated power correspondence, and then controls the inverter bridge according to the target control power so that the inverter bridge outputs the target output power. Here, the power correspondence characterizes the relationship between the target output power and the target control power, and the power correspondence is determined based on the sample output power and sample control power. The sample output power is obtained based on the sample control power. This disclosure corrects the target control power of the inverter by pre-setting the power correspondence and the target output power, so that the actual output power of the inverter controlled by the target control power is the same as the target output power, thereby improving the control accuracy of the inverter.

[0062] Figure 4 This is a flowchart illustrating another control method for an inverter according to an exemplary embodiment, such as... Figure 4 As shown, step 102 can be achieved in the following way:

[0063] Step 1021, determining the target active control power according to the target active output power, the target reactive output power and the preset power correspondence.

[0064] Step 1022, determining the target reactive control power according to the target active output power, the target reactive output power and the preset power correspondence.

[0065] For example, the target output power can include the target active output power and the target reactive output power, wherein the target active output power can be understood as a target value of the preset expected active power output by the inverter, and the target reactive output power can be understood as a target value of the preset expected reactive power output by the inverter. Correspondingly, the target control power includes the target active control power and the target reactive control power, the target active control power can be understood as a target value of the active power actually input to the control system of the inverter, and the target reactive control power can be understood as a target value of the reactive power actually input to the control system of the inverter. Correspondingly, the preset power correspondence can include the relationship between the target active control power and the target active output power and the target reactive output power, and the relationship between the target reactive control power and the target active output power and the target reactive output power. The preset power correspondence may, for example, be as shown in Formula 2.

[0066]

[0067] Wherein, P obj is the target active control power, Q obj is the target reactive control power, P obj_m is the target active output power, Q obj_m is the target reactive output power, D1, D2, E1, E2, F1, F2 are constants.

[0068] In some embodiments, the target active output power and the target reactive output power can be obtained by the preset power correspondence corresponding to the target active control power, and the target active output power and the target reactive output power can be obtained by the preset power correspondence corresponding to the target reactive control power. That is, the target active control power and the target reactive control power are both determined by the target active output power and the target reactive output power.

[0069] Figure 5 is a flowchart of another control method of an inverter according to an example embodiment, as shown in Figure 5 The method further includes:

[0070] Step 104, determining the preset power correspondence matching the inverter from the pre-generated multiple power correspondences, each power correspondence matching at least one preset inverter.

[0071] In an example, in the case of multiple preset inverters, each preset inverter can be pre-generated with a corresponding power correspondence relationship through experiments on multiple preset sample inverters, wherein one preset sample inverter corresponds to at least one preset inverter, and the power correspondence relationship obtained through the preset sample inverter experiment matches the preset inverter corresponding to the preset sample inverter. Thus, the control power of the preset inverter matched with the power correspondence relationship can be corrected through each power correspondence relationship.

[0072] In some embodiments, after obtaining the target output power of the inverter, the sample inverter matched with the inverter can be determined from the pre-generated multiple power correspondence relationships, and the power correspondence relationship generated through the sample inverter experiment can be used as the preset power correspondence relationship. Then, the target control power corresponding to the target output power can be determined through the preset power correspondence relationship matched with the inverter, and the output current of the inverter bridge of the inverter can be controlled according to the target control power, so that the inverter bridge can accurately output the target output power.

[0073] The following describes how the power correspondence relationship is generated, wherein the sample inverter of the following content can have the same relevant parameters as the actual inverter described above, that is, the relationship between the control power and the output power of the sample inverter is equivalent to the relationship between the control power and the output power of the inverter in actual use, thereby improving the output accuracy. In addition, in other embodiments, the sample inverter can also have certain differences in relevant parameters from the inverter used in actual use. Although there are certain differences in relevant parameters, the differences are not large, which can meet the case that one pre-generated power correspondence relationship can match multiple different inverters, and thus the power correspondence relationship generated through one sample inverter experiment can be applied to multiple inverters, that is, the target control power of multiple inverters can be corrected through one power correspondence relationship, thereby reducing the experimental cost.

[0074] Figure 6 is a flowchart of a power correspondence relationship generation method according to an example embodiment, as shown in Figure 6 The preset power correspondence relationship is pre-generated in the following manner:

[0075] Step 201: Obtain the sample control power.

[0076] Step 202: Control the inverter bridge of the sample inverter according to the sample control power, obtain the output power of the sample inverter, and use the output power of the sample inverter as the sample output power.

[0077] Step 203: Generate the preset power correspondence relationship according to the sample control power and the sample output power.

[0078] In one application scenario, the sample control power includes multiple, and one implementation of step 203 can be:

[0079] The multiple sample control powers and the sample output power corresponding to each sample control power are fitted to obtain the preset power correspondence.

[0080] For example, the manner of generating the preset power correspondence can be: first, obtaining the sample control power, wherein the sample control power can be multiple, and the sample control power can be understood as the target value of the power of the actual input sample inverter controller. Then the output current of the inverter bridge of the sample inverter can be controlled according to the sample control power, and the output power of the inverter bridge of the sample inverter, i.e. the output power of the sample inverter, can be obtained according to the output voltage and output current of the inverter bridge of the sample inverter, and the output power of the sample inverter is taken as the sample output power.

[0081] In some embodiments, the output current of the inverter bridge can be controlled according to multiple different sample control powers, so as to obtain multiple output powers of the sample inverter, i.e. multiple sample output powers corresponding to multiple sample control powers. Then each sample control power and the sample output power corresponding to the sample control power are taken as a sample group, and function fitting is performed on multiple sample groups to obtain the preset power correspondence. For example, the function fitting manner can be fitting a straight line through the least square method to obtain the linear relationship between the sample control power and the sample output power, and the linear relationship is taken as the preset power correspondence, or the closest function relationship can be automatically fitted according to the distribution of sample points, and the present disclosure does not make specific limitations.

[0082] Figure 7 is another flowchart of a method for generating a power correspondence according to an example embodiment, as shown in Figure 7 Step 202 can be implemented by the following steps:

[0083] Step 2021, according to multiple sample active control powers and a preset reactive control power, control the inverter bridge of the sample inverter to obtain multiple active output powers and multiple reactive output powers output by the sample inverter, and take the multiple active output powers as the first sample active output power and the multiple reactive output powers as the first sample reactive output power.

[0084] Step 2022, according to multiple sample reactive control powers and a preset active control power, control the inverter bridge of the sample inverter to obtain multiple active output powers and multiple reactive output powers output by the sample inverter, and take the multiple active output powers as the second sample active output power and the multiple reactive output powers as the second sample reactive output power.

[0085] In an example, the sample control power can include sample active control power and sample reactive control power, and the sample output power can include sample active output power and sample reactive output power. Since there is a linear coupling between the sample active control power and the sample reactive control power, the output power of the inverter can be controlled according to the sample active control power and the preset reactive control power, and the sample reactive control power and the preset active control power, respectively, so as to obtain a plurality of sample active output powers and sample reactive output powers corresponding to a plurality of sample active control powers, and a plurality of sample active output powers and sample reactive output powers corresponding to a plurality of sample reactive control powers. The preset reactive control power and the preset active control power can each be a constant value.

[0086] In some embodiments, the preset reactive control power can be set as any constant, and a plurality of sample active control powers can be preset. The output current of the inverter bridge of the sample inverter can be controlled according to each sample active control power and the preset reactive control power in turn, so as to obtain first sample active output power and first sample reactive output power corresponding to each sample active control power output by the sample inverter, thereby obtaining a plurality of first sample active output powers and a plurality of first sample reactive output powers. Preferably, in order to reduce the amount of calculation and avoid unnecessary redundant calculation, the preset reactive control power can be set as 0, and a plurality of sample active control powers can be preset. The output current of the inverter bridge of the sample inverter can be controlled according to each sample active control power in turn, so as to obtain first sample active output power and first sample reactive output power corresponding to each sample active control power output by the sample inverter, thereby obtaining a plurality of first sample active output powers and a plurality of first sample reactive output powers. The first sample reactive output power is the reactive power coupled only when the sample active control power is input.

[0087] In some embodiments, the preset active power control power can be set as any constant, and a plurality of sample reactive power control powers can be preset. In turn, the output current of the inverter bridge of the sample inverter is controlled according to each sample reactive power control power, to obtain a second sample active output power and a second sample reactive output power corresponding to each sample reactive power control power output by the sample inverter, thereby obtaining a plurality of second sample active output powers and a plurality of second sample reactive output powers. Preferably, in order to reduce the amount of calculation and avoid unnecessary redundant calculation, the preset reactive power control power can be set to 0, and a plurality of sample reactive power control powers can be preset. In turn, the output current of the inverter bridge of the sample inverter is controlled according to each sample reactive power control power, to obtain a second sample active output power and a second sample reactive output power corresponding to each sample reactive power control power output by the sample inverter, thereby obtaining a plurality of second sample active output powers and a plurality of second sample reactive output powers. The second sample active output power is the active power generated by coupling under the condition of only inputting the sample reactive power control power.

[0088] In the above manner, four types of sample groups can be obtained, and each type of sample group can include a plurality of sample groups. The first type of sample group includes the sample active power control power and the first sample active output power, the second type of sample group includes the sample active power control power and the first sample reactive output power, the third type of sample group includes the sample reactive power control power and the second sample reactive output power, and the fourth type of sample group includes the sample reactive power control power and the second sample active output power.

[0089] In one application scenario, one implementation of step 2021 can be:

[0090] For each sample active power control power, the inverter bridge of the sample inverter is controlled according to the sample active power control power and the preset reactive power control power multiple times, to obtain a plurality of active output powers and a plurality of reactive output powers corresponding to the sample active power control power, and the plurality of active output powers are taken as first sub-sample active output powers and the plurality of reactive output powers are taken as first sub-sample reactive output powers.

[0091] The average of the plurality of first sub-sample active output powers is taken as the first sample active output power corresponding to the sample active power control power, and the average of the plurality of first sub-sample reactive output powers is taken as the first sample reactive output power corresponding to the sample active power control power.

[0092] For each sample active control power, the output current of the inverter bridge of the sample inverter can be controlled according to the sample active power and the preset reactive control power in a preset period, and each time a corresponding active output power and a corresponding reactive output power are obtained, so that a plurality of active output powers and a plurality of reactive output powers corresponding to the sample active control power are obtained, and the plurality of active output powers are taken as first sub-sample active output powers and the plurality of reactive output powers are taken as first sub-sample reactive output powers. In some embodiments, the average of the plurality of first sub-sample active output powers can be taken as the first sample active output power corresponding to the sample active control power, and the average of the plurality of first sub-sample reactive output powers can be taken as the first sample reactive output power corresponding to the sample active control power. In this way, by taking the average of multiple experiments, more accurate first sample active output power and first sample reactive output power can be obtained.

[0093] In another application scenario, an implementation of step 2022 can be:

[0094] For each sample reactive control power, the inverter bridge of the sample inverter can be controlled according to the sample active control power and the sample reactive control power in a preset period, and each time a corresponding active output power and a corresponding reactive output power are obtained, so that a plurality of active output powers and a plurality of reactive output powers corresponding to the sample reactive control power are obtained, and the plurality of active output powers are taken as second sub-sample active output powers and the plurality of reactive output powers are taken as second sub-sample reactive output powers.

[0095] The average of the plurality of second sub-sample active output powers can be taken as the second sample active output power corresponding to the sample reactive control power, and the average of the plurality of second sub-sample reactive output powers can be taken as the second sample reactive output power corresponding to the sample reactive control power.

[0096] For each sample reactive control power, the inverter bridge of the sample inverter can be controlled according to the sample active control power and the sample reactive control power in a preset period, and each time a corresponding active output power and a corresponding reactive output power are obtained, so that a plurality of active output powers and a plurality of reactive output powers corresponding to the sample reactive control power are obtained, and the plurality of active output powers are taken as second sub-sample active output powers and the plurality of reactive output powers are taken as second sub-sample reactive output powers. In some embodiments, the average of the plurality of second sub-sample active output powers can be taken as the second sample active output power corresponding to the sample reactive control power, and the average of the plurality of second sub-sample reactive output powers can be taken as the second sample reactive output power corresponding to the sample reactive control power. In this way, by taking the average of multiple experiments, more accurate second sample active output power and second sample reactive output power can be obtained.

[0097] Figure 8 is a flowchart of another method for generating a power correspondence according to an example embodiment, as Figure 8 As shown in FIG. 3, step 203 can be implemented by the following steps:

[0098] Step 2031, a first target active output power-target active control power correspondence is fitted according to the plurality of first sample active output powers, the plurality of sample active control powers, and the preset reactive control power.

[0099] Step 2032, a first target reactive output power-target active control power correspondence is fitted according to the plurality of first sample reactive output powers, the plurality of sample active control powers, and the preset reactive control power.

[0100] Step 2033, a second target reactive output power-target reactive control power correspondence is fitted according to the plurality of second sample reactive output powers, the plurality of sample reactive control powers, and the preset active control power.

[0101] Step 2034, a second target active output power-target reactive control power correspondence is fitted according to the plurality of second sample active output powers, the plurality of sample reactive control powers, and the preset active control power.

[0102] Step 2035, the preset power correspondence is determined according to the first correspondence, the second correspondence, the third correspondence, the fourth correspondence, and the preset equivalence.

[0103] In an application scenario, the preset equivalence includes that the target active output power is a sum of the first target active output power and the second target active output power, and the target reactive output power is a sum of the first target reactive output power and the second target reactive output power.

[0104] For example, the first corresponding relationship between the first target active output power and the target active control power can be obtained by function fitting according to the sample active control power, the first sample active output power and the preset reactive control power in the plurality of first sample groups. Similarly, the second corresponding relationship between the first target reactive output power and the target active control power can be obtained by function fitting according to the sample active control power, the first sample reactive output power and the preset reactive control power in the plurality of second sample groups. Similarly, the third corresponding relationship between the second target reactive output power and the target reactive control power can be obtained by function fitting according to the sample reactive control power, the second sample reactive output power and the preset active control power in the plurality of third sample groups. Similarly, the fourth corresponding relationship between the second target active output power and the target reactive control power can be obtained by function fitting according to the sample reactive control power, the second sample active output power and the preset active control power in the plurality of fourth sample groups.

[0105] For example, when the preset active control power and the preset reactive control power are both 0, and the fitting mode is fitting by the least square method, the first corresponding relationship, the second corresponding relationship, the third corresponding relationship and the fourth corresponding relationship obtained by fitting are linear relationships. For example, the first corresponding relationship can be represented by formula 3, the second corresponding relationship can be represented by formula 4, the third corresponding relationship can be represented by formula 5, and the fourth corresponding relationship can be represented by formula 6.

[0106] P self =A1*P obj +B1 (Formula 3)

[0107] Q fromP =A2*P obj +B2 (Formula 4)

[0108] Q self =A3*Q obj +B3 (Formula 5)

[0109] P fromQ =A4*Q obj +B4 (Formula 6)

[0110] Wherein, P self is the first target active output power, Q fromP is the first target reactive output power, Q self is the second target reactive output power, P fromQ is the second target active output power, and A1, A2, A3, A4, B1, B2, B3 and B4 are constants.

[0111] In some embodiments, the preset power correspondence relationship can be determined according to the first correspondence relationship, the second correspondence relationship, the third correspondence relationship, the fourth correspondence relationship and a preset equivalence relationship. The preset equivalence relationship can be as shown in formula 7, that is, the target active output power is the sum of the first target active output power and the second target active output power, and the target reactive output power is the sum of the first target reactive output power and the second target reactive output power.

[0112]

[0113] According to formula 3, formula 4, formula 5, formula 6 and formula 7, the preset power correspondence relationship shown in formula 8 and formula 9 can be obtained.

[0114]

[0115] Wherein:

[0116]

[0117] After simplification, we get:

[0118]

[0119] Wherein:

[0120]

[0121] In summary, the present disclosure first obtains the target output power of the inverter, determines the target control power corresponding to the target output power through the pre-generated power correspondence relationship, and then controls the inverter bridge according to the target control power, so that the inverter bridge outputs the target output power. Wherein, the power correspondence relationship represents the relationship between the target output power and the target control power, and the power correspondence relationship is a correspondence relationship determined according to the sample output power and the sample control power, and the sample output power is obtained according to the sample control power. The present disclosure corrects the target control power of the inverter through the preset power correspondence relationship and the target output power, so that the actual output power of the inverter controlled by the target control power is the same as the target output power, and the control accuracy of the inverter is improved.

[0122] Figure 9 is a block diagram of a control device of an inverter according to an exemplary embodiment, as shown in Figure 9 The device 300 includes:

[0123] The acquisition module 301 is configured to acquire the target output power of the inverter.

[0124] The determining module 302 is configured to determine a target control power corresponding to a target output power according to a preset power correspondence relationship, the power correspondence relationship including a correspondence relationship between the target output power and the target control power, and the power correspondence relationship being determined according to a sample output power and a sample control power, the sample output power being obtained by controlling a sample inverter to output according to the sample control power.

[0125] The control module 303 is configured to control an inverter bridge of the inverter to output the target output power according to the target control power.

[0126] In an application scenario, the target output power includes a target active output power and a target reactive output power, and the target control power includes a target active control power and a target reactive control power. The power correspondence relationship includes a relationship between the target active control power and the target active output power and the target reactive output power, and a relationship between the target reactive control power and the target active output power and the target reactive output power.

[0127] The determining module 302 is configured to:

[0128] determine the target active control power according to the target active output power, the target reactive output power, and the preset power correspondence relationship.

[0129] determine the target reactive control power according to the target active output power, the target reactive output power, and the preset power correspondence relationship.

[0130] Figure 10 is another block diagram of a control device of an inverter according to an example embodiment, as shown in Figure 10 The device 300 further includes:

[0131] The matching module 304 is configured to determine a preset power correspondence relationship matched with the inverter from a plurality of preset power correspondence relationships pre-generated, each power correspondence relationship being matched with at least one preset inverter.

[0132] In another application scenario, the preset power correspondence relationship is pre-generated by the following method:

[0133] obtaining a sample control power.

[0134] controlling an inverter bridge of a sample inverter according to the sample control power to obtain an output power of the sample inverter, and taking the output power of the sample inverter as a sample output power.

[0135] generating the preset power correspondence relationship according to the sample control power and the sample output power.

[0136] In another application scenario, the sample control power includes multiple, and the preset power corresponding relationship is generated according to the sample control power and the sample output power, including:

[0137] The multiple sample control powers and the sample output power corresponding to each sample control power are fitted to obtain the preset power corresponding relationship.

[0138] In another application scenario, the sample control power includes: sample active control power and sample reactive control power, and the sample output power includes: sample active output power and sample reactive output power. According to the sample control power, the inverter bridge of the sample inverter is controlled to obtain the output power of the sample inverter, and the output power of the sample inverter is taken as the sample output power, including:

[0139] According to the multiple sample active control powers and the preset reactive control power, the inverter bridge of the sample inverter is controlled to obtain multiple active output powers and multiple reactive output powers output by the sample inverter, and the multiple active output powers are taken as the first sample active output power, and the multiple reactive output powers are taken as the first sample reactive output power. The first sample reactive output power is the coupled reactive power.

[0140] According to the multiple sample reactive control powers and the preset active control power, the inverter bridge of the sample inverter is controlled to obtain multiple active output powers and multiple reactive output powers output by the sample inverter, and the multiple active output powers are taken as the second sample active output power, and the multiple reactive output powers are taken as the second sample reactive output power. The second sample active output power is the coupled active power.

[0141] In another application scenario, according to the multiple sample active control powers and the preset reactive control power, the inverter bridge of the sample inverter is controlled to obtain multiple active output powers and multiple reactive output powers output by the sample inverter, including:

[0142] For each sample active control power, multiple times according to the sample active control power and the preset reactive control power, the inverter bridge of the sample inverter is controlled to obtain multiple active output powers and multiple reactive output powers corresponding to the sample active control power, and the multiple active output powers are taken as the first sub-sample active output power, and the multiple reactive output powers are taken as the first sub-sample reactive output power.

[0143] The average of the multiple first sub-sample active output powers is taken as the first sample active output power corresponding to the sample active control power, and the average of the multiple first sub-sample reactive output powers is taken as the first sample reactive output power corresponding to the sample active control power.

[0144] In another application scenario, based on multiple sample reactive power control powers and a preset active power control power, the inverter bridge of the sample inverter is controlled to obtain multiple active output powers and multiple reactive output powers from the sample inverter, including:

[0145] For each sample reactive power control power, the inverter bridge of the sample inverter is controlled multiple times based on the sample reactive power control power and the preset active power control power to obtain multiple active output powers and multiple reactive output powers corresponding to the sample reactive power control power. The multiple active output powers are used as the second sub-sample active output power, and the multiple reactive output powers are used as the second sub-sample reactive output power.

[0146] The average value of the active power output of multiple second sub-samples is taken as the active power output of the second sample corresponding to the reactive power control power of the sample, and the average value of the reactive power output of multiple second sub-samples is taken as the reactive power output of the second sample corresponding to the reactive power control power of the sample.

[0147] In another application scenario, the preset power correspondence is obtained by fitting multiple sample control powers and the corresponding sample output power for each sample control power, including:

[0148] Based on the active power output of multiple first samples, the active power control power of multiple samples, and the preset reactive power control power, a first correspondence between the first target active power output power and the target active power control power is obtained by fitting.

[0149] Based on multiple first sample reactive power outputs, multiple sample active power control powers, and the preset reactive power control power, a second correspondence between the first target reactive power output and the target active power control power is obtained by fitting.

[0150] Based on multiple second sample reactive power outputs, multiple sample reactive power control powers, and the preset reactive power control power, a third correspondence between the second target reactive power output power and the target reactive power control power is obtained by fitting.

[0151] Based on the active power output of multiple second samples, the reactive power control power of multiple samples, and the preset reactive power control power, a fourth correspondence between the second target active power output power and the target reactive power control power is obtained by fitting.

[0152] The preset power correspondence is determined based on the first correspondence, the second correspondence, the third correspondence, the fourth correspondence, and the preset equivalence relation.

[0153] In another application scenario, the preset equivalence relations include: the target active power output is the sum of the first target active power output and the second target active power output, and the target reactive power output is the sum of the first target reactive power output and the second target reactive power output.

[0154] As to the apparatus in the above-mentioned embodiments, the specific manner in which each module performs operations has been described in detail in the embodiments related to the method, and will not be described in detail here.

[0155] To sum up, the present disclosure first acquires the target output power of the inverter, determines the target control power corresponding to the target output power through the pre-generated power correspondence relationship, and then controls the inverter bridge according to the target control power, so that the inverter bridge outputs the target output power. Wherein, the power correspondence relationship represents the relationship between the target output power and the target control power, and the power correspondence relationship is a correspondence relationship determined according to the sample output power and the sample control power, and the sample output power is obtained according to the sample control power. The present disclosure corrects the target control power of the inverter according to the preset power correspondence relationship and the target output power, so that the actual output power of the inverter controlled by the target control power is the same as the target output power, and the control accuracy of the inverter is improved.

[0156] The present disclosure also shows a controller of an inverter, and the method of controlling the inverter by the controller has been described in detail in the embodiments related to the method, and will not be described in detail here.

[0157] The present disclosure also shows an inverter system comprising an inverter and a controller of the inverter, and the method of controlling the inverter by the controller has been described in detail in the embodiments related to the method, and will not be described in detail here.

[0158] The preferred embodiments of the present disclosure are described in detail above in combination with the drawings, but the present disclosure is not limited to the specific details in the above-mentioned embodiments. Within the technical concept range of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all belong to the protection range of the present disclosure.

[0159] In addition, it should be noted that each specific technical feature described in the above-mentioned specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present disclosure will not describe various possible combination manners.

[0160] In addition, various different embodiments of the present disclosure can also be combined in any manner, as long as they do not deviate from the idea of the present disclosure, and they should also be considered as disclosed by the present disclosure.

Claims

1. A control method of an inverter, characterized by, The method comprises: acquiring a target output power of an inverter; determining a target control power corresponding to the target output power through a preset power correspondence relationship, wherein the preset power correspondence relationship comprises a correspondence relationship between the target output power and the target control power, the preset power correspondence relationship is determined according to a sample output power and a sample control power, the sample output power is obtained by controlling a sample inverter to output according to the sample control power, the target output power comprises a target active output power and a target reactive output power, the target control power comprises a target active control power and a target reactive control power, the preset power correspondence relationship comprises a relationship between the target active control power and the target active output power and the target reactive output power, and a relationship between the target reactive control power and the target active output power and the target reactive output power; controlling an inverter bridge of the inverter according to the target control power, so that the inverter bridge outputs the target output power; The method further comprises: determining the preset power correspondence relationship matched with the inverter from a plurality of preset power correspondence relationships, wherein each preset power correspondence relationship is matched with at least one preset inverter; The preset power correspondence relationship is generated in advance through the following manner: acquiring a sample control power; controlling an inverter bridge of the sample inverter according to the sample control power, obtaining an output power of the sample inverter, and taking the output power of the sample inverter as the sample output power; generating the preset power correspondence relationship according to the sample control power and the sample output power.

2. The method of claim 1, wherein, The determination of the target control power corresponding to the target output power through the preset power correspondence relationship comprises: determining the target active control power according to the target active output power, the target reactive output power and the preset power correspondence relationship; determining the target reactive control power according to the target active output power, the target reactive output power and the preset power correspondence relationship.

3. The method of claim 2, wherein, The sample control power comprises a plurality of sample control powers, and the generation of the preset power correspondence relationship according to the sample control power and the sample output power comprises: fitting a plurality of sample control powers and sample output powers corresponding to each sample control power to obtain the preset power correspondence relationship.

4. The method of claim 3, wherein, The sample control power comprises a sample active control power and a sample reactive control power, the sample output power comprises a sample active output power and a sample reactive output power, and the control of the inverter bridge of the sample inverter according to the sample control power to obtain the output power of the sample inverter and taking the output power of the sample inverter as the sample output power comprises: According to the preset active control power and the plurality of sample reactive control powers, the inverter bridge of the sample inverter is controlled to obtain a plurality of active output powers and a plurality of reactive output powers output by the sample inverter, and the plurality of active output powers are taken as second sample active output powers and the plurality of reactive output powers are taken as second sample reactive output powers. According to the preset active control power and the plurality of sample reactive control powers, the inverter bridge of the sample inverter is controlled to obtain a plurality of active output powers and a plurality of reactive output powers output by the sample inverter, and the plurality of active output powers are taken as second sample active output powers and the plurality of reactive output powers are taken as second sample reactive output powers.

5. The method of claim 4, wherein, The control of the inverter bridge of the sample inverter according to the plurality of sample active control powers and the preset reactive control power to obtain a plurality of active output powers and a plurality of reactive output powers output by the sample inverter comprises: For each sample active control power, the inverter bridge of the sample inverter is controlled according to the sample active control power and the preset reactive control power multiple times to obtain a plurality of active output powers and a plurality of reactive output powers corresponding to the sample active control power, and the plurality of active output powers are taken as first sub-sample active output powers and the plurality of reactive output powers are taken as first sub-sample reactive output powers; The average of the plurality of first sub-sample active output powers is taken as the first sample active output power corresponding to the sample active control power, and the average of the plurality of first sub-sample reactive output powers is taken as the first sample reactive output power corresponding to the sample active control power.

6. The method of claim 4, wherein, The control of the inverter bridge of the sample inverter according to the plurality of sample reactive control powers and the preset active control power to obtain a plurality of active output powers and a plurality of reactive output powers output by the sample inverter comprises: For each sample reactive control power, the inverter bridge of the sample inverter is controlled according to the sample reactive control power and the preset active control power multiple times to obtain a plurality of active output powers and a plurality of reactive output powers corresponding to the sample reactive control power, and the plurality of active output powers are taken as second sub-sample active output powers and the plurality of reactive output powers are taken as second sub-sample reactive output powers; The average of the plurality of second sub-sample active output powers is taken as the second sample active output power corresponding to the sample reactive control power, and the average of the plurality of second sub-sample reactive output powers is taken as the second sample reactive output power corresponding to the sample reactive control power.

7. The method of claim 4, wherein, The target control power comprises a target active control power and a target reactive control power; and the fitting of the plurality of sample control powers and the sample output power corresponding to each sample control power to obtain the preset power corresponding relationship comprises: According to the plurality of first sample active output powers, the plurality of sample active control powers, and the preset reactive control power, a first corresponding relationship between a first target active output power and the target active control power is fitted. According to the plurality of first sample active output powers, the plurality of sample active control powers, and the preset reactive control power, a first corresponding relationship between a first target active output power and the target active control power is fitted. According to the first sample reactive output power, the sample active control power and the preset reactive control power, a second corresponding relationship between the first target reactive output power and the target active control power is fitted; According to the second sample reactive output power, the sample reactive control power and the preset active control power, a third corresponding relationship between the second target reactive output power and the target reactive control power is fitted; According to the second sample active output power, the sample reactive control power and the preset active control power, a fourth corresponding relationship between the second target active output power and the target reactive control power is fitted; The preset power corresponding relationship is determined according to the first corresponding relationship, the second corresponding relationship, the third corresponding relationship, the fourth corresponding relationship and a preset equivalent relationship.

8. The method of claim 7, wherein, The preset equivalent relationship includes: The target active output power is the sum of the first target active output power and the second target active output power, and the target reactive output power is the sum of the first target reactive output power and the second target reactive output power.

9. A controller of an inverter, characterized by comprising: The controller is used to execute the control method of the inverter in any one of claims 1-8.

10. An inverter system characterized by comprising: The inverter and the controller of the inverter in claim 9 are included.

Images