阅读说明：本技术 逆变器母线电压调整方法、装置、控制器及存储介质 (Inverter bus voltage adjusting method and device, controller and storage medium ) 是由 尹韶文 尹雪芹 翁宏达 黄伟 尹继波 于 2020-05-28 设计创作，主要内容包括：本发明公开了一种逆变器母线电压调整方法、装置、控制器及存储介质。所述方法包括：获取逆变器最大占空比、电网峰值电压和逆变输出电流；基于逆变器最大占空比、电网峰值电压和逆变输出电流,获取母线电压估算值；对母线电压估算值进行调整处理,确定目标母线电压；基于目标母线电压对逆变器中的DC/DC变换器的占空比进行调节,以使输出母线电压与目标母线电压一致。本发明的技术方案对逆变器的输出母线电压进行调整到与目标母线电压一致,得到准确且合理的输出母线电压能够稳定输出,提高逆变器逆变效率。(The invention discloses a method and a device for adjusting bus voltage of an inverter, a controller and a storage medium. The method comprises the following steps: acquiring the maximum duty ratio of an inverter, the peak voltage of a power grid and the inversion output current; acquiring a bus voltage estimated value based on the maximum duty ratio of the inverter, the peak voltage of the power grid and the inversion output current; adjusting the estimated value of the bus voltage to determine a target bus voltage; the duty cycle of a DC/DC converter in the inverter is adjusted based on the target bus voltage to bring the output bus voltage into agreement with the target bus voltage. According to the technical scheme, the output bus voltage of the inverter is adjusted to be consistent with the target bus voltage, the accurate and reasonable output bus voltage can be stably output, and the inversion efficiency of the inverter is improved.)

1. An inverter bus voltage adjustment method is characterized by comprising the following steps:

acquiring the maximum duty ratio of an inverter, the peak voltage of a power grid and the inversion output current;

obtaining a bus voltage estimated value based on the maximum duty ratio of the inverter, the peak voltage of the power grid and the inversion output current;

adjusting the estimated bus voltage value to determine the target bus voltage at the current moment;

and adjusting the duty ratio of the DC/DC converter in the inverter based on the target bus voltage at the current moment so that the output bus voltage is consistent with the target bus voltage at the current moment.

2. The method of adjusting inverter bus voltage according to claim 1, wherein obtaining the estimated bus voltage value based on the maximum inverter duty cycle, the peak grid voltage, and the inverted output current comprises:

calculating the maximum duty ratio of the inverter, the peak voltage of the power grid and the inversion output current by adopting a bus voltage estimation formula to obtain an estimated value of bus voltage, wherein the bus voltage estimation formula is U_bus＝(a/m)*(U_max+bI_out) + c, where m is the inverter maximum duty cycle, a is the correction factor for the inverter maximum duty cycle, U_maxFor peak voltage of the grid, I_outThe inverter output current is obtained, b is a regulating coefficient of the inverter output current, and c is a correction coefficient of the bus voltage.

3. The method for adjusting the bus voltage of the inverter according to claim 1, wherein the adjusting the estimated bus voltage value to determine the target bus voltage at the current time comprises:

and carrying out anti-shake treatment on the estimated bus voltage value, and determining the target bus voltage at the current moment.

4. The method for adjusting the bus voltage of the inverter as claimed in claim 3, wherein the step of performing anti-shake processing on the estimated bus voltage value to determine the target bus voltage at the current time comprises:

acquiring an estimated voltage change value based on the estimated value of the bus voltage at the current moment and the target bus voltage at the previous moment;

if the estimated voltage change value is a negative value, the change state corresponding to the bus voltage estimated value is a descending state, and the target bus voltage at the current moment is determined based on the comparison result of the absolute value of the estimated voltage change value and a preset voltage change value;

and if the estimated voltage change value is a positive value, the change state corresponding to the bus voltage estimated value is a rising state, and the bus voltage estimated value at the current moment is determined as the target bus voltage at the current moment.

5. The inverter bus voltage adjustment method according to claim 4, wherein the determining a target bus voltage at a current time based on a comparison result of an absolute value of the estimated voltage change value and a preset voltage change value includes:

if the absolute value of the estimated voltage change value is smaller than or equal to a preset voltage change value, determining the target bus voltage at the previous moment as the target bus voltage at the current moment;

and if the absolute value of the estimated voltage change value is larger than the preset voltage change value, determining the estimated value of the bus voltage at the current moment as the target bus voltage at the current moment.

6. The method of claim 1, wherein the adjusting the estimated bus voltage value to determine a target bus voltage at a current time further comprises:

and carrying out limit processing on the estimated bus voltage value, and determining the target bus voltage at the current moment.

7. The method of claim 6, wherein the limiting the estimated bus voltage value to determine the target bus voltage at the current time comprises:

if the estimated value of the bus voltage is smaller than the lower limit value of the bus voltage, determining the lower limit value of the bus voltage as the target bus voltage at the current moment;

if the estimated value of the bus voltage is larger than the upper limit value of the bus voltage, determining the upper limit value of the bus voltage as the target bus voltage at the current moment;

and if the estimated bus voltage value is between the bus voltage lower limit value and the bus voltage upper limit value, determining the estimated bus voltage value as the target bus voltage at the current moment.

8. An inverter bus voltage adjustment device, comprising:

the acquisition module is used for acquiring the maximum duty ratio of the inverter, the peak voltage of a power grid and the inversion output current;

the voltage estimation module is used for acquiring a bus voltage estimated value based on the maximum duty ratio of the inverter, the peak voltage of the power grid and the inversion output current;

the voltage adjustment processing module is used for adjusting the estimated value of the bus voltage and determining the target bus voltage at the current moment;

and the adjustment execution module is used for adjusting the duty ratio of the DC/DC converter in the inverter based on the target bus voltage at the current moment so as to enable the output bus voltage to be consistent with the target bus voltage at the current moment.

9. An inverter controller comprising a memory, a processor, and an inverter controller program stored in the memory and executable on the processor, wherein the processor implements the inverter bus voltage adjustment method of any one of claims 1 to 7 when executing the inverter controller program.

10. A computer-readable storage medium storing an inverter controller program, wherein the inverter controller program, when executed by a processor, implements the inverter bus voltage adjustment method according to any one of claims 1 to 7.

Technical Field

The invention relates to the field of inverters, in particular to a method and a device for adjusting bus voltage of an inverter, a controller and a storage medium.

Background

In a photovoltaic power generation or energy storage system, a grid-connected inverter generally adopts a two-stage structure, wherein a front stage is a DC/DC converter, and a rear stage is an inverter circuit. The DC/DC converter needs to control the output bus voltage to be higher than the voltage required by the inverter circuit according to the preset bus voltage reference value, and the inverter circuit can output the output bus voltage to the power grid, but the efficiency of the grid-connected inverter is reduced due to the excessively high output bus voltage.

In the prior art, VBUS is Vmax + α (Vout) + β (Iout), where VBUS is a bus voltage estimated value, Vmax is a grid peak voltage, Vout is a grid voltage, Iout is an inverter output current, α (Vout) is a grid voltage increment, and β (Iout) is an inverter output current increment, where if the grid voltage is a direct current, the grid voltage peak is a grid voltage, and if the grid voltage is an alternating current, the grid voltage peak is a product of a grid voltage value and 1.414. When the inverter works, the bus voltage estimated value VBUS is adjusted in real time along with the change of the power grid voltage Vout and the inversion output current Iout, and the bus voltage estimated value VBUS is obtained as Vmax + alpha (Vout) + beta (Iout).

In the prior art, only the influence of the change of a power grid voltage value Vout and a grid-connected current value Iout on the output bus voltage is considered, the factors such as the maximum duty ratio of a rear-stage inverter circuit and the like are not considered, the estimation application range of the output bus voltage is narrow, when the maximum duty ratio of an inverter is set and changed, the accurate and reasonable output bus voltage cannot be obtained, the inversion waveform can be distorted, and the inversion efficiency is reduced.

Disclosure of Invention

The embodiment of the invention provides a method and a device for adjusting bus voltage of an inverter, a controller and a storage medium, which are used for solving the problems that accurate and reasonable output bus voltage cannot be obtained and the inversion efficiency of the inverter is reduced.

An inverter bus voltage adjustment method comprising:

acquiring the maximum duty ratio of an inverter, the peak voltage of a power grid and the inversion output current;

obtaining a bus voltage estimated value based on the maximum duty ratio of the inverter, the peak voltage of the power grid and the inversion output current;

adjusting the estimated bus voltage value to determine the target bus voltage at the current moment;

and adjusting the duty ratio of the DC/DC converter in the inverter based on the target bus voltage at the current moment so that the output bus voltage is consistent with the target bus voltage at the current moment.

Further, the obtaining an estimated value of a bus voltage based on the maximum duty cycle of the inverter, the peak voltage of the power grid, and the inverter output current includes:

calculating the maximum duty ratio of the inverter, the peak voltage of the power grid and the inversion output current by adopting a bus voltage estimation formula to obtain an estimated value of bus voltage, wherein the bus voltage estimation formula is U_bus＝(a/m)*(U_max+bI_out) + c, where m is the inverter maximum duty cycle, a is the correction factor for the inverter maximum duty cycle, U_maxFor peak voltage of the grid, I_outThe inverter output current is obtained, b is a regulating coefficient of the inverter output current, and c is a correction coefficient of the bus voltage.

Further, the adjusting the estimated bus voltage value to determine the target bus voltage at the current time includes:

and carrying out anti-shake treatment on the estimated bus voltage value, and determining the target bus voltage at the current moment.

Further, the performing anti-shake processing on the estimated bus voltage value to determine the target bus voltage at the current time includes:

acquiring an estimated voltage change value based on the estimated value of the bus voltage at the current moment and the target bus voltage at the previous moment;

if the estimated voltage change value is a negative value, the change state corresponding to the bus voltage estimated value is a descending state, and the target bus voltage at the current moment is determined based on the comparison result of the absolute value of the estimated voltage change value and a preset voltage change value;

and if the estimated voltage change value is a positive value, the change state corresponding to the bus voltage estimated value is a rising state, and the bus voltage estimated value at the current moment is determined as the target bus voltage at the current moment.

Further, the determining the target bus voltage at the current moment based on the comparison result of the absolute value of the estimated voltage change value and the preset voltage change value includes:

if the absolute value of the estimated voltage change value is smaller than a preset voltage change value, determining the target bus voltage at the previous moment as the target bus voltage at the current moment;

and if the absolute value of the estimated voltage change value is larger than the preset voltage change value, determining the estimated value of the bus voltage at the current moment as the target bus voltage at the current moment.

Further, the adjusting the estimated bus voltage value to determine the target bus voltage at the current time further includes:

and carrying out limit processing on the estimated bus voltage value, and determining the target bus voltage at the current moment.

Further, the limiting processing of the estimated bus voltage value to determine the target bus voltage at the current time includes:

if the estimated value of the bus voltage is smaller than the lower limit value of the bus voltage, determining the lower limit value of the bus voltage as the target bus voltage at the current moment;

if the estimated value of the bus voltage is larger than the upper limit value of the bus voltage, determining the upper limit value of the bus voltage as the target bus voltage at the current moment;

and if the estimated bus voltage value is between the bus voltage lower limit value and the bus voltage upper limit value, determining the estimated bus voltage value as the target bus voltage at the current moment.

An inverter bus voltage adjustment device comprising:

the acquisition module is used for acquiring the maximum duty ratio of the inverter, the peak voltage of a power grid and the inversion output current;

the voltage estimation module is used for acquiring a bus voltage estimated value based on the maximum duty ratio of the inverter, the peak voltage of the power grid and the inversion output current;

the voltage adjustment processing module is used for adjusting the estimated value of the bus voltage and determining the target bus voltage at the current moment;

and the adjustment execution module is used for adjusting the duty ratio of the DC/DC converter in the inverter based on the target bus voltage at the current moment so as to enable the output bus voltage to be consistent with the target bus voltage at the current moment.

An inverter controller comprises a memory, a processor and an inverter controller program stored in the memory and capable of running on the processor, wherein the processor realizes the inverter bus voltage adjusting method when executing the inverter controller program.

A computer-readable storage medium storing an inverter controller program that when executed by a processor implements the above-described inverter bus voltage adjustment method.

According to the method and the device for adjusting the bus voltage of the inverter, the inverter controller and the storage medium, the inverter controller can obtain the estimated value of the bus voltage based on the maximum duty ratio of the inverter, the peak voltage of a power grid and the inverted output current, dynamically analyze and adjust the estimated value of the bus voltage in real time to determine the target bus voltage at the current moment, and then adjust the duty ratio of a DC/DC converter in the inverter based on the target bus voltage at the current moment to enable the output bus voltage to be consistent with the target bus voltage at the current moment. The purpose is to adjust the output bus voltage of the inverter to be consistent with the target bus voltage at the current moment by the inverter controller, and the inverter bus voltage can be accurately adjusted, so that the grid-connected efficiency is improved, the output bus voltage is reasonably and stably output, and the inverter inversion efficiency is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.

FIG. 1 is a flow chart of a method for adjusting the bus voltage of an inverter according to an embodiment of the present invention;

FIG. 2 is another flow chart of a method for adjusting inverter bus voltage according to an embodiment of the present invention;

FIG. 3 is another flow chart of a method for adjusting inverter bus voltage according to an embodiment of the present invention;

FIG. 4 is another flow chart of a method for adjusting inverter bus voltage in accordance with an embodiment of the present invention;

FIG. 5 is a schematic diagram of an inverter bus voltage regulator in accordance with an embodiment of the present invention;

fig. 6 is a schematic diagram of an inverter controller according to an embodiment of the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The embodiment provides an inverter bus voltage adjusting method, which can be applied to an inverter controller, wherein the inverter controller can obtain a bus voltage estimated value based on the maximum duty ratio of an inverter, the peak voltage of a power grid and an inversion output current, perform dynamic analysis and real-time adjustment processing on the bus voltage estimated value, determine a target bus voltage at the current moment, and adjust the duty ratio of a DC/DC converter in the inverter based on the target bus voltage at the current moment so as to enable the output bus voltage to be consistent with the target bus voltage at the current moment. The purpose is to adjust the output bus voltage of the inverter to be consistent with the target bus voltage at the current moment by the inverter controller, and the inverter bus voltage can be accurately adjusted so as to improve grid-connected efficiency, output bus voltage can be reasonably and stably output, and inverter inversion efficiency is improved.

In an embodiment, as shown in fig. 1, a method for adjusting a bus voltage of an inverter is provided, which is described by taking an example of applying the method to an inverter controller, and includes the following steps:

s10: and acquiring the maximum duty ratio of the inverter, the peak voltage of the power grid and the inversion output current.

The maximum duty ratio of the inverter is a parameter of an output waveform of the inverter and is set by a user in a self-defined mode. The peak voltage of the power grid is the peak voltage of the external power grid of the inverter and can be determined by the effective voltage of the power grid obtained by the inverter. The effective voltage of the power grid is the effective voltage of an external power grid of the inverter, and it needs to be explained that when the external power grid is direct current, the peak voltage of the power grid is equal to the effective voltage of the power grid; when the external power grid is alternating current, the peak voltage of the power grid is equal to the effective voltage of the power gridThe product of (a), grid peak voltage ≈ grid effective voltage ≈ 1.414. The inverter output current is the current output by the inverter.

In this example, the inverter controller obtains the maximum duty ratio of the inverter input by the user, and collects the peak voltage of the power grid and the inversion output current in real time, so that the inverter controller can perform subsequent voltage adjustment processing according to the maximum duty ratio of the inverter, the peak voltage of the power grid and the inversion output current obtained in real time. The inverter controller can obtain reliable and accurate parameters such as the maximum duty ratio of the inverter, the peak voltage of a power grid, the inverter output current and the like in real time, so that the reliability of the method for adjusting the bus voltage of the inverter is improved.

S20: and obtaining the estimated value of the bus voltage based on the maximum duty ratio of the inverter, the peak voltage of the power grid and the inversion output current.

The bus voltage estimation value is an estimation value for estimating the output bus voltage of the inverter by calculating the maximum duty ratio of the inverter, the peak voltage of a power grid and the inversion output current. It will be appreciated that the basis for the inverter controller to make accurate and reliable adjustments to the output bus voltage of the inverter based on the estimated bus voltage value may be based on the estimated bus voltage value.

It should be noted that, when the obtained maximum duty cycle of the inverter and the peak voltage of the power grid remain unchanged, the estimated value of the bus voltage is dynamically adjusted according to the inverter output current obtained in real time. And when the obtained maximum duty ratio of the inverter and the obtained inverter output current are kept unchanged, dynamically adjusting the bus voltage estimated value according to the power grid peak voltage obtained in real time. When the peak voltage of the power grid and the inversion output current are kept unchanged, the bus voltage estimated value can be dynamically adjusted according to the maximum duty ratio of the inverter obtained in real time.

S30: and adjusting the estimated bus voltage value to determine the target bus voltage at the current moment.

And the target bus voltage at the current moment is a reference voltage for adjusting the output bus voltage.

It is understood that the estimated value of the bus voltage for estimating the output bus voltage is obtained based on the inverter maximum duty cycle, the grid peak voltage and the inverted output current. In order to output the stable and reasonable output of the output bus voltage. Therefore, the bus voltage estimated value is dynamically analyzed and adjusted in real time, the target bus voltage at the current moment is determined, the purpose is to enable the inverter controller to adjust the output bus voltage of the inverter to be consistent with the target bus voltage at the current moment, the output bus voltage can be reasonably and stably output, and the inverter efficiency of the inverter is improved.

S40: and adjusting the duty ratio of the DC/DC converter in the inverter based on the target bus voltage at the current moment so that the output bus voltage is consistent with the target bus voltage at the current moment.

The DC/DC converter is a device for boosting or reducing voltage in the inverter.

Specifically, the DC/DC converter compares the target bus voltage at the current time with the output bus voltage to obtain a voltage difference between the target bus voltage and the output bus voltage at the current time, and feeds back the voltage difference between the target bus voltage and the output bus voltage at the current time to the inverter controller. Further, the inverter controller adjusts the duty ratio of the DC/DC converter according to the voltage difference between the target bus voltage at the present time and the output bus voltage, so that the purpose of making the output bus voltage consistent with the target bus voltage at the present time is achieved, and the output bus voltage can be stably output.

In this embodiment, the inverter controller may obtain an estimated value of the bus voltage based on the maximum duty cycle of the inverter, the peak voltage of the power grid, and the inverted output current, perform dynamic analysis and real-time adjustment on the estimated value of the bus voltage, determine a target bus voltage at the current time, and adjust the duty cycle of the DC/DC converter in the inverter based on the target bus voltage at the current time, so that the output bus voltage is consistent with the target bus voltage at the current time. The purpose is to adjust the output bus voltage of the inverter to be consistent with the target bus voltage at the current moment by the inverter controller, and the inverter bus voltage can be accurately adjusted so as to improve grid-connected efficiency, output bus voltage can be reasonably and stably output, and inverter inversion efficiency is improved.

In one embodiment, in step S20, obtaining the estimated bus voltage based on the maximum inverter duty cycle, the peak grid voltage, and the inverted output current includes: calculating the maximum duty ratio of the inverter, the peak voltage of the power grid and the inversion output current by adopting a bus voltage estimation formula to obtain a bus voltage estimation value, wherein the bus voltage estimation formula is U_bus＝(a/m)*(U_max+bI_out) + c, where m is the inverter maximum duty cycle, a is the correction factor for the inverter maximum duty cycle, U_maxFor peak voltage of the grid, I_outThe inverter output current is obtained, b is a regulating coefficient of the inverter output current, and c is a correction coefficient of the bus voltage.

Wherein, U_busFor bus voltage estimation, U_maxFor peak voltage of the grid, I_outTo invert the output current. And the correction coefficient a of the maximum duty ratio of the inverter, the adjustment coefficient b of the inverter output current and the correction coefficient c of the bus voltage are parameters set by a user in a self-defined way. And the correction coefficient a of the maximum duty ratio of the inverter is used for correcting the maximum duty ratio of the inverter. And the regulating coefficient b of the inversion output current is used for calculating the bus voltage increment corresponding to the inversion output current. And the correction coefficient c of the bus voltage is used for correcting the estimated value of the bus voltage, so that the estimated value of the bus voltage is closer to the output bus voltage.

Specifically, the inverter maximum duty ratio U is obtained based on real time_maxPeak voltage U of power grid_maxAnd the inverted output current I_out. From the bus voltage estimation formula U_bus＝(a/m)*(U_max+bI_out)+c，U_bus＝(a/m)*U_max+(a/m)*bI_out+ c, the estimated bus voltage is (a/m) × U_max、(a/m)*bI_outAnd c. Understandably, when the maximum duty ratio m of the inverter and the peak voltage U of the power grid are obtained_maxInverting the output current I while keeping the same_outWhen changed, according to Δ U_bus＝(a/m)*b*ΔI_outAnd dynamically adjusting the bus voltage estimated value. When the obtained maximum duty ratio m and the obtained inversion output current I of the inverter_outWhen kept constant, according to Δ U_bus＝(a/m)*ΔU_maxAnd dynamically adjusting the bus voltage estimated value. When the obtained maximum duty ratio m of the inverter changes and becomes k, according to U_bus＝(a/k)*(U_max+bI_out) And dynamically adjusting the bus voltage estimated value. Wherein, Delta U_busThe difference, Δ I, between the current bus voltage estimate and the previous bus voltage estimate_outIs the difference, Δ U, between the inverted output current at the present time and the inverted output current at the previous time_maxAnd k is the maximum duty ratio of the inverter after the maximum duty ratio m of the inverter is changed.

As an example, the maximum occupancy of the inverter may be takenThe air ratio m is 0.96, the correction coefficient a of the maximum duty ratio of the inverter is 1, the regulation coefficient b of the inverter output current is 0.5, the correction coefficient c of the bus voltage is 3, the above values are only used for explaining the principle, and the specific values can be set according to the actual situation. When peak voltage U of power grid_maxAt 320V, inverting output current I_outAt 20A, U can be calculated_bus＝(1/0.96)*(320+0.5*20)+3＝346.75V。

The maximum duty ratio m of the inverter equal to the previous moment at the current moment is 0.96, and the peak voltage U of the power grid_maxAt 320V, inverting output current I_outWhen the current time is changed from 20A at the previous time to 40A at the current time according to the delta U_bus＝(a/m)*b*ΔI_out，ΔU_bus(1/0.96) × 0.5 ═ 40-20 ═ 10.42V. According to Δ U_bus10.42V, for U_busThe bus voltage is adjusted to 346.75V, and the adjusted bus voltage estimated value is delta U_bus+U_bus＝357.17V。

The maximum duty ratio m of the inverter equal to the previous moment at the current moment is 0.96, and the inverter output current I_out20A, the peak voltage U of the power grid_maxWhen the voltage changes from 320V at the last moment to 300V at the current moment according to the delta U_bus＝(a/m)*ΔU_max，ΔU_bus(1/0.96) × (300-. According to Δ U_bus20.83V, for U_busThe bus voltage is adjusted to 346.75V, and the adjusted bus voltage estimated value is delta U_bus+U_bus＝325.92V。

The peak voltage U of the power grid equal to the last moment_maxAt 320V, inverting output current I_out20A, when the maximum duty cycle m of the inverter is changed from 0.96 to 0.90, the estimated value of the bus voltage is U_bus＝(a/k)*(U_max+bI_out)，U_bus＝(1/0.90)*(320+0.5*20)＝366.67V。

In the embodiment, the inverter maximum duty ratio m and the grid peak voltage U are obtained when the inverter controller obtains_maxInverting the output current I while keeping the same_outWhen changed, according to Δ U_bus＝(a/m)*b*ΔI_outActing on the bus voltage estimateAnd (6) state adjustment. When the obtained maximum duty ratio m and the obtained inversion output current I of the inverter_outWhen kept constant, according to Δ U_bus＝(a/m)*ΔU_maxAnd dynamically adjusting the bus voltage estimated value. When the obtained maximum duty ratio m of the inverter changes and becomes k, according to U_bus＝(a/k)*(U_max+bI_out) And dynamically adjusting the bus voltage estimated value. And the inverter controller adjusts the output bus voltage according to the bus voltage estimated value, so that the waveform of the output bus voltage is protected from being distorted or the optimal efficiency of the output bus voltage is ensured.

In one embodiment, in step S30, performing adjustment processing on the output bus voltage based on the estimated bus voltage value to determine a target bus voltage at the current time includes: and carrying out anti-shake treatment on the estimated value of the bus voltage, and determining the target bus voltage at the current moment.

The anti-shake processing of the estimated bus voltage value refers to a processing process of enabling the estimated bus voltage value to be stably output according to a stable voltage value when the frequency or amplitude of rising or falling of the estimated bus voltage value is too large, namely, preventing the frequency or amplitude of bus voltage jump from being too large.

Specifically, the inverter controller performs anti-shake processing on the output bus voltage through the bus voltage estimated value, specifically, by analyzing the frequency or amplitude of the rise or fall of the real-time bus voltage estimated value, the frequency or amplitude of the rise or fall of the output bus voltage can be analyzed. Further, the target bus voltage at the current moment is determined according to the frequency or amplitude of the increase or decrease of the bus voltage estimated value, so that the inverter controller adjusts the output bus voltage to be consistent with the target bus voltage at the current moment, and the output bus voltage can be stably output.

In the embodiment, the inverter controller determines the target bus voltage at the current moment according to the frequency or amplitude of the rise or fall of the estimated bus voltage value, so that the inverter controller adjusts the output bus voltage to be consistent with the target bus voltage at the current moment. Further, the inverter controller performs anti-shake processing on the output bus voltage according to the target bus voltage at the current moment, so that the output bus voltage can be stably output.

In an embodiment, as shown in fig. 2, the anti-shake processing is performed on the estimated bus voltage value to determine the target bus voltage at the current time, and the method includes:

s311: and acquiring an estimated voltage change value based on the estimated value of the bus voltage at the current moment and the target bus voltage at the previous moment.

The current time and the last time are two adjacent time points. The estimated voltage change value is the difference value between the estimated value of the bus voltage at the current moment and the target bus voltage at the previous moment after two adjacent time points.

Specifically, based on the estimated value of the bus voltage at the current moment and the target bus voltage at the previous moment, the target bus voltage at the previous moment is subtracted from the estimated value of the bus voltage at the current moment to obtain a difference value between the estimated value of the bus voltage at the current moment and the target bus voltage at the previous moment, and the estimated voltage change value is obtained according to the difference value between the estimated value of the bus voltage at the current moment and the target bus voltage at the previous moment.

As an example, the target bus voltage at the previous time is U_bus1The estimated value of the bus voltage at the current moment is U_bus2Then the voltage change value DeltaU is estimated_bus＝U_bus2-U_bus1。

S312: and if the estimated voltage change value is a negative value, the change state corresponding to the bus voltage estimated value is a descending state, and the target bus voltage at the current moment is determined based on the comparison result of the absolute value of the estimated voltage change value and the preset voltage change value.

The preset voltage change value is a parameter set by a user in a self-defined way and is used as a parameter for estimating the voltage change value to compare. The target bus voltage at the current moment is obtained by the target bus voltage at the previous moment after two adjacent time points. The comparison result is obtained by comparing the estimated voltage change value corresponding to the output bus voltage with the preset voltage change value.

Specifically, if the estimated value of the bus voltage at the current moment is smaller than the target bus voltage at the previous moment, the estimated value of the bus voltage at the current moment is subtracted from the target bus voltage at the previous moment, and the estimated voltage change value is a negative value. At this time, the change state corresponding to the estimated bus voltage value obtained in real time is a falling state, and correspondingly, the change state of the output bus voltage corresponding to the estimated bus voltage value is also a falling state. In order to prevent the output bus voltage from frequently jumping to influence the performance of the inverter, the estimated voltage change value corresponding to the output bus voltage is compared with the preset voltage change value to obtain a comparison result. And then based on the comparison result, determining the target bus voltage at the current moment, and enabling the inverter controller to adjust the output bus voltage to be consistent with the target bus voltage at the current moment, so that the output bus voltage can be stably output, and the waveform of the output bus voltage is protected from frequent jumping.

S313: and if the estimated voltage change value is a positive value, the change state corresponding to the bus voltage estimated value is a rising state, and the bus voltage estimated value at the current moment is determined as the target bus voltage at the current moment.

Specifically, if the estimated value of the bus voltage at the current moment is greater than the target bus voltage at the previous moment, the estimated value of the bus voltage at the current moment is subtracted from the target bus voltage at the previous moment, and the estimated voltage change value is a positive value. At this time, the change state corresponding to the estimated bus voltage value obtained in real time is an increasing state, and correspondingly, the change state of the output bus voltage corresponding to the estimated bus voltage value is also an increasing state. When the output bus voltage is in a rising state, in order to keep the output efficiency of the output bus voltage, the estimated value of the bus voltage at the current moment is determined as the target bus voltage at the current moment, so that the output bus voltage continuously outputs the rising voltage, the inverter controller adjusts the output bus voltage to be consistent with the target bus voltage at the current moment, and the output efficiency of the output bus voltage is ensured.

In this embodiment, the inverter controller obtains an estimated voltage change value based on a current bus voltage estimated value and a previous target bus voltage, determines that a change state of the output bus voltage is a drop state according to that the change state corresponding to the bus voltage estimated value is the drop state when the estimated voltage change value is a negative value, and determines the current target bus voltage based on a comparison result between an absolute value of the estimated voltage change value and a preset voltage change value, so that the inverter controller adjusts the output bus voltage based on the current target bus voltage, the output bus voltage can be stably output, and the waveform of the output bus voltage is protected from frequent jumping. When the estimated voltage change value is a positive value, determining that the change state of the output bus voltage is a rising state according to the fact that the change state corresponding to the bus voltage estimated value is a rising state, determining the bus voltage estimated value at the current moment as the target bus voltage at the current moment, enabling the output bus voltage to continuously output the rising voltage, enabling the inverter controller to adjust the output bus voltage to be consistent with the target bus voltage at the current moment, and ensuring that the inversion waveform is not distorted.

In one embodiment, as shown in fig. 3, the determining the target bus voltage at the current time based on the comparison result between the absolute value of the estimated voltage variation value and the preset voltage variation value in step S312 includes:

s3121: and if the absolute value of the estimated voltage change value is less than or equal to the preset voltage change value, determining the target bus voltage at the previous moment as the target bus voltage at the current moment.

Specifically, when the absolute value of the estimated voltage change value is less than or equal to the preset voltage change value, the target bus voltage at the previous moment is determined as the target bus voltage at the current moment, so that the inverter controller adjusts the output bus voltage to be consistent with the target bus voltage at the current moment, the output bus voltage can be stably output, and the waveform of the output bus voltage is further ensured not to frequently jump.

As an example, the target bus voltage at the previous time is U_bus1The estimated value of the bus voltage at the current moment is U_bus2Then the absolute value of the estimated voltage change value is DeltaU_bus＝|U_bus2-U_bus1L, preset voltage variation value is Δ U_setWhen Δ U_bus≤ΔU_set<ΔU_setThen U will be_bus1And determining the target bus voltage at the current moment.

As an example, when the absolute value of the estimated voltage change value is greater than the difference between the target bus voltage at the previous time and the preset voltage change value and is less than the target bus voltage at the previous time, understandably, when the difference between the target bus voltage at the previous time and the preset voltage change value of the output bus voltage corresponding to the estimated bus voltage value frequently jumps with the target bus voltage at the previous time, the target bus voltage at the previous time is determined as the target bus voltage at the current time, so that the output bus voltage can be stably output, and the waveform of the output bus voltage is ensured not to frequently jump. For example, the target bus voltage at the previous time is U_bus1The estimated value of the bus voltage at the current moment is U_bus2Then the absolute value of the estimated voltage change value is DeltaU_bus＝|U_bus2-U_bus1L, preset voltage variation value is Δ U_setWhen (U)_bus1－ΔU_set)<ΔU_bus≦U_bus1Then, U will be_bus1And determining the target bus voltage at the current moment.

S3122: and if the absolute value of the estimated voltage change value is larger than the preset voltage change value, determining the bus voltage estimated value at the current moment as the target bus voltage at the current moment.

Specifically, when the absolute value of the estimated voltage change value is greater than the preset voltage change value, it can be understood that, at this time, the absolute value of the estimated voltage change value already exceeds the range of the preset voltage change value, and the estimated value of the bus voltage at the current moment is determined as the target bus voltage at the current moment, so that the bus voltage output is more reasonable, the inverter efficiency is improved, and the inversion waveform is improved.

As an example, the target bus voltage at the previous time is U_bus1The estimated value of the bus voltage at the current moment is U (330V)_bus2310V, the absolute value of the estimated voltage change value is Δ U_bus＝|U_bus2-U_bus1A preset voltage of |310 | -330| -20VConversion value of Δ U_set＝1。ΔU_bus>ΔU_setWill U is_bus2310V is determined as the target bus voltage at the present moment.

In this embodiment, when the absolute value of the estimated voltage change value is smaller than the preset voltage change value, the target bus voltage at the previous time is determined as the target bus voltage at the current time; when the absolute value of the estimated voltage change value is larger than the preset voltage change value, the estimated value of the bus voltage is determined as the target bus voltage at the current moment, so that the bus voltage output is more reasonable, the efficiency of the inverter is improved, and the inversion waveform is improved.

In an embodiment, in step S30, the adjusting process is performed on the output bus voltage based on the estimated bus voltage value, and the determining the target bus voltage at the current time further includes: and performing limit processing on the output bus voltage based on the estimated bus voltage value, and determining the target bus voltage at the current moment.

The limiting processing of the output bus voltage means that when the output bus voltage is too large or too small, the output bus voltage is maintained within a preset voltage range, and abnormal large current is prevented from occurring when the output bus voltage is too high and devices are damaged or a system is too low.

Specifically, the inverter controller estimates the output bus voltage by the bus voltage estimation value, and the magnitude of the output bus voltage can be analyzed by analyzing the magnitude of the bus voltage estimation value obtained in real time. Furthermore, according to the estimated value of the bus voltage, the estimated value of the bus voltage which is too high or too low is limited, and the target bus voltage at the current moment is determined, so that the inverter controller adjusts the output bus voltage to be consistent with the target bus voltage at the current moment, and abnormal large current is prevented from occurring in a device or a system with too low output bus voltage due to too high output bus voltage.

In this embodiment, the inverter controller may analyze the magnitude of the output bus voltage by analyzing the magnitude of the estimated value of the bus voltage obtained in real time, and according to the magnitude of the estimated value of the bus voltage, limit the estimated value of the bus voltage that is too high or too low, and determine the target bus voltage at the current time, so as to adjust the output bus voltage to be consistent with the target bus voltage at the current time by the inverter controller, thereby preventing the device from being damaged due to the too high output bus voltage or the system from generating abnormal large current due to the too low output bus voltage.

In one embodiment, as shown in fig. 4, in step S30, performing a limiting process on the output bus voltage based on the estimated bus voltage value to determine the target bus voltage at the current time includes:

s321: and if the estimated value of the bus voltage is smaller than the lower limit value of the bus voltage, determining the lower limit value of the bus voltage as the target bus voltage at the current moment.

The bus voltage lower limit value is a voltage value set by a user in a self-defined mode and is used for limiting the excessively small bus voltage estimated value.

Specifically, as known from P ═ U × I, when the inverter power is not changed, a lower output bus voltage may cause a larger direct-current side current, and when the estimated value of the bus voltage is smaller than the bus voltage lower limit value, the lower limit value of the bus voltage is determined as the target bus voltage at the present time, so that the inverter controller adjusts the output bus voltage to be consistent with the target bus voltage at the present time, and the abnormal large current in the system with too low output bus voltage is prevented.

As an example, the bus voltage estimate is U_busThe voltage limit of the bus is U_downlimit. When U is turned_bus<U_downlimitIn time, the bus voltage is reduced by a limit value U_downlimitAnd determining the target bus voltage at the current moment.

S322: and if the estimated value of the bus voltage is larger than the upper limit value of the bus voltage, determining the upper limit value of the bus voltage as the target bus voltage at the current moment.

The lower limit value of the bus voltage is a voltage value set by a user in a self-defined mode and is used for limiting the excessive estimated value of the bus voltage.

Specifically, in order to prevent the device from being damaged by the overhigh output bus voltage, when the estimated value of the bus voltage is larger than the upper limit value of the bus voltage, the upper limit value of the bus voltage is determined as the target bus voltage at the current moment, so that the inverter controller adjusts the output bus voltage to be consistent with the target bus voltage at the current moment, and the device is prevented from being damaged by the overhigh output bus voltage.

As an example, the bus voltage estimate is U_busThe upper limit value of the bus voltage is U_uplimit. When U is turned_bus>U_uplimitThe upper limit value U of the bus voltage is set_uplimitAnd determining the target bus voltage at the current moment.

S323: and if the estimated bus voltage value is between the lower bus voltage limit value and the upper bus voltage limit value, determining the estimated bus voltage value as the target bus voltage at the current moment.

Specifically, when the estimated value of the bus voltage is between the lower limit value of the bus voltage and the upper limit value of the bus voltage, the possibility that the device is damaged due to overhigh output bus voltage or abnormal large current occurs in a system due to overlow output bus voltage is avoided, and the estimated value of the bus voltage is directly determined as the target bus voltage at the current moment, so that the inverter controller adjusts the output bus voltage to be consistent with the target bus voltage at the current moment, and the output efficiency of the output bus voltage is ensured.

As an example, the bus voltage estimate is U_busThe upper limit value of the bus voltage is U_uplimitThe voltage limit of the bus is U_downlimit. When U is turned_uplimit>U_bus>U_downlimitThen, the bus voltage estimated value U is compared_busAnd determining the target bus voltage at the current moment.

In the embodiment, when the estimated value of the bus voltage is smaller than the lower limit value of the bus voltage, the inverter controller determines the lower limit value of the bus voltage as the target bus voltage at the current moment; when the estimated value of the bus voltage is larger than the upper limit value of the bus voltage, determining the upper limit value of the bus voltage as the target bus voltage at the current moment; the bus voltage upper limit value and the bus voltage lower limit value are used for ensuring that the target bus voltage at the current moment is in a reasonable range and ensuring the reliability of the system.

It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

In one embodiment, an inverter bus voltage adjusting device is provided, which corresponds to the inverter bus voltage adjusting method in the above embodiments one to one. As shown in fig. 5, the inverter bus voltage adjusting apparatus includes an obtaining module 10, a voltage estimating module 20, a voltage adjustment processing module 30, and a regulation performing module 40. The functional modules are explained in detail as follows:

the acquisition module 10 is configured to acquire a maximum duty ratio of the inverter, a peak voltage of a power grid, and an inverter output current;

the voltage estimation module 20 is configured to obtain an estimated value of the bus voltage based on the maximum duty ratio of the inverter, the peak voltage of the power grid, and the inversion output current;

the voltage adjustment processing module 30 is configured to perform adjustment processing on the estimated value of the bus voltage, and determine a target bus voltage at the current time;

and the adjusting execution module 40 is used for adjusting the duty ratio of the DC/DC converter in the inverter based on the target bus voltage at the current moment so as to enable the output bus voltage to be consistent with the target bus voltage at the current moment.

Further, the voltage estimation module 20 includes:

an estimation formula submodule for calculating the maximum duty ratio of the inverter, the peak voltage of the power grid and the inversion output current by adopting a bus voltage estimation formula to obtain the bus voltage estimation value, wherein the bus voltage estimation formula is U_bus＝(a/m)*(U_max+bI_out) + c, where m is the inverter maximum duty cycle, a is the correction factor for the inverter maximum duty cycle, U_maxFor peak voltage of the grid, I_outThe inverter output current is obtained, b is a regulating coefficient of the inverter output current, and c is a correction coefficient of the bus voltage.

Further, the voltage adjustment processing module 30 includes:

and the estimated value anti-shake sub-module is used for carrying out anti-shake processing on the estimated value of the bus voltage and determining the target bus voltage at the current moment.

Further, the voltage adjustment processing module 30 further includes:

the estimated change value submodule acquires an estimated voltage change value based on the bus voltage estimated value at the current moment and the target bus voltage at the previous moment;

the descending state submodule is used for determining the target bus voltage at the current moment based on the comparison result of the absolute value of the estimated voltage change value and the preset voltage change value when the estimated voltage change value is a negative value and the change state corresponding to the bus voltage estimated value is a descending state;

and the rising state submodule is used for determining the change state corresponding to the bus voltage estimated value as a rising state when the estimated voltage change value is a positive value, and determining the bus voltage estimated value at the current moment as the target bus voltage at the current moment.

Further, the voltage adjustment processing module 30 further includes:

the first determining submodule is used for determining the target bus voltage at the previous moment as the target bus voltage at the current moment when the absolute value of the estimated voltage change value is smaller than the preset voltage change value;

the second determining submodule is used for determining the target bus voltage at the previous moment as the target bus voltage at the current moment when the absolute value of the estimated voltage change value is larger than the target voltage difference value and smaller than the target bus voltage at the previous moment, and the target voltage difference value is the difference value between the target bus voltage at the previous moment and the preset voltage change value;

and the third determining submodule is used for determining the estimated value of the bus voltage at the current moment as the target bus voltage at the current moment when the absolute value of the estimated voltage change value is larger than the preset voltage change value.

Further, the voltage adjustment processing module 30 further includes:

and the estimation limiting submodule is used for carrying out limiting value processing on the estimated value of the bus voltage and determining the target bus voltage at the current moment.

Further, the voltage adjustment processing module 30 further includes:

the fourth determining submodule is used for determining the lower limit value of the bus voltage as the target bus voltage at the current moment when the estimated value of the bus voltage is smaller than the lower limit value of the bus voltage;

the fifth determining submodule is used for determining the upper limit value of the bus voltage as the target bus voltage at the current moment when the estimated value of the bus voltage is greater than the upper limit value of the bus voltage;

and the sixth determining submodule is used for determining the estimated bus voltage value as the target bus voltage at the current moment when the estimated bus voltage value is between the lower bus voltage limit value and the upper bus voltage limit value.

For specific limitations of the inverter bus voltage adjusting device, reference may be made to the above limitations of the inverter bus voltage adjusting method, which are not described herein again. Each module in the inverter bus voltage adjusting apparatus may be wholly or partially implemented by software, hardware, or a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the inverter controller, and can also be stored in a memory in the inverter controller in a software form, so that the processor can call and execute operations corresponding to the modules.

In one embodiment, an inverter controller is provided, the internal structure of which may be as shown in fig. 6. The inverter controller includes a processor, a memory, a network interface, and a database connected by a system bus. Wherein the processor of the inverter controller is configured to provide computational and control capabilities. The memory of the inverter controller includes a nonvolatile storage medium and an internal memory. The nonvolatile storage medium stores an operating system, an inverter control program, and a database. The internal memory provides an environment for the operation of the operating system and the inverter control program in the nonvolatile storage medium. The database of the inverter controller is used for inverter bus voltage regulation (function definition of the supplementary database). The network interface of the inverter controller is used for communicating with an external terminal through network connection. The inverter control program is executed by a processor to realize an inverter bus voltage adjusting method.

In one embodiment, an inverter controller is provided, which includes a memory, a processor, and an inverter control program stored in the memory and executable on the processor, and the processor executes the inverter control program to implement the steps of the inverter bus voltage adjusting method in the above embodiments, such as steps S10 to S40. Alternatively, the processor implements the functions of each module/unit in this embodiment of the inverter bus voltage adjusting apparatus, for example, the functions of the modules 10 to 40, when executing the inverter control program. To avoid repetition, further description is omitted here.

In an embodiment, a computer-readable storage medium is provided, where an inverter control program is stored on the computer-readable storage medium, and the inverter control program, when executed by a processor, implements the steps of the inverter bus voltage adjusting method in the foregoing embodiments, such as steps S10 to S40, which are not repeated herein to avoid repetition. Alternatively, when executed by the processor, the inverter control program implements the functions of each module/unit in the embodiment of the inverter bus voltage adjusting apparatus, such as the functions of the modules 10 to 40, and is not described herein again to avoid redundancy.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by the inverter control program, which can be stored in a non-volatile computer readable storage medium, and the inverter control program, when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.