Alternating current control method and controller

Abstract

The invention provides an alternating current control method and a controller, the alternating current control method is applied to the controller, the controller comprises a PI controller and at least one peak filter, and the PI controller and the at least one peak filter are connected in series; the method comprises the steps that a controller obtains a given alternating current signal and an error signal of a DC / AC conversion circuit of target equipment; the error signal represents an error between a given AC signal and an actual output signal of the DC / AC conversion circuit; processing the error signal through a PI controller and a peak filter to obtain a control signal; wherein the target resonant frequencies of different peak filters are different; and based on the control signal, controlling a DC / AC conversion circuit of the target equipment to output an actual output signal according to a given AC signal, basically eliminating a steady-state error under a power frequency, and eliminating a harmonic wave of a specified frequency according to a demand.

Description

Technical Field

[0001] The present application relates to the field of AC power conversion, and more particularly, to an AC power control method and a controller. Background Art

[0002] Grid-connected equipment such as photovoltaic grid-connected inverters, energy storage inverters, and UPSs that require DC / AC conversion, or equipment with AC loads, all need to control the sinusoidality of the output AC current. However, due to grid voltage distortion during grid connection, fluctuations on the DC side, or due to non-ideal characteristics of devices, etc., the output AC current often contains low-frequency harmonic components, and sometimes this component exceeds the local standards, resulting in inability to be sold locally.

[0003] At the same time, the traditional current control method for DC / AC conversion is a closed-loop feedback control method using a PI regulator. However, a PI (Proportional Integral) controller cannot eliminate the steady-state error of AC variables, which will result in a fixed phase difference between the output current and the given current signal. Summary of the Invention

[0004] In view of this, the purpose of the present application is to provide an AC power control method and a controller, which can basically eliminate the steady-state error at the power frequency, can eliminate harmonics of specified frequencies according to requirements, and at the same time, the original low-frequency anti-disturbance characteristics are affected very little.

[0005] An AC power control method provided by an embodiment of the present application is applied to a controller, and the controller includes a PI controller and at least one spike filter, and the PI controller and at least one spike filter are connected in series; the method includes:

[0006] The controller obtains a given AC signal and an error signal of the DC / AC conversion circuit of the target device; the error signal represents the error between the given AC signal and the actual output signal of the DC / AC conversion circuit;

[0007] Process the error signal through the PI controller and the spike filter to obtain a control signal; wherein, the target resonance frequencies of different spike filters are different;

[0008] Based on the control signal, control the DC / AC conversion circuit of the target device to output an actual output signal according to the given AC signal.

[0009] In some embodiments, in the AC power control method, before the controller obtains the given AC signal and the error signal of the DC / AC conversion circuit of the target device, the method further includes:

[0010] Configure the PI controller in the controller;

[0011] Configure the first spike filter in the controller according to the power frequency of the DC / AC conversion circuit of the target device;

[0012] Configure the second spike filter of the controller according to the harmonic frequency of the actual output signal of the DC / AC conversion circuit of the target device.

[0013] In some embodiments, in the AC control method, configuring the first spike filter in the controller according to the power frequency of the DC / AC conversion circuit of the target device includes:

[0014] Based on the power frequency of the DC / AC conversion circuit of the target device, configure the transfer function of the first spike filter for the power frequency signal, so that the gain of the controller with the first spike filter connected in series satisfies the target gain condition at the power frequency.

[0015] In some embodiments, in the AC control method, configuring the second spike filter in the controller according to the harmonic frequency of the actual output signal of the DC / AC conversion circuit of the target device includes:

[0016] Based on the harmonic frequency of the DC / AC conversion circuit of the target device, determine the number of second spike filters for eliminating harmonics;

[0017] According to the target harmonic frequency to be eliminated by the second spike filter, configure the transfer function of the second spike filter, and the open-loop gain of the second spike filter at the target harmonic frequency is greater than the preset gain.

[0018] In some embodiments, in the AC control method, configuring the transfer function of the second spike filter includes:

[0019] Configure the specified parameters of the transfer function of the second spike filter to configure the open-loop gain and bandwidth of the transfer function of the second spike filter at the target harmonic frequency.

[0020] In some embodiments, in the AC control method, the transfer function of the spike filter is

[0021] wherein, ω0 represents the resonant frequency of the spike filter, and the resonant frequency is the power frequency or the harmonic frequency; ξ2 is the second parameter, ξ1 is the first parameter, ξ2 > ξ1, and s represents the operator of the transfer function.

[0022] In some embodiments, in the AC control method, based on the ξ2 and ξ1, determine the open-loop gain and bandwidth of the transfer function of the spike filter at the target resonant frequency.

[0023] In some embodiments, the AC control method further includes:

[0024] The controller obtains the actual output signal of the DC / AC conversion circuit of the target device;

[0025] Determine the error signal based on the given AC signal and the actual output signal of the DC / AC conversion circuit of the target device.

[0026] In some embodiments, in the AC control method, the spike filter includes a first resonant filter with a target resonant frequency of the power frequency and a second resonant filter with a target resonant frequency of the harmonic frequency;

[0027] Process the error signal through a PI controller and a spike filter to obtain a control signal, including:

[0028] Process the error signal through a PI controller and process the error signal with a frequency of the power frequency through the first spike filter;

[0029] Process the error signal with a frequency of the harmonic frequency through the second spike filter.

[0030] In some embodiments, a controller is further provided. The controller includes a PI controller and at least one spike filter, and the PI controller and the at least one spike filter are connected in series;

[0031] The controller is used for:

[0032] Obtain the given AC signal and the error signal of the DC / AC conversion circuit of the target device; the error signal characterizes the error between the given AC signal and the actual output signal of the DC / AC conversion circuit;

[0033] Process the error signal through a PI controller and a spike filter to obtain a control signal; wherein, the target resonant frequencies of different spike filters are different;

[0034] Based on the control signal, control the DC / AC conversion circuit of the target device to output an actual output signal according to the given AC signal.

[0035] In an embodiment of the present application, an AC control method and a controller are provided. The AC control method is applied to the controller, and the controller includes a PI controller and at least one spike filter, and the PI controller and the at least one spike filter are connected in series; the method includes: the controller obtains a given AC signal and an error signal of the DC / AC conversion circuit of the target device; the error signal represents the error between the given AC signal and the actual output signal of the DC / AC conversion circuit; the error signal is processed by the PI controller and the spike filter to obtain a control signal; wherein, the target resonance frequencies of different spike filters are different; based on the control signal, the DC / AC conversion circuit of the target device is controlled to output an actual output signal according to the given AC signal; by using the method of connecting a PI controller in series with a spike filter to replace the traditional PI regulator, the steady-state error at the power frequency can be eliminated, and the harmonics of a specified frequency can be eliminated according to requirements, while the original low-frequency anti-disturbance characteristics are affected very little. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1 Shows a schematic diagram of the principle of the traditional PI regulator described in the embodiments of the present application;

[0038] Figure 2 Shows a flowchart of the AC control method described in the embodiments of the present application;

[0039] Figure 3 Shows a schematic diagram of the structure of a current loop described in the embodiments of the present application;

[0040] Figure 4 Shows a schematic diagram of the structure of another current loop described in the embodiments of the present application;

[0041] Figure 5 Shows a connection diagram of the DC / AC conversion circuit described in the embodiments of the present application;

[0042] Figure 6 Shows a flowchart of another AC control method described in the embodiments of the present application;

[0043] Figure 7 Shows a current waveform diagram of the output of the experimental device under the control of the traditional PI regulator described in the embodiments of the present application;

[0044] Figure 8 ShowsFigure 7 Analysis results of the harmonic content of the current waveform diagram in

[0045] Figure 9 The figure shows the current waveform diagram output by the experimental equipment under the control of the current loop described in the embodiments of the present application;

[0046] Figure 10 shows Figure 9 Analysis results of the harmonic content of the current waveform diagram in Detailed implementation manners

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It should be understood that the accompanying drawings in the present application are only for the purposes of illustration and description, and are not used to limit the protection scope of the present application. In addition, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in the present application illustrate the operations implemented according to some embodiments of the present application. It should be understood that the operations in the flowchart may not be implemented in sequence, and the steps without logical context relationships may be reversed or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart or remove one or more operations from the flowchart under the guidance of the content of the present application.

[0048] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application claimed, but only represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0049] It should be noted that the term "including" will be used in the embodiments of the present application to indicate the existence of the features stated thereafter, but does not exclude adding other features.

[0050] Grid-connected photovoltaic inverters, energy storage inverters, UPS, etc., grid-connected devices or devices with AC loads that require DC / AC conversion all need to control the sinusoidality of the output AC current. However, due to grid voltage distortion during grid connection, fluctuations on the DC side, or due to non-ideal characteristics of devices, etc., the output AC current often contains low-frequency harmonic components, and sometimes this component exceeds the local standards, resulting in inability to be sold locally.

[0051] Meanwhile, the traditional current control method for DC / AC conversion is a closed-loop feedback control method using a PI regulator. However, the PI (Proportional Integral) controller cannot eliminate the steady-state error of the AC variable, which will result in a fixed phase difference between the output current and the given current signal.

[0052] Here, the PI regulator can also be referred to as a PI controller.

[0053] Please refer to Figure 1 , Figure 1 which shows a schematic diagram of the principle of the traditional PI regulator described in the embodiments of the present application. As Figure 1 shown, for the PI controller, a current signal is given, and the current signal actually output by the feedback target device is also given. The PI controller adjusts according to the given current signal and the feedback current signal. The purpose is to control the target device based on the error between the feedback current signal and the given current signal, eliminate the steady-state error of the AC variable, and make there be no phase difference between the output current and the given current signal. However, in fact, the PI (Proportional Integral) controller cannot eliminate the steady-state error of the AC variable, which will result in a fixed phase difference between the output current and the given current signal.

[0054] Based on this, in the embodiments of the present application, an AC control method and a controller are provided. The AC control method is applied to the controller, and the controller includes a PI controller and at least one spike filter. The PI controller and at least one spike filter are connected in series. The method includes: the controller obtains a given AC signal and an error signal of the DC / AC conversion circuit of the target device; the error signal represents the error between the given AC signal and the actual output signal of the DC / AC conversion circuit; the error signal is processed by the PI controller and the spike filter to obtain a control signal; where the target resonance frequencies of different spike filters are different; based on the control signal, the DC / AC conversion circuit of the target device is controlled to output an actual output signal according to the given AC signal; by using the method of connecting the PI controller in series with the spike filter to replace the traditional PI regulator, the steady-state error at the power frequency can be eliminated, and the harmonics of the specified frequency can be eliminated according to requirements. At the same time, the original low-frequency anti-disturbance characteristics are affected very little.

[0055] Please refer to Figure 2 , Figure 2 which shows a flowchart of the AC control method described in the embodiments of the present application. The AC control method is applied to the controller, and the controller includes a PI controller and at least one spike filter. The PI controller and at least one spike filter are connected in series. The method includes the following steps S201 - S203:

[0056] S201. The controller obtains the given AC signal and the error signal of the DC / AC conversion circuit of the target device; the error signal represents the error between the given AC signal and the actual output signal of the DC / AC conversion circuit.

[0057] S202. Process the error signal through a PI controller and a spike filter to obtain a control signal; among them, the target resonance frequencies of different spike filters are different.

[0058] S203. Based on the control signal, control the DC / AC conversion circuit of the target device to output an actual output signal according to the given AC signal.

[0059] The current loop includes a PI controller and at least one spike filter (Peak Filter), and the PI controller and at least one spike filter are connected in series.

[0060] In the embodiments of the present application, the spike filter (Peak Filter) can also be referred to as PF or Peak Filter.

[0061] Both the PI controller and the spike filter can be implemented through hardware circuit experiments or through software programs.

[0062] Here, the error signal can be used to represent both the voltage error between the given AC signal and the actual output signal and the current error between the given AC signal and the actual output signal. That is to say, the controller can be used to control the current or voltage of the actual output signal of the DC / AC conversion circuit.

[0063] When the controller is used to control the magnitude of the actual output signal current, the PI controller and at least one spike filter form a current loop.

[0064] When the controller is used to control the magnitude of the actual output signal voltage, the PI controller and at least one spike filter form a voltage loop.

[0065] In the embodiments of the present application, taking the controller for adjusting and controlling the magnitude of the actual output signal current as an example, the AC control process described in the embodiments of the present application is specifically described.

[0066] Please refer to Figure 3 , Figure 3 shows a schematic structural diagram of a current loop described in the embodiments of the present application; please refer to Figure 4 , Figure 4 shows a schematic structural diagram of another current loop described in the embodiments of the present application.

[0067] Please refer to Figure 3 and Figure 4, when there are n spike filters, the n spike filters are PF1, PF2, ……PFn respectively. The n spike filters can be connected in series before the PI controller or after the PI controller. Engineers can make a choice according to actual needs.

[0068] The controller is used to implement current control of the DC / AC conversion circuit of the target device. The controller can adjust the current value and / or voltage value of the output current of the DC / AC conversion circuit by adjusting the PI parameters, and further control the amplitude, frequency, etc. of the output current.

[0069] As Figure 3 and Figure 4 shown, i ref represents the given AC signal, K pwm represents the gain caused by PWM modulation; represents the filter inductor and the parasitic resistance of the filter inductor; i o represents the actual output signal of the DC / AC conversion circuit of the target device.

[0070] The current loop adjusts the actual output signal of the DC / AC conversion circuit of the target device according to the given AC signal and the error signal, so as to achieve precise control of the current of the DC / AC conversion circuit of the target device.

[0071] In the step S201, the controller obtains the given AC signal and the error signal of the DC / AC conversion circuit of the target device; the error signal represents the error between the given AC signal and the actual output signal of the DC / AC conversion circuit.

[0072] Exemplarily, the target device can be devices such as a photovoltaic grid-connected inverter, an energy storage inverter, a UPS, etc.

[0073] The AC control method described in the embodiments of the present application further includes:

[0074] The controller obtains the actual output signal of the DC / AC conversion circuit of the target device;

[0075] Determine the error signal based on the given AC signal and the actual output signal of the DC / AC conversion circuit of the target device.

[0076] There is a phase difference and harmonics between the actual output signal and the given AC signal of the DC / AC conversion circuit. Therefore, the error signal represents the phase difference between the actual output signal and the given AC signal, and the harmonics in the actual output signal.

[0077] Please refer to Figure 5 , the DC / AC conversion circuit is a circuit that converts direct current (DC) into alternating current (AC), and is also called an inverter circuit.

[0078] The DC / AC conversion circuit generally includes a rectifier circuit and an inverter circuit. The rectifier circuit converts a DC power supply into a pulsating DC power supply. Common types of rectifier circuits include single-phase bridge rectifier circuits and three-phase bridge rectifier circuits. The inverter circuit is the core conversion part that converts the pulsating DC power supply into an AC power supply, and its basic structure is mainly composed of components such as switching tubes, filter inductors, and capacitors.

[0079] Generally, the DC / AC conversion circuit also includes an input filter circuit to filter out high-frequency noise and harmonics in the DC power supply to ensure the normal operation of the internal circuit of the inverter, and an output filter circuit to filter out high-frequency noise and harmonics in the output of the inverter circuit, thereby providing a clean AC output.

[0080] The working principle of the DC / AC conversion circuit is mainly based on PWM (Pulse Width Modulation) technology. Based on the PWM wave, the conduction time of the switching tube is controlled to make the output waveform close to a sine wave.

[0081] In the embodiments of the present application, the spike filter includes a first spike filter and a second spike filter. The first spike filter is used to eliminate the steady-state error for the power frequency, and the second spike filter is used to eliminate specified harmonics.

[0082] The number of the second spike filters can be one or more. For example, if only the second harmonic needs to be eliminated, then one second spike filter is configured in the controller; if the second harmonic and the third harmonic need to be eliminated, then two second spike filters are configured in the controller.

[0083] Based on this, please refer to Figure 6 , before the controller in the embodiments of the present application obtains the given AC signal and the error signal of the DC / AC conversion circuit of the target device, the method further includes the following steps S601 - S603:

[0084] S601. Configure the PI controller in the controller;

[0085] S602. Configure the first spike filter in the controller according to the power frequency of the DC / AC conversion circuit of the target device;

[0086] S603. Configure the second spike filter of the controller according to the harmonic frequency of the actual output signal of the DC / AC conversion circuit of the target device.

[0087] The power frequency refers to the rated frequency adopted by power generation, transmission, transformation, and distribution equipment, as well as industrial and civil electrical equipment, with the unit of hertz (Hz), usually 50Hz or 60Hz.

[0088] In the step S601, configure the PI controller in the controller, that is, set the parameters of the PI controller; specifically, configure parameters such as the open-loop gain K and the time constant T of the PI controller.

[0089] In the step S602, configure the first spike filter in the controller according to the power frequency of the DC / AC conversion circuit of the target device; specifically, based on the power frequency of the DC / AC conversion circuit of the target device, configure the transfer function of the first spike filter for the power frequency signal, so that the gain of the controller connected in series with the first spike filter at the power frequency meets the target gain condition.

[0090] That is, set the resonant frequency of the first spike filter to the power frequency.

[0091] In the step S603, configure the second spike filter of the controller according to the harmonic frequency of the actual output signal of the DC / AC conversion circuit of the target device, including:

[0092] Based on the harmonic frequency of the DC / AC conversion circuit of the target device, determine the number of second spike filters for eliminating harmonics;

[0093] According to the target harmonic frequency to be eliminated by the second spike filter, configure the transfer function of the second spike filter, and the open-loop gain of the second spike filter at the target harmonic frequency is greater than the preset gain.

[0094] Here, the open-loop gain of the second spike filter at the target harmonic frequency should be large enough.

[0095] That is, set the resonant frequency of the second spike filter to the target harmonic frequency to be eliminated.

[0096] Specifically, the transfer function of the spike filter is

[0097]

[0098] Among them, ω0 represents the resonant frequency of the spike filter, and the resonant frequency is the power frequency or the harmonic frequency; ξ2 is the second parameter, ξ1 is the first parameter, ξ2 > ξ1, and s represents the operator of the transfer function.

[0099] In the embodiment of the present application, configure the specified parameters of the transfer function of the second spike filter to configure the open-loop gain and bandwidth of the transfer function of the second spike filter at the target harmonic frequency.

[0100] In the embodiment of the present application, based on the ξ2 and ξ1, determine the open-loop gain and bandwidth of the transfer function of the spike filter at the target resonant frequency.

[0101] In step S202, the controller processes the error signal of the target resonant frequency through a PI controller and the spike filter to obtain a control signal; wherein, the target resonant frequencies of different spike filters are different.

[0102] Specifically, the spike filter includes a first resonant filter with a power frequency as the target resonant frequency and a second resonant filter with a harmonic frequency as the target resonant frequency;

[0103] Processing the error signal through a PI controller and a spike filter to obtain a control signal includes:

[0104] Processing the error signal through a PI controller and processing the error signal with a power frequency through the first spike filter;

[0105] Processing the error signal with a harmonic frequency through the second spike filter.

[0106] That is to say, the target resonant frequency of the first spike filter is the power frequency, and its transfer function is: Its gain at the target resonant frequency ω0 is infinite. Therefore, when the target resonant frequency of the first spike filter is the power frequency, the gain of the controller (such as the current loop) at the power frequency is infinite, thereby greatly reducing the steady-state error, and it can be said that the steady-state error is eliminated.

[0107] The target resonant frequency of the second spike filter is the target harmonic frequency to be eliminated. Since the target resonance in the given AC signal is 0, the output of the second spike filter with the target resonant frequency is 0, thereby eliminating the target resonance.

[0108] Here, the controller processes the error signal to obtain a control signal for controlling the DC / AC conversion circuit of the target device, and the control signal can be a PWM wave.

[0109] In step S203, based on the control signal, control the DC / AC conversion circuit of the target device to output an actual output signal according to the given AC signal.

[0110] The controller sends the control signal to the DC / AC conversion circuit of the target device to control the DC / AC conversion circuit of the target device to output an actual output signal according to the given AC signal. Since the steady-state error of the system is basically eliminated, there is basically no phase difference between the actual output signal and the given AC signal, or rather, the phase difference is very small. Because the specified harmonics are eliminated through the second spike filter, the actually output AC current no longer contains low-frequency harmonic components, ensuring the quality of the AC power supply.

[0111] As an example only, the control signal is a PWM wave. The controller sends the PWM wave to the DC / AC conversion circuit of the target device. The PWM wave controls the conduction time of the switching tubes (such as MOS tubes) in the inverter circuit of the DC / AC conversion circuit of the target device, so as to convert the DC voltage into an alternating current without specified harmonics and with a very small phase difference.

[0112] In the embodiment of the present application, by using PI in series with PF in the controller to replace the traditional PI regulator, the steady-state error at power frequency is eliminated, and harmonics of specified frequencies can be eliminated according to requirements. At the same time, the original low-frequency anti-disturbance characteristics are not affected. The following are the comparison results of the simulation effects of using the PI regulator and using the current loop described in the embodiment of the present application.

[0113] For the experimental equipment, a two-frequency fluctuation interference quantity of the DC bus voltage (this interference exists in all single-phase inverters) is introduced to obtain the current waveform diagram of the experimental equipment output under the control of the traditional PI regulator; and the current waveform diagram of the experimental equipment output under the control of the current loop described in the embodiment of the present application.

[0114] Please refer to Figure 7 , Figure 7 shows the current waveform diagram of the experimental equipment output under the control of the traditional PI regulator described in the embodiment of the present application.

[0115] Based on Figure 7 the shown current waveform diagram, analyze the third harmonic in the alternating current output by the experimental equipment, and obtain the harmonic content analysis result as shown in Figure 8 . In the alternating current output by the experimental equipment under the control of the traditional PI regulator, the third harmonic reaches about 3.6%.

[0116] Under the condition that all other conditions remain unchanged, the control method described in the embodiment of the present application is used for control. When PF with a PI series resonance point at the triple frequency (150 Hz) is used in the current loop, the output current waveform is as follows Figure 9 shown. Figure 9 shows the current waveform diagram of the experimental equipment output under the control of the current loop described in the embodiment of the present application.

[0117] Based on Figure 9 the shown current waveform diagram, analyze the third harmonic in the alternating current output by the experimental equipment, and obtain the harmonic content analysis result as shown in Figure 10 . In the alternating current output by the experimental equipment under the control of the current loop described in the present application, the content of the third harmonic is less than 0.1%.

[0118] Based on the same inventive concept, an embodiment of the present application further provides a controller corresponding to the AC control method. Since the principle of solving problems by the controller in the embodiment of the present application is similar to that of the above AC control method in the embodiment of the present application, the implementation of the controller can refer to the implementation of the method, and the repeated parts will not be elaborated.

[0119] The embodiment of the present application also provides a controller, which includes a PI controller and at least one spike filter, and the PI controller and the at least one spike filter are connected in series;

[0120] The controller is used for:

[0121] Obtain the given AC signal and the error signal of the DC / AC conversion circuit of the target device; the error signal represents the error between the given AC signal and the actual output signal of the DC / AC conversion circuit;

[0122] Process the error signal through the PI controller and the spike filter to obtain a control signal; wherein, the target resonance frequencies of different spike filters are different;

[0123] Based on the control signal, control the DC / AC conversion circuit of the target device to output the actual output signal according to the given AC signal.

[0124] In some embodiments, the controller is further used to configure the PI controller in the controller before obtaining the given AC signal and the error signal of the DC / AC conversion circuit of the target device;

[0125] Configure the first spike filter in the controller according to the power frequency of the DC / AC conversion circuit of the target device;

[0126] Configure the second spike filter of the controller according to the harmonic frequency of the actual output signal of the DC / AC conversion circuit of the target device.

[0127] In some embodiments, when the controller configures the first spike filter in the controller according to the power frequency of the DC / AC conversion circuit of the target device, it specifically uses:

[0128] Based on the power frequency of the DC / AC conversion circuit of the target device, configure the transfer function of the first spike filter for the power frequency signal, so that the gain of the controller with the first spike filter connected in series satisfies the target gain condition.

[0129] In some embodiments, when the controller configures the second spike filter in the controller according to the harmonic frequency of the actual output signal of the DC / AC conversion circuit of the target device, it specifically uses:

[0130] Determine the number of second spike filters for eliminating harmonics based on the harmonic frequencies of the DC / AC conversion circuit of the target device;

[0131] Configure the transfer function of the second spike filter according to the target harmonic frequencies to be eliminated by the second spike filter, and the open-loop gain of the second spike filter at the target harmonic frequencies is greater than a preset gain.

[0132] In some embodiments, when configuring the transfer function of the second spike filter, the controller is specifically configured to:

[0133] Configure the specified parameters of the transfer function of the second spike filter to configure the open-loop gain and bandwidth of the transfer function of the second spike filter at the target harmonic frequencies.

[0134] In some embodiments, the transfer function of the spike filter in the controller is

[0135]

[0136] where ω0 represents the resonant frequency of the spike filter, and the resonant frequency is the power frequency or a harmonic frequency; ξ2 is the second parameter, ξ1 is the first parameter, ξ2 > ξ1, and s represents the operator of the transfer function.

[0137] In some embodiments, the controller is further configured to determine the open-loop gain and bandwidth of the transfer function of the spike filter at the target resonant frequency based on ξ2 and ξ1.

[0138] In some embodiments, the controller is further configured to:

[0139] Obtain the actual output signal of the DC / AC conversion circuit of the target device;

[0140] Determine an error signal based on the given AC signal and the actual output signal of the DC / AC conversion circuit of the target device.

[0141] In some embodiments, the spike filter in the controller includes a first resonant filter with a power frequency as the target resonant frequency and a second resonant filter with a harmonic frequency as the target resonant frequency;

[0142] When the controller processes the error signal through a PI controller and a spike filter to obtain a control signal, it is specifically configured to:

[0143] Process the error signal through a PI controller and process the error signal with a frequency of power frequency through the first spike filter;

[0144] Process the error signal with a frequency of harmonic frequency through the second spike filter.

[0145] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working process of the controller described above can refer to the corresponding process in the method embodiments, and will not be elaborated herein.

[0146] In several embodiments provided by the present application, it should be understood that the disclosed controller can be implemented in other ways. The embodiments of the controller described above are only illustrative. For example, in terms of logical function division, there may be other division methods in actual implementation. For another example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some communication interfaces. The indirect coupling or communication connection of devices or modules can be in electrical, mechanical or other forms.

[0147] The modules described as separate components may or may not be physically separated. The components shown as modules may or may not be physical units, that is, they can be located in one place, or can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0148] In addition, in each embodiment of the present application, the functional units of the controller can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0149] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile computer-readable storage medium executable by a processor. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a platform server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, ROM, RAM, magnetic disks, or optical discs that can store program codes.

[0150] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present application, and all should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An AC control method, characterized in that, Applied to a controller, the controller includes a PI controller and at least one spike filter, and the PI controller and the at least one spike filter are connected in series; the method includes: The controller obtains a given AC signal and an error signal of the DC / AC conversion circuit of the target device; the error signal represents the error between the given AC signal and the actual output signal of the DC / AC conversion circuit; Process the error signal through the PI controller and the spike filter to obtain a control signal; wherein, the target resonance frequencies of different spike filters are different; Based on the control signal, control the DC / AC conversion circuit of the target device to output an actual output signal according to the given AC signal.

2. The AC control method according to claim 1, wherein Before the controller obtains the given AC signal and the error signal of the DC / AC conversion circuit of the target device, the method further includes: Configure the PI controller in the controller; Configure the first spike filter in the controller according to the power frequency of the DC / AC conversion circuit of the target device; Configure the second spike filter of the controller according to the harmonic frequency of the actual output signal of the DC / AC conversion circuit of the target device.

3. The AC control method according to claim 2, wherein Configuring the first spike filter in the controller according to the power frequency of the DC / AC conversion circuit of the target device includes: Based on the power frequency of the DC / AC conversion circuit of the target device, configure the transfer function of the first spike filter for the power frequency signal, so that the gain of the controller connected in series with the first spike filter at the power frequency meets the target gain condition.

4. The AC control method according to claim 2, wherein Configuring the second spike filter in the controller according to the harmonic frequency of the actual output signal of the DC / AC conversion circuit of the target device includes: Based on the harmonic frequency of the DC / AC conversion circuit of the target device, determine the number of second spike filters for eliminating harmonics; According to the target harmonic frequency to be eliminated by the second spike filter, configure the transfer function of the second spike filter, and the open-loop gain of the second spike filter at the target harmonic frequency is greater than the preset gain.

5. The AC control method according to claim 4, characterized in that Configuring the transfer function of the second spike filter includes: Configure the specified parameters of the transfer function of the second spike filter to configure the open-loop gain and bandwidth of the transfer function of the second spike filter at the target harmonic frequency.

6. The AC control method according to claim 2, characterized in that, The transfer function of the spike filter is wherein, ω0 represents the resonance frequency of the spike filter, and the resonance frequency is the power frequency or the harmonic frequency; ξ2 is the second parameter, ξ1 is the first parameter, ξ2 > ξ1, and s represents the operator of the transfer function.

7. The AC control method according to claim 6, characterized in that, Based on the ξ2 and ξ1, determine the open-loop gain and bandwidth of the transfer function of the spike filter at the target resonance frequency.

8. The AC control method according to claim 1, wherein The method further includes: The controller obtains the actual output signal of the DC / AC conversion circuit of the target device; Determine the error signal based on the given AC signal and the actual output signal of the DC / AC conversion circuit of the target device.

9. The AC control method according to claim 1, characterized in that, The spike filter includes a first resonance filter with a target resonance frequency of the power frequency and a second resonance filter with a target resonance frequency of the harmonic frequency; Processing the error signal through the PI controller and the spike filter to obtain a control signal includes: Process the error signal through a PI controller, and process the error signal with a power frequency through the first spike filter; Process the error signal with a harmonic frequency through the second spike filter.

10. A controller, characterized in that, The controller includes a PI controller and at least one spike filter, and the PI controller and at least one spike filter are connected in series; The controller is configured to: Obtain a given AC signal and an error signal of the DC / AC conversion circuit of the target device; the error signal represents the error between the given AC signal and the actual output signal of the DC / AC conversion circuit; Process the error signal through a PI controller and a spike filter to obtain a control signal; wherein, the target resonance frequencies of different spike filters are different; Based on the control signal, control the DC / AC conversion circuit of the target device to output an actual output signal according to the given AC signal.

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