KR102662694B1 - Apparatus for compensating voltage ripple and method thereof - Google Patents

Abstract

The present invention is a voltage ripple compensation method, comprising: extracting a ripple voltage component value (△Vdc) of a voltage (Vdc) input from a power supply unit; calculating an integrated output voltage (Vdc_d) based on the extracted ripple voltage component value (△Vdc) and an integral control function; Obtaining an HPF output voltage (Vdc_d_hpf) by applying a High Pass Filter (HPF) filter to the calculated integrated output voltage (Vdc_d); Matching the phase of the obtained HPF output voltage (Vdc_d_hpf) with the phase of the ripple voltage component value (△Vdc); and outputting the phase-matched final output voltage (Vdc_comp).

Description

Voltage ripple compensation device and method {APPARATUS FOR COMPENSATING VOLTAGE RIPPLE AND METHOD THEREOF}

The present invention relates to a voltage ripple compensation device and method. More specifically, the present invention relates to a voltage ripple compensation device and method, and more specifically, to improve the current waveform through ripple reduction characteristics according to DC voltage ripple compensation and to perform current control more stably in step response variations, thereby improving the system It relates to a voltage ripple compensation device and method that can improve voltage stability.

For transmission through overhead lines and/or submarine cables in the power transmission network, alternating current (AC) power is converted to direct current (DC) power for use. This conversion reduces the cost per kilometer of line and/or cable by eliminating the need to compensate for the AC capacitive load imposed by the transmission line or cable, thus converting from AC to DC when required, such as for long distance transmission. You can save money by converting.

In this case, since the conversion of AC/DC power operates at different frequencies, additional devices such as power converters, converters, and inverters are required at each interface for conversion between AC and DC power. Here, the power converter operates in, for example, a linked operation mode in which it operates in connection with the grid power of the power supply unit and an independent operation mode in which it is separated from the grid power and independently supplies power to the load.

In addition, the reference voltage used to control such power converters, inverters, converters, etc. includes an offset, and when such an offset occurs, the reference voltage has a frequency corresponding to the output frequency (generally 60Hz). A ripple of components occurs.

In other words, the ripple of the frequency component generated due to offset distorts the waveform of the alternating current output from the inverter and the direct current current input, causing the temperature of the transformer to rise, and at the same time affecting current control. and makes the grid voltage unstable, the demand and importance of methods to remove the ripple component for this reference voltage have increased.

According to this trend, technology to remove ripple has been developed, but according to the conventional ripple removal technology, various problems including reduced power supply efficiency, generation of switching noise, and increase in the number of parts still exist.

Therefore, a voltage ripple compensation device and method that can improve the voltage stability of the system by improving the current waveform and performing more stable current control in step response fluctuations through ripple reduction characteristics according to DC voltage ripple compensation. Demand is gradually increasing in the industry.

Therefore, the present invention was created to solve the above-mentioned problems, and the purpose of the present invention is to improve the current waveform through ripple reduction characteristics according to DC voltage ripple compensation and to perform current control more stably in step response fluctuations, The aim is to provide a voltage ripple compensation device and method that can improve the voltage stability of the system.

According to the features of the present invention for achieving the above-described object, there is provided a voltage ripple compensation method, comprising: extracting a ripple voltage component value (△Vdc) of a voltage (Vdc) input from a power supply unit; calculating an integrated output voltage (Vdc_d) based on the extracted ripple voltage component value (△Vdc) and an integral control function; Obtaining an HPF output voltage (Vdc_d_hpf) by applying a High Pass Filter (HPF) filter to the calculated integrated output voltage (Vdc_d); Matching the phase of the obtained HPF output voltage (Vdc_d_hpf) with the phase of the ripple voltage component value (△Vdc); and outputting the phase-matched final output voltage (Vdc_comp).

In addition, the step of matching the phase of the HPF output voltage (Vdc_d_hpf) and the phase of the ripple voltage component value (△Vdc) includes applying time delay compensation to the phase of the HPF output voltage (Vdc_d_hpf) and the ripple voltage component value. It is characterized by matching the phases of (△Vdc).

In addition, the step of acquiring the HPF output voltage (Vdc_d_hpf) is characterized in that the noise signal included in the integrated output voltage (Vdc_d) is removed by passing a signal in a frequency band of 20 Hz or higher through the HPF filter.

In addition, the step of acquiring the HPF output voltage (Vdc_d_hpf) is characterized by removing the offset voltage included in the integrated output voltage (Vdc_d) using the DC component reduction characteristic of the HPF filter.

Additionally, a computer-readable recording medium according to another embodiment of the present invention for solving the above technical problem may have a program for performing the above method recorded thereon.

Additionally, a voltage ripple compensation device according to another embodiment of the present invention for solving the above technical problem includes a voltage input unit that receives a voltage (Vdc) from a power supply unit; a ripple extraction unit that extracts a ripple voltage component value (△Vdc) of the voltage (Vdc) input from the voltage input unit; an integral controller that outputs an integrated output voltage (Vdc_d) by applying an integral control function to the ripple voltage component value (△Vdc) extracted by the ripple extractor; A filter unit that applies a High Pass Filter (HPF) filter to the integrated output voltage (Vdc_d) output through the integral controller and outputs an HPF output voltage (Vdc_d_hpf); A delay compensation unit that matches the phase of the HPF output voltage (Vdc_d_hpf) output through the filter unit and the phase of the ripple voltage component value (△Vdc); and a voltage output unit that outputs a final output voltage (Vdc_comp) whose phase is matched through the delay compensation unit.

In addition, the delay compensation unit applies time delay compensation to the phase of the HPF output voltage (Vdc_d_hpf) to match the phase of the ripple voltage component value (△Vdc).

In addition, the filter unit is characterized in that it removes the noise signal included in the integrated output voltage (Vdc_d) by passing a signal in a frequency band of 20 Hz or higher using the HPF filter.

In addition, the filter unit is characterized in that it removes the offset voltage included in the integrated output voltage (Vdc_d) using the DC component reduction characteristic of the HPF filter.

The present invention has the effect of improving the voltage stability of the system by improving the current waveform and performing more stable current control in step response fluctuations through ripple reduction characteristics according to DC voltage ripple compensation.

Additionally, the present invention has the effect of reducing costs because it does not require separate equipment or parts for DC filtering.

In addition, the present invention has the effect of preventing distortion of the output alternating current and input direct current waveforms by removing the ripple component included in the input reference voltage.

Figure 1 shows a functional block diagram of a voltage ripple compensation device 100 according to an embodiment of the present invention.
Figure 2 shows a flowchart (S200) for explaining the operation method of the voltage ripple compensation device according to an embodiment of the present invention.
Figures 3 and 4 respectively show an algorithm for explaining the operation method of a voltage ripple compensation device according to an embodiment of the present invention and a detailed configuration diagram thereof.

Hereinafter, embodiments according to the present invention will be described with reference to the attached drawings. When adding reference numerals to components in each drawing, it should be noted that identical components are given the same reference numerals as much as possible even if they are shown in different drawings. Additionally, when describing embodiments of the present invention, if detailed descriptions of related known configurations or functions are judged to impede understanding of the embodiments of the present invention, the detailed descriptions will be omitted. In addition, embodiments of the present invention will be described below, but the technical idea of the present invention is not limited or limited thereto and may be modified and implemented in various ways by those skilled in the art.

Throughout the specification, when a part is said to be "connected" to another part, this includes not only the case where it is "directly connected," but also the case where it is "indirectly connected" with another element in between. . Throughout the specification, when a part is said to “include” a certain element, this means that it may further include other elements rather than excluding other elements, unless specifically stated to the contrary. Additionally, when describing the components of an embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, or order of the component is not limited by the term.

FIG. 1 shows a functional block diagram of a voltage ripple compensation device 100 according to an embodiment of the present invention, and FIG. 2 is a flowchart for explaining the operation method of the voltage ripple compensation device 100 according to an embodiment of the present invention. S200) are shown, respectively.

1 and 2, the voltage ripple compensation device 100 according to an embodiment of the present invention includes a voltage input unit 110, a ripple extractor 120, an integration controller 130, a filter unit 140, It may be composed of a delay compensation unit 150, a voltage output unit 160, etc.

For reference, the voltage ripple compensation device 100 may be configured to execute each step constituting the operating method of the voltage ripple compensation device 100 described in more detail below, for example, as shown in FIG. 2. As shown, the voltage ripple compensation device 100 may be configured to execute each step of the operation method (S200) of the voltage ripple compensation device.

The voltage input unit 110 may receive voltage (Vdc) from a power supply unit. For example, the voltage input unit 110 may receive a voltage (Vdc) including ripple from a power supply unit to transfer the output voltage processed through an algorithm to a converter or inverter. That is, the voltage input unit 110 may sequentially pass the DC link voltage, that is, the reference voltage (Vdc) through an algorithm to remove ripple, and then output it as an input to a converter or inverter.

The ripple extractor 120 may extract the ripple voltage component value (ΔVdc) of the voltage (Vdc) input through the voltage input unit 110 (S210). Here, the ripple voltage component value (ΔVdc) means the effective value of the alternating current component remaining in the voltage (Vdc) input through the voltage input unit 110, and the ripple extractor 120 outputs the input voltage (Vdc). By removing the double frequency component, the ripple voltage component value (ΔVdc) corresponding to the output frequency can be extracted.

Additionally, in another embodiment of the present invention, the ripple extractor 120 may be implemented to extract the ripple voltage component value (ΔVdc) through a measuring device such as a typical oscilloscope or multimeter. For example, when the ripple extractor 120 is implemented as an oscilloscope, the voltage sensitivity is increased to prevent the waveform from being exposed on the screen, the input coupling is controlled to AC mode to output only the alternating current component, and then the voltage range ( By setting Volt/Div) low, you can measure the ripple voltage component value (ΔVdc).

Additionally, if the ripple extractor 120 is implemented as a multimeter, the ripple voltage component value (ΔVdc) may be measured by connecting a capacitor in series to the positive lead and then controlling it in AC mode. However, the method of extracting the ripple voltage component value (ΔVdc) through the ripple extractor 120 is not limited to these.

The integral controller 130 may calculate the integrated output voltage (Vdc_d) by applying an integral control function to the ripple voltage component value (ΔVdc) extracted through the ripple extractor 120 (S220). For example, the integration controller 130 may calculate the integrated output voltage (Vdc_d) by performing integration on the ripple voltage component value (ΔVdc) for one period corresponding to the fundamental frequency.

The filter unit 140 may preferably be implemented as a High Pass Filter (HPF) filter, and the integrated output voltage (Vdc_d) calculated by the integral controller 130 is applied to the filter unit 140 to generate the HPF output voltage. (Vdc_d_hpf) can be obtained (S230). For example, the filter unit 140 can pass signals in a frequency band of 20 Hz or higher, and thereby remove noise signals included in the integrated output voltage (Vdc_d).

That is, the filter unit 140 is implemented as a high-pass filter to block low-frequency components, for example, frequencies below 20 Hz, while passing frequencies above 20 Hz, so that they are included in the integrated output voltage (Vdc_d). By removing noise, the high-frequency components of the input signal can be made clearer.

Additionally, in another embodiment of the present invention, the filter unit 140 may remove the offset voltage included in the integrated output voltage (Vdc_d) through the DC component reduction characteristics of the HPF filter. For example, the signal of the integrated output voltage (Vdc_d) calculated through the integral controller 130 is formed to pass through the filter unit 140 so that the DC offset can be removed. To implement this, the filter unit 140 is It can be set to an enabled state.

The delay compensation unit 150 may match the phase of the HPF output voltage (Vdc_d_hpf) passing through the filter unit 140 with the phase of the ripple voltage component value (ΔVdc) extracted through the ripple extractor 120 (S240) ). For example, the phase of the HPF output voltage (Vdc_d_hpf) obtained through the filter unit 140 may have a leading characteristic due to the phase characteristics of the filter unit 140, and therefore the delay compensation unit 150 may output the HPF By applying time delay compensation to the voltage (Vdc_d_hpf), the phase of the HPF output voltage (Vdc_d_hpf) and the phase of the ripple voltage component value (ΔVdc) can be matched.

The voltage output unit 160 may output the final output voltage (Vdc_comp) that is the same as the phase of the ripple voltage component value (ΔVdc) (S250). For example, the final output voltage (Vdc_comp) output from the voltage output unit 160 may be a reference voltage input for controlling a converter or inverter, and through this, the alternating current output from the converter, inverter, etc. and the input Distortion of the direct current waveform can be prevented and the grid voltage can be stabilized.

Figures 3 and 4 respectively show an algorithm for explaining the operation method of the voltage ripple compensation device according to an embodiment of the present invention and a detailed configuration diagram thereof.

Referring to FIGS. 3 and 4 , the algorithm implemented in the voltage ripple compensation device 100 may serve to remove the ripple component of the reference voltage input to a converter, inverter, etc.

Specifically, the algorithm implemented in the voltage ripple compensation device 100 calculates the ripple voltage component value (ΔVdc) of the DC voltage (Vdc) input through the voltage input unit 110 using a formula, and the calculated ripple voltage component value ( ΔVdc) can be output as an integrated output voltage (Vdc_d) through the integral controller 130. In this case, since an offset voltage exists in the integrated output voltage (Vdc_d), the offset voltage can be removed using the DC component reduction characteristic of the filter unit 140, that is, the HPF filter. At this time, the HPF output voltage (Vdc_d_hpf) is formed as a leading phase due to the HPF phase characteristics of the filter unit 140, so the phase and ripple voltage component value of the HPF output voltage (Vdc_d_hpf) are generated through the time delay of the delay compensation unit 150. By forming the phase of (ΔVdc) to be the same, ripple can be reduced.

As described above, according to the voltage ripple compensation device and method according to an embodiment of the present invention, the current waveform is improved through ripple reduction characteristics according to DC voltage ripple compensation and current control is more stable in step response fluctuations. By performing this, the voltage stability of the system can be improved.

Additionally, the present invention can reduce costs because it does not require separate equipment or parts for DC filtering.

Additionally, the present invention can prevent distortion of the output alternating current and input direct current waveforms by removing the ripple component included in the input reference voltage.

Meanwhile, various embodiments described in this specification may be implemented by hardware, middleware, microcode, software, and/or a combination thereof. For example, various embodiments may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), and field programmable gate arrays (FPGAs). ), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions presented herein, or a combination thereof.

Additionally, for example, various embodiments may be encoded or embodied in a computer-readable medium containing instructions. Instructions contained or encoded in a computer-readable medium may cause a programmable processor or other processor to perform a method, for example, when the instructions are executed. Storage media may be any available media that can be accessed by a computer. For example, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage media, magnetic disk storage media or other magnetic storage devices, or any desired program code containing instructions or instructions accessible by a computer. It may include any other medium that can be used to store data in the form of data structures.

Such hardware, software, firmware, etc. may be implemented within the same device or within individual devices to support the various operations and functions described herein. Additionally, components, units, modules, components, etc. described as “~” in the present invention may be implemented together or individually as separate but interoperable logic devices. The description of different features for modules, units, etc. is intended to highlight different functional embodiments and does not necessarily imply that they must be realized by individual hardware or software components. Rather, functionality associated with one or more modules or units may be performed by separate hardware or software components or may be integrated within common or separate hardware or software components.

Although operations are shown in the drawings in a particular order, it should not be understood that these operations are performed in the particular order shown, or in sequential order, or that all depicted operations need to be performed to achieve the desired results. . In some environments, multitasking and parallel processing can be advantageous. Moreover, the distinction of various components in the above-described embodiments should not be construed as requiring such a distinction in all embodiments, and the described components may generally be integrated together into a single software product or packaged into multiple software products. It must be understood that it can be done.

As described above, the optimal embodiments are disclosed in the drawings and specifications. Although specific terms are used here, they are used only for the purpose of explaining the present invention and are not used to limit the meaning or scope of the present invention described in the claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the attached patent claims.

100: voltage ripple compensation device 110: voltage input unit
120: Ripple extractor 130: Integral controller
140: filter unit 150: delay compensation unit
160: voltage output unit

Claims (9)

As a voltage ripple compensation method,
Extracting the ripple voltage component value (△Vdc) of the voltage (Vdc) input from the power supply unit;
calculating an integrated output voltage (Vdc_d) based on the extracted ripple voltage component value (△Vdc) and an integral control function;
Obtaining an HPF output voltage (Vdc_d_hpf) by applying a High Pass Filter (HPF) filter to the calculated integrated output voltage (Vdc_d);
Matching the phase of the obtained HPF output voltage (Vdc_d_hpf) with the phase of the ripple voltage component value (△Vdc); and
A voltage ripple compensation method comprising outputting a final output voltage (Vdc_comp) whose phase is matched. According to claim 1,
The step of matching the phase of the HPF output voltage (Vdc_d_hpf) with the phase of the ripple voltage component value (△Vdc),
A voltage ripple compensation method characterized by applying time delay compensation to match the phase of the HPF output voltage (Vdc_d_hpf) and the phase of the ripple voltage component value (△Vdc). According to claim 1,
The step of acquiring the HPF output voltage (Vdc_d_hpf) is,
A voltage ripple compensation method, characterized in that the noise signal included in the integrated output voltage (Vdc_d) is removed by passing a signal in a frequency band of 20 Hz or higher through the HPF filter. According to claim 1,
The step of acquiring the HPF output voltage (Vdc_d_hpf) is,
A voltage ripple compensation method, characterized in that the offset voltage included in the integrated output voltage (Vdc_d) is removed using the DC component reduction characteristic of the HPF filter. A computer-readable recording medium on which a program for performing the method according to any one of claims 1 to 4 is recorded. As a voltage ripple compensation device,
A voltage input unit that receives voltage (Vdc) from the power supply unit;
a ripple extractor that extracts a ripple voltage component value (△Vdc) of the voltage (Vdc) input from the voltage input unit;
an integral controller that outputs an integrated output voltage (Vdc_d) by applying an integral control function to the ripple voltage component value (△Vdc) extracted by the ripple extractor;
A filter unit that applies a High Pass Filter (HPF) filter to the integrated output voltage (Vdc_d) output through the integral controller and outputs an HPF output voltage (Vdc_d_hpf);
A delay compensation unit that matches the phase of the HPF output voltage (Vdc_d_hpf) output through the filter unit and the phase of the ripple voltage component value (△Vdc); and
A voltage ripple compensation device including a voltage output unit that outputs a final output voltage (Vdc_comp) whose phase is matched through the delay compensation unit. According to claim 6,
The delay compensation unit applies time delay compensation to the phase of the HPF output voltage (Vdc_d_hpf) to match the phase of the ripple voltage component value (△Vdc). According to claim 6,
The filter unit passes a signal in a frequency band of 20 Hz or higher using the HPF filter to remove a noise signal included in the integrated output voltage (Vdc_d). According to claim 6,
The filter unit is a voltage ripple compensation device, characterized in that it removes the offset voltage included in the integrated output voltage (Vdc_d) using the DC component reduction characteristic of the HPF filter.

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