Control device, system and program

Abstract

To suppress the phenomenon that an electromagnetic noise generated due to switching operation tends to increase and become observable.SOLUTION: A control device according to one embodiment of the present invention is connected to first and second switching control devices for converting an AC signal to a DC signal and outputting the resulting signal, or converting a DC signal to an AC signal and outputting the resulting signal. The control device controls the operation timing of the first and second switching control devices on the basis of a first distance that is equivalent to the distance between a target point equivalent to a point where the electromagnetic noises radiated from the first and second switching control devices are suppressed and the first switching control device, and a second distance that is equivalent to the distance between the target point and the second switching control device.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a control device, a system, and a program. [Background technology]

[0002] In recent years, power generation methods using renewable energy, such as solar power generation and wind power generation, have become widespread. Accordingly, there has been an increase in the number of power conditioners (PCS: Power Conditioning Subsystems) installed within a certain area, each of which includes an inverter circuit for converting DC voltage generated using renewable energy into AC voltage.

[0003] The inverter circuits included in the PCSs described above generate electromagnetic noise due to their switching operations. When multiple such inverter circuits are installed within a certain area, the electromagnetic noise generated by each inverter circuit interferes with and reinforces each other. Therefore, there is a need for new technology that can prevent the increase in electromagnetic noise caused by this phenomenon from being observed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6204113 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present invention is to provide a control device, system, and program that can suppress the increase in electromagnetic noise generated in conjunction with switching operations from being observed. [Means for solving the problem]

[0006] A control device according to one embodiment is connected to a first switching control device and a second switching control device, each of which converts an AC signal into a DC signal and outputs the DC signal, or converts a DC signal into an AC signal and outputs the DC signal. The control device includes a transmitter / receiver that communicates with the first switching control device and the second switching control device, and a timing controller that controls operation timings of the first switching control device and the second switching control device based on a first distance that corresponds to the distance between the first switching control device and a target point that corresponds to a point where electromagnetic noise radiated from the first switching control device and the second switching control device is suppressed, and a second distance that corresponds to the distance between the target point and the second switching control device. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of a schematic configuration of a switching system according to the first embodiment. [Figure 2] FIG. 2 is a diagram showing a detailed configuration of the switching control device according to the embodiment. [Figure 3] FIG. 3 is a diagram showing a detailed configuration of a switching control unit included in the switching control device according to the embodiment. [Figure 4] FIG. 4 is a diagram for explaining the process of generating a PWM signal performed by the PWM signal generating unit shown in FIG. [Figure 5] FIG. 5 is a diagram for explaining the control of the operation timing of the switching control device performed by the central control device according to the embodiment. [Figure 6] FIG. 6 is a diagram for explaining a case where the noise enhancement effect occurs. [Figure 7] FIG. 7 is a diagram showing a detailed configuration of the central control device according to the embodiment. [Figure 8] FIG. 8 is a flowchart showing an example of the operation of the central control device according to the embodiment. [Figure 9]FIG. 9 is a diagram for explaining the control of the operation timing of the switching control device performed by the central control device according to the embodiment. [Figure 10] FIG. 10 is a diagram for explaining the control of the operation timing of the switching control device performed by the central control device according to the embodiment. [Figure 11] FIG. 11 is a diagram illustrating an example of a schematic configuration of a switching system according to the second embodiment. [Figure 12] FIG. 12 is a flowchart showing an example of the operation of the central control device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment will be described with reference to the drawings. It should be noted that the disclosure is merely an example, and the invention is not limited to the contents described in the following embodiments. Modifications that can be easily conceived by a person skilled in the art are naturally included in the scope of the disclosure. For clearer explanation, the size, shape, etc. of each part may be changed from the actual embodiment and shown schematically in the drawings. In multiple drawings, corresponding elements may be given the same reference numerals, and detailed explanations may be omitted.

[0009] (First embodiment) Fig. 1 is a diagram showing an example of a schematic configuration of a switching system 1 according to this embodiment. As shown in Fig. 1, the switching system 1 includes a plurality of switching control devices 2 and a central control device 3. The central control device 3 may be simply referred to as a control device. The number of switching control devices 2 included in the switching system 1 may be any number as long as it is at least two or more.

[0010] Each of the plurality of switching control devices 2 includes a switching unit 4, and performs switching control by turning on and off the switching unit 4 in the device itself at a predetermined timing.

[0011] Each switching control device 2 is a power conversion device that converts DC voltage generated by a renewable energy power generation device such as a photovoltaic (PV) device into AC voltage. This type of power conversion device is also called a power conditioner (PCS: Power Conditioning Subsystem). Note that the power conversion device may have a mode for converting DC voltage into AC voltage (in other words, a mode for converting a DC signal into an AC signal) and a mode for converting AC voltage into DC voltage (in other words, a mode for converting an AC signal into a DC signal).

[0012] The central control device 3 is connected to a plurality of switching control devices 2 and controls the operations of the plurality of switching control devices 2. Specifically, the central control device 3 generates control parameters for each switching control device 2 regarding the timing at which the switching control device 2 performs a switching operation, and supplies (notifies) these to the switching control device 2. The control parameters may also be referred to as control information.

[0013] For example, the central control device 3 generates a first control parameter related to the timing at which one of the plurality of switching control devices 2 performs a switching operation, and a second control parameter related to the timing at which another of the plurality of switching control devices 2 performs a switching operation. The central control device 3 supplies the first control parameter to one of the plurality of switching control devices 2 described above, and supplies the second control parameter to another of the plurality of switching control devices 2 described above.

[0014] One of the above-mentioned multiple switching control devices 2 controls the switching of the switching unit 4 therein based on a first control parameter supplied from the central control device 3. Similarly, another of the above-mentioned multiple switching control devices 2 controls the switching of the switching unit 4 therein based on a second control parameter supplied from the central control device 3.

[0015] 1 can be a noise source that generates electromagnetic noise because it performs switching operations. Here, let us assume that the value of the electromagnetic noise generated and observed from one switching control device 2 in conjunction with the switching operation of that switching control device 2 is "1," and consider a situation in which N switching control devices 2 are arranged closely together.

[0016] In such a situation, for example, if the electromagnetic noise generated from each of the N switching control devices 2 is uncorrelated, the value of the electromagnetic noise generated and observed from each switching control device 2 will remain "1".

[0017] On the other hand, in the above-mentioned situation, when the timing at which N switching control devices 2 perform their switching operations is the same, the electromagnetic noise itself generated from each switching control device 2 remains unchanged, but depending on the position from which the electromagnetic noise is observed, the value of the observed electromagnetic noise is emphasized "N times." Furthermore, when not only the timing at which N switching control devices 2 perform their switching operations but also the waveform shape (frequency characteristics) of the electromagnetic noise generated from each switching control device 2 are the same, the value of the electromagnetic noise generated from each switching control device 2 and observed is emphasized "N×N times."

[0018] In this situation where multiple noise sources are placed in close proximity, the electromagnetic noises generated by each of the multiple noise sources may interfere with and reinforce each other. Here, this phenomenon is called the "noise enhancement effect."

[0019] Therefore, the central control device 3 according to this embodiment controls the operation of each of the multiple switching control devices 2 so as to prevent the electromagnetic noise generated from each of the multiple switching control devices 2 from being increased and observed due to the above-mentioned noise enhancement effect. Specifically, the central control device 3 generates different control parameters for each of the multiple switching control devices 2 to be controlled and supplies these to the switching control devices 2. Note that the multiple switching control devices 2 to be controlled may be all the switching control devices 2 connected to the central control device 3, or may be multiple switching control devices 2 that may cause the noise enhancement effect.

[0020] 2 is a diagram showing a detailed configuration of the switching control device 2 according to this embodiment. Note that the multiple switching control devices 2 shown in FIG. 1 all have the same configuration.

[0021] As shown in FIG. 2, the switching control device 2 includes a switching unit 4, a transformer 5, and a switching control unit 6.

[0022] The switching unit 4 has one or more switching elements, and may include, for example, a boost chopper circuit 4a and an inverter circuit 4b. The boost chopper circuit 4a converts the voltage amplitude of the input DC voltage. The inverter circuit 4b generates an AC voltage by switching on and off its switching elements based on a PWM (Pulse Width Modulation) signal generated using a carrier signal and a reference signal (described later). Note that the elements included in the switching unit 4 are not limited to the boost chopper circuit 4a and the inverter circuit 4b described above, and may include other elements that perform DC / AC conversion, voltage, current, frequency, number of phases, etc. while suppressing power loss. Specifically, the switching unit 4 may include a converter circuit.

[0023] The transformer 5 converts the voltage amplitude of the AC voltage to generate a commercial power supply voltage of, for example, 100V.

[0024] The switching control unit 6 performs switching control to turn on and off the switching unit 4 at predetermined timing. In other words, the switching control unit 6 controls the operations of the step-up chopper circuit 4a and the inverter circuit 4b included in the switching unit 4.

[0025] The switching control unit 6 may be a semiconductor chip that performs digital signal processing such as a CPU (Central Processing Unit) or a DSP (Digital Signal Processor), or a discrete digital circuit component, or may be a semiconductor chip that performs analog signal processing or a discrete analog circuit component.

[0026] 3 is a diagram showing a detailed configuration of the switching control unit 6 included in the switching control device 2 according to this embodiment. As shown in FIG. 3, the switching control unit 6 includes a PWM signal generating unit 6a, a reference signal generating unit 6b, and a carrier signal generating unit 6c.

[0027] The PWM signal generating unit 6a generates a PWM signal for controlling the on / off of the switching unit 4. As will be described in detail later, the PWM signal generating unit 6a generates the PWM signal by comparing the magnitude of a reference signal generated by a reference signal generating unit 6b with that of a carrier signal generated by a carrier signal generating unit 6c.

[0028] The reference signal generating unit 6b generates a compensation value for matching the AC voltage output from the switching unit 4 with a target value, and generates a reference signal based on the compensation value. The generated reference signal is sent to the PWM signal generating unit 6a.

[0029] The carrier signal generating unit 6c generates a carrier signal based on the control parameters supplied from the central control unit 3. More specifically, the carrier signal generating unit 6c generates a carrier signal having at least one of a frequency and a phase indicated by the control parameters supplied from the central control unit 3. The generated carrier signal is sent to the PWM signal generating unit 6a.

[0030] In this embodiment, the control parameters supplied from the central control device 3 may indicate the phase of the carrier signal at a reference time, or may indicate the time when the phase of the carrier signal becomes zero. Furthermore, the control parameters supplied from the central control device 3 may include a signal obtained by modulating a carrier frequency, which is the frequency of the carrier signal. The control parameters may further indicate, for example, the waveform shape or signal amplitude of the carrier signal, in addition to the values ​​related to the phase and carrier frequency described above.

[0031] Furthermore, in this embodiment, it is assumed that the carrier signal generated by the carrier signal generating unit 6c is a triangular wave signal, but the carrier signal generated by the carrier signal generating unit 6c may have any waveform, such as a sawtooth wave signal, a sine wave signal, or a rectangular wave signal.

[0032] FIG. 4 is a diagram for explaining the process of generating a PWM signal performed by the PWM signal generating unit 6a shown in FIG.

[0033] The reference signal s1 generated by the reference signal generating unit 6b has a frequency similar to the frequency (for example, 50 Hz to 60 Hz) of the AC voltage output from the switching unit 4. The carrier signal s2 generated by the carrier signal generating unit 6c is a signal having a frequency much higher than that of the reference signal s1, and is, for example, a triangular wave signal as described above.

[0034] For example, the PWM signal generating unit 6a sets the PWM signal to a high level when the signal amplitude of the reference signal s1 is greater than the signal amplitude of the carrier signal s2, and sets the PWM signal to a low level when the signal amplitude of the reference signal s1 is equal to or less than the signal amplitude of the carrier signal s2. As a result, a PWM signal s3 with a varying pulse width is generated as shown in FIG. 4. The generated PWM signal s3 is sent to the switching unit 4.

[0035] The switching unit 4 performs a switching operation of switching on and off one or more switching elements included in the switching unit 4 based on the PWM signal s3 from the PWM signal generating unit 6a.

[0036] The central control device 3 can control the pulse width of the PWM signal s3 by controlling at least one of the frequency and phase of the carrier signal s2. The central control device 3 according to this embodiment controls the phase of the carrier signal s2 and controls the pulse width of the PWM signal s3, thereby controlling the timing at which electromagnetic noise is emitted from the multiple switching control devices 2.

[0037] FIG. 5 is a diagram for explaining a case where the phases of the carrier signals s2A and s2B of the two switching control devices 2_1 and 2_2 are controlled and the pulse widths of the PWM signals s3A and s3B are controlled to control the timing at which electromagnetic noise is emitted from the two switching control devices 2_1 and 2_2. As shown in FIG. 5, the phase of the carrier signal s2A of the switching control device 2_1 and the phase of the carrier signal s2B of the switching control device 2_2 are controlled to be shifted by π (180 degrees) from each other by control parameters respectively supplied from the central control device 3. This makes it possible to prevent the switching control device 2_2 from performing a switching operation at timings T1, T2, T3, ... at which the switching control device 2_1 performs a switching operation, as shown in FIG. 5. In other words, it is possible to shift the timing at which electromagnetic noise is emitted from the two switching control devices 2_1 and 2_2.

[0038] However, simply changing the timings at which electromagnetic noise is emitted from the multiple switching control devices 2 to different timings will not be sufficient to deal with the case shown in FIG.

[0039] Fig. 6 shows a case where two switching control devices 2_1 and 2_2 operate with a time difference |Δt| (i.e., generate carrier signals with a time difference |Δt|) and emit electromagnetic noise from the two switching control devices 2_1 and 2_2 with a time difference |Δt|. Note that Fig. 6 assumes a case where the distance from switching control device 2_1 to predetermined point L is d_1, the distance from switching control device 2_2 to predetermined point L is d_2, and the switching control device 2_2 operates after a time equivalent to |Δt| has elapsed since the switching control device 2_1 operated.

[0040] Here, assuming that the propagation speed of the electromagnetic noise radiated from each of the switching control devices 2_1 and 2_2 is c (a constant value), the electromagnetic noise radiated from the switching control device 2_1 reaches point L after time t_1 (=d_1 / c) from the time the electromagnetic noise is radiated. On the other hand, the electromagnetic noise radiated from the switching control device 2_2 reaches point L after time t_2 (=d_2 / c) from the time the electromagnetic noise is radiated.

[0041] At this time, if the relationship t_1=t_2+|Δt| holds between the above-mentioned times t_1, t_2 and the time difference |Δt|, the electromagnetic noise radiated from the switching control devices 2_1 and 2_2 arrives at point L at the same time, causing a noise emphasis effect at point L. In other words, at point L which satisfies the relationship d_1=d_2+c×|Δt|, the electromagnetic noise radiated from the switching control devices 2_1 and 2_2 arrives at point L at the same time, causing a noise emphasis effect.

[0042] Therefore, even if communication equipment or broadcasting equipment is installed at such a point L, there is a possibility that these equipment will not be able to properly receive the desired radio waves used for communication or broadcasting due to the noise enhancement effect described above.

[0043] Therefore, the central control device 3 according to this embodiment does not simply vary the timing at which electromagnetic noise is emitted from the multiple switching control devices 2, but defines points where it is desired to suppress electromagnetic noise as target points and controls the timing at which electromagnetic noise is emitted from the multiple switching control devices 2 so as to prevent a noise enhancement effect from occurring at those target points. As will be described in more detail below, the central control device 3 sets the operation timing of each switching control device 2 based on the distance between each switching control device 2 and the target point, thereby preventing a noise enhancement effect from occurring at those target points.

[0044] Fig. 7 is a diagram showing a detailed configuration of the central control device 3 according to this embodiment. As shown in Fig. 7, the central control device 3 includes a storage unit 8, a timing control unit 9, and a transmission / reception unit 10. Note that, as shown in Fig. 7, the switching control device 2 may further include a transmission / reception unit 7 for communicating with the central control device 3, in addition to the configuration shown in Figs. 2 and 3.

[0045] The storage unit 8 stores information necessary for controlling the operation timing of the multiple switching control devices 2 that are to be controlled. Specifically, the storage unit 8 stores distance information regarding the distance between each of the switching control devices 2 that are to be controlled, and distance information regarding the distance between each of the switching control devices 2 and a target point. Note that in addition to the distance information described above, or instead of the distance information described above, the storage unit 8 may also store position information regarding the positions of each of the switching control devices 2 and the target point. The storage unit 8 may also store information regarding the frequency and period of the carrier signal of each of the switching control devices 2.

[0046] The timing control unit 9 generates control parameters related to the timing at which the switching control device 2 performs a switching operation, based on the various information stored in the storage unit 8. In addition to generating the control parameters described above, the timing control unit 9 may also generate various instructions for starting (starting up) and stopping (shutting down) the switching control device 2. The generated control parameters and various instructions are transmitted (supplied) to the switching control device 2 via the transmitting / receiving unit 10.

[0047] Fig. 8 is a flowchart showing an example of the operation of the central control device 3 according to this embodiment. Note that the series of operations shown in Fig. 8 is executed, for example, before the multiple switching control devices 2 to be controlled start operating.

[0048] First, the central control device 3 generates operation timing values ​​(hereinafter simply referred to as "operation timings") that are within a range that can be set for any of the multiple switching control devices 2 to be controlled, and the number of operation timing values ​​is the same as the number of these switching control devices 2 (step S1). Note that the "operation timings" here do not refer to the timings at which the switching control devices 2 are turned on and off, but rather refer to, for example, the timings at which the phase of the carrier signal of the switching control devices 2 becomes zero.

[0049] The central control device 3 uses, for example, a random number generator to randomly generate the same number of operation timings as the number of switching control devices 2. Furthermore, with regard to the time corresponding to the above-mentioned range in which the operation timings of the plurality of switching control devices 2 can be set (settable range), for example, half the period of the carrier signal used in a predetermined switching control device 2 among the plurality of switching control devices 2 to be controlled may be set as an upper limit.

[0050] Next, the central control device 3 rearranges the multiple operation timings generated in the process of step S1 in chronological order, and executes a process of allocating these multiple operation timings in order to the multiple switching control devices 2 to be controlled (step S2). In the following, it is assumed that the number of switching control devices 2 to be controlled is N (where N is an integer equal to or greater than 2). In addition, it is assumed that there is one target point, which is a point where it is desired to suppress the noise enhancement effect.

[0051] Here, the central control device 3 focuses on the pair (2_i, 2_j) of switching control devices 2 to which operation timings t_i and t_j are assigned in the processing of step S2 (step S3). Note that the above-mentioned i is an integer that satisfies the relationship 1≦i≦N. Also, the above-mentioned j is an integer that satisfies the relationship 1≦j≦N and also satisfies the relationship j≠i.

[0052] The central control device 3 calculates the difference |Δt_i_j| between the operation timing t_i assigned to the switching control device 2_i and the operation timing assigned to the switching control device 2_j (step S4).

[0053] The central control device 3 calculates the difference |Δd_i_j| between the distances d_i and d_j based on distance information stored in the memory unit 8 indicating the distance d_i from the switching control device 2_i to the target point and distance information indicating the distance d_j from the switching control device 2_j to the target point (step S5).

[0054] Thereafter, the central control device 3 checks whether the difference in operation timing |Δt_i_j| calculated in the processing of step S4 and the difference in distance |Δd_i_j| calculated in the processing of step S5 satisfy the following equation (1) (step S6).

[0055] |Δt_i_j|≠|Δd_i_j| / c ···(1) Note that the above c is the propagation speed of electromagnetic noise, and is assumed to be a constant value here.

[0056] If it is confirmed in the processing of step S6 that the above-mentioned equation (1) is not satisfied, that is, if it is confirmed that the electromagnetic noise emitted from the pair of switching control devices 2 (2_i, 2_j) in question produces a noise enhancement effect at the target point (No in step S6), the processing of step S1 described above is executed again, and the same number of operation timings as the number of switching control devices 2 (i.e., N operation timings) are generated again.

[0057] On the other hand, if it is confirmed in the processing of step S6 that the above-mentioned equation (1) is satisfied, that is, if it is confirmed that the electromagnetic noise emitted from the pair of switching control devices 2 (2_i, 2_j) under consideration does not produce a noise enhancement effect at the target point (Yes in step S6), the central control device 3 checks whether all possible pairs of switching control devices 2 (2_i, 2_j) have been considered with respect to the pair of switching control devices 2 (2_i, 2_j) (step S7).

[0058] In the processing of step S7, if it is confirmed that there is a pair (2_i, 2_j) of switching control devices 2 that has not yet been focused on (No in step S7), the processing of step S3 described above is executed again, and processing is executed to focus on the pair (2_i, 2_j) of switching control devices 2 that has not yet been focused on.

[0059] On the other hand, if it is confirmed in the processing of step S7 that all possible pairs of switching control devices 2 (2_i, 2_j) have been considered (Yes in step S7), the central control device 3 generates control parameters indicating the assigned operation timing for each switching control device 2, supplies these to the switching control device 2 (step S8), and terminates this series of operations.

[0060] In the above-described series of operations, it is confirmed that electromagnetic noise radiated from all possible pairs (2_i, 2_j) of switching control devices 2 does not cause a noise enhancement effect at the target point. However, this is not limited to this. For example, electromagnetic noise radiated from a predetermined number of pairs (2_i, 2_j) of switching control devices 2 may be allowed to cause a noise enhancement effect at the target point. For example, the central control device 3 may allow electromagnetic noise radiated from one pair of switching control devices 2 to cause a noise enhancement effect at the target point, but may not allow electromagnetic noise radiated from two or more pairs of switching control devices 2 to cause a noise enhancement effect at the target point. In other words, it may allow one pair (2_i, 2_j) of switching control devices 2 to not satisfy the above-described formula (1), but may not allow two or more pairs (2_i, 2_j) of switching control devices 2 to not satisfy the above-described formula (1).

[0061] Furthermore, in the processing of step S2 described above, operation timings may be assigned in descending order of the timing at which the phase of the carrier signal becomes zero. Specifically, the operation timings t_1, t_2, ... may be assigned to the switching control device 2 having the earliest timing at which the phase of the carrier signal becomes zero, the earliest operation timing t_1 may be assigned to the switching control device 2 having the second earliest timing at which the phase of the carrier signal becomes zero, and so on.

[0062] Furthermore, while it has been assumed here as an example that the operation timing of each switching control device 2 is generated randomly, the present invention is not limited to this. For example, the central control device 3 may calculate the distance differences |Δd_i_j| described above for all of the switching control devices 2 to be controlled, identify the maximum value |Δd_i_j_max| of these distance differences, and generate and set the operation timings so that the difference |Δt_i_j_adj| between any two consecutive operation timings is greater than |Δd_i_j_max| / c. This makes it possible to simply execute the processes of steps S3 to S7 described above or to omit these processes, thereby reducing the amount of processing by the central control device 3 and the processing load on the central control device 3.

[0063] Note that when the difference |Δt_i_j_adj| between two consecutive operation timings is set to be larger than |Δd_i_j_max| / c, if the difference |Δt_i_j_adj| becomes a large value, it may be impossible to set a large number of operation timings within the settable range. In other words, it may be impossible to set the same number of operation timings as the number of switching control devices 2 to be controlled within the settable range. In this case, the central control device 3 may execute the series of operations shown in FIG. 8 described above to set the operation timings of the switching control devices 2 to be controlled. In other words, if the central control device 3 can set the operation timings so that the difference |Δt_i_j_adj| between two consecutive operation timings is both larger than |Δd_i_j_max| / c, it may set the operation timings using this setting method. If the central control device 3 cannot set the operation timings using this setting method, it may execute the series of operations shown in FIG. 8 to set the operation timings.

[0064] Furthermore, although it is assumed here that there is one target point, if there are multiple target points, the processes of steps S3 to S7 described above are executed for all of the target points. Note that, as described above, when the operation timings are set so that the difference |Δt_i_j_adj| between two consecutive operation timings is greater than |Δd_i_j_max| / c, the central control device 3 may calculate the maximum value |Δd_i_j_max| of the distance differences described above for each of the multiple target points, identify the largest value |Δd_i_j_MAX| among these maximum distance differences, and set the operation timings so that the difference |Δt_i_j_adj| between two consecutive operation timings is greater than |Δd_i_j_MAX| / c.

[0065] Here, a method for setting the operation timings of multiple switching control devices 2 to be controlled, which is different from the various methods described above, will be described with reference to Fig. 9. For example, as shown in Fig. 9, the central control device 3 may set the operation timings of the switching control devices 2_1, 2_2 to be controlled so that the difference |Δt| between the operation timings of the switching control devices 2_1, 2_2 becomes larger than the value obtained by dividing the distance D between the switching control devices 2_1, 2_2 by the propagation speed c of electromagnetic noise.

[0066] This setting method focuses on the difference |Δd| (=|d_1-d_2|) in the distance from each of the switching control devices 2_1, 2_2 to the target point 100 and the distance D between the switching control devices 2_1, 2_2, and utilizes the fact that theoretically there is no point that satisfies the relationship |Δd|>D. In other words, the central control device 3 sets the operation timings of the switching control devices 2_1, 2_2 so that the difference |Δt| in the operation timings of the switching control devices 2_1, 2_2 satisfies the relationship c×|Δt|>D (in other words, |Δt|>D / c), thereby making it possible to set operation timings that do not cause a noise emphasis effect no matter where the target point 100 is located.

[0067] As shown in FIG. 10, when the number of switching control devices 2 to be controlled is three or more, such as eight, the central control device 3 sets the operation timing of each of the switching control devices 2_1 to 2_8 so that each of the differences |Δt_1| to |Δt_7| between two consecutive operation timings is greater than the value obtained by dividing the distance D_max between the two furthest-located switching control devices 2_1, 2_8 by the propagation speed c of electromagnetic noise.

[0068] 10, a method for setting the operation timings of multiple switching control devices 2 to be controlled, which is different from the various methods described above, will be described. For each switching control device 2 to be controlled, the central control device 3 may calculate the distance to the furthest other switching control device 2, and set the operation timings of these two switching control devices 2 so that the difference between the operation timings of these two switching control devices 2 is greater than the value obtained by dividing the calculated distance by the propagation speed c of electromagnetic noise.

[0069] For example, assume a case where the operation timing of the switching control device 2_8 shown in Fig. 10 is set. In this case, the central control device 3 calculates a distance D_max_8 from the switching control device 2_8 to the switching control device 2_1 located farthest from the switching control device 2_8, and sets the operation timings of the switching control devices 2_1 and 2_8 so that the difference |Δt_1_8| between the operation timings of the switching control devices 2_1 and 2_8 satisfies the relationship D_max_8 / c.

[0070] Similarly, when setting the operation timing of the switching control device 2_7 shown in Figure 10, the central control device 3 calculates the distance D_max_7 from the switching control device 2_7 to the switching control device 2_1, which is located farthest from the switching control device 2_7, and sets the operation timing of the switching control devices 2_1 and 2_7 so that the difference |Δt_1_7| between the operation timings of the switching control devices 2_1 and 2_7 satisfies the relationship D_max_7 / c.

[0071] 10 , the distance D_max_7 between the switching control devices 2_1 and 2_7 is smaller than the distance D_max_8 between the switching control devices 2_1 and 2_8. Therefore, the difference in operation timing for a switching control device 2 located near the center of a group of controlled objects including multiple switching control devices 2 to be controlled, such as the switching control device 2_7, tends to be smaller than the difference in operation timing for a switching control device 2 located near the periphery of the group of controlled objects. In other words, this setting method is useful in cases where, for example, when the difference |Δt_1| to |Δt_7| between two consecutive operation timings is set to be larger than D_max / c, the differences |Δt_1| to |Δt_7| become large values, making it impossible to set the same number of operation timings as the number of switching control devices 2 to be controlled within the settable range.

[0072] As a simple method, the central control device 3 may also set the operation timing of each switching control device 2 so as to shift the time corresponding to the above-mentioned settable range by a time equivalent to the value obtained by dividing the time by the number of switching control devices 2 to be controlled.

[0073] The setting of the operation timing of each switching control device 2 to be controlled as described above may be performed, for example, only for those switching control devices 2 that satisfy a predetermined condition among the plurality of switching control devices 2 to be controlled. As an example, the setting of the operation timing may be performed only for those switching control devices 2 that have the same frequency (carrier frequency) of the carrier signal among the plurality of switching control devices 2 to be controlled.

[0074] For example, if the switching control devices 2_1, 2_3, 2_5, and 2_7 shown in FIG. 10 operate at a carrier frequency f_1 and the switching control devices 2_2, 2_4, 2_6, and 2_8 operate at a carrier frequency f_2 different from the carrier frequency f_1, the central control device 3 sets the operation timings of these switching control devices 2 by executing one of the various setting methods described above for the switching control devices 2_1, 2_3, 2_5, and 2_7 that operate at the carrier frequency f_1, and also sets the operation timings of these switching control devices 2 by executing one of the various setting methods described above for the switching control devices 2_2, 2_4, 2_6, and 2_8 that operate at the carrier frequency f_2.

[0075] As another example, the operation timing may be set only for those switching control devices 2 that are located within a predetermined distance from each other among a plurality of switching control devices 2 to be controlled. The predetermined distance is set to, for example, a distance at which the intensity of electromagnetic noise emitted from the switching control devices 2 becomes equal to or less than a predetermined level due to distance attenuation.

[0076] For example, if the distance between the switching control devices 2_1 and 2_8 shown in Figure 10 is greater than the above-mentioned predetermined distance and the distances between the switching control devices 2_1 to 2_7 are within the above-mentioned predetermined distances, the central control device 3 targets the switching control devices 2_1 to 2_7 and executes one of the various setting methods described above to set the operation timing of these switching control devices 2.

[0077] As an example, the above-mentioned predetermined distance is set to a distance at which the intensity of the electromagnetic noise is equal to or less than a predetermined level, but the present invention is not limited to this. The above-mentioned predetermined distance may be set to a distance at which the intensity is equal to or less than a predetermined level even if a noise enhancement effect occurs due to two switching control devices 2. In this case, assuming that the value of the electromagnetic noise radiated from one switching control device 2 is "1", the above-mentioned predetermined distance is set to "4(=(1×2) 2) may be set to a distance that can tolerate electromagnetic noise equivalent to ". In this way, the operation timings are set in a small number of switching control devices 2, and even if the settable range is limited, it is possible to set a large number of operation timings within the settable range.

[0078] 8 or any of the various setting methods described above at preset time intervals to update the control parameters supplied to each switching control device 2. This makes it possible to deal with changes in the operating state or operating environment of the switching control device 2, for example, the occurrence of drift in which the frequency of the carrier signal of the switching control device 2 changes due to temperature changes or the like.

[0079] The switching system 1 according to the first embodiment described above includes a central control device 3 that controls the operation timing of each switching control device 2 based on the distance between each switching control device 2 to be controlled and the target point 100. This makes it possible to prevent the noise emphasis effect from occurring at the target point 100.

[0080] (Second embodiment) Next, a second embodiment will be described. As shown in Fig. 11, the switching system 1 according to the second embodiment differs from the configuration according to the first embodiment in that a measuring device 101 is provided at a target point 100 where it is desired to suppress electromagnetic noise.

[0081] Although details will be described later, the central control device 3 according to this embodiment differs from the configuration according to the first embodiment described above in that, due to the provision of a measuring device 101 at the target point 100, there is no need to store in the storage unit 8 distance information relating to the distance between each of the switching control devices 2 to be controlled, or distance information relating to the distance between each of the switching control devices 2 to be controlled and the target point 100. Below, differences from the first embodiment described above will be mainly described, and explanations of similarities to the first embodiment described above will be omitted.

[0082] 11 is a diagram showing a detailed configuration of the measurement device 101 according to this embodiment. As shown in FIG. 11, the measurement device 101 includes a noise measurement unit 102 and a transmission / reception unit 103.

[0083] The transmitter / receiver 103 communicates with the switching control device 2 and the central control device 3, and, for example, receives instructions from the central control device 3 regarding the start and end of electromagnetic noise measurement, and transmits the electromagnetic noise measurement results to the central control device 3.

[0084] As described above, the central control device 3 according to this embodiment transmits a measurement start instruction to start measuring electromagnetic noise and a measurement end instruction to end measuring electromagnetic noise to the measuring device 101 via the transceiver 10. The central control device 3 according to this embodiment also transmits an operation start instruction to cause one of the switching control devices 2 to perform a switching operation (in other words, an operation start instruction to start emitting electromagnetic noise) at the timing when it transmits the above-mentioned measurement start instruction to the measuring device 101. Furthermore, the central control device 3 according to this embodiment also transmits an operation end instruction to cause the switching control device 2 operating in accordance with the above-mentioned operation start instruction to end its switching operation (in other words, an operation end instruction to end emitting electromagnetic noise) at the timing when it transmits the above-mentioned measurement end instruction to the measuring device 101.

[0085] The noise measurement unit 102 includes, for example, an antenna, and measures the electromagnetic noise radiated from each switching control device 2. More specifically, the noise measurement unit 102 measures the time from when it receives a measurement start instruction sent from the central control device 3 (i.e., from when a given switching control device 2 radiates electromagnetic noise in accordance with the above-mentioned operation start instruction) until it receives the electromagnetic noise. In other words, the noise measurement unit 102 measures the time (hereinafter referred to as the arrival time) for the electromagnetic noise radiated from the given switching control device 2 to reach the target point 100.

[0086] After measuring the arrival time, the noise measurement unit 102 calculates the distance between the predetermined switching control device 2 and the target point 100 based on the arrival time and the propagation speed c (a constant value) of the electromagnetic noise. Distance information indicating the calculated distance is transmitted to the central control device 3 via the transmission / reception unit 103 as a noise measurement result.

[0087] This allows the central control device 3 to acquire (receive) distance information relating to the distance between each switching control device 2 to be controlled and the target point 100 from the measuring device 101 provided at the target point 100, eliminating the need to store the distance information in advance in the storage unit 8. Being able to acquire distance information from the measuring device 101 provided at the target point 100 in this manner is particularly useful when the target point 100 (communications equipment or broadcasting equipment) moves. For example, if the target point 100 is always located in the same place, the central control device 3 only needs to store distance information relating to the distance between the switching control device 2 and the target point 100 in advance in the storage unit 8. However, if the target point 100 moves, the distance between the switching control device 2 and the target point 100 changes, and the distance information relating to the distance cannot be stored in the storage unit 8. The central control device 3 according to this embodiment can handle such cases.

[0088] Fig. 12 is a flowchart showing an example of the operation of the central control device 3 according to this embodiment. Note that the series of operations shown in Fig. 12 is executed, for example, before the multiple switching control devices 2 to be controlled start operating. In addition, the following description will be given assuming that the number of switching control devices 2 to be controlled is N (where N is an integer equal to or greater than 2) and that there is one target point 100.

[0089] First, the central control device 3 sends an operation start instruction to one of the multiple switching control devices 2 to be controlled, instructing it to start emitting electromagnetic noise, and also sends a measurement start instruction to the measuring device 101 installed at the target point 100 where the electromagnetic noise is to be suppressed, instructing it to start measuring the electromagnetic noise (step S11).

[0090] Subsequently, the central control device 3 receives distance information indicating the distance between the switching control device 2 and the target point 100 as a noise measurement result from the switching control device 2 operating in accordance with the operation start instruction transmitted in the processing of step S11 (step S12). The received distance information may be temporarily stored in the storage unit 8, for example.

[0091] The central control device 3 checks whether or not an operation start instruction has been sent to all of the switching control devices 2 to be controlled (step S13).

[0092] If it is confirmed in the processing of step S13 that there is a switching control device 2 that has not yet sent an operation start instruction (No in step S13), the processing of step S11 described above is executed again, and a process of sending an operation start instruction to the switching control device 2 that has not yet sent an operation start instruction is executed.

[0093] On the other hand, if it is confirmed in the processing of step S13 that an operation start instruction has been sent to all switching control devices 2 to be controlled (Yes in step S13), the central control device 3 sequentially executes the processing of steps S1 to S8 shown in FIG. 8, sets the operation timing of each switching control device 2, and terminates this series of operations.

[0094] The distance information temporarily stored in the storage unit 8 may be deleted from the storage unit 8 when the series of operations is completed.

[0095] Furthermore, here we have shown a case where the operation timings of multiple switching control devices 2 to be controlled are set by executing the processing of steps S1 to S8 shown in Figure 8, but this is not limited to this, and the operation timings of each switching control device 2 may be set by executing any of the various setting methods shown in the first embodiment above.

[0096] The central control device 3 may execute, for example, a series of operations shown in FIG. 12 at predetermined time intervals to update the control parameters supplied to each switching control device 2.

[0097] Although the present embodiment assumes that there is one target point 100, i.e., one measuring device 101, if there are multiple target points 100, the central control device 3 transmits a measurement start instruction to all measuring devices 101 in the process of step S11 described above. As described above, the central control device 3 sequentially transmits an operation start instruction to each of the multiple switching control devices 2 to be controlled, and controls the operation of the multiple switching control devices 2 so that while one switching control device 2 is operating, the other switching control devices 2 do not operate. This allows the central control device 3 to acquire, from each measuring device 101, distance information regarding the distance between the switching control device 2 operating in accordance with the operation start instruction and the target point 100 where the central control device 3 is located. Furthermore, if there are three or more target points 100, for example, the central control device 3 can estimate the position of the switching control device 2 operating in accordance with the operation start instruction based on the intensity of electromagnetic noise measured by the measuring devices 101 located at each target point 100.

[0098] The switching system 1 according to the second embodiment described above further includes a measuring device 101 that is provided at a target point 100 where it is desired to suppress electromagnetic noise and that transmits distance information relating to the distance between each switching control device 2 and the target point 100. This eliminates the need for the central control device 3 to store in advance in the storage unit 8 distance information relating to the distance between each switching control device 2 to be controlled and the target point 100, and makes it possible to deal with cases where the target point 100 moves, for example.

[0099] According to at least one of the embodiments described above, it is possible to provide a control device, system, and program that can prevent electromagnetic noise generated by switching operations from increasing and being observed.

[0100] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as defined in the claims. [Explanation of symbols]

[0101] 1...switching system, 2...switching control device, 3...central control device, 4...switching unit, 4a...boost chopper circuit, 4b...inverter circuit, 5...transformer, 6...switching control unit, 6a...PWM signal generation unit, 6b...reference signal generation unit, 6c...carrier signal generation unit, 7...transmitter / receiver unit, 8...memory unit, 9...timing control unit, 10...transmitter / receiver unit, 100...target point, 101...measuring device, 102...noise measurement unit, 103...transmitter / receiver unit

Claims

1. A control device connected to a first switching control device and a second switching control device, which converts an AC signal into a DC signal and outputs the DC signal, or converts a DC signal into an AC signal and outputs the AC signal, a transmitting / receiving unit that communicates with the first switching control device and the second switching control device; a timing control unit that controls operation timings of the first switching control device and the second switching control device based on a first distance corresponding to a distance between the first switching control device and a target point corresponding to a point where electromagnetic noise radiated from the first switching control device and the second switching control device is suppressed, and a second distance corresponding to a distance between the target point and the second switching control device; A control device comprising:

2. The timing control unit controlling the first switching control device and the second switching control device so as to shift their operation timings from each other; The control device according to claim 1 .

3. The timing control unit controlling the operation timing of the first switching control device and the operation timing of the second switching control device to be shifted by a time corresponding to a value obtained by dividing a time corresponding to a settable range of the operation timings of the first switching control device and the second switching control device by the number of the first switching control device and the second switching control device; The control device according to claim 2 .

4. a time corresponding to a settable range of the operation timings of the first switching control device and the second switching control device corresponds to half a value of a period of a carrier signal of the first switching control device or the second switching control device; The control device according to claim 3 .

5. The timing control unit controlling operation timings of the first switching control device and the second switching control device based on a difference between the first distance and the second distance; The control device according to claim 1 or 2.

6. The timing control unit controlling operation timings of the first switching control device and the second switching control device further based on a distance between the first switching control device and the second switching control device; The control device according to claim 5 .

7. The timing control unit controlling operation timings of the first switching control device and the second switching control device when the first switching control device and the second switching control device perform switching operations based on carrier signals of the same frequency; The control device according to claim 1 or 2.

8. The timing control unit controlling operation timings of the first switching control device and the second switching control device when the second switching control device is present within a distance where the intensity of electromagnetic noise radiated from the first switching control device is equal to or less than a predetermined level; The control device according to claim 1 or 2.

9. The timing control unit controlling the operation timings of the first switching control device and the second switching control device at predetermined time intervals; The control device according to claim 1 or 2.

10. the transmitting / receiving unit further communicates with a measuring device that is installed at the target point and measures electromagnetic noise, and receives distance information regarding the first distance and distance information regarding the second distance as measurement results by the measuring device. The control device according to claim 1 or 2.

11. a first switching control device and a second switching control device that convert an AC signal into a DC signal and output the DC signal, or that convert a DC signal into an AC signal and output the DC signal; a controller connected to the first switching controller and the second switching controller; Equipped with The control device a transmitting / receiving unit that communicates with the first switching control device and the second switching control device; a timing control unit that controls operation timings of the first switching control device and the second switching control device based on a first distance corresponding to a distance between the first switching control device and a target point corresponding to a point where electromagnetic noise radiated from the first switching control device and the second switching control device is suppressed, and a second distance corresponding to a distance between the target point and the second switching control device; A system comprising:

12. A program executed by a control device connected to a first switching control device and a second switching control device, which converts an AC signal into a DC signal and outputs the DC signal, or converts a DC signal into an AC signal and outputs the AC signal, The control device communicating with the first switching controller and the second switching controller; controlling operation timings of the first switching control device and the second switching control device based on a first distance corresponding to a distance between the first switching control device and a target point corresponding to a point where electromagnetic noise radiated from the first switching control device and the second switching control device is suppressed, and a second distance corresponding to a distance between the target point and the second switching control device; A program to execute.

Images