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, it has become common to install a large number of power conditioners (PCS: Power Conditioning Subsystems) within a certain range, each of which includes an inverter circuit for converting DC voltage generated using renewable energy into AC voltage.

[0003] However, the inverter circuit included in the above-mentioned PCS generates electromagnetic noise due to switching operation. If many such inverter circuits are provided within a certain area, the electromagnetic noise generated by each inverter circuit will interfere with each other and reinforce each other. For this reason, it is desirable to realize a new technology that can suppress the increase in electromagnetic noise caused by such a phenomenon and prevent it 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] An object of the present invention is to provide a control device, a system, and a 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 that convert an AC signal into a DC signal and output the DC signal, or converts a DC signal into an AC signal and output the DC signal. The control device includes a transmitting / receiving unit that communicates with the first switching control device and the second switching control device, and 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 that corresponds to a 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 description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of a schematic configuration of a switching system according to a first embodiment. [Diagram 2] FIG. 2 is a diagram showing a detailed configuration of the switching control device according to the embodiment. [Diagram 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. [Diagram 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 emphasis 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 PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment will be described with reference to the drawings. In addition, the disclosure is merely an example, and the invention is not limited to the contents described in the following embodiments. Modifications that a person skilled in the art can easily conceive are naturally included in the scope of the disclosure. In order to make the explanation clearer, the size, shape, etc. of each part may be changed from the actual embodiment and shown diagrammatically. 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 a schematic configuration example 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 multiple 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, for example, a power conversion device that converts a DC voltage generated by a renewable energy power generation device such as a photovoltaic (PV) device into an 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 in which a DC voltage is converted into an AC voltage (in other words, a mode in which a DC signal is converted into an AC signal) and a mode in which an AC voltage is converted into a DC voltage (in other words, a mode in which an AC signal is converted 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) the control parameters 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 multiple switching control devices 2 performs a switching operation, and a second control parameter related to the timing at which another of the multiple switching control devices 2 performs a switching operation. The central control device 3 supplies the first control parameter to one of the multiple switching control devices 2 described above, and supplies the second control parameter to the other of the multiple switching control devices 2 described above.

[0014] One of the above-mentioned multiple switching control devices 2 performs switching control of the switching unit 4 in the own device based on a first control parameter supplied from the central control device 3. Similarly, another of the above-mentioned multiple switching control devices 2 performs switching control of the switching unit 4 in the own device 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 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 at "1."

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

[0018] In this way, when multiple noise sources are placed close to each other, the electromagnetic noises generated by each of the multiple noise sources may interfere with each other and reinforce each other. This phenomenon is called the "noise enhancement effect."

[0019] Therefore, the central control device 3 according to this embodiment controls the operation of each switching control device 2 so as to suppress the electromagnetic noise generated from each of the multiple switching control devices 2 from being amplified and observed due to the above-mentioned noise emphasis 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 emphasis effect.

[0020] Fig. 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 includes, 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 switches on and off the switching elements in its own circuit based on a PWM (Pulse Width Modulation) signal generated using a carrier signal and a reference signal, which will be described later, to generate an AC voltage. 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, and the like, 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 a predetermined timing. In other words, the switching control unit 6 controls the operations of the boost 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] Fig. 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. Although details will be described later, the PWM signal generating unit 6a generates the PWM signal by comparing the magnitude relationship between a reference signal generated by a reference signal generating unit 6b and a carrier signal generated by a carrier signal generating unit 6c.

[0028] The reference signal generating unit 6b generates a compensation value for making the AC voltage output from the switching unit 4 coincide 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 controller 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 controller 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 controller 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. The control parameters supplied from the central controller 3 may include a signal modulated with a carrier frequency, which is the frequency of the carrier signal. The control parameters may further indicate, for example, the waveform shape and signal amplitude of the carrier signal, in addition to the values ​​related to the phase and carrier frequency described above.

[0031] In addition, 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 shape, 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 approximately equal 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 of electromagnetic noise emission 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 the control parameters respectively supplied from the central control device 3. According to this, as shown in FIG. 5, it is possible to prevent the switching control device 2_2 from performing a switching operation at the timings T1, T2, T3, ... at which the switching control device 2_1 performs a switching operation. In other words, it is possible to shift the timing of electromagnetic noise emission from the two switching control devices 2_1 and 2_2.

[0038] However, simply changing the timings at which electromagnetic noise is radiated from the multiple switching control devices 2 to different timings cannot 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 the switching control device 2_1 to a predetermined point L is d_1, the distance from the switching control device 2_2 to the 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 operates.

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

[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 noises radiated from the switching control devices 2_1, 2_2 reach point L simultaneously, 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 noises radiated from the switching control devices 2_1, 2_2 reach point L simultaneously, 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 the equipment will not be able to properly receive the desired radio waves used for communication or broadcasting due to the above-mentioned noise emphasis effect.

[0043] Therefore, the central control device 3 according to this embodiment does not simply set different timings for emitting electromagnetic noise from the multiple switching control devices 2, but defines a point where it is desired to suppress electromagnetic noise as a target point and controls the timing for emitting electromagnetic noise from the multiple switching control devices 2 so that a noise emphasis effect does not occur at the target point. As will be described in detail later, 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 suppressing the occurrence of a noise emphasis effect at the target point.

[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 required to control the operation timing of the multiple switching control devices 2 to be controlled. Specifically, the storage unit 8 stores distance information related to the distance between each of the switching control devices 2 to be controlled and distance information related to the distance between each of the switching control devices 2 and a target point. Note that the storage unit 8 may store position information related to the positions of each of the switching control devices 2 and the target point in addition to or instead of the above-mentioned distance information. The storage unit 8 may further store information related to 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 various information stored in the storage unit 8. In addition to generating the above-mentioned control parameters, the timing control unit 9 may 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 whose number is the same as the number of these switching control devices 2 (step S1). Note that the "operation timing" here does not refer to the timing at which the switching control device 2 is turned on and off, but rather refers to, for example, the timing at which the phase of the carrier signal of the switching control device 2 becomes zero.

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

[0050] Next, the central control device 3 executes a process of rearranging the multiple operation timings generated in the process of step S1 in chronological order, and sequentially allocating these multiple operation timings 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 the following, it is also assumed that there is one target point, which is a point where it is desired to suppress the noise emphasis effect.

[0051] Here, the central control device 3 focuses on a pair (2_i, 2_j) of switching control devices 2 to which operation timings t_i and t_j are assigned in the process 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 controller 3 calculates the difference |Δt_i_j| between the operation timing t_i assigned to the switching controller 2_i and the operation timing assigned to the switching controller 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 radiated from the pair (2_i, 2_j) of switching control devices 2 in question generates a noise enhancement effect at the target point (No in step S6), the processing of the above-mentioned step S1 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 radiated from the focused pair of switching control devices 2 (2_i, 2_j) 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 regard 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 devices 2 (step S8), and terminates this series of operations.

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

[0061] Furthermore, in the process of step S2 described above, the operation timings may be assigned in order from the switching control device 2 having the earliest timing at which the phase of the carrier signal becomes zero. Specifically, the operation timings t_1, t_2, ... may be assigned to each switching control device 2, such that the earliest operation timing t_1 is assigned to the switching control device 2 having the earliest timing at which the phase of the carrier signal becomes zero, and the second earliest operation timing t_2 is assigned to the switching control device 2 having the second earliest timing at which the phase of the carrier signal becomes zero.

[0062] Further, 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, and for example, the central control device 3 may calculate the above-mentioned distance differences |Δd_i_j| for all of the multiple 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 successive 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 reducing the processing load on the central control device 3.

[0063] In addition, when the difference |Δt_i_j_adj| between two successive 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 is considered that a large number of operation timings cannot be set within the settable range. In other words, there is a possibility that the same number of operation timings as the number of switching control devices 2 to be controlled cannot be set 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 both of the differences |Δt_i_j_adj| between two successive operation timings are larger than |Δd_i_j_max| / c, the central control device 3 may set the operation timings using this setting method, and if the central control device 3 cannot set the operation timings using this setting method, the central control device 3 may execute the series of operations shown in FIG. 8 to set the operation timings.

[0064] In addition, although it is assumed here that there is one target point, when there are multiple target points, the above-mentioned steps S3 to S7 are executed for all the target points. Note that, as described above, when the operation timing is set so that the difference |Δt_i_j_adj| between two successive 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 above-mentioned distance difference for each of the multiple target points, specify the largest value |Δd_i_j_MAX| among the maximum values ​​of the distance difference, and set the operation timing so that the difference |Δt_i_j_adj| between two successive 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 a difference |Δt| between the operation timings of the switching control devices 2_1, 2_2 to be controlled is greater than a 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 there is theoretically 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] In addition, 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 switching control devices 2_1, 2_8 that are located furthest from each other 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 the 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 a difference |Δt_1_8| between the operation timings of the switching control devices 2_1 and 2_8 satisfies the relationship of D_max_8 / c.

[0070] Similarly, when setting the operation timing of the switching control device 2_7 shown in FIG. 10, the central control device 3 calculates the distance D_max_7 to the switching control device 2_1, which is located the farthest from the switching control device 2_7, and sets the operation timing of the switching control devices 2_1, 2_7 so that the difference |Δt_1_7| between the operation timings of the switching control devices 2_1, 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 a plurality of 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. That is, this setting method is useful in cases where, for example, when the difference |Δt_1| to |Δt_7| between two successive operation timings is set to be larger than D_max / c, the difference |Δt_1| to |Δt_7| becomes a large value, and it is not possible 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 set the operation timing of each switching control device 2 so as to shift the time corresponding to the above-mentioned settable range by an amount 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 multiple switching control devices 2 to be controlled. As one example, the setting of the operation timing may be performed only for those switching control devices 2 that have the same carrier signal frequency (carrier frequency) among the multiple switching control devices 2 to be controlled.

[0074] For example, in the case where 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 targets the switching control devices 2_1, 2_3, 2_5, and 2_7 operating at the carrier frequency f_1 and sets the operation timings of these switching control devices 2 by executing one of the various setting methods described above, while targeting the switching control devices 2_2, 2_4, 2_6, and 2_8 operating at the carrier frequency f_2 and sets the operation timings of these switching control devices 2 by executing one of the various setting methods described above.

[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 a distance at which the intensity of electromagnetic noise radiated from the switching control devices 2 becomes equal to or lower than a predetermined level due to distance attenuation, for example.

[0076] For example, if the distance between the switching control devices 2_1 and 2_8 shown in FIG. 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 any of the various setting methods described above to set the operation timings 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 becomes equal to or lower 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 becomes equal to or lower than a predetermined level even if a noise emphasis 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 the "100 Hz to 100 Hz switching control devices 2." 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 change 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 a 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 is different from the configuration according to the first embodiment in that a measuring device 101 is provided at a target point 100 where electromagnetic noise is to be suppressed.

[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 regarding the distance between each switching control device 2 to be controlled and distance information regarding the distance between each switching control device 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 unit 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 for instructing the start of electromagnetic noise measurement and a measurement end instruction for instructing the end of electromagnetic noise measurement to the measuring device 101 via the transmitting / receiving unit 10. The central control device 3 according to this embodiment also transmits an operation start instruction (in other words, an operation start instruction for instructing the start of electromagnetic noise radiation) for causing one of the switching control devices 2 to perform a switching operation at the timing when the central control device 3 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 (in other words, an operation end instruction for instructing the end of electromagnetic noise radiation) for causing the switching control device 2 operating according to the above-mentioned operation start instruction to end the switching operation at the timing when the central control device 3 transmits the above-mentioned measurement end instruction to the measuring device 101.

[0085] The noise measurement unit 102 is configured to include, 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 transmitted from the central control device 3 (i.e., from when a specific 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 it takes for the electromagnetic noise radiated from the specific switching control device 2 to reach the target point 100 (hereinafter referred to as the arrival time).

[0086] When the noise measurement unit 102 measures the above-mentioned arrival time, it calculates the distance between a given 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] According to this, the central control device 3 can acquire (receive) distance information on 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, and it is not necessary to store the distance information in advance in the storage unit 8. In this way, it is useful to acquire distance information from the measuring device 101 provided at the target point 100, especially when the target point 100 (communication equipment or broadcasting equipment) moves. For example, if the target point 100 is always located at the same place, the central control device 3 can store distance information on the distance between the switching control device 2 and the target point 100 in the storage unit 8 in advance, but when the target point 100 moves, the distance between the switching control device 2 and the target point 100 changes, and therefore the distance information on the distance cannot be stored in the storage unit 8. The central control device 3 according to this embodiment can handle such a case.

[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 a plurality of switching control devices 2 to be controlled start operating. Also, here, the explanation 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] Next, 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 according to the operation start instruction transmitted in the process 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 transmitted 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 transmitted an operation start instruction (No in step S13), the processing of step S11 described above is executed again, and a process of transmitting an operation start instruction to the switching control device 2 that has not yet transmitted 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] Further, although the case has been shown here in which the operation timings of the multiple switching control devices 2 to be controlled are set by executing the processing of steps S1 to S8 shown in FIG. 8, this is not limited thereto, 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 described above.

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

[0097] In addition, here, it is assumed that there is one target point 100, that is, one measuring device 101. However, in the case where 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 transmits an operation start instruction to one of the multiple switching control devices 2 to be controlled in sequence, and controls the operation of the multiple switching control devices 2 so that the other switching control devices 2 do not operate while one switching control device 2 is operating. In this way, the central control device 3 can obtain distance information from each measuring device 101 regarding the distance between the switching control device 2 operating according to the operation start instruction and the target point 100 where the central control device 3 is provided. In addition, in the case where three or more target points 100 are provided, for example, the central control device 3 can also estimate the position of the switching control device 2 operating according to the operation start instruction based on the intensity of the electromagnetic noise measured by the measuring device 101 provided 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 electromagnetic noise is desired to be suppressed and 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 previously store 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 handle 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 suppress the increase in electromagnetic noise generated by switching operations from 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 implemented 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 in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described 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, the first switching control device converting an AC signal into a DC signal and outputting the DC signal, or converting a DC signal into an AC signal and outputting the DC 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 is Controlling the first switching control device so as to shift an operation timing from an operation timing of the second switching control device. The control device according to claim 1 .

3. The timing control unit is controlling the operation timing of the first switching control device and the operation timing of the second switching control device to be shifted from each other 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 range in which the operation timings of the first switching control device and the second switching control device can be set corresponds to half 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 is 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 is 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 is 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 is 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 at which the intensity of electromagnetic noise radiated from the first switching control device becomes equal to or lower than a predetermined level; The control device according to claim 1 or 2.

9. The timing control unit is controlling operation timings of the first switching control device and the second switching control device at preset 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 a measurement result 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 converts 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 includes: 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, the first switching control device converting an AC signal into a DC signal and outputting the DC signal, or converting a DC signal into an AC signal and outputting the AC signal, The control device includes: 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 for executing the above.

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