Control device, switching system, and control method

Abstract

To prevent generation of large electromagnetic noise due to noise enhancement effect.SOLUTION: A control device includes: a noise measurement unit configured to measure electromagnetic noise in a surrounding environment; and a control unit configured to control timing of turning on or off a switching circuit on the basis of the electromagnetic noise measured by the noise measurement unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] 2. Description of the Related Art When multiple inverter devices are connected to an AC system, a technique has been proposed for variably controlling the PWM (Pulse Width Modulation) frequency of each inverter device based on the noise generation status in the surrounding environment.

[0003] However, even if the PWM frequencies of a plurality of inverter devices are variably controlled, there is a risk that the on / off timings of the switching elements in the plurality of inverter devices will overlap, resulting in a noise enhancement effect and generating large electromagnetic noise. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-189143 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, one embodiment of the present invention provides a control device, a switching system, and a control method that prevent large electromagnetic noise from being generated due to the noise enhancement effect. [Means for solving the problem]

[0006] In order to solve the above problems, according to one embodiment of the present invention, a noise measurement unit that measures electromagnetic noise in the surrounding environment; and a control unit that controls the on / off timing of the switching unit based on the electromagnetic noise measured by the noise measurement unit. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a block diagram showing a schematic configuration of a control device and a switching system according to a first embodiment. [Figure 2A] FIG. 4 is a diagram showing the waveform of electromagnetic noise in the surrounding environment measured by the electromagnetic noise measuring unit. [Figure 2B] FIG. 10 is a diagram showing an example in which the switching unit performs switching operations during a period from time t2 to t3 and a period from time t6 to t7. [Figure 3] FIG. 2 is a block diagram showing an example of the internal configuration of a switching control unit. [Figure 4] FIG. 2 is a block diagram showing the internal configuration of a switching unit. [Figure 5] 3 is a signal waveform diagram of a command signal w1, a carrier signal w2, and a PWM signal W3. [Figure 6] FIG. 5 shows an example in which the phase of the carrier signal w2 is shifted by 180 degrees. [Figure 7] FIG. 10 is a block diagram showing a schematic configuration of a control device and a switching system according to a second embodiment. [Figure 8A] FIG. 4 is a diagram showing time-series information of electromagnetic noise measured by an electromagnetic noise measuring unit. [Figure 8B] FIG. 4 is a diagram showing time-series information of electromagnetic noise predicted by an electromagnetic noise prediction unit. [Figure 8C] FIG. 4 is a diagram showing timings at which a switching unit performs a switching operation. [Figure 9] FIG. 10 is a diagram showing another example of the waveform of power supply noise measured by the electromagnetic noise measuring unit. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of a control device, a switching system, and a control method will be described with reference to the drawings. The following description will focus on the main components of the control device and the switching system, but the control device and the switching system may include components and functions that are not shown or described. The following description does not exclude components and functions that are not shown or described.

[0009] (First embodiment) Fig. 1 is a block diagram showing a schematic configuration of a control device 1 and a switching system 2 according to a first embodiment. The switching system 2 in Fig. 1 includes a switching unit 3 and a control device 1. The control device 1 includes an electromagnetic noise measuring unit 4 and a switching control unit 5. There may be cases where multiple pairs of switching units 3 and control devices 1 are provided within the switching system 2.

[0010] The switching unit 3 has one or more switching elements and performs switching operations to turn the switching elements on or off at predetermined timing. The switching unit 3 has an inverter, a converter, a transformer, etc., and converts DC / AC, voltage, current, frequency, number of phases, etc., while suppressing power loss.

[0011] The switching unit 3 is used in a power conversion device that converts DC voltage generated by a renewable energy power generation facility such as a photovoltaic (PV) device into AC voltage. This type of power conversion device is also called a power conditioning subsystem (PCS). The power conversion device may incorporate not only the switching unit 3 shown in FIG. 1 but also the control device 1. The power conversion device may have a mode for converting DC voltage to AC voltage and a mode for converting AC voltage to DC voltage.

[0012] The electromagnetic noise measurement unit 4 measures electromagnetic noise in the surrounding environment. The surrounding environment refers to any noise source located around the switching system 2 in FIG. 1, and the type of noise source does not matter. For example, the electromagnetic noise measurement unit 4 measures electromagnetic noise using an antenna. More specifically, the electromagnetic noise may be measured using a directional antenna so as not to be affected by the electromagnetic noise from the switching unit 3. In this case, it is desirable to orient the directivity of the directional antenna in a direction different from the direction in which the switching unit 3 is located.

[0013] When the electromagnetic noise measuring unit 4 measures electromagnetic noise in the surrounding environment, the switching operation of the switching unit 3 may be stopped. This allows the electromagnetic noise measuring unit 4 to measure electromagnetic noise in the surrounding environment without electromagnetic noise being generated by the switching unit 3, thereby enabling more accurate measurement of electromagnetic noise in the surrounding environment.

[0014] The switching control unit 5 controls the timing of turning on or off the switching unit 3 based on the electromagnetic noise measured by the electromagnetic noise measuring unit 4. For example, when the electromagnetic noise measuring unit 4 outputs a noise signal indicating the level of electromagnetic noise, the switching control unit 5 controls the on or off switching of the switching unit 3 in accordance with the timing when the level of the noise signal becomes equal to or lower than a predetermined threshold. Also, when the electromagnetic noise measuring unit 4 outputs a noise signal indicating the timing when electromagnetic noise is generated, the switching control unit 5 controls the on or off switching of the switching unit 3 in accordance with the timing when the noise signal is not generated. The switching control unit 5 may be a semiconductor chip or discrete digital circuit component that performs digital signal processing, such as a CPU (Central Processing Unit) or DSP (Digital Signal Processor), or may be a semiconductor chip or discrete component that performs analog signal processing.

[0015] 2A and 2B are diagrams illustrating the processing control of the switching control unit 5. Fig. 2A shows the waveform of electromagnetic noise in the surrounding environment measured by the electromagnetic noise measurement unit 4. The horizontal axis of Fig. 2A and Fig. 2B represents time, and the vertical axis represents the signal level of the electromagnetic noise. Fig. 2A shows an example in which electromagnetic noise occurs at times t1 to t2, t3 to t4, t5 to t6, and t7 to t8.

[0016] If the switching unit 3 performs a switching operation at a timing that coincides with the occurrence of electromagnetic noise in the surrounding environment, there is a risk of large electromagnetic noise being generated due to a noise enhancement effect. Therefore, as shown in Fig. 2B, the switching control unit 5 causes the switching unit 3 to perform a switching operation at a timing that differs from the occurrence of electromagnetic noise in the surrounding environment.

[0017] 2B shows an example in which the switching unit 3 performs a switching operation during a period from time t2 to t3 and during a period from time t6 to t7 under the control of the switching control unit 5. More specifically, in the example of Fig. 2B, the switching control unit 5 causes the switching unit 3 to perform a switching operation at a time tA that is later than time t2 and before time t3, a time tB that is later than time tA and before time t3, a time tC that is later than time t6 and before time t7, and a time tD that is later than time tC and before time t7.

[0018] This allows the timing of electromagnetic noise generation in the switching unit 3, which is switched by the switching control unit 5, to be shifted from the timing of electromagnetic noise generation in the surrounding environment, eliminating the risk of electromagnetic noise becoming larger due to the noise enhancement effect.

[0019] 3 is a block diagram showing an example of the internal configuration of the switching control unit 5. The switching control unit 5 in FIG. 3 has a compensation unit 6, a switch timing adjustment unit 7, a carrier signal generation unit 8, and a PWM signal generation unit 9.

[0020] The compensation unit 6 generates a compensation value so that the AC signal output by the switching unit 3 matches the target signal, and also generates a command signal based on the compensation value. In this specification, the compensation unit 6 may be referred to as a command signal generation unit. The command signal is input to the PWM signal generation unit 9 and the switch timing adjustment unit 7.

[0021] The switch timing adjustment unit 7 sets at least one of the waveform shape, frequency, or phase of the carrier signal based on the command signal from the compensation unit 6 and the waveform of the electromagnetic noise measured by the electromagnetic noise measurement unit 4 so that the switching unit 3 performs switching operation outside of the period when electromagnetic noise is observed.

[0022] The carrier signal generator 8 generates a carrier signal based on the waveform, frequency, or phase of the carrier signal set by the switch timing adjuster 7. The carrier signal is, for example, a triangular wave signal. Note that the carrier signal may be a sawtooth wave signal, a sine wave signal, a square wave signal, or the like, and the waveform shape is not important.

[0023] The PWM signal generating unit 9 generates a PWM signal for turning on or off the switching unit 3. The PWM signal generating unit 9 generates the PWM signal by comparing the magnitude relationship between the carrier signal generated by the carrier signal generating unit 8 and the command signal generated by the compensation unit 6.

[0024] In this way, the switching control unit 5 controls the on / off timing of the switching unit 3 using a carrier signal whose waveform, frequency, or phase is controlled based on the electromagnetic noise measured by the electromagnetic noise measuring unit 4.

[0025] 4 is a block diagram showing the internal configuration of the switching unit 3. The switching unit 3 has a step-up chopper circuit 11, an inverter circuit 12, and a transformer 13.

[0026] A DC voltage Vdc generated by a renewable energy power generation facility such as a solar power generation facility is input to the boost chopper circuit 11. The boost chopper circuit 11 converts the voltage amplitude of the input DC voltage Vdc. The inverter circuit 12 converts the output voltage of the boost chopper circuit 11 into an AC voltage Vac. The inverter circuit 12 generates the AC voltage Vac by turning on or off the switching unit 3 based on a PWM signal generated using a carrier signal and a command signal, which will be described later. The transformer 13 converts the voltage amplitude of the AC voltage Vac to generate a commercial power supply voltage of, for example, 100 V. The switching control unit 5 controls the boost chopper circuit 11 and the inverter circuit 12.

[0027] 5 and 6 are signal waveform diagrams of the command signal w1, carrier signal w2, and PWM signal W3. The command signal w1 generated by the compensation unit 6 has a frequency similar to that of the AC signal output by the switching unit 3 (e.g., 50 Hz to 60 Hz). The carrier signal w2 generated by the carrier signal generation unit 8 is a signal with a much higher frequency than the command signal w1, such as a triangular wave signal. The PWM signal generation unit 9 sets the PWM signal W3 to a high level when the signal amplitude of the command signal w1 is greater than that of the carrier signal w2, and sets the PWM signal W3 to a low level when the signal amplitude of the command signal w1 is equal to or less than that of the carrier signal w2. As a result, a PWM signal W3 with a variable pulse width is generated, as shown in FIG. 5.

[0028] Figure 6 shows an example in which the phase of carrier signal w2 is shifted by 180 degrees from that of Figure 5. As shown in Figure 6, when the phase of carrier signal w2 is shifted, the timing at which PWM signal W3 goes high is shifted. In this way, by controlling the phase of carrier signal w2 in carrier signal generator 8, the timing and duration at which PWM signal W3 goes high can be controlled.

[0029] The PWM signal W3 is used to control the on / off switching timing of the switching unit 3. The carrier signal generating unit 8 controls at least one of the frequency and phase of the carrier signal w2, thereby controlling the pulse width of the PWM signal W3. This makes it possible to control the timing at which the switching unit 3 performs its switching operation, and therefore the timing at which electromagnetic noise is generated.

[0030] As described above, in the first embodiment, the power supply noise measurement unit measures electromagnetic noise in the surrounding environment and supplies the measurement results to the switch timing adjustment unit 7. The switch timing adjustment unit 7 sets at least one of the waveform shape, frequency, and phase of the carrier signal based on the command signal from the compensation unit 6 and the waveform of the electromagnetic noise measured by the electromagnetic noise measurement unit 4 so that the switching unit 3 performs switching operations outside of the period when electromagnetic noise is observed. The carrier signal generation unit 8 generates a carrier signal according to the settings of the switch timing adjustment unit 7. The PWM signal generation unit 9 compares the magnitude of the carrier signal generated by the carrier signal generation unit 8 with the command signal generated by the compensation unit 6 to generate a PWM signal. The switching unit 3 is controlled to switch on or off based on the PWM signal. This allows the switching unit 3 to perform switching operations at a timing when the electromagnetic noise in the surrounding environment is low, preventing a noise enhancement effect between the electromagnetic noise in the surrounding environment and the electromagnetic noise from switching.

[0031] (Second embodiment) Fig. 7 is a block diagram showing a schematic configuration of a control device 1 and a switching system 2 according to the second embodiment. The switching system 2 in Fig. 7 differs from that in Fig. 1 in the configuration of the control device 1. The control device 1 in Fig. 7 has an electromagnetic noise prediction unit 14 in addition to an electromagnetic noise measurement unit 4 and a switching control unit 5.

[0032] The electromagnetic noise prediction unit 14 predicts electromagnetic noise after the measurement based on the electromagnetic noise measured by the electromagnetic noise measurement unit 4. The switching control unit 5 controls the on / off timing of the switching unit 3 based on the electromagnetic noise predicted by the electromagnetic noise prediction unit 14. The internal configuration of the switch control unit is the same as that shown in FIG.

[0033] The electromagnetic noise prediction unit 14 may predict time series information of electromagnetic noise after the measurement based on time series information of electromagnetic noise measured by the electromagnetic noise measurement unit 4. Here, the time series information includes predicted information of electromagnetic noise for the period after the measurement of the electromagnetic noise. The switching control unit 5 turns on or off the switching unit 3 at a timing that does not overlap with the predicted period of occurrence of electromagnetic noise included in the time series information.

[0034] The electromagnetic noise prediction unit 14 predicts electromagnetic noise in the surrounding environment that does not include electromagnetic noise generated from the switching unit 3, based on the control signal that turns on or off the switching unit 3 output by the switching control unit 5. The switching control unit 5 controls the on or off timing of the switching unit 3 so that the timing of the electromagnetic noise generated from the switching unit 3 differs from the timing of occurrence of the electromagnetic noise predicted by the electromagnetic noise prediction unit 14.

[0035] 8A, 8B, and 8C are diagrams showing time-series information of electromagnetic noise predicted by the electromagnetic noise prediction unit 14. In these diagrams, the horizontal axis represents time and the vertical axis represents the signal level of the electromagnetic noise. FIG. 8A is a waveform diagram of the electromagnetic noise measured by the electromagnetic noise measurement unit 4. As shown in FIG. 8A, electromagnetic noise occurs at times t1 to t2, t3 to t4, t5 to t6, and t7 to t8.

[0036] The electromagnetic noise prediction unit 14 predicts electromagnetic noise from time t9 onwards based on the electromagnetic noise measured by the electromagnetic noise measurement unit 4 before time t8. If the electromagnetic noise in the surrounding environment is periodic, the electromagnetic noise prediction unit 14 predicts that electromagnetic noise will occur at times t10 to t11, t12 to t13, and t14 to t15, as shown in Fig. 8B, based on the timing of occurrence of the electromagnetic noise measured from times t1 to t8 shown in Fig. 8A. Fig. 8B shows time-series information of the electromagnetic noise predicted by the electromagnetic noise prediction unit 14. Note that periodicity refers to the occurrence of electromagnetic noise with the same or similar waveforms at regular time intervals.

[0037] The switching control unit 5 causes the switching unit 3 to perform switching operations at the timings shown in Fig. 8C based on the time-series information of electromagnetic noise from the electromagnetic noise prediction unit 14. Time tE in Fig. 8C is a time between time t9 and time t10. Time tF is a time between time t13 and time t14. Time tG is a time after time tF and before time t14. Times tE, tF, and tG in Fig. 8C are all outside the predicted period of electromagnetic noise occurrence predicted by the electromagnetic noise prediction unit 14. By performing switching operations starting from times tE, tF, and tG, it is possible to prevent the noise enhancement effect of electromagnetic noise and suppress the maximum signal amplitude level of electromagnetic noise.

[0038] 8A, 8B, and 8C illustrate an example in which the switching unit 3 performs a switching operation during a period when it is predicted that no electromagnetic noise will occur. As a modification, the switching control unit 5 may perform a switching operation during a period when the predicted level of electromagnetic noise is, for example, half or less of the average level of electronic noise. In this case, too, the noise enhancement effect can be prevented, and the maximum signal amplitude level of the electromagnetic noise can be suppressed.

[0039] The electromagnetic noise prediction method used by the electromagnetic noise prediction unit 14 can be a method using an autoregressive integrated and moving average (ARIMA) process model or a method using a time-series data prediction algorithm using machine learning or deep learning. For example, if a switching control system is connected to a power grid with an output of 50 Hz and the switching unit 3 operates in synchronization with the grid, electromagnetic noise occurs periodically with a cycle of 20 ms (= 1 / 50 Hz). In this way, when electromagnetic noise occurs periodically, the cycle timing of the electromagnetic noise can be determined by calculating the autocorrelation coefficient, allowing the electromagnetic noise to be predicted.

[0040] Furthermore, the electromagnetic noise prediction unit 14 uses the on / off switching control information of the switching unit 3 to generate a waveform of the electromagnetic noise generated from its own switching unit 3 from the timing of the occurrence of the electromagnetic noise of its own switching unit 3, and subtracts this waveform from the electromagnetic noise waveform measured by the electromagnetic noise measurement unit 4, thereby detecting the electromagnetic noise in the surrounding environment of its own switching unit 3. By controlling the frequency of the carrier signal, etc. in the switch timing adjustment unit 7 based on the detected electromagnetic noise of the surrounding environment, it is possible to cause the switching to perform a switching operation at a timing different from the timing of the occurrence of the detected electromagnetic noise of the surrounding environment.

[0041] Alternatively, the electromagnetic noise measuring unit 4 may measure electromagnetic noise in the surrounding environment using a directional antenna so as not to measure electromagnetic noise generated by its own switching unit 3. In this case, there is no need to subtract the waveform of the electromagnetic noise generated by its own switching unit 3 from the electromagnetic noise waveform measured by the electromagnetic noise measuring unit 4.

[0042] FIG. 9 is a diagram showing another example of a waveform of power supply noise measured by the electromagnetic noise measurement unit 4. A power conversion device that connects a DC voltage Vdc output from a renewable energy power generation facility such as a solar power generation facility to a commercial AC power supply converts the DC voltage Vdc into an AC voltage Vac of, for example, 50 Hz. Therefore, as shown in FIG. 9, electromagnetic noise is generated from the power conversion device with a period of, for example, 50 Hz. When the electromagnetic noise prediction unit 14 determines from measurement by the electromagnetic noise measurement unit 4 that electromagnetic noise is generated with a period of 50 Hz, it predicts that electromagnetic noise will be generated with the same period after the measurement. Then, the switching control unit 5 causes the switching unit 3 to perform a switching operation during a period different from the predicted period of electromagnetic noise generation predicted by the electromagnetic noise prediction unit 14.

[0043] As described above, in the second embodiment, the electromagnetic noise prediction unit 14 predicts time-series information about electromagnetic noise after the measurement based on the electromagnetic noise measured by the electromagnetic noise measurement unit 4. Because electromagnetic noise is periodic, the electromagnetic noise prediction unit 14 can predict the time-series information about electromagnetic noise relatively accurately. Based on the predicted time-series information about electromagnetic noise, the switching control unit 5 causes the switching unit 3 to perform switching operations at timings that do not overlap with the predicted period of electromagnetic noise occurrence. As a result, even if the period for measuring electromagnetic noise by the electromagnetic noise measurement unit 4 is short, the predicted period of electromagnetic noise occurrence can be accurately predicted over a long period of time. By controlling the timing of the switching operation of the switching unit 3 based on the prediction results, it is possible to prevent noise enhancement effects and suppress the maximum signal amplitude level of electromagnetic noise.

[0044] [Note] [Item 1] a noise measurement unit for measuring electromagnetic noise in the surrounding environment; a control unit that controls the on / off timing of a switching unit based on the electromagnetic noise measured by the noise measurement unit. [Item 2] Item 1. The control device according to item 1, wherein the control unit controls the switching unit to switch on or off at a timing different from the timing of occurrence of the electromagnetic noise measured by the noise measurement unit. [Item 3] the noise measurement unit outputs a noise signal indicating a level of electromagnetic noise; 3. The control device according to item 1 or 2, wherein the control unit controls the switching unit to switch on or off in accordance with the timing when the level of the noise signal becomes equal to or lower than a predetermined value. [Item 4] the noise measurement unit outputs a noise signal indicating the timing of occurrence of electromagnetic noise; 3. The control device according to item 1 or 2, wherein the control unit controls the switching unit to switch on or off in accordance with a timing when the noise signal is not generated. [Item 5] a noise prediction unit that predicts electromagnetic noise after measurement based on the electromagnetic noise measured by the noise measurement unit; 3. The control device according to item 1 or 2, wherein the control unit controls the timing of switching the switching unit on or off based on the electromagnetic noise predicted by the noise prediction unit. [Item 6] 6. The control device according to item 5, wherein the noise prediction unit predicts time-series information of electromagnetic noise from the time of measurement onward based on time-series information of electromagnetic noise measured by the noise measurement unit. [Item 7] 7. The control device according to item 6, wherein the control unit turns on or off the switching unit at a timing that does not overlap with a predicted period of occurrence of electromagnetic noise included in the time-series information. [Item 8] the noise prediction unit predicts electromagnetic noise in the surrounding environment, not including electromagnetic noise generated from the switching unit, based on a control signal output from the control unit for turning on or off the switching unit; 8. The control device according to any one of items 5 to 7, wherein the control unit controls the timing of turning on or off the switching unit so as to differ from the timing of occurrence of electromagnetic noise in the surrounding environment predicted by the noise prediction unit. [Item 9] 9. The control device according to any one of items 1 to 8, wherein the noise measurement unit measures electromagnetic noise around the switching unit while the switching operation of the switching unit is stopped. [Item 10] 10. The control device according to any one of items 1 to 9, wherein the control unit controls the timing of turning on or off the switching unit using a carrier signal whose waveform, frequency, or phase is controlled based on the electromagnetic noise measured by the noise measurement unit. [Item 11] a timing control unit that sets at least one of a waveform shape, a frequency, and a phase of the carrier signal so that the switching unit turns on or off at a timing different from the occurrence timing of the electromagnetic noise measured by the noise measurement unit; Item 11. The control device according to item 10, further comprising: a carrier signal generating unit that generates the carrier signal based on at least one of the waveform shape, frequency, or phase of the carrier signal set by the timing control unit. [Item 12] a command signal generating unit that generates a command signal so that the output signal of the switching unit coincides with a target signal; a PWM signal generating unit that compares the magnitude relationship between the command signal and the carrier signal to generate a PWM (Pulse Width Modulation) signal; Item 12. The control device according to item 11, wherein the switching unit is controlled to be switched on or off by the PWM signal. [Item 13] 13. The control device according to any one of items 1 to 12, wherein the noise measurement unit measures electromagnetic noise using a directional antenna having directivity in a direction different from the arrangement direction of the switching unit. [Item 14] 14. The control device according to any one of items 1 to 13, wherein the noise measurement unit measures electromagnetic noise around the switching unit in a power conversion device that converts DC voltage generated by a renewable energy power generation facility into AC voltage. [Item 15] A switching unit; a noise measurement unit that measures electromagnetic noise around the switching unit; a control unit that controls the on / off timing of the switching unit based on the electromagnetic noise measured by the noise measurement unit. [Item 16] A power conversion device is provided that converts DC voltage generated by the renewable energy power generation facility into AC voltage, Item 16. The switching system according to item 15, wherein the power conversion device includes the switching unit. [Item 17] Measure the electromagnetic noise around the switching part, A control method for controlling the on / off timing of the switching unit based on the measured electromagnetic noise.

[0045] The aspects of the present disclosure are not limited to the individual embodiments described above, but include various modifications that may be conceived by those skilled in the art, and the effects of the present disclosure are not limited to the above-described contents. In other words, various additions, modifications, and partial deletions are possible within the scope of the conceptual idea and spirit of the present disclosure, which is derived from the contents defined in the claims and their equivalents. [Explanation of symbols]

[0046] 1 control device, 2 switching system, 3 switching section, 4 electromagnetic noise measurement section, 5 switching control section, 6 compensation section, 7 switch timing adjustment section, 8 carrier signal generation section, 9 PWM signal generation section, 11 boost chopper circuit, 12 inverter circuit, 13 transformer, 14 electromagnetic noise prediction section

Claims

1. a noise measurement unit for measuring electromagnetic noise in the surrounding environment; a control unit that controls the on / off timing of a switching unit at a timing different from the occurrence timing of the electromagnetic noise measured by the noise measuring unit, based on the electromagnetic noise measured by the noise measuring unit.

2. A noise measurement unit that measures electromagnetic noise in the surrounding environment; a control unit that controls the on / off timing of the switching unit based on the electromagnetic noise measured by the noise measurement unit, the noise measurement unit outputs a noise signal indicating a level of electromagnetic noise; The control unit controls the switching unit to switch on or off in accordance with the timing when the level of the noise signal becomes equal to or lower than a predetermined value.

3. A noise measurement unit that measures electromagnetic noise in the surrounding environment; a control unit that controls the on / off timing of the switching unit based on the electromagnetic noise measured by the noise measurement unit, the noise measurement unit outputs a noise signal indicating the timing of occurrence of electromagnetic noise; The control unit controls the switching unit to switch on or off in accordance with a timing when the noise signal is not generated.

4. A noise measurement unit that measures electromagnetic noise in the surrounding environment; a control unit that controls the on / off timing of the switching unit based on the electromagnetic noise measured by the noise measurement unit, a noise prediction unit that predicts electromagnetic noise after measurement based on the electromagnetic noise measured by the noise measurement unit; The control unit controls the timing of switching the switching unit on or off based on the electromagnetic noise predicted by the noise prediction unit.

5. The control device according to claim 4 , wherein the noise prediction unit predicts time-series information of the electromagnetic noise from the time of measurement onward based on the time-series information of the electromagnetic noise measured by the noise measurement unit.

6. The control device according to claim 5 , wherein the control unit turns on or off the switching unit at a timing that does not overlap with a predicted period of occurrence of electromagnetic noise included in the time-series information.

7. the noise prediction unit predicts electromagnetic noise in the surrounding environment, not including electromagnetic noise generated from the switching unit, based on a control signal output from the control unit for turning on or off the switching unit; The control device according to claim 4 , wherein the control unit controls the timing of turning on or off the switching unit so as to differ from the timing of occurrence of electromagnetic noise in the surrounding environment predicted by the noise prediction unit.

8. A noise measurement unit that measures electromagnetic noise in the surrounding environment; a control unit that controls the on / off timing of the switching unit based on the electromagnetic noise measured by the noise measurement unit, The noise measurement unit measures electromagnetic noise around the switching unit while the switching operation of the switching unit is stopped.

9. 2. The control device according to claim 1, wherein the control unit controls the timing of turning on or off the switching unit using a carrier signal whose waveform, frequency, or phase is controlled based on the electromagnetic noise measured by the noise measurement unit.

10. a timing control unit that sets at least one of a waveform shape, a frequency, and a phase of the carrier signal so that the switching unit turns on or off at a timing different from a timing at which the electromagnetic noise measured by the noise measurement unit occurs; The control device according to claim 9 , further comprising: a carrier signal generating unit that generates the carrier signal based on at least one of a waveform shape, a frequency, and a phase of the carrier signal set by the timing control unit.

11. a command signal generating unit that generates a command signal so that the output signal of the switching unit coincides with a target signal; a PWM signal generating unit that compares the magnitude relationship between the command signal and the carrier signal to generate a PWM (Pulse Width Modulation) signal; The control device according to claim 10 , wherein the switching unit is controlled to be switched on or off by the PWM signal.

12. A noise measurement unit that measures electromagnetic noise in the surrounding environment; a control unit that controls the on / off timing of the switching unit based on the electromagnetic noise measured by the noise measurement unit, The noise measurement unit measures electromagnetic noise using a directional antenna having directivity in a direction different from the direction in which the switching unit is arranged.

13. The control device according to claim 1 , wherein the noise measurement unit measures electromagnetic noise around the switching unit in a power conversion device that converts a DC voltage generated by a renewable energy power generation facility into an AC voltage.

14. A switching unit; a noise measurement unit that measures electromagnetic noise around the switching unit; a control unit that controls the on / off timing of the switching unit at a timing different from the occurrence timing of the electromagnetic noise measured by the noise measurement unit, based on the electromagnetic noise measured by the noise measurement unit.

15. A power conversion device is provided that converts DC voltage generated by the renewable energy power generation facility into AC voltage, The switching system according to claim 14 , wherein the power conversion device includes the switching unit.

16. Measure the electromagnetic noise around the switching part, A control method for controlling the on / off timing of the switching unit based on the measured electromagnetic noise at a timing different from the timing at which the measured electromagnetic noise occurs.

Images