JP2022104369A - Waveform measuring instrument and data acquisition method - Google Patents

Abstract

To provide an improved waveform measuring instrument and data acquisition method.SOLUTION: A waveform measuring instrument comprises: a determination circuit; a detector; and a computation circuit. The determination circuit determines whether an input of a first AC signal corresponding to a first signal to the waveform measuring instrument is in a halting state. The detector operates, when it is determined by the determination circuit that the input of the first AC signal to the waveform measuring instrument is not in the halting state, to detect one of a rising edge of the first signal or a falling edge thereof as a computation timing. The detector operates, when it is determined by the determination circuit that the input of the first AC signal to the waveform measuring instrument is in the halting state, to detect both the rising edge of the first signal and the falling edge thereof as the computation timing. The computation circuit calculates a computation value in a computation section to be set by the computation timing, using the first AC signal.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a waveform measuring instrument and a method for acquiring data.

Conventionally, a waveform measuring instrument that calculates the calculated value of the input data in real time when the data is input is known (for example, Non-Patent Document 1).

Etsuro Nakayama, Chiaki Yamamoto, "ScopeCorder DL850 Real-time Math Function of DL850 ScopeCorder", Yokogawa Electric Co., Ltd., Yokogawa Giho, Vol.55 No.1 (2012), p9 -P14

There is room for improvement in conventional waveform measuring instruments. For example, the data at the time of starting the device is useful for the analysis of the device. It is desired that the calculated value of the data at the time of starting the device is calculated by the waveform measuring instrument.

The present disclosure has been made in view of the above points, and an object of the present disclosure is to provide an improved waveform measuring instrument and a method for acquiring data.

The waveform measuring instrument according to some embodiments is the determination circuit for determining whether or not the input of the first AC signal corresponding to the first signal to the waveform measuring instrument is in the stopped state, and the determination circuit. When it is determined that the input of the first AC signal to the waveform measuring instrument is not in the stopped state, it operates so as to detect one of the rising edge and the falling edge of the first signal as the calculation timing. When the determination circuit determines that the input of the first AC signal to the waveform measuring instrument is in the stopped state, it operates to detect both the rising edge and the falling edge of the first signal as calculation timings. It includes a detector and a calculation circuit that calculates a calculation value in a calculation section set by the calculation timing using the first AC signal. With such a configuration, the calculation timing can be detected by the detector at the time of starting the device for inputting the first AC signal to the waveform measuring device. By detecting the calculation timing at the time of starting the device, the calculation value at the time of starting the device can be calculated. Therefore, according to this embodiment, an improved waveform measuring instrument is provided.

In the waveform measuring instrument according to the embodiment, when the determination circuit determines that the calculation timing is not detected within a set period exceeding 1 times the period of the first signal, the first determination circuit to the waveform measuring instrument is used. It may be determined that the input of the AC signal is in the stopped state. By using such a setting period, it is possible to efficiently determine whether or not the input of the AC voltage to the waveform measuring instrument is in the stopped state.

In the waveform measuring instrument according to the embodiment, the determination circuit determines that the input of the first AC signal to the waveform measuring instrument is in the stopped state, and then the second and subsequent times of the calculation timing detected. The cycle of the first signal may be detected by the calculation timing detected in the above, and the set period may be set by the detected cycle. By detecting the cycle of the first signal according to the calculation timing detected from the second time onward, the cycle of the first signal is detected with high accuracy, so that the input of the first AC signal to the waveform measuring instrument is stopped. Whether or not it can be determined more accurately.

In the waveform measuring instrument according to the embodiment, when the determination circuit determines that the input of the first AC signal to the waveform measuring instrument is not in the stopped state, the setting period is set according to the latest cycle of the first signal. May be updated. By updating the set period according to the latest cycle of the first signal, the determination circuit can more accurately determine whether or not the input of the first AC signal to the waveform measuring instrument is in the stopped state.

In the waveform measuring instrument according to one embodiment, the arithmetic circuit may calculate an effective value of AC voltage or AC current as the arithmetic value. With such a configuration, it is possible to analyze the electrical characteristics at the time of starting the device for inputting the first AC signal to the waveform measuring device with higher accuracy.

In the waveform measuring instrument according to one embodiment, the arithmetic circuit may calculate a power value by using the first AC signal and the second AC signal as the arithmetic value. With such a configuration, it is possible to analyze the electrical characteristics at the time of starting the device for inputting the first AC signal to the waveform measuring device with higher accuracy.

The data acquisition method according to some embodiments is to determine whether or not the input of the first AC signal corresponding to the first signal to the waveform measuring instrument is in the stopped state, and to the waveform measuring instrument. When it is determined that the input of the first AC signal is not in the stopped state, it operates so as to detect one of the rising edge and the falling edge of the first signal as the calculation timing, and performs the operation to detect the waveform measuring instrument. When it is determined that the input of the first AC signal is in the stopped state, it operates so as to detect both the rising edge and the falling edge of the first signal as the calculation timing, and is set by the calculation timing. The calculation value in the calculation section is calculated by using the first AC signal. With such a configuration, the calculation timing can be detected by the detector at the time of starting the device for inputting the first AC signal to the waveform measuring device. By detecting the calculation timing at the time of starting the device, the calculation value at the time of starting the device can be calculated. Therefore, according to the present embodiment, an improved method for acquiring data is provided.

The present disclosure provides an improved waveform measuring instrument and a method for acquiring data.

It is a block diagram of the waveform measuring instrument which concerns on one Embodiment. It is a figure which shows an example of the waveform of the AC voltage and the AC current displayed on the display shown in FIG. 1. It is a timing chart which shows an example of the operation of the waveform measuring instrument shown in FIG. It is a flowchart which shows the detection method of the calculation timing by the waveform measuring instrument shown in FIG. It is a flowchart which shows the calculation method of the calculated value by the waveform measuring instrument shown in FIG. It is a block diagram of the waveform measuring instrument which concerns on a comparative example.

Hereinafter, one embodiment of the present disclosure will be described with reference to the drawings. In the components shown in the drawings below, the same components are designated by the same reference numerals.

The waveform measuring instrument 1 as shown in FIG. 1 is used for measuring an AC signal of an apparatus. The waveform measuring instrument 1 can simultaneously display the waveform of the AC signal of the device and the calculated value calculated by using the AC signal. Hereinafter, the waveform measuring instrument 1 will be used for measuring the AC signal of the synchronous motor mounted on the automobile. The synchronous motor is, for example, a three-phase synchronous motor. However, the waveform measuring instrument 1 may be used for measuring an AC signal of any device.

As described below, the waveform measuring instrument 1 can calculate an calculated value such as a power value at the time of starting the synchronous motor. When the synchronous motor is started, for example, when the power of the synchronous motor is turned on, or when the synchronous motor changes from the non-driving state to the driving state.

The first signal and the second signal are input to the waveform measuring instrument 1 from the synchronous motor. The first signal corresponds to the first AC signal of the synchronous motor. The second signal corresponds to the second AC signal of the synchronous motor.

Hereinafter, the first AC signal is assumed to be a U-phase AC voltage. That is, the first signal corresponds to the U-phase AC voltage. Further, it is assumed that the second alternating current signal is a U-phase alternating current. That is, the second signal corresponds to the U-phase alternating current. However, the first AC signal may be a U-phase AC current, and the second AC signal may be a U-phase AC voltage. Further, the first AC signal and the second AC signal may be V-phase or W-phase AC voltage and AC current, respectively, or may be V-phase or W-phase AC current and AC voltage, respectively.

The waveform measuring instrument 1 as shown in FIG. 1 is configured to measure the AC voltage and AC current of one of the U phase, V phase, and W phase. However, the waveform measuring instrument 1 may be configured to measure the AC voltage and the AC current of two or more phases of the U phase, the V phase, and the W phase.

As shown in FIG. 1, the waveform measuring instrument 1 includes an amplifier 10, an amplifier 11, an AD (Analog to Digital) converter 12, an AD converter 13, a memory controller 14, a memory 15, and a detector 16. A determination circuit 17, an arithmetic circuit 18, a memory controller 19, a memory 20, a generation circuit 21, and a display 22. The waveform measuring instrument 1 may further include a timing generator that outputs a sampling signal to the AD converter 12, the AD converter 13, the memory controller 14, and the like.

The first signal is input to the amplifier 10. The amplifier 10 normalizes the first signal according to the input voltage range of the AD converter 12. For example, the amplifier 10 normalizes (adjusts) the voltage width of the first signal so that the voltage width of the first signal is within the input voltage range of the AD converter 12. The amplifier 10 outputs the normalized first signal to the AD converter 12.

A second signal is input to the amplifier 11. The amplifier 11 normalizes the second signal according to the input voltage range of the AD converter 13. For example, the amplifier 11 normalizes (adjusts) the voltage width of the second signal so that the voltage width of the second signal is within the input voltage range of the AD converter 13. The amplifier 11 outputs the normalized second signal to the AD converter 13.

The first signal after normalization is input to the AD converter 12 from the amplifier 10. The AD converter 12 converts the normalized first signal into digital data according to the sampling cycle of the sampling signal. The first signal after being converted into digital data is the data as shown in FIG. The digital data as the first signal is output by the AD converter 12 at each sampling cycle. The AD converter 12 outputs the first signal after conversion to digital data to the memory controller 14, the detector 16 and the arithmetic circuit 18 according to the sampling timing.

A second signal after normalization is input to the AD converter 13 from the amplifier 11. The AD converter 13 converts the normalized second signal into digital data according to the sampling cycle of the sampling signal. The second signal after being converted into digital data is the data as shown in FIG. The digital data as the second signal is output by the AD converter 13 at each sampling cycle. The AD converter 13 outputs the second signal after conversion to digital data to the memory controller 14 and the arithmetic circuit 18 according to the sampling timing.

The memory controller 14 includes at least one processor, at least one dedicated circuit, or a combination thereof. The processor is, for example, a general-purpose processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), a dedicated processor specialized for a specific process, or the like. The dedicated circuit is, for example, FPGA (Field-Programmable Gate Array) or ASIC (Application Specific Integrated Circuit).

The first signal after being converted into digital data is input to the memory controller 14 from the AD converter 12. The memory controller 14 stores the information of the first signal in the memory 15 according to the sampling cycle of the sampling signal. Further, a second signal after being converted into digital data is input to the memory controller 14 from the AD converter 13. The memory controller 14 stores the information of the second signal in the memory 15 according to the sampling cycle of the sampling signal.

The memory 15 includes at least one semiconductor memory, at least one magnetic memory, at least one optical memory, or at least two combinations thereof. The semiconductor memory is, for example, RAM (Random Access Memory) or ROM (Read Only Memory). The RAM is, for example, SRAM (Static Random Access Memory) or DRAM (Dynamic Random Access Memory). The ROM is, for example, EEPROM (Electrically Erasable Programmable Read Only Memory) or the like.

Information of the first signal and information of the second signal are stored in the memory 15. The information of the first signal stored in the memory 15 corresponds to the analog waveform data indicating the U-phase AC voltage displayed on the display 22. Further, the information of the second signal stored in the memory 15 corresponds to the analog waveform data indicating the U-phase alternating current displayed on the display 22.

The detector 16 includes at least one processor, at least one dedicated circuit, or a combination thereof. The processor is, for example, a general-purpose processor such as a CPU or GPU, a dedicated processor specialized for a specific process, or the like. The dedicated circuit is, for example, FPGA or ASIC.

The first signal after being converted into digital data is input to the detector 16 from the AD converter 12. The detector 16 can detect the rising edge and the falling edge of the first signal.

As an example of detecting the rising edge of the first signal, as shown in FIG. 2, in the detector 16, when the first signal increases from the first set value to the second set value through the zero crossing point, the first signal becomes large. The timing of passing through the zero cross point is detected as the rising edge of the first signal. The first set value is smaller than the zero cross point. The second set value is larger than the zero cross point. The cellocross point is a point where the voltage value of the AC voltage becomes the reference voltage value. The reference voltage value is, for example, 0 [V]. The first set value and the second set value may be appropriately set in consideration of noise and the like. However, the rising edge of the first signal is not limited to the timing at which the first signal passes through the zero crossing point. The rising edge of the first signal may be the timing at which the first signal passes through an arbitrary point set between the first set value and the second set value. Further, when the first signal increases from the reference voltage value to the second set value, the detector 16 may detect the timing when the first signal is the reference voltage value as the rising edge of the first signal. ..

As an example of detecting the falling edge of the first signal, as shown in FIG. 2, the detector 16 uses the first signal when the first signal decreases from the second set value to the first set value through the zero crossing point. Detects the timing of passing through the zero cross point as the falling edge of the first signal. However, the falling edge of the first signal is not limited to the timing of passing through the zero crossing point. The falling edge of the second signal may be the timing at which the second signal passes through an arbitrary point set between the first set value and the second set value. Further, when the first signal becomes smaller from the reference voltage value to the first set value, the detector 16 may detect the timing when the first signal is the reference voltage value as the falling edge of the first signal. good.

The detector 16 can detect at least one of the rising edge and the falling edge of the first signal as the calculation timing. As will be described later, the calculation timing is used for setting a calculation section as shown in FIG. 3 for the calculation circuit 18 to calculate the calculation value.

Here, when the synchronous motor is in the driving state, the input of the AC voltage from the synchronous motor to the waveform measuring instrument 1 is not in the stopped state. That is, as shown in FIG. 3, when the synchronous motor is in the driving state, the first signal changes periodically. On the other hand, when the synchronous motor is in the non-driving state, the input of the AC voltage from the synchronous motor to the waveform measuring instrument 1 is stopped. That is, as shown in FIG. 3, when the synchronous motor is in the non-driving state, the first signal does not change periodically.

When the synchronous motor is in the driving state, that is, when the input of the AC voltage from the synchronous motor to the waveform measuring instrument 1 is not in the stopped state, the first signal periodically repeats rising and falling. By periodically repeating the rising and falling edges of the first signal, the detector 16 periodically detects the calculation timing if any of the rising edge and the falling edge of the first signal is detected as the calculation timing. be able to. By periodically detecting the calculation timing, the calculation circuit 18 described later can periodically set the calculation section according to the calculation timing and periodically calculate the calculation value in the calculation section.

When the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is not in the stopped state, the detector 16 detects one of the rising edge and the falling edge of the first signal as the calculation timing. Works like this. In the present embodiment, when the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is not in the stopped state, the detector 16 is preset among the rising edge and the falling edge of the first signal. It operates so as to detect one of them as the calculation timing. Which of the rising edge and the falling edge of the first signal is detected as the calculation timing is set in advance according to, for example, the specifications of the waveform measuring instrument 1. In the present embodiment, the determination signal is input from the determination circuit 17 to the detector 16. The determination signal indicates the determination result of the determination circuit 17. The determination signal is set to a low level when the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is not in the stopped state. The detector 16 operates so as to detect one of the rising edge and the falling edge of the first signal as the calculation timing when the determination signal is low level.

For example, as shown in FIG. 3, the determination signal is set to a low level between time t1 and time t2 and after time t3. The detector 16 detects the rising edge of the first signal as one of the rising edge and the falling edge of the first signal, which is preset between the time t1 and the time t2 and after the time t3, as the calculation timing. Works like this.

When the synchronous motor is in the non-driving state, that is, when the input of the AC voltage from the synchronous motor to the waveform measuring instrument 1 is in the stopped state, the first signal does not change periodically. Here, the synchronous motor changes from the non-driving state to the driving state according to, for example, the traveling state of the automobile on which the synchronous motor is mounted. Information on calculated values such as the power value when the synchronous motor changes from the non-driving state to the driving state, that is, when the synchronous motor is started, is useful for analyzing the characteristics of the synchronous motor. By the way, when the synchronous motor changes from the non-drive state to the drive state, the phases of the AC voltage and the AC current are adjusted in the synchronous motor. Depending on the phase of the adjusted AC voltage, when the synchronous motor changes from the non-driving state to the driving state, the first signal corresponding to the AC voltage rises or falls. Therefore, when the detector 16 is operating so as to detect one of the rising edge and the falling edge of the first signal as the calculation timing, the synchronous motor has changed from the non-driving state to the driving state. Immediately after that, the detector 16 may not be able to detect the calculation timing. For example, consider a case where the detector 16 operates so as to detect the rising edge of the first signal as the calculation timing as one of the rising edge and the falling edge of the first signal, which is preset. In this case, at the time t3 shown in FIG. 3, the first signal goes down. As a result, the detector 16 cannot detect the calculation timing at time t3. If the calculation timing cannot be detected at time t3, the calculation circuit 18 described later cannot set the calculation section a6 and cannot calculate the calculation value in the calculation section a6.

Therefore, when the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state, the detector 16 detects both the rising edge and the falling edge of the first signal as the calculation timing. Works like this. In this embodiment, as described above, the determination signal is input from the determination circuit 17 to the detector 16. The determination signal is set to a high level when the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state. The detector 16 operates so as to detect both the rising edge and the falling edge of the first signal as the calculation timing when the determination signal is at a high level.

For example, as shown in FIG. 3, the determination signal is set to a high level between time t2 and time t3. The detector 16 operates so as to detect both the rising edge and the falling edge of the first signal as the calculation timing between the time t2 and the time t3. With such a configuration, the detector 16 can detect the falling edge of the first signal as the calculation timing at time t3.

Here, it is difficult to predict the phase of the AC voltage of the synchronous motor at the start of measurement of the waveform measuring device 1. That is, it is difficult to predict whether the first signal will rise or fall at the start of measurement of the waveform measuring instrument 1.

Therefore, the detector 16 operates so as to detect both the rising edge and the falling edge of the first signal as the calculation timing at the start of the measurement of the waveform measuring device 1. In the present embodiment, the determination signal is set to a high level at the start of measurement of the waveform measuring device 1. As described above, the detector 16 operates so as to detect both the rising edge and the falling edge of the first signal as the calculation timing when the determination signal is at a high level. For example, the time before the time t1 as shown in FIG. 3 is the time when the measurement of the waveform measuring instrument 1 starts. The detector 16 detects the falling edge of the first signal as the calculation timing at time t1.

The detector 16 outputs the detected calculation timing information to the determination circuit 17 and the calculation circuit 18. The detector 16 may output the detected calculation timing information to the memory controller 19.

The determination circuit 17 includes at least one processor, at least one dedicated circuit, or a combination thereof. The processor is, for example, a general-purpose processor such as a CPU or GPU, a dedicated processor specialized for a specific process, or the like. The dedicated circuit is, for example, FPGA or ASIC.

The determination circuit 17 determines whether or not the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state. An example of this determination process will be described later. The determination circuit 17 outputs a determination signal indicating the determination result of the determination circuit 17 to the detector 16. When the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state, the determination circuit 17 sets the determination signal to a high level. On the other hand, when the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is not in the stopped state, the determination circuit lowers the determination signal to a low level. The determination circuit 17 considers that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state at the start of the measurement of the waveform measuring instrument 1, and determines that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state. You may judge. That is, the determination circuit 17 may set the determination signal to a high level at the start of measurement of the waveform measuring device 1. For example, at a time before the time t1 as shown in FIG. 3, the determination signal is set to a high level.

<Judgment processing>
When the input of the AC voltage to the waveform measuring instrument 1 is not in the stopped state, that is, when the determination signal is at the low level, the detector 16 inputs the calculation timing information to the determination circuit 17. The determination circuit 17 detects the period T1 of the first signal based on the input calculation timing information. The determination circuit 17 detects, for example, the period from the detection of the calculation timing by the detector 16 to the detection of the next calculation timing by the detector 16 as the period T1 of the first signal.

The determination circuit 17 sets a period exceeding 1 times the period T1 of the first signal as the setting period T2. The determination circuit 17 determines whether or not the calculation timing is detected by the detector 16 within the set period T2 that exceeds 1 times the period T1. The set period T2 is expressed as, for example, the formula: T1 × n (n> 1).

When the determination circuit 17 determines that the calculation timing is detected by the detector 16 within the set period T2, the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is not in the stopped state. When the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is not in the stopped state, the determination circuit 17 holds the determination signal at a low level.

On the other hand, when the determination circuit 17 determines that the calculation timing is not detected by the detector 16 within the set period T2, the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state. When the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state, the determination circuit 17 sets the determination signal to a high level. For example, at time t2 as shown in FIG. 3, the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state, and sets the determination signal to a high level.

By using such a set period T2, it is possible to efficiently determine whether or not the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state.

When the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state and then the calculation timing is detected by the detector 16, the determination circuit 17 is in the stopped state when the input of the AC voltage to the waveform measuring instrument 1 is stopped. It is determined that there is no such thing. The determination circuit 17 lowers the determination signal at the calculation timing first detected by the detector 16 after determining that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state. For example, as shown in FIG. 3, at time t3, the detector 16 detects the calculation timing. The calculation timing detected at time t3 is the calculation timing first detected after the determination circuit 17 determines at time t2 that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state. At time t3, the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is not in the stopped state, and sets the determination signal to a low level. Further, at time t1, the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is not in the stopped state, and sets the determination signal to a low level.

Here, the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state, and then the first signal is based on the calculation timing detected after the second calculation timing. The period T1 may be detected. Further, the determination circuit 17 may set the set period T2 according to the detected cycle T1. For example, at time t2 as shown in FIG. 3, the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state. At time t4, the second calculation timing is detected by the detector 16 after time t2. Further, at time t5, the detector 16 detects the third calculation timing after time t2. The determination circuit 17 detects the period from the time t4 to the time t5 as the cycle T1 of the first signal, and sets the set period T2 by the cycle T1 of the detected first signal.

In this way, the determination circuit 17 detects the cycle T1 of the first signal at the calculation timing detected from the second time onward after the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state. The period T1 of one signal is detected with high accuracy. Here, as described above, when the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state, the detector 16 has both the rising edge and the falling edge of the first signal. Operates to detect as the calculation timing. Further, as described above, when the synchronous motor changes from the non-drive state to the drive state, the phase of the AC voltage is adjusted in the synchronous motor. As a result, the interval between the first calculation timing and the second calculation timing detected after the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state is the cycle of the first signal. It may be smaller than T1. By detecting the cycle T1 of the first signal according to the calculation timing detected from the second time onward, the cycle T1 of the first signal is detected accurately, so that the input of the AC voltage to the waveform measuring instrument 1 is stopped. It is possible to more accurately determine whether or not there is.

When the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is not in the stopped state, the determination circuit 17 may update the set period T2 by the latest cycle T1 of the first signal. The determination circuit 17 may determine whether or not the calculation timing is detected by the detector 16 within the set period T2 after the update. Here, when the synchronous motor changes from the driven state to the non-driven state, the cycle of the AC voltage may become longer with the passage of time. By updating the set period T2 with the latest cycle T1, the determination circuit 17 can more accurately determine whether or not the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state.

The arithmetic circuit 18 includes at least one processor, at least one dedicated circuit, or a combination thereof. The processor is, for example, a general-purpose processor such as a CPU or GPU, a dedicated processor specialized for a specific process, or the like. The dedicated circuit is, for example, FPGA or ASIC.

The first signal is input to the arithmetic circuit 18 from the AD converter 12. A second signal is input to the arithmetic circuit 18 from the AD converter 13. Information on the calculation timing is input from the detector 16 to the calculation circuit 18.

The calculation circuit 18 calculates the calculation value in the calculation section. The calculation circuit 18 sets a calculation section according to the calculation timing.

The calculation circuit 18 sets, for example, a section from the detection of the calculation timing by the detector 16 to the detection of the next calculation timing by the detector 16 as the calculation section. For example, as shown in FIG. 3, the arithmetic circuit 18 sets arithmetic intervals a1, a2, a3, a4, a6, a7, a8.

When the determination signal is input from the determination circuit 17 as described later, the arithmetic circuit 18 sets a period from the detection of the arithmetic timing by the detector 16 to the first high level of the determination signal as an arithmetic interval. You can do it. For example, as shown in FIG. 3, the arithmetic circuit 18 sets the period from the detection of the arithmetic timing by the detector 16 to the high level of the determination signal as the arithmetic interval a5.

A part of the plurality of calculation sections has, for example, the same length as one cycle of the first signal. For example, the calculation intervals a2 to a4, a7, and a8 as shown in FIG. 3 have the same length as one cycle of the first signal. Another part of the plurality of arithmetic intervals is shorter than, for example, one cycle of the first signal. For example, as shown in FIG. 3, the calculation sections a1 and a6 immediately after the times t1 and t3 when the determination signal changes from high level to low level are shorter than one cycle of the first signal.

The arithmetic circuit 18 may calculate the effective value of the AC voltage using the first signal as the arithmetic value. As an example of calculating the effective value of the AC voltage, the digital data of the first signal for each sampling cycle as shown in FIG. 2 is input from the AD converter 12 to the arithmetic circuit 18. The arithmetic circuit 18 calculates the squared value of the digital data of the first signal for each sampling cycle. The calculation circuit 18 calculates the cumulative value obtained by accumulating the squared values over the calculation interval. The calculation circuit 18 calculates the effective value of the AC voltage by dividing the cumulative value by the number of digital data of the first signal in the calculation section, that is, the number of samplings to calculate the square root.

The arithmetic circuit 18 may calculate the effective value of the alternating current using the second signal as the arithmetic value. As an example of calculating the effective value of the alternating current, the digital data of the second signal for each sampling cycle as shown in FIG. 2 is input from the AD converter 13 to the arithmetic circuit 18. The arithmetic circuit 18 calculates the squared value of the digital data of the second signal for each sampling cycle. The calculation circuit 18 calculates the cumulative value obtained by accumulating the squared values over the calculation interval. The calculation circuit 18 calculates the effective value of the alternating current by dividing the cumulative value by the number of digital data of the second signal in the calculation section, that is, the number of samplings to calculate the square root.

The calculation circuit 18 may calculate the power value using the first signal and the second signal as the calculation value. The power value is, for example, an active power value, an apparent power value, or the like.

As an example of calculating the active power value, the arithmetic circuit 18 has digital data of the first signal and digital data of the second signal for each sampling cycle as shown in FIG. 2 from each of the AD converter 12 and the AD converter 13. Is entered. The arithmetic circuit 18 calculates a multiplication value obtained by multiplying the digital data of the first signal and the digital data of the second signal for each sampling period. The calculation circuit 18 calculates the cumulative value obtained by accumulating the multiplication values over the calculation interval. The calculation circuit 18 calculates the active power value by dividing the cumulative value by the number of digital data of the first signal or the second signal in the calculation section, that is, the number of samplings.

As an example of calculating the apparent power value, the arithmetic circuit 18 calculates the effective value of the AC voltage and the effective value of the AC current as described above. The arithmetic circuit 18 calculates the apparent power value by multiplying the effective value of the AC voltage and the effective value of the AC current.

The calculation circuit 18 outputs the calculated calculation value information to the memory controller 19.

The memory controller 19 includes at least one processor, at least one dedicated circuit, or a combination thereof. The processor is, for example, a general-purpose processor such as a CPU or GPU, a dedicated processor specialized for a specific process, or the like. The dedicated circuit is, for example, FPGA or ASIC.

Information on the calculated value is input to the memory controller 19 from the arithmetic circuit 18. The memory controller 19 stores the information of the calculated value in the memory 20. Information on the calculation timing may be input to the memory controller 19 from the detector 16. The memory controller 19 may store the information of the calculated value input after the information of the calculated timing is input in the memory 20.

The memory 20 includes at least one semiconductor memory, at least one magnetic memory, at least one optical memory, or at least two combinations thereof. The semiconductor memory is, for example, RAM or ROM. The RAM is, for example, SRAM or DRAM. The ROM is, for example, EEPROM or the like.

Information on the calculated value is stored in the memory 20.

The generation circuit 21 includes at least one processor, at least one dedicated circuit, or a combination thereof. The processor is, for example, a general-purpose processor such as a CPU or GPU, a dedicated processor specialized for a specific process, or the like. The dedicated circuit is, for example, FPGA or ASIC.

The generation circuit 21 reads out the information of the first signal and the information of the second signal after being converted into digital data from the memory 15 when the waveform of the waveform measuring instrument 1 is displayed. Further, the generation circuit 21 reads out the information of the calculated value from the memory 20 when the waveform of the waveform measuring device 1 is displayed. The generation circuit 21 uses the information of the first signal to generate analog waveform data indicating the AC voltage of the U phase. The generation circuit 21 uses the information of the second signal to generate analog waveform data indicating the U-phase alternating current. The generation circuit 21 generates waveform display data from analog waveform data indicating a U-phase AC voltage, analog waveform data indicating a U-phase AC current, and calculated value information. The waveform display data is data to be displayed on the display 22.

The display 22 includes at least one display output interface. The display output interface is, for example, a display. The display is, for example, an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence) display.

The display 22 displays the waveform display data generated by the generation circuit 21.

FIG. 4 is a flowchart showing a method of detecting the calculation timing by the waveform measuring instrument 1 shown in FIG. The waveform measuring instrument 1 starts the process as shown in FIG. 4 when the measurement by the waveform measuring instrument 1 is started. The waveform measuring instrument 1 may end the process as shown in FIG. 4 when the measurement by the waveform measuring instrument 1 is completed. The calculation timing detection method may be realized as a detection program executed by the processor of the waveform measuring instrument 1. The detector may be stored on a non-temporary computer-readable medium.

The determination circuit 17 considers that the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state at the start of the measurement of the waveform measuring instrument 1, and sets the determination signal to a high level (step S10). When the determination signal is set to a high level, the detector 16 operates so as to detect both the rising edge and the falling edge of the first signal as the calculation timing (step S11). After the processing of step S11, the detector 16 detects either the rising edge or the falling edge of the first signal as the calculation timing (step S12).

When the calculation timing is detected by the detector 16 by the process of step S12, the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is not in the stopped state (step 13). When the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is not in the stopped state, the determination circuit 17 sets the determination signal to a low level (step S14). When the determination signal is set to a low level, the detector 16 operates so as to detect one of the rising edge and the falling edge of the first signal as the calculation timing (step S15).

In the process of step S16, the detector 16 detects one of the rising edge and the falling edge of the first signal as the calculation timing. After the processing of step S16, the detector 16 again detects one of the rising edge and the falling edge of the first signal as the calculation timing (step S17).

The determination circuit 17 detects the period from the calculation timing detected in the process of step S16 to the calculation timing detected in the process of step S17 as the cycle T1 of the first signal (step S18).

The determination circuit 17 determines whether or not the calculation timing is detected by the detector 16 within the set period T2 that exceeds the period T1 (step S19).

When the determination circuit 17 determines that the calculation timing is detected by the detector 16 within the set period T2 (step S19: YES), the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is not in the stopped state (step). S20). After executing the process of step S20, the waveform measuring instrument 1 returns to the process of step S18. In the process of step S18 again, the determination circuit 17 updates the set period T2 with the latest cycle T1 of the first signal.

On the other hand, when the determination circuit 17 determines that the calculation timing is not detected by the detector 16 within the set period T2 (step S19: NO), the determination circuit 17 determines that the input of the AC voltage to the waveform measuring instrument 1 is stopped. (Step S21). After executing the process of step S21, the waveform measuring instrument 1 returns to the process of step S10.

FIG. 5 is a flowchart showing a method of calculating a calculated value by the waveform measuring instrument 1 shown in FIG. The waveform measuring instrument 1 may execute the process shown in FIG. 5 in parallel with the process shown in FIG. The calculation method of the calculated value may be realized as a calculation program to be executed by the processor of the waveform measuring instrument 1. The calculator may be stored on a non-temporary computer-readable medium.

The calculation circuit 18 sets a calculation section (step S30). The calculation circuit 18 sets, for example, a section from the detection of the calculation timing by the detector 16 to the detection of the next calculation timing by the detector 16 as the calculation section.

The calculation circuit 18 calculates the calculation value in the calculation section (step S31). The calculation circuit 18 outputs the calculated calculation value information to the memory controller 19.

The memory controller 19 stores the information of the calculated value input from the arithmetic circuit 18 in the memory 20 (step S32).

Hereinafter, the effect of the waveform measuring instrument 1 according to the present embodiment will be described while comparing it with a comparative example.

FIG. 6 is a block diagram of the waveform measuring instrument 101 according to the comparative example. The waveform measuring instrument 101 includes an amplifier 10, an amplifier 11, an AD converter 12, an AD converter 13, a memory controller 14, a memory 15, a detector 16, an arithmetic circuit 18, and a memory controller 19. It includes a memory 20, a generation circuit 21, and a display 22.

The waveform measuring instrument 101 according to the comparative example does not include the determination circuit 17 unlike the waveform measuring instrument 1 according to the present embodiment. In the waveform measuring instrument 101, the detector 16 operates so as to detect one of the rising edge and the rising edge of the first signal as the calculation timing. Due to such a configuration, in the waveform measuring instrument 101 according to the comparative example, the calculation timing when the synchronous motor changes from the non-driven state to the driven state may not be detected by the detector 16. For example, the detector 16 is assumed to operate so as to detect the rising edge of the first signal as one of the rising edge and the rising edge of the first signal, which is preset. In this case, the detector 16 cannot detect the calculation timing at the time t3 as shown in FIG. If the calculation timing cannot be detected at time t3, the calculation section a6 cannot be set, and the calculation value in the calculation section a6 cannot be calculated.

On the other hand, the waveform measuring instrument 1 according to the present embodiment includes a determination circuit 17 for determining whether or not the input of the AC voltage to the waveform measuring instrument 1 is in the stopped state. Further, in the waveform measuring device 1 according to the present embodiment, when the determination circuit 17 determines that the input of the AC voltage to the waveform measuring device 1 is in the stopped state, the detector 16 has a rising edge of the first signal and It operates to detect both rising edges as calculation timing. With such a configuration, the calculation timing can be detected by the detector 16 when the synchronous motor changes from the non-drive state to the drive state, that is, when the synchronous motor is started. By detecting the calculation timing at the start of the synchronous motor, the calculated value at the start of the synchronous motor can be calculated. For example, the detector 16 can detect the calculation timing at the time t3 as shown in FIG. When the detector 16 detects the calculation timing at time t3, the calculation circuit 18 can set the calculation section a6. The calculation circuit 18 can calculate the calculation value in the calculation section a6 by setting the calculation section a6. Therefore, according to the present embodiment, an improved waveform measuring instrument 1 and a method for acquiring data are provided.

Further, in the waveform measuring instrument 1 according to the present embodiment, the calculation circuit 18 can calculate the effective value of the AC voltage, the effective value of the AC current, and the power value at the start of the synchronous motor as the calculated values. With such a configuration, it is possible to analyze the electrical characteristics of the synchronous motor at the time of starting with higher accuracy. That is, the transition state at the time of starting the synchronous motor can be analyzed more accurately.

Although the embodiments according to the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications or modifications based on the present disclosure. It should be noted, therefore, that these modifications or modifications are within the scope of this disclosure. For example, the functions and the like included in each component or each step can be rearranged so as not to be logically inconsistent, and a plurality of components or steps can be combined or divided into one. ..

For example, in the above embodiment, the measurement target of the waveform measuring device 1 has been described as being an AC signal of a synchronous motor. However, the measurement target of the waveform measuring device 1 is not limited to the AC signal of the synchronous motor. The measurement target of the waveform measuring instrument 1 may be an AC signal of any device whose AC signal is difficult to predict whether the AC signal rises or falls at the time of activation.

For example, the determination circuit 17 may output the determination signal to the arithmetic circuit 18 and the memory controller 19. In this case, the arithmetic circuit 18 may calculate the arithmetic value when the determination signal is low level. Further, the memory controller 19 may store the information of the calculated value input from the arithmetic circuit 18 when the determination signal is low level in the memory 20.

For example, in the waveform measuring device 1, when the determination circuit 17 determines that the input of the AC voltage as the first AC signal to the waveform measuring device 1 is in the stopped state, the calculation result of the calculation circuit 18 is set to zero. May be provided.

For example, in the above embodiment, the first AC signal is described as being an AC voltage. However, the first alternating current signal may be an alternating current. In this case, the determination circuit 17 may determine whether or not the input of the alternating current to the waveform measuring instrument 1 is in the stopped state based on the period of the first signal corresponding to the alternating current. Further, the calculation circuit 18 may calculate the effective value of the alternating current as the calculation value in the calculation section using the first signal.

1 Waveform measuring instrument 10, 11 Amplifier 12, 13 AD converter 14 Memory controller 15 Memory 16 Detector 17 Judgment circuit 18 Calculation circuit 19 Memory controller 20 Memory 21 Generation circuit 22 Display

Claims (7)

It is a waveform measuring instrument
A determination circuit for determining whether or not the input of the first AC signal corresponding to the first signal to the waveform measuring instrument is in the stopped state, and
When the determination circuit determines that the input of the first AC signal to the waveform measuring instrument is not in the stopped state, one of the rising edge and the falling edge of the first signal is detected as the calculation timing. When it is determined by the determination circuit that the input of the first AC signal to the waveform measuring instrument is in the stopped state, both the rising edge and the falling edge of the first signal are detected as calculation timings. With a detector that works to
A waveform measuring instrument comprising an arithmetic circuit for calculating an arithmetic value in an arithmetic interval set by the arithmetic timing using the first AC signal. In the waveform measuring instrument according to claim 1,
When the determination circuit determines that the calculation timing is not detected within a set period exceeding 1 times the period of the first signal, it is determined that the input of the first AC signal to the waveform measuring instrument is stopped. Waveform measuring instrument to judge. In the waveform measuring instrument according to claim 2,
The determination circuit is the first according to the calculation timing detected after the second of the calculation timings detected after determining that the input of the first AC signal to the waveform measuring device is in the stopped state. A waveform measuring instrument that detects the cycle of one signal and sets the set period according to the detected cycle. In the waveform measuring instrument according to claim 2,
The determination circuit is a waveform measuring instrument that updates the set period according to the latest cycle of the first signal when it is determined that the input of the first AC signal to the waveform measuring instrument is not in the stopped state. In the waveform measuring instrument according to any one of claims 1 to 4,
The arithmetic circuit is a waveform measuring instrument that calculates an effective value of AC voltage or AC current as the arithmetic value. In the waveform measuring instrument according to any one of claims 1 to 4,
The arithmetic circuit is a waveform measuring instrument that calculates a power value by using the first AC signal and the second AC signal as the arithmetic value. Determining whether or not the input of the first AC signal corresponding to the first signal to the waveform measuring instrument is in the stopped state, and
When it is determined that the input of the first AC signal to the waveform measuring instrument is not in the stopped state, it operates so as to detect one of the rising edge and the falling edge of the first signal as the calculation timing. When it is determined that the input of the first AC signal to the waveform measuring instrument is in the stopped state, it operates so as to detect both the rising edge and the falling edge of the first signal as calculation timings.
A method for acquiring data, including calculating a calculated value in a calculated section set by the calculated timing using the first AC signal.

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