JP5844125B2 - Power ratio measuring apparatus and power ratio measuring method - Google Patents

Description

  The present invention measures the first power based on the first voltage signal and the first current signal for the first system, and the second power for the second system having a shorter cycle than the first voltage signal and the first current signal. The present invention relates to a power ratio measuring device and a power ratio measuring method for measuring a second power based on two voltage signals and a second current signal and calculating a ratio of the other power to one of the two measured powers. is there.

  When measuring power, as disclosed in Patent Document 1 below, first, the fundamental frequency of an input signal (voltage and current) that is a source of power calculation is set to zero cross of the input signal (one of voltage and current). And a half period of the input signal calculated from the determined fundamental frequency or a period that is an integral multiple of one period is defined as a sampling period. Next, the period in which the first half is assigned to this sampling period and the second half is assigned to the calculation period for power calculation is defined as one measurement period, and this one measurement period is repeated continuously. This captures the instantaneous waveform data by sampling the input signal (voltage and current) during the sampling period, and calculates the effective value of the input signal (voltage and current) based on the instantaneous waveform data during the calculation period. The operation of calculating and outputting the effective value of the electric power based on the effective value is repeated, and the measured electric power is output every measurement period.

Japanese Patent Laying-Open No. 2005-318088 (page 2-7, FIG. 3)

  However, for example, the power conversion efficiency of an AC-AC converter that converts and outputs a signal having a commercial frequency (50 Hz or 60 Hz) into a signal having a frequency different from the frequency (lower frequency or higher frequency) is continuously measured. As in the case, the power conversion efficiency is measured and output based on the two measured powers while measuring each power of two systems having different frequencies (input system and output system in the AC-AC converter device). When it is necessary to repeatedly execute the operation, when the power measurement method described above is applied to each power measurement with a shorter power conversion efficiency measurement period (that is, with a shorter calculation period), the following improvements Issues to be generated occur.

  That is, in two systems having different frequencies, the periods of the signals from which the power is measured are different (the time interval between a pair of adjacent zero crosses in one system and the pair of adjacent zero crosses in the other system). The time interval between them does not match), the measurement period (measurement timing) of the power calculated based on the waveform data of the signals (voltage and current) between the zero crosses also differs.

  For this reason, for example, the state where the power of the two systems changes so as to increase gradually (in the above converter device, when the power of the output system increases, the power of the input system also increases accordingly. In the state), the power for a signal with a long period is calculated and gradually increases for a signal with a short period until the next power is calculated (until the calculated power is updated). The power to be calculated is sequentially calculated. Therefore, even if the actual power conversion efficiency is in a substantially constant state, the power calculated for a signal with a short period and the constant power calculated for a signal with a long period are increased in this way. Based on this, since the power conversion efficiency calculated in the power measurement period for a signal with a short period is calculated as a value that increases sequentially, there arises a problem that this should be improved.

  On the other hand, when the power of the two systems changes so as to gradually decrease (in the above converter device, when the power of the output system decreases, the power of the input system also decreases accordingly) In the state), until a new power is calculated for a signal with a long period (while the calculated power is constant), a gradually decreasing power is sequentially calculated for a signal with a short period. Therefore, even if the actual power conversion efficiency is almost constant, the power conversion efficiency calculated in the power measurement period for signals with a short period is calculated as a value that decreases sequentially, which is improved. The problem that should be generated occurs. In other words, a problem to be solved that power conversion efficiency (ratio) different from actual power conversion efficiency (ratio of power of two systems) is calculated (measured) occurs.

  The present invention has been made in order to improve such a problem, and it is a main object of the present invention to provide a power ratio measuring apparatus and a power ratio measuring method capable of accurately measuring a ratio for each power of two systems having different frequencies. And

In order to achieve the above object, the power ratio measuring apparatus according to the present invention measures the first power based on the first voltage signal and the first current signal for the first system, and the first voltage signal and the first The second power is measured based on the second voltage signal and the second current signal for the second system having a shorter cycle than the current signal, and the ratio of the other power to one of the two measured powers is determined. A power ratio measuring device including a processing unit for calculating, wherein one of a rising zero crossing point and a falling zero crossing point for one of the first voltage signal and the first current signal is defined as a first zero crossing. a first detector for detecting as a point, the rising zero cross point and falling for said one signal of the same type as the signal of the second voltage signal and the second current signal Ri and a second detector for detecting the one of the second zero-cross point of the zero-crossing point, the processing unit, the first voltage signal between the pair of the first zero-cross point adjacent and the first current A first power calculation process for calculating the first power based on a signal; and between all the pairs of second zero cross points adjacent to each other for all the second zero cross points included between the pair of first zero cross points. second to based on the second voltage signal and the second current signal calculating an additive average value of each power the calculated calculates the power between the respective pair of second zero-crossing point as the second power After the end of one cycle of the first system defined by the pair of first zero cross points, a power calculation process and a ratio calculation process for calculating the ratio based on the calculated first power and second power To run.

The power ratio measuring apparatus according to claim 2 is the power ratio measuring apparatus according to claim 1, wherein the processing unit is configured to perform the second immediately before the pair of first zero cross points in the second power calculation process. Based on the second voltage signal and the second current signal between the zero cross point and the first second zero cross point among the second zero cross points included between the pair of first zero cross points. The total power between the pair of second zero cross points is calculated as the initial total power, and the period length between the first first zero cross point of the pair of first zero cross points and the first second zero cross point is calculated. And calculating the ratio of the period length between the pair of second zero-cross points as an initial ratio, and multiplying the initial total power by the initial ratio to calculate the first first zero-cross. Power measurement processing for measuring power between the first zero-cross point and the first zero-cross point as an initial partial power, and between the second zero-cross point immediately after the pair of first zero-cross points and the pair of first zero-cross points The total electric power between the pair of second zero cross points based on the second voltage signal and the second current signal between the last second zero cross points of all the second zero cross points included in Calculated as the total power for the end of the period, and between the pair of second zero cross points with respect to the period length between the last first zero cross point and the last second zero cross point of the pair of first zero cross points. The ratio with respect to the period length is calculated as an end ratio, and the total power at the end is multiplied by the end ratio, and the last second zero cross point and the last first zero cross point are calculated. Power running and final power measurement process of measuring the end portion power, power between the pair of second zero-cross point and the calculated, the beginning portion power and said end portion power of the additive average said values second The ratio is calculated as electric power.

The power ratio measuring method according to claim 3 measures the first power based on the first voltage signal and the first current signal for the first system, and uses the first voltage signal and the first current signal. The second power is measured based on the second voltage signal and the second current signal for the second system with a short cycle, and the power for calculating the ratio of the other power to the one of the two measured powers In the ratio measurement method, one of a rising zero cross point and a falling zero cross point for one of the first voltage signal and the first current signal is detected as a first zero cross point , and the first zero cross point is detected. one of the rising zero cross point and the falling zero-cross point of said one signal of the same type as the signal of the second voltage signal and the second current signal A zero-cross point detection processing for detecting a second zero-crossing point, the first power calculation process of calculating said first power based on the first voltage signal and the first current signal between a pair of the first zero-cross point adjacent And, based on the second voltage signal and the second current signal between all the pairs of the second zero cross points adjacent to each other for all the second zero cross points included between the pair of first zero cross points. a second power calculating process of calculating an additive average value of each the calculated power as the second power to calculate the power between the pair of second zero-crossing point, the first power and second power the calculated A ratio calculation process for calculating the ratio based on the first zero cross point is executed after the end of one cycle of the first system defined by the pair of first zero cross points.

The power ratio measurement method according to claim 4 is the power ratio measurement method according to claim 3, wherein in the second power calculation process, the second zero cross point immediately before the pair of first zero cross points and the pair. A pair of second zero crosses based on the second voltage signal and the second current signal between the first zero cross points of all the second zero cross points included between the first zero cross points of the first zero cross points. The total power between the points is calculated as the initial total power, and the pair of time lengths between the first first zero cross point and the first second zero cross point of the pair of first zero cross points are calculated. The ratio of the period length between the second zero cross points is calculated as an initial ratio, and the initial total power is multiplied by the initial ratio to calculate the first first zero cross point and the first zero cross point. An initial power measurement process for measuring power between two zero cross points as an initial partial power, and all of the second zero cross points immediately after the pair of first zero cross points and the pair of first zero cross points. Based on the second voltage signal and the second current signal between the last second zero cross point of the second zero cross points, the entire power between the pair of second zero cross points is calculated as the final total power And the ratio of the period length between the last first zero cross point and the last second zero cross point of the pair of first zero cross points to the period length between the pair of second zero cross points. Calculated as an end ratio and multiplying the end total power by the end ratio, the power between the last second zero cross point and the last first zero cross point is ended. Perform the final power measurement process of measuring a minute power in the ratio calculation processing, power between the pair of second zero-cross point and the calculated, an additive average value of the beginning portion power and said final partial powers the The ratio is calculated as the second power.

According to the power ratio measuring device according to claim 1 and the power ratio measuring method according to claim 3, the first power for one period of the first system and all pairs included in this one period of the first system. of both the second power is additive average value of power for the second system between the second zero-crossing point, was calculated after more long period of the first system ends, yet the second line of the shorter period since the second voltage is to be calculated by the additive average as described above, or at least one of the second voltage signal and a second current signal of the second system-side varies (increases within this period of the first system even decreased or), the influence of the ratio of the change by reduced, the ratio close to the ratio of the actual can be accurately measured.

According to the power ratio measuring apparatus according to claim 2 and the power ratio measuring method according to claim 4, the first power of one cycle of the first system and the first system including a plurality of short second system cycles. both the second power is additive average value of the power at each period of the second system at the same time as one cycle, calculated after a longer period of the first system ends, yet shorter period the since the second voltage of two systems is calculated by additive average as described above, at least one of the second voltage signal and a second current signal of the second system-side variability within this period of the first system (increase or decrease or) even if the influence of the ratio of the change by reduced, the ratio close to the ratio of the actual can be accurately measured.

  In addition, according to the power ratio measuring apparatus and the power ratio measuring method, the first ratio based on the second voltage signal and the second current signal in the same period as the first period of the first system including a plurality of short second system periods. Since the second power is calculated, the second power can be calculated more accurately, and as a result, the ratio can be measured more accurately.

1 is a configuration diagram of a power efficiency measuring device 1. FIG. FIG. 4 is a waveform diagram for explaining the operation of the power efficiency measuring device 1. FIG. 6 is a waveform diagram for explaining another operation of the power efficiency measuring apparatus 1.

  Hereinafter, embodiments of a power ratio measuring apparatus will be described with reference to the accompanying drawings. As an example, a commercial frequency (50 Hz or 60 Hz) signal (AC voltage) is input, and an AC-AC converter that generates a signal (AC voltage) having a frequency different from the commercial frequency and supplies the signal to the load is measured. As an object, an example in which a power ratio measuring device is used as a power efficiency measuring device that measures a ratio of output power to input power (power conversion efficiency) will be described.

  First, the configuration of the power efficiency measuring apparatus 1 will be described with reference to FIG.

  The power efficiency measuring apparatus 1 includes, as an example, a first voltage / current measurement unit 2 (hereinafter also simply referred to as “measurement unit 2”), a second voltage / current measurement unit 3 (hereinafter also simply referred to as “measurement unit 3”), A processing unit 4, a storage unit 5, and an output unit 6 are provided to measure and output the power efficiency A of an AC-AC converter 7 (hereinafter also simply referred to as “converter 7”) as a measurement target. The converter 7 receives a commercial frequency signal (AC voltage V1 as the first voltage signal) and a second frequency signal having a frequency different from the commercial frequency (frequency is several times (for example, about 5 times) or more). A 2 kHz AC voltage V 2) as a voltage signal is generated and output to the load 8. The power efficiency measuring device 1 outputs power (input power W1 as first power) for an input system (first system) of the converter 7 and an output system (AC voltage V2 having a shorter cycle than the AC voltage V1). The power of the second system) (output power W2 as the second power) is measured, and the ratio of the other power to one of the two powers W1 and W2 (in this example, as one power The ratio of the output power W2 as the other power to the input power W1, that is, the power efficiency A (= W2 / W1)) is measured.

  The measuring unit 2 is connected to the electric circuit 11 constituting the input system via the voltage probes 21 and 21, detects the AC voltage V1 (signal shown by a solid line in FIG. 2), samples it at a predetermined sampling period, A voltage measuring device (not shown) that outputs voltage data Dv1 indicating an instantaneous voltage value, and an alternating current I1 (first current signal; signal indicated by a broken line in FIG. 2) connected to the electric circuit 11 via a current probe 22 It comprises a current measuring device (not shown) that detects and samples at the same sampling period and outputs current data Di1 indicating the instantaneous current value.

  The measuring unit 3 is connected to the electric circuit 12 constituting the output system via the voltage probes 31 and 31 to detect the AC voltage V2 (a signal indicated by a solid line in FIG. 2) and performs sampling at the same sampling cycle as that of the measuring unit 2. Then, another voltage measuring device (not shown) that outputs voltage data Dv2 indicating the instantaneous voltage value is connected to the electric circuit 12 via the current probe 32, and an alternating current I2 (second current signal; broken line in FIG. 2). And a current measuring device (not shown) that outputs current data Di2 indicating the instantaneous current value by sampling at the same sampling period.

  The processing unit 4 is configured by, for example, a computer, calculates a power efficiency A by executing storage processing, zero-cross point detection processing, power calculation processing, and output processing, and outputs the power efficiency A to the output unit 6. The storage unit 5 is composed of a semiconductor memory such as a RAM or a hard disk drive (HDD), and stores voltage data Dv1, current data Di1, voltage data Dv2, and current data Di2. Further, the storage unit 5 stores the power efficiency A calculated by the processing unit 4. For example, the output unit 6 includes an interface circuit as an external device (not shown) (including an external storage device such as an external storage medium), and outputs information on the power efficiency A to the connected external device. In this example, as an example, since the external device is configured by a removable memory as an external storage medium, the output unit 6 sequentially outputs and stores information on the power efficiency A in the removable memory.

  Next, the operation of the power efficiency measuring apparatus 1 will be described with reference to the drawings, and a power efficiency measuring method (an example of a power ratio measuring method) will also be described. The measurement unit 2 is connected in advance to the electric circuit 11 through the voltage probes 21 and 21 and the current probe 22, and the measurement unit 3 is connected in advance to the electric circuit 12 through the voltage probes 31 and 31 and the current probe 32. It is assumed that

  In the power efficiency measuring apparatus 1, the measuring unit 2 detects the AC voltage V1 for the electric circuit 11 through the voltage probes 21 and 21, and also detects the AC current I1 through the current probe 22, and the voltage data Dv1 and The current data Di1 is output to the processing unit 4 at a predetermined sampling period. Similarly, the measuring unit 3 also detects the AC voltage V2 with respect to the electric circuit 12 via the voltage probes 31 and 31, and also detects the AC current I2 via the current probe 32, so that the voltage data Dv2 and the current data Di2 are detected. Are output to the processing unit 4 at the same sampling period as the measurement unit 2.

  The processing unit 4 acquires the voltage data Dv1 and the current data Di1 from the measurement unit 2 and outputs the voltage data Dv2 and the current data Di2 from the measurement unit 3, and sequentially stores them in the storage unit 5. Repeat the storage process. Further, the processing unit 4 executes a zero cross point detection process in parallel with the storage process.

  In the zero-cross point detection process, the processing unit 4 functions as a first detection unit, and corresponds to one data of the voltage data Dv1 and the current data Di1 as shown in FIG. The first zero cross point P1 (hereinafter, also referred to as “zero cross point P1”) is detected for the signal to be transmitted (one signal of the alternating voltage V1 and the alternating current I1 (in this example, the alternating voltage V1).

  Further, the processing unit 4 functions as a second detection unit, and is one of the voltage data Dv2 and the current data Di2 (the same type corresponding to one of the above-described input systems (the input system is voltage data). As shown in FIG. 2, a signal corresponding to one of the voltage data Dv2 and the current data Di2 (the AC voltage V2 and the AC current I2) is based on the voltage data if present and the current data if current data. A second zero-cross point P2 (hereinafter also referred to as “zero-cross point P2”) is detected for a signal of the same type (in this example, AC voltage V2) as one of the above-described input systems.

  Further, in this example, as an example, the processing unit 4 employs a configuration that detects a zero cross point (rising zero cross point) that crosses zero while the AC voltage V1 and the AC voltage V2 change from the negative side toward the positive side. However, it is also possible to adopt a configuration in which a zero cross point (falling zero cross point) that crosses zero while changing from the positive side to the negative side is detected.

  In this state, the processing unit 4 identifies a system having a long cycle (low frequency) among the input system and the output system based on the detected zero cross points P1 and P2. Further, the processing unit 4 is based on the zero-cross point (in this example, the zero-cross point P1) for the identified system having a long cycle, and a pair of zero-cross points P1 (when distinguished from each other, the start of the AC voltage V1 in one cycle T1) In the power calculation period Tc starting from when the zero cross point P1b of the zero cross point P1 is detected as "P1a" and the final zero cross point P1 is also referred to as "P1b"), the above power calculation process is first executed. .

  In this power calculation process, the processing unit 4 performs a process between the pair of zero cross points P1 based on the voltage data Dv1 and the current data Di1 included in the pair of zero cross points P1 (this one cycle T1). The effective value Vrms1 of the alternating voltage V1 and the effective value Irms1 of the alternating current I1 are calculated and stored in the storage unit 5. Subsequently, the processing unit 4 multiplies the calculated effective value Vrms1 and the effective value Irms1 to calculate the input power (effective input power) W1 for this one cycle T1, and stores the calculated input power W1 in the storage unit. 5 (first power calculation process).

  In addition, the processing unit 4 includes voltage data Dv2 and current data between all adjacent pairs of second zero-cross points P2 (between three pairs of second zero-cross points P2 in FIG. 2) included in the cycle T1. Based on Di2 (voltage data Dv2 and current data Di2 included in each cycle T2 of AC voltage V2), effective value Vrms2 and AC current of AC voltage V2 between each pair of second zero cross points P2 (each cycle T2) The effective value Irms2 of I2 is calculated and stored in the storage unit 5. Next, the processing unit 4 multiplies the effective value Vrms1 and the effective value Irms1 for each cycle T2 to calculate the power in each cycle T2, and then calculates the average value of each calculated power, The output power (effective output power) W2 in a period corresponding to the one cycle T1 is stored in the storage unit 5 (second power calculation process).

  Finally, the processing unit 4 calculates the power efficiency A (= W2 / W1) in the one cycle T1 based on the calculated input power W1 and output power W2, and stores it in the storage unit 5 ( Ratio calculation process). Thereby, the power calculation process is completed.

  The processing unit 4 executes an output process following the power calculation process described above in the power calculation period Tc. In this output process, the processing unit 4 reads the information of the power efficiency A stored in the storage unit 5 and outputs it to the output unit 6 together with time data as an example. The output unit 6 stores the information on the power efficiency A together with the corresponding time data in the connected removable memory. Thereby, the output process is completed.

  The processing unit 4 repeatedly executes the power calculation process and the output process described above at a predetermined cycle (in this example, at a cycle (T1 × 2)). Thereby, the power efficiency A in one cycle T1 included in this cycle is sequentially stored in the removable memory in a cycle defined in advance.

  As described above, in the power efficiency measuring apparatus 1, the processing unit 4 is within one cycle of the longer cycle T1 of the cycles T1 and T2 of the signals of the two systems (the input system and the output system of the converter 7). Based on the voltage data Dv1 for the AC voltage V1 (between the pair of zero cross points P1) and the current data Di1 for the AC current I1, the input power at the end of this cycle T1 (the power calculation period Tc after the cycle T1). Measure W1. In addition, the processing unit 4 uses the voltage data Dv2 for the AC voltage V2 and the current data for the AC current I2 between all the pairs of zero cross points P2 included in one cycle of the cycle T1 (between the pair of zero cross points P1). Based on Di2, by calculating and averaging the power between each pair of zero-cross points P2 at the end point of this period T1 (power calculation period Tc), a period corresponding to one period T1 (period in this example) The output power W2 in a period of three cycles of T2) is calculated. Further, the processing unit 4 calculates (measures) the power efficiency A based on the input power W1 and the output power W2 at the end of the cycle T1 (power calculation period Tc).

  Therefore, according to the power efficiency measuring apparatus 1, the input power W1 calculated based on the data Dv1 and Di1 for one period in the period T1 and a plurality of periods in the period T1 (in the above example, the period T2 The output power W2 that is the average value of the power in each cycle T2 calculated based on each data Dv2 and Di2 (after three) is obtained at the end of one cycle of the longer cycle T1 (after the end). Since the power (W2 and W2 are calculated at the same timing) and the output power W2 of the shorter cycle T2 is averaged, the power (output system) side of the shorter cycle T2 is calculated. Even if the AC voltage V2 and the AC current I2 fluctuate (increase or decrease) within one cycle T1, the effect of this fluctuation on the power efficiency A is reduced, and the power efficiency close to the actual power efficiency It is possible to accurately measure.

  The configuration of the power efficiency measuring device 1 is not limited to the above. For example, as described above for the example in which the output power W2 is calculated based on the data Dv2 and Di2 for a plurality of periods (three periods in the above example) within the period T1, the calculation of the output power W2 ( In the measurement), the output power W2 is calculated using also the voltage data Dv2 for the AC voltage V2 and the current data Di2 for the AC current I2 included in the cycle T2 which is partially applied to one cycle of the cycle T1. Can also be adopted.

  Hereinafter, a power efficiency measuring apparatus 1A employing this configuration will be described with reference to FIGS. The configuration of the power efficiency measuring device 1A is the same as that of the power efficiency measuring device 1, and the contents of the effective value calculation process and the power calculation process executed by the processing unit 4A are different from the contents of the same process executed by the processing unit 4. Just do it. For this reason, since each component other than the processing unit 4 of the power efficiency measuring device 1A is the same as that of the power efficiency measuring device 1, the same reference numerals are given and redundant description is omitted.

  The power efficiency measuring apparatus 1A includes a measuring unit 2, a measuring unit 3, a processing unit 4A, a storage unit 5, and an output unit 6.

  The processing unit 4A is configured by a computer, for example, and executes storage processing, zero-cross point detection processing, power calculation processing, and output processing. In this case, the processing unit 4A executes the same processing as the processing unit 4 for the storage process, the zero cross point detection process, and the output process.

  The processing unit 4A performs the first power calculation process in the same manner as the processing unit 4 of the power efficiency measuring apparatus 1 in the power calculation process executed in the power calculation period Tc following the longer period T1 of the periods T1 and T2. Execute to calculate the input power W1. Specifically, as shown in FIG. 3, the processing unit 4A, based on the voltage data Dv1 and the current data Di1 included between the pair of zero cross points P1 (zero cross points P1a, P1b), The effective value Vrms1 of the alternating voltage V1 between the points P1 and the effective value Irms1 of the alternating current I1 are calculated and stored in the storage unit 5. Subsequently, the processing unit 4 multiplies the calculated effective value Vrms1 and the effective value Irms1 to calculate the input power (effective input power) W1 for this one cycle T1, and stores the calculated input power W1 in the storage unit. 5 is memorized.

  Further, in the second power calculation process executed in the power calculation period Tc, the processing unit 4A performs a pair of all adjacent pairs included in the cycle T1 in the same manner as the processing unit 4 of the power efficiency measurement device 1. Based on the voltage data Dv2 and current data Di2 between the second zero cross points P2 (between three pairs of second zero cross points P2 in FIG. 3), between each pair of second zero cross points P2 (each period T2). The effective value Vrms2 of the alternating voltage V2 and the effective value Irms2 of the alternating current I2 are calculated, and the calculated effective value Vrms2 and the effective value Irms2 are multiplied to calculate the electric power in each period T2.

  Further, the processing unit 4A is different from the processing unit 4, and further, between the initial zero-cross point P2 of the first cycle T2 and the initial zero-cross point P1a of the cycle T1 among the cycles T2 included in the cycle T1. The initial partial power W2ap in the period Ta (hereinafter also referred to as “starting period Ta”) is calculated. The processing unit 4A also includes a period Tb (hereinafter referred to as “end period”) between the zero cross point P2 at the end of the last period T2 and the zero cross point P1b at the end of the period T1 among the periods T2 included in the period T1. The final partial power W2bp at (also referred to as “Tb”) is calculated.

  Specifically, a method for calculating the initial partial power W2ap and the final partial power W2bp will be described.

  First, when calculating the initial partial power W2ap, the processing unit 4A firstly sets the zero cross point P2 immediately before the pair of zero cross points P1 (the period T2 including the above initial period Ta (in particular, “period T2a”). The initial zero cross point P2a) of the first zero cross point P2 (also the final zero cross point P2b in the period T2a) of all zero cross points P2 included between the pair of zero cross points P1) Based on the voltage data Dv2 of the alternating voltage V2 and the current data Di2 of the alternating current I2 (that is, the voltage data Dv2 and the current data Di2 within the period T2a), the pair of adjacent zero cross points P2a and P2b (period) The effective value Vrms2 and the effective value Irms2 at T2a) are calculated. Next, the processing unit 4A multiplies the calculated effective value Vrms1 and the effective value Irms1 to calculate the initial overall power W2at in the entire cycle T2a.

  Subsequently, the processing unit 4A calculates a ratio B (= Ta / T2) with respect to the period T2a for the period length of the initial period Ta as an initial ratio (hereinafter also referred to as an initial ratio B), and uses this ratio B as the initial total power. By multiplying W2at, power in the initial period Ta (that is, initial partial power W2ap) is calculated (initial power measurement process).

  Next, when calculating the final partial power W2bp, the processing unit 4A first sets the zero cross point P2 immediately after the pair of zero cross points P1 (the period T2 including the above-described final period Tb (in particular, “period T2b”). Between the final zero-cross point P2b) and the last zero-cross point P2 of all the zero-cross points P2 included between the pair of zero-cross points P1 (the initial zero-cross point P2a in the period T2b). Based on the voltage data Dv2 of the alternating voltage V2 and the current data Di2 of the alternating current I2 (voltage data Dv2 and current data Di2 within the period T2b), the pair of adjacent zero cross points P2a and P2b (period T2b) The effective value Vrms2 and the effective value Irms2 are calculated. Next, the processing unit 4A multiplies the calculated effective value Vrms1 and the effective value Irms1 to calculate the final total power W2bt in the entire cycle T2b.

  Subsequently, the processing unit 4A calculates a ratio C (= Tb / T2) with respect to the period T2 with respect to the period length of the end period Tb as an end ratio (hereinafter also referred to as end ratio C), and uses this ratio C as the end total power By multiplying W2bt, power in the final period Tb (that is, final partial power W2bp) is calculated (final power measurement process).

  Thereafter, in the second power calculation process, the processing unit 4A calculates the average value of the power, the initial partial power W2ap, and the final partial power W2bp in each cycle T2 included in the cycle T1 calculated as described above. Is calculated as output power W2 in a period corresponding to one cycle T1, and is stored in the storage unit 5. Thereby, the second power calculation process is completed.

  Finally, the processing unit 4A calculates the power efficiency A (= W2 / W1) in the one cycle T1 based on the calculated input power W1 and output power W2, and stores it in the storage unit 5 ( Ratio calculation process). Thereby, the power calculation process is completed.

  As described above, in the power efficiency measuring apparatus 1A, the processing unit 4A is within one cycle of the longer cycle T1 of the cycles T1 and T2 of the signals of the two systems (the input system and the output system of the converter 7). Based on the voltage data Dv1 for the AC voltage V1 (between the pair of zero cross points P1) and the current data Di1 for the AC current I1, the input power at the end of this cycle T1 (the power calculation period Tc after the cycle T1). Measure W1. In addition, the processing unit 4 uses the voltage data Dv2 for the AC voltage V2 and the current data for the AC current I2 between all the pairs of zero cross points P2 included in one cycle of the cycle T1 (between the pair of zero cross points P1). Based on Di2, at the end of this cycle T1, the power between each pair of zero-cross points P2 (each cycle T2), the average value of the initial partial power W2ap and the final partial power W2bp (average value in the same period as the cycle T1) Is calculated as the output power W2. Further, the processing unit 4 calculates (measures) the power efficiency A based on the input power W1 and the output power W2 at the end of the cycle T1.

  Therefore, according to the power efficiency measuring apparatus 1A, the input power W1 calculated based on the data Dv1 and Di1 for one period in the period T1 is the same as one period of the period T1 including the plurality of periods T2. Both the output power W2, which is the average value of the power in each cycle T2 calculated based on the voltage data Dv2 and the current data Di2 in the period, are calculated at the end of one cycle of the longer cycle T1 (after the end). (That is, both powers W1 and W2 are calculated at the same timing), and the output power W2 of the shorter cycle T2 is averaged, so that the AC on the shorter cycle T2 (output system) side is changed. Even if the voltage V2 and the alternating current I2 fluctuate (increase or decrease) within one period T1, the influence of the fluctuation on the power efficiency A is reduced, and the actual power efficiency The closer power efficiency A can be accurately measured.

  Moreover, according to this power efficiency measuring apparatus 1A, since the output power W2 is calculated based on the voltage data Dv2 and the current data Di2 in the same period as one period of the period T1 including the plurality of periods T2, the output power W2 is output. The power W2 can be calculated more accurately, and as a result, the power efficiency A can be measured more accurately.

  In the power efficiency measuring devices 1 and 1A described above, the processing units 4 and 4A employ a configuration in which the zero cross point P1 and the zero cross point P2 are detected. Instead of this configuration, for example, a comparator is used. The detection unit for detecting the zero cross is configured separately from the processing units 4 and 4A, and the detection unit functions as the first detection unit and the second detection unit to detect the zero cross point P1 and the zero cross point P2. Can also be adopted.

  Moreover, although the example in which the cycle T2 of the output system is shorter than the cycle T1 of the input system has been described, the power efficiency measuring devices 1 and 1A are also used when the cycle T2 of the output system is longer than the cycle T1 of the input system. The power efficiency A can be measured by applying. The power efficiency measuring device 1 will be described as an example. In this case, the processing unit 4 uses the voltage data Dv2 and the AC current I2 for the AC voltage V2 within one cycle of the longer cycle T2 (between a pair of zero cross points P2). The output power W2 is measured at the end of the cycle T2 (the power calculation period Tc after the cycle T2) based on the current data Di2 for the. In addition, the processing unit 4 uses the voltage data Dv1 for the AC voltage V1 and the current data for the AC current I1 between all the pairs of zero cross points P1 included in one cycle of the cycle T2 (between the pair of zero cross points P2). Based on Di1, the input power W1 is calculated by calculating and averaging the power between each pair of zero cross points P1 (power in each period T1) at the end of the period T2 (power calculation period Tc). To do. Further, the processing unit 4 calculates (measures) the power efficiency A based on the input power W1 and the output power W2 at the end of the cycle T2 (power calculation period Tc). That is, the above-described operation with the measuring unit 2 connected to the electric circuit 12 through the voltage probes 21 and 21 and the current probe 22 and the measuring unit 3 connected to the electric circuit 11 through the voltage probes 31 and 31 and the current probe 32. In the same manner, the power efficiency A is calculated.

  Therefore, the power efficiency measuring apparatus 1 can perform the same operation as when the output system cycle T2 is shorter than the input system cycle T1, even when the output system cycle T2 is longer than the input system cycle T1. Even if the AC voltage V1 and AC current I1 on the system (input system) side with a short period T1 fluctuate (increase or decrease) within one period T2, the influence of the fluctuation on the power efficiency A is reduced. Thus, the power efficiency A close to the actual power efficiency can be measured.

  In the power efficiency measuring apparatuses 1 and 1A, the processing units 4 and 4A have a cycle (T1 × 2) as a predetermined cycle, that is, twice the longer cycle of the cycles T1 and T2. The power calculation process and the output process are repeatedly executed in a cycle. However, the present invention is not limited to this configuration, and the power calculation process and the output process are repeatedly executed in a cycle of an arbitrary multiple of 1 or more. A configuration can also be adopted.

  Moreover, although the example which uses a power ratio measuring apparatus as power efficiency measuring apparatus 1 and 1A which measures the power conversion efficiency of the converter 7 was given and demonstrated, for example with respect to two independent loads from two independent AC electric circuits It is also possible to use the power ratio measuring device as a ratio measuring device that measures the ratio of one of the two powers supplied to the other.

1, 1A Power efficiency measuring device 2, 3 Measuring unit 4, 4A Processing unit A Power conversion efficiency I1, I2 AC current V1, V2 AC voltage W1 Input power W2 Output power

Claims (4)

The first power is measured based on the first voltage signal and the first current signal for the first system, and the second voltage signal for the second system having a shorter cycle than the first voltage signal and the first current signal. And a power ratio measuring device including a processing unit that measures the second power based on the second current signal and calculates a ratio of the other power to one of the two measured powers,
A first detector for detecting one of a rising zero cross point and a falling zero cross point for one of the first voltage signal and the first current signal as a first zero cross point;
A second detector for detecting one of a rising zero cross point and a falling zero cross point for the same type of signal as the one of the second voltage signal and the second current signal as a second zero cross point ; And
The processor is
A first power calculation process for calculating the first power based on the first voltage signal and the first current signal between a pair of adjacent first zero cross points;
Each of the pairs based on the second voltage signal and the second current signal between all of the pair of adjacent second zero cross points of all the second zero cross points included between the pair of first zero cross points. a second power calculating process of calculating an additive average value of each the calculated power as the second power to calculate the power between the second zero-cross point of
A power ratio measurement device that executes a ratio calculation process for calculating the ratio based on the calculated first power and second power after the end of one cycle of the first system defined by the pair of first zero cross points. . In the second power calculation process, the processing unit includes:
The second zero cross point immediately before the pair of first zero cross points and the first second zero cross point among the second zero cross points included between the pair of first zero cross points. Based on the two voltage signals and the second current signal, the entire power between the pair of second zero cross points is calculated as an initial total power, and the first first zero cross point of the pair of first zero cross points and Calculating the ratio of the period length between the first second zero cross point to the period length between the pair of second zero cross points as an initial ratio, and multiplying the initial total power by the initial ratio; An initial power measurement process for measuring the power between the first first zero cross point and the first second zero cross point as an initial partial power;
The second zero cross point immediately after the pair of first zero cross points and the last second zero cross point of all the second zero cross points included between the pair of first zero cross points. Based on the two voltage signals and the second current signal, the entire power between the pair of second zero cross points is calculated as the final total power, and the last first zero cross point of the pair of first zero cross points and Calculating the ratio of the period length between the last second zero cross points to the period length between the pair of second zero cross points as an end ratio, and multiplying the total end power and the end ratio, Performing an end power measurement process for measuring power between the last second zero cross point and the last first zero cross point as an end partial power;
The calculated power between the pair of second zero-crossing point was, the beginning portion power and the power ratio measuring apparatus according to claim 1, wherein the additive average of the end portion power to calculate the ratio as the second power. The first power is measured based on the first voltage signal and the first current signal for the first system, and the second voltage signal for the second system having a shorter cycle than the first voltage signal and the first current signal. And measuring a second power based on the second current signal and calculating a ratio of the other power to one of the two measured powers,
One of the rising zero crossing point and the falling zero crossing point for one of the first voltage signal and the first current signal is detected as the first zero crossing point , and the second voltage signal and the second current signal are detected. A zero cross point detection process for detecting one of a rising zero cross point and a falling zero cross point for a signal of the same type as the one of the current signals as a second zero cross point;
A first power calculation process for calculating the first power based on the first voltage signal and the first current signal between a pair of adjacent first zero cross points;
Each of the pairs based on the second voltage signal and the second current signal between all of the pair of adjacent second zero cross points of all the second zero cross points included between the pair of first zero cross points. a second power calculating process of calculating an additive average value of each the calculated power as the second power to calculate the power between the second zero-cross point of
A power ratio measurement method for executing a ratio calculation process for calculating the ratio based on the calculated first power and second power after the end of one cycle of the first system defined by the pair of first zero cross points. . In the second power calculation process,
The second zero cross point immediately before the pair of first zero cross points and the first second zero cross point among the second zero cross points included between the pair of first zero cross points. Based on the two voltage signals and the second current signal, the entire power between the pair of second zero cross points is calculated as an initial total power, and the first first zero cross point of the pair of first zero cross points and Calculating the ratio of the period length between the first second zero cross point to the period length between the pair of second zero cross points as an initial ratio, and multiplying the initial total power by the initial ratio; An initial power measurement process for measuring the power between the first first zero cross point and the first second zero cross point as an initial partial power;
The second zero cross point immediately after the pair of first zero cross points and the last second zero cross point of all the second zero cross points included between the pair of first zero cross points. Based on the two voltage signals and the second current signal, the entire power between the pair of second zero cross points is calculated as the final total power, and the last first zero cross point of the pair of first zero cross points and Calculating the ratio of the period length between the last second zero cross points to the period length between the pair of second zero cross points as an end ratio, and multiplying the total end power and the end ratio, Performing an end power measurement process for measuring power between the last second zero cross point and the last first zero cross point as an end partial power;
In said ratio calculation process, the power between the pair of second zero-cross point and the calculated, according to claim 3, wherein for calculating the ratio of the additive average of the beginning portion power and said end portion power as said second power Power ratio measurement method.

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