Temperature rise test method for reactors

Abstract

The present invention provides a method for testing a reactor temperature rise in accordance with actual operating conditions using a simple test circuit. The method includes the steps of passing a test current having a test frequency and a test current value through the reactor, wherein the test current generates a target copper loss (Wcut) based on the copper loss (Wcu21) when a fundamental current is passed and the copper loss (Wcu22) when a higher harmonic current is passed, and a target iron loss (Wfet) based on the iron loss (Wfe21) when a fundamental current is passed and the iron loss (Wfe22) when a higher harmonic current is passed.

Description

Technical Field

[0001] The present invention relates to a temperature rise test method for a reactor into which currents of multiple frequencies flow. Background Art

[0002] There are various methods for testing the performance of reactors. Among them, Non-Patent Document 1 describes a temperature rise test method for testing the temperature rise of a reactor during use. Non-Patent Document 1 stipulates that, as a test simulating a situation where a higher harmonic current is superimposed on the fundamental current and flows in, power is supplied under the following conditions (1) or (2).

[0003] Here, the case of permissible current category I is exemplified. (1) A fifth harmonic current having a fifth harmonic content ratio of 35% of the fundamental current is superimposed on the rated current at the rated frequency and continuously flows through the reactor (hereinafter referred to as conventional test X). (2) A fundamental current having a loss equivalent to the total loss described later is continuously flowed through the reactor (hereinafter referred to as conventional test Y). The total loss is the sum of the measured loss of the reactor when the rated current at the rated frequency is passed through and the measured loss of the reactor when the fifth harmonic current having a fundamental current ratio of 35% is passed through.

[0004] Prior art literature

[0005] Non-patent literature

[0006] Non-Patent Document 1: Japan Industrial Standards Research Council, "Japanese Industrial Standards (JIS) High-voltage and Extra-high-voltage Phase-advancing Capacitors and Accessories - Part 2: Series Reactors (JIS C4902-2: 2010)" Summary of the Invention

[0007] Problems to be solved by the invention

[0008] Although the conventional test X can simulate the power-on state that matches the actual use state, there is a problem of current mixing between the fundamental power supply and the higher harmonic power supply in the test circuit. As a circuit structure to avoid current mixing, for example, Figure 4 However, using Figure 4 The test of the circuit shown has the problem of increasing in scale.

[0009] Conventional test Y does not reflect the frequency dependence of copper and iron losses included in reactor losses, but instead uses only the fundamental current to calculate the total losses. Consequently, there is a problem with not accurately simulating copper and iron losses in the presence of superimposed fundamental and harmonic currents.

[0010] An object of one embodiment of the present invention is to implement a temperature rise test of a reactor that conforms to actual usage conditions using a simple test circuit.

[0011] Technical means to solve the problem

[0012] In order to solve the above-mentioned problem, a temperature rise test method for a reactor according to one embodiment of the present invention includes: a step of calculating a target copper loss based on the copper loss when a fundamental current of a specified current value is applied, and the respective copper losses when a higher harmonic current of a specified order of each specified current value is applied; a step of calculating a target iron loss based on the iron loss when the fundamental current is applied, and the iron loss when each higher harmonic current is applied; a step of calculating the frequency and current value of the current that causes the target copper loss and the target iron loss as a test frequency and a test current value, respectively; and a step of applying a test current having the test frequency and the test current value to the reactor until the temperature of a specified portion of the reactor becomes constant.

[0013] Effects of the Invention

[0014] According to one embodiment of the present invention, a temperature rise test of a reactor that conforms to actual usage conditions can be implemented with a simple test circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a circuit diagram showing a test circuit of the temperature rise test method according to the first embodiment of the present invention.

[0016] Figure 2 This is a graph showing a comparison of examples of losses during power-on in the temperature rise tests of Conventional Test X, Conventional Test Y, and Embodiments 1 and 2.

[0017] Figure 3 This is a diagram showing an example of a hysteresis curve of a distorted wave magnetic flux including a third harmonic.

[0018] Figure 4 1 is a circuit diagram showing an example of a circuit for carrying out conventional test X.

[0019] Explanation of symbols

[0020] 100: Test circuit

[0021] E1: Variable frequency power supply

[0022] C1: Compensation capacitor

[0023] L1: Test reactor

[0024] Wcu21: Copper loss when fundamental current is flowing

[0025] Wcu22, Wcu22m: Copper loss when high-order harmonic current is energized

[0026] Wcut: target copper loss

[0027] Wfe21: Iron loss when fundamental current is flowing

[0028] Wfe22, Wfe22m: Iron loss when high-order harmonic current is energized

[0029] Wfet: target iron loss

[0030] Wfet1: Corrected target iron loss (target iron loss)

[0031] WT21: Total loss when fundamental current is flowing

[0032] WT22, WT22m: Total losses when high-order harmonic currents are applied

[0033] WTt, WTt1: target total loss

[0034] 200: Test circuit for previous test X

[0035] Ex1: Fundamental power supply

[0036] Ex2: High-order harmonic power supply

[0037] Cx1: Capacitor for high-order harmonic compensation

[0038] Cx2: Capacitor for fundamental wave compensation DETAILED DESCRIPTION

[0039] [Implementation Method 1]

[0040] The following describes a first embodiment of the present invention in detail. A phase-advancing capacitor is used in combination with a series inductor, or a so-called filter inductor, and a capacitor. When a capacitor and a reactor are used in combination, harmonic currents flow through the reactor in addition to the fundamental current.

[0041] The temperature rise test method of the present invention is a method for testing reactors that can simulate the temperature rise caused by the superposition of higher harmonic currents on the fundamental current, as described above. Reactors come in various types, including hollow-core, magnetically shielded hollow-core, and gapped iron-core types. The temperature rise test method of the present invention primarily uses electromagnetic steel sheets and is designed for reactors consisting of windings and an iron core (magnetically shielded hollow-core and gapped iron-core types).

[0042] <Structure of Test Circuit 100>

[0043] Figure 1FIG. 1 is a circuit diagram showing a test circuit 100 of a temperature rise test method according to the first embodiment of the present invention. Figure 1 As shown, the test circuit 100 includes a variable-frequency power supply E1, a compensation capacitor C1, and a test reactor L1. The test circuit 100 is a circuit for performing a temperature rise test on the test reactor L1.

[0044] The variable-frequency power supply E1 has a variable frequency and current value. It supplies a test current having a test frequency fex and a test current value lex (described later) to the test reactor L1. Compensation capacitor C1 reduces the power supply capacity of the variable-frequency power supply E1 required to supply the required current to the test reactor L1.

[0045] <Flow of temperature rise test method>

[0046] Below, refer to Figure 1 and Figure 2 The flow of the temperature rise test method according to the first embodiment will be described. Figure 2 This is a graph showing a comparison of examples of various losses during power-on in the temperature rise tests of Conventional Test X, Conventional Test Y, and Embodiments 1 and 2.

[0047] A fundamental wave current of a predetermined first current value i21 is passed through the test reactor L1 via the variable-frequency power supply E1, and the loss (total loss WT21) of the test reactor L1 during the passage of the fundamental wave current is measured (step S1). The first current value i21 is, for example, the rated current value of the test reactor L1.

[0048] Furthermore, a harmonic current having a second current value i22 is passed through the test reactor L1, and the loss (total loss WT22) when the harmonic current is passed is measured (step S2). The harmonic current is, for example, the fifth harmonic of the fundamental wave, and can be set to a current having a current value of 35% of the fundamental wave current.

[0049] Next, a target copper loss Wcut is calculated based on the copper loss Wcu21 when a fundamental current of a first current value i21 is applied and the copper loss Wcu22 when a harmonic current of a predetermined second current value i22 is applied (step S3). More specifically, the target copper loss Wcut is calculated as the sum of the copper loss Wcu21 when a fundamental current is applied and the copper loss Wcu22 when a harmonic current is applied.

[0050] The copper loss Wcu21 when the fundamental wave current is passed and the copper loss Wcu22 when the harmonic current is passed are previously obtained by calculation. Specifically, they can be obtained using the following formula (1).

[0051] [Number 1]

[0052] (Formula 1)Wcu =R dc ×I 2 +R e ×I 2 ×f 2

[0053] In formula (1), Wcu represents copper loss, Rdc represents the DC resistance of the winding, Re represents the AC resistivity, which corresponds to the eddy current loss of the winding, f represents the frequency, and I represents the current. The DC resistance Rdc is the measured value of the test reactor L1, while the AC resistivity Re can be calculated through simulation using the finite element method.

[0054] Next, based on the iron loss Wfe21 when the fundamental current is flowing and the iron loss Wfe22 when the harmonic current is flowing, the target iron loss Wfet is calculated (step S4). In the first embodiment, more specifically, the target iron loss Wfet is calculated as the sum of the iron loss Wfe21 when the fundamental current is flowing and the iron loss Wfe22 when the harmonic current is flowing.

[0055] Here, the iron loss Wfe21 when the fundamental current is flowing is obtained by subtracting the copper loss Wcu21 when the fundamental current is flowing from the total loss WT21 when the fundamental current is flowing. The iron loss Wfe22 when the harmonic current is flowing is obtained by subtracting the copper loss Wcu22 when the harmonic current is flowing from the total loss WT22 when the harmonic current is flowing.

[0056] In the first embodiment, as described above, the measured total losses are separated into iron loss and copper loss by calculation. Specifically, the measured total loss WT21 is separated into copper loss Wcu21 and iron loss Wfe21, and the measured total loss WT22 is separated into copper loss Wcu22 and iron loss Wfe22. Furthermore, if the temperature rise test is conducted on a transformer, since there are two windings, the loss under no-load conditions (when the other winding is open-circuited) can be considered as the iron loss, and the loss under short-circuited conditions (when the other winding is short-circuited) can be considered as the copper loss. However, since a reactor has only one winding, it is not possible to measure the iron loss and copper loss separately. Therefore, it is necessary to separate the iron loss and copper loss by calculation as described above.

[0057] Next, the frequency and current value of the current that causes the target copper loss Wcut and the target iron loss Wfet are calculated as the test frequency fex and the test current value Iex, respectively (step S5). The test frequency fex and the test current value Iex can be calculated by the simultaneous equations of the following formula (2).

[0058] [Number 2]

[0059]

[0060] In formula (2), Rdc is the DC resistance of the winding, and Re is the AC resistance coefficient equivalent to the eddy current loss of the winding. As mentioned above, these values ​​are known. Wfe is the iron loss. n is the Steinmetz constant (about 1.6), which is determined by the material constituting the test inductor L1. Kh is the hysteresis loss coefficient, and Ke is the eddy current loss coefficient, which is a coefficient obtained by the iron loss Wfe21 when the fundamental current is energized, and the iron loss Wfe22 when the higher harmonic current is energized. Therefore, the unknowns in formula (2) are frequency and current, which are obtained by solving the simultaneous equations and become the test frequency fex and the test current value Iex respectively.

[0061] exist Figure 2 In the example of the first embodiment shown, the test frequency fex as the solution to the simultaneous equations takes a value between the fundamental frequency 50 Hz and the fifth harmonic frequency 250 Hz, and is calculated to be approximately 130 Hz, for example.

[0062] Next, a test current having a test frequency fex and a test current value lex is passed through the test reactor L1 until the temperature of a predetermined portion of the test reactor L1 becomes constant (step S6). The predetermined portion temperature may be, for example, the temperature of the winding of the test reactor L1. Alternatively, it may be the temperature of the core. Furthermore, if the test reactor L1 is an oil-filled reactor, the predetermined portion temperature may also be the temperature of the insulating oil. As described above, the temperature rise test of Embodiment 1 is carried out.

[0063] In addition, the above description describes the case where one harmonic current is superimposed on the fundamental current. In contrast, when one or more harmonic currents are superimposed on the fundamental current, the target copper loss Wcut and the target iron loss Wfet are calculated as follows.

[0064] The target copper loss Wcut is calculated in step S3 based on the copper loss Wcu21 and copper loss Wcu22m when a fundamental current of a predetermined first current value i21 is applied. The copper loss Wcu22m is the copper loss when a harmonic current of a predetermined second current value i22m of a predetermined order is applied. Here, m represents the order of the selected harmonic current. The copper loss Wcu22m represents the copper loss when a harmonic current of the selected order is applied. Therefore, the copper loss Wcu22m has the selected order.

[0065] For example, the case where the higher harmonic currents superimposed on the fundamental current are the fifth and seventh harmonics will be described. In this case, the target copper loss Wcut is calculated based on the copper loss Wcu21 when a fundamental current of a predetermined first current value i21 is applied, the copper loss Wcu225 when a fifth harmonic current of a predetermined second current value i225 is applied, and the copper loss Wcu227 when a seventh harmonic current of a predetermined second current value i227 is applied. Specifically, the target copper loss Wcut is calculated as the sum of the copper loss Wcu21 when the fundamental current is applied and the copper loss Wcu22m when the higher harmonic currents of the predetermined orders are applied. In this example, the target copper loss Wcut is calculated as the sum of the copper loss Wcu21, the copper loss Wcu225, and the copper loss Wcu227.

[0066] The target iron loss Wfet is obtained in step S4 based on the iron loss Wfe21 when a fundamental wave current of a predetermined first current value i21 is passed, and the iron loss Wfe22m when harmonic currents of predetermined orders are passed.

[0067] For example, the case where the higher harmonic currents superimposed on the fundamental current are the fifth and seventh harmonics will be described. In this case, the target iron loss Wfet is calculated based on the iron loss Wfe21 when a fundamental current of a predetermined first current value i21 is applied, the iron loss Wfe225 when a fifth harmonic current of a predetermined second current value i225 is applied, and the iron loss Wfe227 when a seventh harmonic current of a predetermined second current value i227 is applied. In other words, the target iron loss Wfet is calculated as the sum of the iron loss Wfe21 when the fundamental current is applied and the iron loss Wfe22m when the higher harmonic currents of predetermined orders are applied. In this example, the target iron loss Wfet is calculated as the sum of the iron loss Wfe21, the iron loss Wfe225, and the iron loss Wfe227.

[0068] Here, the iron loss Wfe22m when a higher harmonic current of a specified order is passed is obtained by subtracting the copper loss Wcu22m when a higher harmonic current of a specified order is passed from the total loss WT22m when a higher harmonic current of a specified order is passed. Specifically, the iron loss Wfe225 is obtained by subtracting the copper loss Wcu225 from the total loss WT225 when a fifth harmonic current is passed. Similarly, the iron loss Wfe227 is obtained by subtracting the copper loss Wcu227 from the total loss WT227 when a seventh harmonic current is passed. In addition, in step S2, the total loss WT225 and the total loss WT227 are obtained by passing higher harmonic currents of a specified order (fifth harmonic current and seventh harmonic current) of each specified current value through the test inductor L1, and measuring the loss when each higher harmonic current of a specified order is passed.

[0069] In this way, when simulating the superposition of one or more higher harmonic currents on the fundamental current, calculations are performed based on the copper loss, iron loss, and total loss of each higher harmonic current with any selected order, as well as the copper loss, iron loss, and total loss when the fundamental current is energized.

[0070] <Verification of temperature rise test method>

[0071] The following is based on Figure 2 The temperature rise test method of embodiment 1 was verified. Figure 2 The rated frequency of the fundamental current is 50 Hz. Conventional test X is conducted by superimposing a fifth harmonic current having a fifth harmonic content ratio of 35% on 100% of the fundamental current and passing it through the test reactor, providing a total loss WTx.

[0072] exist Figure 2 The column for Conventional Test X shows the copper loss Wcux calculated using the aforementioned calculation method, along with the iron loss Wfex calculated as the difference between the total loss WTx and the copper loss Wcux. Conventional Test X was actually conducted by passing a current superimposed with harmonics on the fundamental current through the test reactor L1, simulating actual usage.

[0073] The ratios of copper loss Wcux and iron loss Wfex to the total loss WTx in Conventional Test X can be said to simulate actual usage conditions. In other words, the closer the values ​​of each loss in each temperature rise test are to those in Conventional Test X, the more faithfully the test current flowing through test reactor L1 simulates actual usage conditions.

[0074] However, conventional test X requires superimposing harmonics on the fundamental wave and supplying them to the test reactor, resulting in separate currents flowing into the fundamental power supply and the harmonic power supply. When the fundamental power supply is obtained from a commercial power source, the harmonic currents can flow into the commercial power supply system. Furthermore, to ensure that the test current flows through the test reactor even if the harmonic current flows into the commercial power supply system, the power supply capacity of the harmonic power supply must be increased.

[0075] Therefore, in order to prevent the mutual inflow of current between the fundamental power supply and the higher harmonic power supply, it is known that Figure 4 The test circuit configuration shown in FIG. This circuit configuration requires two superimposition transformers (superimposition transformer Tx1 and superimposition transformer Tx2) and two test reactors (test reactors Lx1 and Lx2), resulting in a large test facility. In particular, the need for two test reactors of identical structure makes it economically impossible to perform the conventional test X when only one test reactor is available.

[0076] Next, conventional test Y was verified. As mentioned above, conventional test Y did not reflect the frequency dependence of copper and iron losses included in the reactor's losses, but rather conducted a flow of only the fundamental current. Specifically, a fundamental current of a predetermined first current value i21 was passed through test reactor L1, and the total loss WT21 when the fundamental current was passed was calculated. Furthermore, a harmonic current of a second current value i22 was passed through test reactor L1, and the total loss WT22 when the harmonic current was passed was calculated. Up to this point, the process was identical to that of the temperature rise test method in Implementation 1.

[0077] Then, in the previous test Y, the target total loss WTy is obtained by adding the total loss WT21 when the fundamental current is passed and the total loss WT22 when the higher harmonic current is passed, and only the fundamental current is passed through the test inductor L1 so that the loss of the test inductor L1 becomes the target total loss WTy.

[0078] However, as is clear from equation (2), copper loss and iron loss have different frequency characteristics. Therefore, in conventional experiment Y, it was not possible to fully simulate the actual use state in which two or more currents of different frequencies are superimposed. More specifically, in conventional experiment Y, the copper loss Wcuy was excessively large compared to actual use, and the iron loss Wfey was excessively small compared to actual use.

[0079] exist Figure 2 In conventional test X, the copper loss Wcux was 882W and the iron loss Wfex was 990W. In contrast, in conventional test Y, the copper loss Wcuy was 1150W and the iron loss Wfey was 618W, showing significant differences. The copper loss (1150 / 882) is approximately 1.3 times that of conventional test X, while the iron loss (618 / 990) is approximately 0.6 times that of conventional test X. This indicates that conventional test Y does not adequately simulate the actual operating conditions of the reactor.

[0080] Therefore, in order to pass the temperature rise test in conventional test Y, the reactor windings had to be overdesigned, such as by excessively reducing the winding resistance. Furthermore, since the temperature rise test cannot account for the losses in actual use, even if the reactor passes the temperature rise test, verification of the reactor core is insufficient.

[0081] Next, the temperature rise test method of Embodiment 1 was verified. In conventional test Y, a fundamental wave current was passed so that the loss of test reactor L1 reached the target total loss WTy. In other words, in conventional test Y, the test current frequency was fixed to the same frequency as the fundamental wave, and only the current value was adjusted. In contrast, the temperature rise test method of Embodiment 1 adjusts the test current frequency in addition to the current value, thereby achieving losses that match actual usage conditions.

[0082] like Figure 2 As shown, the target copper loss Wcut of Embodiment 1 matches the value of the copper loss Wcux of Conventional Test X. The target total loss WTt is the same as the target total loss WTy of Conventional Test Y. It can be said that the temperature rise test method of Embodiment 1 can more faithfully simulate actual usage conditions than Conventional Test Y.

[0083] This concludes the effectiveness of the temperature-rise test method in Embodiment 1. This method allows for energization that simulates actual usage without superimposing currents of varying frequencies. Furthermore, by using both fundamental and harmonic power sources in the test circuit, there is no risk of currents flowing into each other, enabling temperature-rise testing with a simple test circuit configuration. Furthermore, a single test reactor is sufficient.

[0084] [Implementation Method 2]

[0085] Embodiment 2 of the present invention will be described below. Embodiment 2 differs from Embodiment 1 in that the target iron loss Wfet is corrected to obtain a corrected target iron loss Wfet1 (target iron loss). The remaining configuration and procedures are the same as those of Embodiment 1.

[0086] right Figure 2 When comparing the values ​​of each loss of the embodiment 1 with the conventional test X, the target iron loss Wfet of the embodiment 1 is smaller than the iron loss Wfex of the conventional test X. This is because the electromagnetic steel sheets constituting the core have nonlinear characteristics, so the loss (the sum of the iron loss when the fundamental current is energized and the iron loss when the fifth harmonic current is energized) is smaller than the iron loss Wfex of the conventional test X. Figure 2 The target iron loss of implementation mode 1 is Wfet886W), and the iron loss when superimposed is ( Figure 2 The iron loss Wfex 990W) of the previous test X becomes larger.

[0087] Figure 3 This is a diagram showing an example of a hysteresis curve of a distorted wave flux including the third harmonic at 50 Hz and 10 kG. Figure 3As shown, it is clear that the shapes of hysteresis curves 31, 32, and 33 change depending on the superposition phase θ of the higher harmonics. Therefore, the magnitude of the iron loss when the higher harmonics are superimposed on the fundamental current varies depending on the superposition phase of the higher harmonics.

[0088] Thus, the behavior of the iron loss when the higher harmonic current is superimposed on the fundamental current is complex. However, the iron loss can be empirically estimated based on the results of superimposition tests on similarly designed reactors or the material properties of the test reactor L1. A more appropriate estimate can be made by setting the iron loss correction factor K and setting the corrected target iron loss Wfet1 to be the value obtained by multiplying the target iron loss Wfet in Embodiment 1 by the correction factor K. The correction factor K is a factor greater than 1.

[0089] In other words, the corrected target iron loss Wfet1 is obtained by multiplying the target iron loss Wfet, which is the sum of the iron loss Wfe21 when the fundamental current is flowing and the iron loss Wfe22 when the harmonic current is flowing, by a predetermined coefficient K. The correction coefficient K is not constant but varies depending on the fundamental magnetic flux density, the magnetic flux density of the harmonics, the superposition phase, the material, and other factors in the reactor.

[0090] Therefore, by compiling the values ​​of correction coefficient K for various reactor designs into a database, correction coefficient K for test reactor L1 can be determined based on the database. By referring to the design conditions of test reactor L1 and determining correction coefficient K based on the database, it is possible to determine test current values ​​and test frequencies that more accurately simulate actual usage conditions.

[0091] exist Figure 2 In the case of , let K = 1.12, and the corrected target iron loss Wfet1 can be calculated as follows. Corrected target iron loss Wfet1 = 886 × 1.12 ≒ 990 (W). Figure 2 The iron loss of X is consistent with that of previous tests.

[0092] Next, similar to step S5 in embodiment 1, the frequency and current value of the current that brings about the target copper loss Wcut and the corrected target iron loss Wfet1 are set as the test frequency fex1 and the test current value Iex1, respectively, and are calculated using the simultaneous equations of formula (2).

[0093] By determining the corrected target iron loss Wfet1 in this manner, it is possible to impart losses substantially equivalent to the superposition test of the conventional test X. As a result, a highly reliable testing method can be provided that takes into account the nonlinear characteristics of the iron core.

[0094] In addition, when simulating the superposition of one or more higher harmonic currents on the fundamental current, the sum of the iron loss Wfe21 when the fundamental current is passed and the iron loss Wfe22m when the higher harmonic currents of the specified order are passed is multiplied by a coefficient greater than 1 to obtain the target iron loss Wfet.

[0095] In the specific examples of the above embodiments 1 and 2, the conditions of the allowable current category I of the series reactor for the phase-advancing capacitor described in non-patent document 1 are used for explanation. The present invention can also be applied to the conditions of the allowable current category II. In this case, the higher harmonic current is the fifth harmonic of the fundamental wave, and has a current value of 55% of the fundamental wave current ratio. In addition, the present invention can also be applied to a filter reactor into which the higher harmonic current flows. In the case of the filter reactor, by adjusting the combination with the capacitor, the resonant frequency can be freely selected. For example, the higher harmonic that flows in can be set to the eleventh harmonic, the thirteenth harmonic, the twenty-third harmonic, etc. Furthermore, by adjusting the structure of the filter circuit, in addition to the fundamental current, there are also cases where multiple higher harmonic currents such as the fifth harmonic and the seventh harmonic flow in, but the present invention can also be applied.

[0096] The present invention is not limited to the embodiments described above. Various modifications can be made within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in the various embodiments.

[0097] 〔Summarize〕

[0098] The temperature rise test method for a reactor (test reactor L1) according to embodiment 1 of the present invention includes: a step (step S3) of calculating a target copper loss (Wcut) based on a copper loss (Wcu21) when a fundamental current of a specified current value (i21) is passed, and respective copper losses (Wcu22m) when harmonic currents of specified orders of specified current values ​​(i22m) are passed; a step (step S4) of calculating a target iron loss (Wfet) based on an iron loss (Wfe21) when the fundamental current is passed, and respective iron losses (Wfe22m) when the harmonic currents are passed; a step (step S5) of calculating the frequency and current value of a current that causes the target copper loss (Wcut) and the target iron loss (Wfet) as a test frequency (fex) and a test current value (lex), respectively; and a step (step S6) of passing a test current having the test frequency and the test current value through the reactor until the temperature of a specified portion of the reactor becomes constant.

[0099] With this configuration, by adjusting the current value and frequency of the test current flowing through the reactor, it is possible to simulate the various losses that would occur if harmonic currents were superimposed on the fundamental current and perform a temperature rise test. As a result, a temperature rise test consistent with actual operating conditions can be performed using a simple test circuit.

[0100] The temperature rise test method for a reactor according to aspect 2 of the present invention is based on the method according to aspect 1, wherein the copper loss (Wcu21) when the fundamental current is passed and the copper loss (Wcu22m) when each of the higher harmonic currents is passed can be calculated in advance.

[0101] According to the above configuration, the copper loss when the fundamental wave current is passed and the copper loss when each harmonic current is passed can be obtained.

[0102] The temperature rise test method for a reactor according to the third embodiment of the present invention is based on the method according to the second embodiment, and may further include the steps of: passing a fundamental current of a specified current value (i21) through the reactor (test reactor L1), and measuring the loss (total loss WT21) when the fundamental current is passed through (step S1); passing a higher harmonic current of the specified order of each specified current value (i22m) through the reactor, and measuring the loss (total loss WT21) when each higher harmonic current is passed through The step of (a) reducing the copper loss (Wcu21) when the fundamental current is energized by subtracting the copper loss (Wcu21) when the fundamental current is energized from the loss (total loss WT21) when the fundamental current is energized is performed (step S2), and the iron loss (Wfe22m) when each of the higher harmonic currents is energized can be obtained by subtracting the copper loss (Wcu22m) when each of the higher harmonic currents is energized from the loss (total loss WT22m) when the each of the higher harmonic currents is energized.

[0103] According to the above configuration, the iron loss when the fundamental wave current is passed and the iron loss when each harmonic current is passed can be obtained.

[0104] The temperature rise test method for an inductor according to mode 4 of the present invention is based on any one of modes 1 to 3, wherein the target copper loss (Wcut) can be calculated as the sum of the copper loss (Wcu21) when the fundamental current is energized and the copper loss (Wcu22m) when each of the higher harmonic currents is energized.

[0105] According to the above configuration, the target copper loss, which is the loss of the winding targeted in the temperature rise test, can be obtained by calculating the sum of the copper loss when the fundamental current is passed and the copper loss when each harmonic current is passed.

[0106] The temperature rise test method for the reactor of mode 5 of the present invention is based on any one of modes 1 to 4, wherein the target iron loss (Wfet) can be calculated as the sum of the iron loss (Wfe21) when the fundamental current is energized and the iron loss (Wfe22m) when each of the higher harmonic currents is energized.

[0107] According to the above configuration, the target core loss in the temperature rise test can be obtained by calculating the sum of the core loss when the fundamental current is passed and the core loss when each harmonic current is passed.

[0108] The temperature rise test method for the reactor of mode 6 of the present invention is based on any one of modes 1 to 4, wherein the target iron loss (Wfet1) is obtained by multiplying the sum of the iron loss (Wfe21) when the fundamental current is energized and the iron loss (Wfe22m) when each of the higher harmonic currents is energized by a coefficient (K) greater than 1.

[0109] The above configuration allows the target iron loss when the test current is applied to match the iron loss in the temperature rise test in which the fundamental wave and harmonics are superimposed. As a result, a highly reliable testing method can be provided that takes into account the nonlinear characteristics of the core.

[0110] A seventh aspect of the present invention is a method for testing a reactor temperature rise according to any one of aspects 1 to 6, wherein the predetermined current value (i21) of the fundamental current can be the rated current value of the reactor (test reactor L1). This configuration enables a temperature rise test that conforms to actual usage conditions.

[0111] A temperature rise test method for a reactor according to aspect 8 of the present invention is based on any one of aspects 1 to 7, wherein the selected harmonic current order can be 5. With this configuration, a temperature rise test that conforms to actual usage conditions can be achieved.

Claims

1. A temperature rise test method for a reactor, comprising: Calculating a target copper loss based on the copper loss when a fundamental current of a predetermined frequency and current value is passed, and the copper loss when a harmonic current of a predetermined order of each predetermined frequency and current value is passed; a step of calculating a target iron loss based on the iron loss when the fundamental current is passed and the iron loss when each of the higher harmonic currents is passed; a step of calculating the frequency and current value of the current that causes the target copper loss and the target iron loss as the test frequency and the test current value, respectively; as well as A step of passing a test current having the test frequency and the test current value through the reactor until the temperature of a predetermined portion of the reactor becomes constant. 2 . The reactor temperature rise test method according to claim 1 , wherein the copper loss when the fundamental wave current is passed and the copper loss when each of the harmonic currents is passed are found in advance by calculation.

3. The reactor temperature rise test method according to claim 2, further comprising: A step of passing a fundamental wave current of a predetermined current value through the reactor and measuring the loss when the fundamental wave current is passed; as well as The steps of passing the specified order harmonic currents of each specified current value into the reactor and measuring the loss when each harmonic current is passed through the reactor, The iron loss when the fundamental wave current is passed is obtained by subtracting the copper loss when the fundamental wave current is passed from the loss when the fundamental wave current is passed. The iron loss when each of the harmonic currents is passed is obtained by subtracting the copper loss when each of the harmonic currents is passed from the loss when each of the harmonic currents is passed. 4 . The reactor temperature rise test method according to claim 1 , wherein the target copper loss is obtained as the sum of the copper loss when the fundamental current is passed and the copper losses when each of the higher harmonic currents is passed. 5 . The reactor temperature rise test method according to claim 1 , wherein the target iron loss is obtained as the sum of the iron loss when the fundamental wave current is passed and the iron loss when each of the higher harmonic currents is passed.

6. The temperature rise test method for a reactor according to any one of claims 1 to 3, wherein the target iron loss is obtained by multiplying the sum of the iron loss when the fundamental current is passed and the iron loss when each of the higher harmonic currents is passed by a coefficient greater than or equal to 1. 7 . The reactor temperature-rise test method according to claim 1 , wherein the predetermined current value of the fundamental wave current is a rated current value of the reactor. 8 . The temperature-rise test method for a reactor according to claim 1 , wherein the selected harmonic current has an order of 5.

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