JP2015141675A - Power conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve accuracy of disconnection detection in a power conditioner adopting a time proportional control system.SOLUTION: As means for solving the above problem, there are provided a power conditioner for comparing a value of resistance calculated from a voltage value and a current value as an effective value having passed through a DC-conversion circuit over the entire interval or part of the section of an ON time with a value of resistance during a normal time of a load, and a power conditioner for comparing a value of resistance calculated from a voltage value and a current value as an effective value having passed through a DC-conversion circuit in an interval of the third cycle and after of the ON time with a value of resistance during a normal time of a load.

Description

  The present invention relates to a technique for detecting an abnormality of a load such as a disconnection in a power regulator that adjusts an applied power to a load such as a heater.

  The power adjuster controls the output voltage by adjusting on / off of a switching element such as a thyristor to adjust the power applied to the load. This power regulator is required not only to adjust applied power but also to detect disconnection of a connected load.

  The basic concept of disconnection detection will be described with reference to FIG. As shown to Fig.1 (a), the some load used as the control object of electric power adjustment is connected in parallel. For example, it is assumed that three loads are connected in parallel and each resistance value is 20Ω. In this case, the resistance value of all three loads is 6.66Ω. When a voltage of 200 V is applied to this load, the current flowing through the load is 30A.

  FIG. 1B shows a case where one of the three loads is disconnected. In this case, the overall resistance value of the two connected loads is 10Ω. Similarly, when 200 V is applied to this load, the current flowing through the load becomes 20 A, which is different from the current value when three loads are connected.

  As described above, when any one of the plurality of loads connected in parallel is disconnected, the resistance value as a whole of the connected loads varies. Therefore, the current value and the voltage value at the load are fed back, and the resistance value calculated from each value is monitored, and when the fluctuation occurs, it is detected that the disconnection has occurred.

  Here, the method of adjusting the power applied to the load such as the heater is roughly divided into a phase control method and a frequency division control method. In recent years, there is a tendency that many phase control methods that can finely adjust the applied power are used. Most of the phase control methods are adopted in the adjustment of applied power to a transformer load of a high-temperature heat treatment apparatus used in semiconductor manufacturing and a heating element used in an industrial furnace or an experimental furnace. As for disconnection detection in the power regulator using the phase control method, for example, there is a technique disclosed in Patent Document 1, and disconnection detection is performed with relatively high accuracy. On the other hand, since the phase control method has a harmonic problem, it tends to be a frequency division control method when applicable.

JP 2010-66119 A

  By the way, the frequency division control method is further subdivided into two types of control methods, one being a “time division control method” and the other being a “time proportional control method”. These two types of control methods will be described with reference to FIG.

  FIG. 2A is a conceptual diagram showing a control mode of the time division control method. The time-sharing control method is a method for controlling on / off of the output in units of one cycle of the AC power supply. For example, when the output is controlled to 50%, ON and OFF are repeated every cycle. The illustrated case is when the output is controlled to 40%. In this case, by setting 5 cycles shown by dividing with a dotted line in the figure as a control period, and intermittently providing 1 cycle on time while alternately sandwiching 1 cycle off time and 2 cycles off time, The output is controlled to 40% with 2 cycles of the control period being on time and 3 cycles being off time.

  FIG.2 (b) is a conceptual diagram which shows the control aspect of a time proportional control system. In the time proportional control method, for example, a predetermined number of cycles, such as 50 cycles or 60 cycles, is used as a control cycle, and output control is performed by apportioning an on time and an off time within the control cycle. The figure shows a case where a 50 Hz AC power supply is controlled and the control cycle is 50 cycles (1 second). In this case, the output is controlled to 40% by setting the on time as 0.4 seconds and the off time as 0.6 seconds.

  Here, the disconnection is detected using the current value and the voltage value fed back as described above. As the fed back current value and voltage value, the current value and the voltage value as effective values obtained by converting the current into a direct current through a predetermined direct current circuit are used.

  Here, the following problems occur in the time proportional control method. FIG. 3 is a conceptual diagram showing the relationship between the AC power supply output when the output is switched from the OFF time to the ON time, and the current value and the voltage value measured as effective values through the DC circuit. The output% on the vertical axis has an effective value of 100%, and the output of the AC power supply is periodically output in the range of + 141% to −141%, which is ± times the effective value.

  First, the AC power supply is periodically output as the on-time arrives (0301). On the other hand, the voltage (0302) fed back as an effective value through a predetermined DC circuit takes about two cycles until the rise reaches a slightly delayed 100%. As for the current (0303) to be fed back, the rise finally reaches 100% only after 3 cycles.

  The rise delay of the voltage value and the current value fed back as the effective value is not simply caused by passing through the DC circuit. The major factor is that the time during which the output off time continues is long in the time proportional control method.

  As shown in FIG. 2A, in the time-sharing control method, the off time is 2 cycles at the longest, which is only 0.04 seconds with a 50 Hz AC power supply. Since the off time and the on time are switched in such an extremely short time, the voltage value and the current value as the effective values that have passed through the DC circuit do not fall down to 0%, and it takes a long time to reach 100%. The rise delay is negligible.

  On the other hand, in the time proportional control method, the off time continues for 0.6 seconds as shown in FIG. During this time, the voltage value and the current value as effective values that have passed through the DC circuit have dropped to 0%. Therefore, it takes time to reach 100%, which appears as a delay in rising.

  It can be obtained, for example, when the load resistance value is calculated based on the voltage value and the current value as the effective values after passing through the DC circuit in the first cycle of the on-time due to an event peculiar to the time proportional control method. The resistance value does not accurately indicate the actual resistance value, and an error occurs in disconnection detection. Therefore, an object of the present invention is to improve the accuracy of disconnection detection in a power regulator that employs a time proportional control method.

  Therefore, in order to solve the above problems, the present invention provides the following power regulator. That is, as the first invention, the power for adjusting the power applied to the load by dividing the on-time and the off-time within the control period by setting a predetermined number of cycles as a unit with one cycle of the AC power supply as a unit. In the regulator, a power application unit that applies power by alternating current during the on time, a resistance value holding unit that retains a normal resistance value that is a resistance value when the load is normal, and all or part of one on time DC voltage effective value acquisition unit for acquiring the AC DC voltage effective value applied in the section, and DC current effective value for acquiring the AC direct current effective value applied in all or a part of one on-time Current load resistance value that is the resistance value of the load using the acquisition unit and the DC voltage effective value and DC current effective value acquired in all sections of the same one on-time or in the same part of the same one on-time. The A power regulator having a current load resistance value calculation unit that outputs and a comparison unit that compares the current load resistance value calculated by the current load resistance value calculation unit and the normal resistance value held by the resistance value holding unit; provide.

  As a second invention, the DC voltage effective value acquisition unit includes third and subsequent DC voltage effective value acquisition means for acquiring the DC voltage effective value in a section after the third cycle of the on-time, and the DC current The effective value acquisition unit has third and subsequent DC current effective value acquisition means for acquiring the DC current effective value in the section after the third cycle of the on-time, and the current load resistance value calculation unit acquires the acquired first A third and subsequent current load resistance value calculating means for calculating a third and subsequent current load resistance value, which is a current load resistance value, using a DC voltage effective value and a DC current effective value in the same section after the third cycle; The comparison section includes third and subsequent comparison means for comparing the third and subsequent current load resistance values calculated by the third and subsequent current load resistance value calculation means with normal resistance values held by the resistance value holding section. Electricity according to one invention Providing regulator.

  As a third invention, the DC voltage effective value acquisition unit includes third cycle DC voltage effective value acquisition means for acquiring the DC voltage effective value in a section of the third cycle of the on-time, and the DC current effective value is acquired. The value acquisition unit includes a third cycle DC current effective value acquisition unit that acquires the DC current effective value in a section of the third cycle of the on-time, and the current load resistance value calculation unit acquires the acquired third cycle A third cycle current load resistance value calculating means for calculating a third cycle current load resistance value, which is a current load resistance value, using a DC voltage effective value and a DC current effective value in the same section of the eye; Includes a third cycle comparison unit that compares the third cycle current load resistance value calculated by the third cycle current load resistance value calculation unit with the normal resistance value held by the resistance value holding unit. Providing a power conditioner according to the present invention or the second invention.

  According to the present invention, it is possible to provide a power regulator that employs a time proportional control method and that can accurately detect disconnection.

Conceptual diagram showing the basic concept of disconnection detection Schematic diagram showing two types of frequency division control methods Conceptual diagram showing AC power supply output and effective values of voltage and current when switching from off to on A block diagram showing an example of composition of a power regulator of Embodiment 1. 1 is a block diagram illustrating an example of a hardware configuration of a power conditioner according to a first embodiment. The flowchart which shows the flow of operation | movement of the power regulator of Embodiment 1. FIG. The block diagram which shows an example of a structure of the power regulator of Embodiment 2. FIG. A conceptual diagram for explaining a power regulator of Embodiment 2. A block diagram showing an example of composition of a power regulator of Embodiment 3. A conceptual diagram for explaining a power regulator of Embodiment 3.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, this invention should not be limited to these embodiments at all, and can be implemented in various modes without departing from the gist thereof. The first embodiment mainly relates to claim 1 and the like. The second embodiment mainly relates to claim 2 and the like. The third embodiment mainly relates to claim 3 and the like.
<Embodiment>
<Overview of embodiment>

The power regulator according to the present embodiment includes a resistance value calculated from a voltage value and a current value as effective values that have passed through a DC circuit in all or a part of the on-time, and a resistance value when the load is normal. It is the electric power regulator which detects the disconnection of load based on the result of comparing.
<Embodiment configuration>

  FIG. 4 is a conceptual diagram showing the configuration of the power regulator according to the present embodiment. The “power regulator” (0400) includes a “power application unit” (0401), a “resistance value holding unit” (0402), a “DC voltage effective value acquisition unit” (0403), and a “DC current effective value acquisition”. Part "(0404)," current load resistance calculation part "(0405), and" comparison part "(0406).

  The “power regulator” (0400) controls the output voltage by controlling on / off of a switching element such as a thyristor to adjust the power applied to the load. The power adjuster in the present embodiment adjusts the power applied to the load by controlling the ratio of the on time and the off time within a control cycle of a predetermined number of cycles in units of one cycle of the AC power supply.

  As described above, there are a plurality of methods for adjusting the power. However, the power regulator of this embodiment employs the time proportional control method among the frequency division control methods. In the frequency division control method, power adjustment is performed by applying a trigger voltage to a switching element such as a thyristor and turning it on and off when the AC voltage becomes 0 V, also called a zero cross control method. The frequency division control method has an advantage that noise is less likely to occur compared to the phase control method because the output is turned on and off in units of one cycle of the AC voltage.

  Then, output control is performed by apportioning the on time and the off time within a predetermined number of control cycles such as 50 cycles or 60 cycles. For example, when controlling a 50 Hz AC power supply, as shown in FIG. 2B, the control cycle is 50 cycles (1 second), 40% of this control cycle is set to the on time, and 60% is turned off. Apportion to time. That is, the output is controlled to 40% by setting 0.4 seconds as the on time and 0.6 seconds as the off time.

  The “power application unit” (0401) applies power by alternating current during the on-time. The on-time and the off-time are switched by the switching element, and power is applied by alternating current during the on-time. The on time, the off time, and the control are performed according to an operation input, a predetermined program, or the like.

  The “resistance value holding unit” (0402) holds a normal resistance value which is a resistance value when the load is normal. The load is a target to which the power adjusted by the power regulator is applied. For example, a lamp load such as a heater of an electric furnace, a halogen lamp or a metal halide lamp (environmental test room that realizes a hot environment, paint baking, etc.) There is lamp dimming. In addition, when several application objects exist in series or parallel, they are made into the integral load as a whole.

  The resistance value at normal time is a state in which no abnormality such as disconnection has occurred in the load to which power is applied, and the DC voltage value and DC current value measured through the DC circuit are both upper limits. It is a resistance value calculated based on each value when the level is reached.

  In the DC voltage effective value acquisition unit and the DC current effective value acquisition unit, which will be described later, when the section for acquiring the DC voltage effective value and the DC current effective value is the first cycle or the second cycle of the on-time, As a normal resistance value for comparison with the current load resistance value calculated on the basis of the DC voltage effective value and DC current effective value acquired in the section, there is no abnormality such as disconnection in the same section as the acquisition section. In some cases, a resistance value calculated based on a DC voltage value and a DC current value measured through a DC circuit may be held.

  The “DC voltage effective value acquisition unit” (0403) acquires the AC DC voltage effective value applied in all or part of one on-time. The DC voltage effective value is a voltage value measured as an effective value through a DC circuit. In order to obtain the DC voltage effective value, a known DC conversion circuit such as an RMS-DC (effective value-DC) converter can be used. Alternatively, it may be acquired by executing a program for obtaining a DC voltage effective value.

  The “one on time” is, for example, 0.4 seconds (20 cycles) shown in FIG. The effective value of the DC voltage in all the sections of the on-time, that is, 20 cycles is acquired. In this case, the DC voltage effective value in each cycle from the first cycle to the 20th cycle may be acquired, and an average value of these values may be calculated to obtain one DC voltage effective value. Good. As described above, the DC voltage effective value that has just entered the on-time may not accurately reflect the substance because the rise is delayed. By setting the average value to the DC voltage effective value, a value in accordance with the substance can be obtained. Further, the DC voltage effective value may be acquired in a cycle in which the DC voltage effective value can be expected to rise sufficiently. For example, the DC voltage effective value in the fifth cycle may be acquired. Further, the section for acquiring the DC voltage effective value may have not only 5 cycles as a unit but also 0.5 cycles as a unit.

  The “DC current effective value acquisition unit” (0404) acquires an AC direct current effective value applied in all or a part of one ON time. The DC current effective value is a current value measured as an effective value through a DC circuit. In order to obtain the DC current effective value, a known DC conversion circuit such as an RMS-DC (effective value-DC) converter can be used as in the DC voltage effective value acquisition unit. Moreover, you may acquire by running the program for obtaining a direct-current effective value.

  “Acquiring the DC current effective value in all or a part of one ON time” is the same as in the DC voltage effective value acquiring unit. The effective value of the direct current fed back as an effective value through the direct current circuit is 100% after the delay of 3 cycles after the start of the on-time, and may not fully reflect the substance. Therefore, when acquiring the DC current effective value in a predetermined cycle, for example, it is preferable that the DC current effective value measured in the fifth cycle is acquired.

  The “current load resistance calculation unit” (0405) uses the DC voltage effective value and the DC current effective value acquired in all the sections of the same on-time or the same partial section of the same on-time. The current load resistance value, which is a resistance value, is calculated. For example, the current load resistance value, which is the resistance value of the load, is calculated using the DC voltage effective value and DC current effective value in the 10th cycle of the same one on-time. For this calculation, the current load resistance value is obtained by, for example, executing a program for performing the calculation, which should be calculated based on Ohm's law.

  The “comparison unit” (0406) compares the current load resistance value calculated by the current load resistance value calculation unit and the normal resistance value held by the resistance value holding unit. If there is no abnormality in the circuit including the load, the calculated current load resistance value and normal resistance value should be equal. Therefore, the current load resistance value is compared with the normal resistance value. For example, when the result of the comparison is that the difference between the values exceeds a predetermined allowable range, it can be determined that a disconnection has occurred. Since the resistance value varies due to the influence of the ambient temperature or the like, an allowable range may be appropriately determined according to the operating environment of the load.

  Further, in the DC voltage effective value acquisition unit and the DC current effective value acquisition unit, when the interval for acquiring the DC voltage effective value and the DC current effective value is the first cycle or the second cycle of the on-time, the acquisition interval described above The resistance value calculated based on the DC voltage value and DC current value measured through the DC circuit when there is no abnormality such as disconnection in the same section as the normal resistance value, the normal resistance value and the current load resistance value And may be configured to be compared.

  Moreover, you may comprise so that an alarm may be issued according to the comparison result of a comparison part. For example, when the difference between the current load resistance value and the normal resistance value exceeds a predetermined value, an alarm is issued as a disconnection has occurred. The warning may appeal to hearing by voice, or may display a message or the like and appeal visually. In addition to the configuration in which the power regulator itself includes a means for issuing an alarm, an instruction may be output to issue an alarm to an external alarm device connected via an interface.

  FIG. 5 is a diagram illustrating an example of a specific hardware configuration of the power conditioner according to the present embodiment. As shown in the figure, the “power regulator” (0500) includes “CPU” (0501), “RAM” (0502), “nonvolatile memory” (0503), “ I / F "(0504). The “voltage DC circuit” (0505), “current DC circuit” (0506), and “power application unit” (0507) are connected via the I / F, and “alarm device” (0508) It may be connected. Various programs including a power adjustment program for adjusting the power output to the load are stored in the nonvolatile memory, and the CPU executes the various programs on the RAM. Each hardware configuration is connected to each other via a data communication path such as a system bus, and exchanges and processes information.

  For example, the CPU executes a voltage effective value acquisition program for acquiring the DC voltage effective value held in the nonvolatile memory, thereby enabling the DC voltage effective value of the voltage applied to the load via the I / F. To get. Then, the acquired DC voltage effective value is stored at a predetermined address in the RAM. Subsequently, the current effective value acquisition program for acquiring the DC current effective value is executed, the DC current effective value is acquired through the I / F, and stored in a predetermined address of the RAM. Then, the current load resistance value, which is the result of executing the current load resistance value calculation program for acquiring the current load resistance value, is stored at a predetermined address in the RAM. Then, a comparison program for comparison is executed, the normal resistance value held in the nonvolatile memory is read, and compared with the stored current load resistance value.

  Moreover, you may hold | maintain the program which outputs the command for an alarm device to emit an alarm with respect to an alarm device. In this case, the CPU executes the program and performs a process of determining whether or not to issue an alarm based on the comparison result. If the determination result indicates that an alarm should be issued, a command for issuing an alarm to the alarm device is output via the I / F. Further, a program for feeding back the comparison result to the power adjustment, a program for stopping the power application according to the comparison result, and the like may be held.

  The present embodiment can also be expressed as an operation method of the power regulator. In other words, a cycle of AC power is used as a unit, a predetermined number of cycles is set as a control period, and the applied power to the load is adjusted by apportioning the on time and the off time within the control period. A power regulator having a power application unit that applies power and a resistance value holding unit that holds a normal resistance value that is a resistance value when the load is normal. Alternatively, a voltage effective value acquisition step for acquiring an AC DC voltage effective value applied in a partial section, and a current effective value for acquiring an AC direct current effective value applied in all sections or a partial section of one on-time. The current load resistance, which is the resistance value of the load, using the DC voltage effective value and DC current effective value acquired in the value acquisition step and all the sections of the same on-time or the same part of the same on-time. A current load resistance value calculating step for calculating a value, and a comparison step for comparing the current load resistance value calculated in the current load resistance value calculating step with a normal resistance value held by the resistance value holding unit It can be expressed as the operation method of the regulator.

FIG. 6 is a flowchart showing an operation method of the power regulator according to the present embodiment. First, an AC direct-current voltage effective value applied in all or part of one on-time is acquired (S0601: voltage effective value acquisition step). And the direct-current effective value of the alternating current applied in the whole area or one part of one ON time is acquired (S0602: Current effective value acquisition step). Then, the current load resistance value, which is the load resistance value, is calculated using the DC voltage effective value and the DC current effective value acquired in the same one on-time all sections or the same one on-time partial section. (S0603: current load resistance value calculating step). Then, the current load resistance value is compared with the normal resistance value held by the resistance value holding unit (S0604: comparison step). Further, it may include a step of issuing an alarm according to the comparison result and a step of outputting a command to issue an alarm to the alarm device according to the comparison result.
<Embodiment 1 effect>

According to the present embodiment, it is possible to provide a power regulator that employs a time proportional control method and that can accurately detect disconnection.
<Embodiment 2>
<Overview of Embodiment 2>

The power regulator of this embodiment is based on Embodiment 1, and the voltage effective value acquisition unit and the power effective value acquisition unit calculate the DC voltage effective value and DC current effective value in the section after the third cycle of the on-time. The current load resistance value is calculated using the acquired DC voltage effective value and DC current effective value.
<Embodiment 2 configuration>

  FIG. 7 is a conceptual diagram showing the configuration of the power regulator according to this embodiment. The “power regulator” (0700) includes a “power application unit” (0701), a “resistance value holding unit” (0702), a “DC voltage effective value acquisition unit” (0703), and a “DC current effective value acquisition”. Part "(0704)," current load resistance value calculation part "(0705), and" comparison part "(0706). The DC voltage effective value acquisition unit has “third and subsequent DC voltage effective value acquisition means” (0707), and the DC current effective value acquisition unit has “third and subsequent DC current effective value acquisition means” (0708). The current load resistance value calculation unit has “third and subsequent current load resistance value calculation means” (0709), and the comparison unit has “third and subsequent comparison means” (0710). Description of each part described in the first embodiment is omitted.

  FIG. 8 is a conceptual diagram for explaining the present embodiment. This figure is based on FIG. 3 described above. As shown in the figure, the solid sine waveform is the AC power supply output (0801). The dotted line indicates the DC voltage effective value (0802), and the alternate long and short dash line indicates the DC current effective value (0803).

  In the power regulator of this embodiment, the DC voltage effective value acquisition unit and the DC current effective value acquisition unit acquire the DC voltage effective value and the DC current effective value, respectively, and the interval after the third cycle of the on-time As a target section for acquisition. Obtain the DC voltage effective value and DC current effective value by excluding the first and second cycle sections that tend to cause a delay in the rise of both the DC voltage effective value and the DC current effective value. In order to calculate the current load resistance value, the resistance value reflecting the actual load state is calculated. By comparing the current load resistance value with the normal resistance value, it is possible to reduce erroneous detection of disconnection.

  The “third and subsequent DC voltage effective value acquisition means” (0707) acquires the DC voltage effective value in the section after the third cycle of the ON time. As shown in FIG. 8, the DC voltage effective value measured through the DC circuit for the section after the third cycle shown as the hatched area is acquired. The configuration and method for acquisition are the same as those of the DC voltage effective value acquisition unit in the first embodiment.

  The “third and subsequent DC current effective value acquisition means” (0708) acquires the DC current effective value in the section after the third cycle of the on-time. As shown in FIG. 8, the effective value of the direct current measured through the direct current circuit for the section after the third cycle shown as the hatched area is acquired. The configuration and method for acquisition are the same as those of the DC current effective value acquisition unit in the first embodiment.

  The “third and subsequent current load resistance value calculation means” (0709) uses the acquired DC voltage effective value and DC current effective value in the same section after the third cycle to obtain the current load resistance value for the third and subsequent current values. Calculate the load resistance value. As shown in FIG. 8, in the section after the third cycle, both the DC voltage effective value and the DC current effective value measured through the DC circuit reach approximately 100%. For this reason, the third and subsequent current load resistance values calculated with the section as an effective value acquisition target sufficiently reflect the actual load state.

  The “third and subsequent comparison means” (0710) compares the third and subsequent current load resistance values calculated by the third and subsequent current load resistance value calculation means with the normal resistance value held by the resistance value holding unit. By comparing the third and subsequent current load resistance values with normal resistance values, it is possible to reduce false detection of disconnection.

  Among the sections after the third cycle, when further specifying the section for acquiring the DC voltage effective value and the DC current effective value, it is preferable to specify according to the desired adjustment range of the power adjustment. This is because, as shown in FIG. 2, when the output of a 50 Hz AC power source is controlled with 50 cycles (1 second) as the control period, the output is 3/50 = 6.0% when the 3 cycles are set as the on time. Disconnection can be detected with an output of 6.0%. On the other hand, if the section to be acquired is the 10th cycle, 10/50 = 20.0% is the lowest limit value at which disconnection detection is possible, and this limits the disconnection detection function. In addition, according to the adjustment range of electric power adjustment, you may provide the structure for pinpointing the suitable area which acquires DC voltage effective value and DC current effective value automatically.

  The power conditioner of the present embodiment can be implemented according to the hardware configuration of the power conditioner of the first embodiment. Therefore, detailed description is omitted.

Further, the case where the present embodiment is expressed as the operation method of the power regulator can also be expressed according to the operation method of the power regulator of the first embodiment. Therefore, detailed description is omitted.
<Embodiment 2 effect>

The power regulator according to the present embodiment can detect disconnection with few false detections by comparing the third and subsequent current load resistance values reflecting the actual load state with normal resistance values.
<Embodiment 3>
<Overview of Embodiment 3>

The power regulator according to the present embodiment is based on the first or second embodiment, and the voltage effective value acquisition unit and the power effective value acquisition unit perform the DC voltage effective value and the DC current effective value in the section of the third cycle of the on-time. And the current load resistance value is calculated using the acquired DC voltage effective value and DC current effective value.
<Embodiment 3 configuration>

  FIG. 9 is a conceptual diagram showing the configuration of the power regulator according to the present embodiment based on the first embodiment. The “power regulator” (0900) includes a “power application unit” (0901), a “resistance value holding unit” (0902), a “DC voltage effective value acquisition unit” (0903), and a “DC current effective value acquisition”. Part "(0904)," current load resistance calculation part "(0905), and" comparison part "(0906). The DC voltage effective value acquisition unit has “third cycle DC voltage effective value acquisition means” (0907), and the DC current effective value acquisition unit has “third cycle DC current effective value acquisition means” (0908). The current load resistance value calculation unit has “third cycle current load resistance value calculation unit” (0909), and the comparison unit has “third cycle comparison unit” (0910). Description of each part described in the first embodiment is omitted.

  FIG. 10 is a conceptual diagram for explaining the present embodiment. This figure is based on FIG. 3 described above. As shown in the figure, the solid sine waveform is the AC power supply output (1001). The dotted line indicates the DC voltage effective value (1002), and the alternate long and short dash line indicates the DC current effective value (1003).

  In the power regulator according to this embodiment, the DC voltage effective value acquisition unit and the DC current effective value acquisition unit acquire the DC voltage effective value and the DC current effective value, respectively. It is characterized in that it is an acquisition target section. In both the DC voltage effective value and the DC current effective value, sections of the first cycle and the second cycle that tend to cause rise delays are excluded, and sections after the fourth cycle are also excluded. The effect of excluding the first cycle and the second cycle is as described in the second embodiment.

  The effect of excluding the fourth and subsequent cycles from the acquisition target section is that disconnection detection without error is possible even when the power output is reduced. For example, as shown in FIG. 2, when 50 Hz AC power is output controlled with a control cycle of 50 cycles (1 second), the output is 3/50 = 6.0% when the 3 cycles are on-time. . Therefore, the lower limit of the output adjustment range can be set to 6.0%. On the other hand, when the section to be acquired is the 10th cycle, 10/50 = 20.0% is the lowest limit of the adjustment range.

  Therefore, in order to realize disconnection detection with little error and at the same time not narrow the output adjustment range as much as possible, the third cycle measured through the DC circuit is a section for acquiring the DC voltage effective value and DC current effective value. It is especially suitable to do.

  “Third cycle DC voltage effective value acquisition means” (0907) acquires the DC voltage effective value in the section of the third cycle of the on-time. As shown in FIG. 10, the effective value of the DC voltage measured through the DC circuit is acquired for the section of the third cycle shown as the hatched area. The configuration and method for acquisition are the same as those of the DC voltage effective value acquisition unit in the first or second embodiment.

  “Third cycle DC current effective value acquisition means” (0908) acquires the DC current effective value in the section of the third cycle of the on-time. As shown in FIG. 10, the effective value of the direct current measured through the direct current circuit is obtained for the section of the third cycle shown as the hatched area. About the structure and method for acquisition, it is the same as that of the direct-current effective value acquisition means in Embodiment 1 or 2.

  The “third cycle current load resistance value calculation means” (0909) uses the acquired DC voltage effective value and DC current effective value in the same section of the third cycle to obtain the third cycle current load that is the current load resistance value. Calculate the resistance value. As shown in FIG. 10, in the section of the third cycle, both the DC voltage effective value and the DC current effective value measured through the DC circuit reach approximately 100%. Therefore, the current load resistance value in the third cycle calculated using the section as an effective value acquisition target sufficiently reflects the actual load state.

  The “third cycle comparison means” (0710) compares the third cycle current load resistance value calculated by the third cycle current load resistance value calculation means with the normal resistance value held by the resistance value holding unit. By comparing the current load resistance value and the normal resistance value in the third cycle, it is possible to reduce erroneous detection of disconnection.

  The power conditioner of the present embodiment can be implemented according to the hardware configuration of the power conditioner of the first or second embodiment. Therefore, detailed description is omitted.

Moreover, also when expressing this embodiment as an operation method of a power regulator, it can express according to the operation method of the power regulator of Embodiment 1 or 2. Therefore, detailed description is omitted.
<Embodiment 3 effects>

  With the power regulator according to the present embodiment, it is possible to realize disconnection detection with less error without narrowing the output adjustment range as much as possible.

0400 Power regulator 0401 Power application unit 0402 Resistance value holding unit 0403 DC voltage effective value acquisition unit 0404 DC current effective value acquisition unit 0405 Current load resistance value calculation unit 0406 comparison unit

Claims (3)

In a power regulator that adjusts the power applied to the load by dividing the on-time and off-time within the control period by setting a predetermined number of cycles as a unit with one cycle of the AC power supply as a unit,
A power application unit that applies power by alternating current during the on-time;
A resistance value holding unit that holds a normal resistance value that is a resistance value when the load is normal;
A DC voltage effective value acquisition unit for acquiring an AC DC voltage effective value applied in all or a part of one on-time;
A DC current effective value acquisition unit for acquiring an AC direct current effective value applied in all or part of one on-time;
The current load resistance value, which is the resistance value of the load, is calculated using the DC voltage effective value and the DC current effective value acquired in the same one on-time all sections or in the same one on-time part. A load resistance value calculation unit;
A comparison unit that compares the current load resistance value calculated by the current load resistance value calculation unit and the normal resistance value held by the resistance value holding unit;
Having a power regulator. The DC voltage effective value acquisition unit,
A third and subsequent DC voltage effective value acquisition means for acquiring the DC voltage effective value in the section after the third cycle of the on-time;
The DC current effective value acquisition unit,
A third and subsequent DC current effective value acquisition means for acquiring the DC current effective value in the section after the third cycle of the on-time;
The current load resistance value calculator is
Third and subsequent current load resistance value calculating means for calculating a third and subsequent current load resistance value, which is a current load resistance value, using the obtained DC voltage effective value and DC current effective value in the same section after the third cycle. Have
The comparison unit includes:
A third and subsequent comparison means for comparing the third and subsequent current load resistance values calculated by the third and subsequent current load resistance value calculation means with normal resistance values held by the resistance value holding unit;
The power regulator according to claim 1. The DC voltage effective value acquisition unit,
A third cycle DC voltage effective value acquisition means for acquiring the DC voltage effective value in the section of the third cycle of the on-time;
The DC current effective value acquisition unit,
3rd cycle direct current effective value acquisition means which acquires the direct current effective value in the section of the 3rd cycle of on time,
The current load resistance value calculator is
There is a third cycle current load resistance value calculating means for calculating the third cycle current load resistance value, which is the current load resistance value, using the obtained DC voltage effective value and DC current effective value in the same section of the third cycle. And
The comparison unit includes:
A third cycle comparison means for comparing the third cycle current load resistance value calculated by the third cycle current load resistance value calculation means and the normal resistance value held by the resistance value holding unit;
The power regulator according to claim 1 or 2.

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