CN108521847B - Power conversion device - Google Patents

Abstract

When the user strictly selects the power conversion device in accordance with the system to which the user is applied, a trial-run confirmation operation is required, and it is not easy to determine whether the power conversion device is optimal or excessively wide. The power conversion device includes an AC conversion unit for outputting AC power, a current detection unit for detecting current flowing in the AC conversion unit, a storage unit for storing current operation detected by the current detection unit, a determination unit for determining an optimum value of a rated current value, and a display operation unit for instructing operation and displaying output.

Description

Power conversion device

technical field

The present invention relates to a power conversion device for driving an AC load.

Background technique

As a background art in the technical field to which the present invention pertains, there is Japanese Patent Laid-Open No. 2004-348662 (Patent Document 1). In this publication, it is described that “when the power switch 25 is pressed, the CPU 11 activates the BIOS stored in the BIOS-ROM 18 to execute system initialization. In this system initialization process, the system configuration determination unit 181 obtains various device information to determine the system. The configuration assumes the AC adapter 1. The AC adapter setting unit 182 updates the register 261 of the PSC 26 in order to execute the maximum rated current control corresponding to the estimated AC adapter 1. On the other hand, the PSC 26 executes the use of the value of the register 261. It shows the maximum rated current control corresponding to the AC adapter 1. Then, when the system initialization is completed, the CPU 11 loads the OS stored in the HDD 20 into the system memory 13 and starts it.". (Summary of Reference Manual)

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2004-348662

SUMMARY OF THE INVENTION

The problem to be solved by the invention

Patent Document 1 describes a method of estimating an AC adapter based on a system configuration of an electronic device, and executing a maximum rated current control for the estimated AC adapter. When the method of Patent Document 1 is used to identify a system in a generally used power conversion device, the system connected to the generally used power conversion device differs greatly among users.

General-purpose power conversion devices are used for light-loaded systems such as fans and pumps, medium-loaded systems such as conveyors and coilers, and heavy-loaded systems such as cranes and elevators. Therefore, the combination of the system varies from user to user, and its load current and operating frequency are also quite different. Therefore, in a general-purpose power conversion device, when the method shown in Patent Document 1 is used to estimate the connected system and detect the maximum rated current required by the power conversion device, since the system differs from user to user, there are applications and loads. There are many combinations of current and operating frequency, which is a very difficult issue to estimate.

In addition, in Patent Document 1, the load current of the AC adapter connected to the personal computer can be estimated in advance. On the other hand, in the power conversion apparatus, the magnitude and frequency of increase and decrease of the current flowing in the power conversion apparatus differ depending on the system connected by the user and the operation of the power conversion apparatus set by the user. Therefore, when a user selects a power conversion device, if a power conversion device with a large margin for the system constructed by the user is used, there is no problem in the operating state, but a very large cost is incurred. On the other hand, if the power conversion device is carefully selected according to the system constructed by the user, it is necessary to confirm the operating state by a test run, and it is difficult to easily determine whether the power conversion device is optimal or excessive.

Technical solutions for solving problems

In order to solve the above-mentioned problems, a power conversion device of the present invention is characterized by comprising: an AC conversion unit that outputs AC power; a current detection unit that detects a current flowing in the AC conversion unit; a storage unit that stores current behavior detected by the current detection unit; A judging part for the optimum value of the rated current value; and a display operation part for command operation and output display, the judging part receives the rated value judgment command from the display operation part, and operates the current input from the storage part and the specified rated capacity by operating The optimum value of the rated current value is determined by comparing the various current reference values below, and the setting output of the optimum value of the rated current value is displayed on the display operation unit.

Invention effect

According to the present invention, it is possible to provide a mechanism for automatically determining an optimum power conversion device suitable for a system constructed by a user and setting its rating.

Problems, structures, and effects other than those described above will be explained by the description of the following embodiments.

Description of drawings

FIG. 1 is a diagram showing an example of the configuration of a power conversion device according to Embodiment 1 of the present invention.

FIG. 2 is a flowchart showing a flow of determination by the optimum determination unit 112 included in the power conversion device of the first embodiment.

FIG. 3 is a diagram showing an example of the current operation detected based on the acquisition command of the automatic setting in the first embodiment.

4 is a table showing the relationship between a plurality of power conversion devices having different rated motor capacities, and a plurality of rated currents and a plurality of protection currents in the first embodiment.

FIG. 5 shows a state in which the display operation unit 115 of the first embodiment is in a display state.

6 is a diagram showing an example of a current operation detected based on an acquisition command of automatic setting in the second embodiment.

FIG. 7 is a diagram showing an example of the current operation detected based on the acquisition command of the automatic setting in the third embodiment.

8 is a table showing a reference example of the rated current and cycle of the power conversion device of Example 3. FIG.

9 is a table showing the relationship between a plurality of power conversion devices having different rated motor capacities, and a plurality of rated currents and a plurality of protection currents in the fourth embodiment.

FIG. 10 is a diagram showing an example of the configuration of a power conversion device according to Embodiment 5 of the present invention.

11 is a flowchart showing a flow of determination by the optimum determination unit 112 included in the power conversion device of the fifth embodiment.

FIG. 12 is a diagram showing an example of the temperature operation detected based on the acquisition command of the automatic setting in the fifth embodiment.

13 is a table showing a reference example of the operating temperature and cycle of the power conversion device of the fifth embodiment.

Detailed ways

As an embodiment of the present invention, Examples 1 to 5 will be described below with reference to the drawings.

In each of the following embodiments, an operation example in the case of determining an optimum power conversion device and its rated value by automatic setting during a test operation of a power conversion device for driving an AC load such as an AC motor connected to a user system will be described.

Example 1

FIG. 1 is a diagram showing a configuration of a power conversion device according to Embodiment 1 of the present invention, and an example of an AC motor used in a user system connected to the power conversion device.

The power conversion device of the present invention includes a three-phase AC power supply 101 , a DC conversion unit 102 , a smoothing capacitor 103 , an AC conversion unit 104 , a current detector 106 , a control unit 111 , an optimum determination unit 112 , a storage unit 113 , and a current detection unit 114 and display operation unit 115 . Then, the AC motor 105 is driven to operate by the power conversion device of the present invention.

The three-phase AC power supply 101 is, for example, a three-phase AC voltage supplied from a power company or an AC voltage supplied from a generator, and is an input to the DC converter 102 .

The DC conversion unit 102 is constituted by, for example, a DC conversion circuit using a diode, a DC conversion circuit using an IGBT and a freewheeling diode, or the like. The DC converter 102 converts the AC voltage input from the three-phase AC power supply 101 into a DC voltage and outputs the DC voltage to the smoothing capacitor 103 . The DC conversion unit 12 shown in FIG. 1 is an example of a DC conversion unit composed of diodes.

The smoothing capacitor 103 smoothes the DC voltage input from the DC converter 102 and outputs it to the AC converter 104 . In addition, when the output of the generator is a DC voltage, the smoothing capacitor 103 may directly input the DC voltage from the generator without going through the DC converter 102 .

The AC conversion unit 104 is constituted by, for example, an AC conversion circuit using an IGBT and a freewheeling diode. Using the DC voltage of the smoothing capacitor 103 as an input, the DC voltage is converted into an AC voltage in accordance with an output command from the control unit 111 , and output to the AC motor 105 . In addition, when the AC converter 104 is constituted by an AC converter that performs AC-AC conversion without the smoothing capacitor 103 , the input AC voltage may be converted into an AC voltage of a different frequency and output to the AC motor 105 .

The current detector 106 is formed of, for example, a Hall CT and/or a shunt resistor. The current detector 106 is disposed on the output side of the power conversion device, detects the AC current flowing in the AC motor 105 , and outputs the detected current to the current detection unit 114 as detected current data. The current detector 106 may be arranged at any position as long as it is arranged at a location where the output current flowing in the AC converter 104 can be estimated or directly detected. FIG. 1 is an example of detecting the current flowing in the AC motor 105 .

The control unit 111 issues a PWM output command to the AC conversion unit 104 using the current operation data of the detected current fed back from the current detection unit 114 in accordance with the output command calculated from the command for driving the AC motor 105 .

The optimum determination unit 112 determines that the input information is trigger information for current operation detection based on the current operation detection command input from the display operation unit 115 , and instructs the storage unit 113 to acquire the current operation. The current operation detection command instructed by the display operation unit 115 is, for example, an ON/OFF signal command, a signal indicating a running state, a time specification from the start of setting, and the like. Here, when it is determined that it is finished, the current operating characteristics stored in the storage unit 113 are acquired. The optimum determination unit 112 determines the optimum value of the rated value based on the current operation input from the storage unit 113 and outputs it to the display operation unit 115 .

The storage unit 113 is composed of, for example, an element (RAM or the like) that temporarily stores data, an EEPROM or a data flash ROM that retains the storage even when the power is turned off, and uses commands from the display operation unit 115 as set value data, and the current detection unit The current operation data of 114 are respectively stored as detection value data. The storage unit 113 outputs the current operation data to the optimum determination unit 112 .

The current detection unit 114 converts, for example, detected current data input from the current detector 106 into current operation data for calculation, and outputs the data to the control unit 111 and the storage unit 113 .

The display operation unit 115 displays a user interface such as a smartphone, a smart watch, a tablet terminal, or a personal computer having an operation panel and input/output terminals, for example. For example, input information operated by a user or an input signal obtained from an external device is output to the optimum determination unit 112 .

FIG. 2 is a flowchart showing the flow of automatic setting performed by the optimum determination unit 112 .

When the optimum determination unit 112 performs rated value determination by automatic setting, first, in order to start rated value determination, in step 201 ( S201 ), the trigger information ( S201).

In step 202 ( S202 ), the optimum determination unit 112 determines whether or not there is a trigger to start determination, and when a trigger occurs (Yes), in step 203 ( S203 ), a current operation acquisition command is issued to the storage unit 113 .

In step 204 (S204), the optimum determination unit 112 inputs the rated value determination command from the display operation unit 115, and updates the state of the current operation acquisition command.

In step 205 ( S205 ), the optimum determination unit 112 determines whether or not the state of the updated current operation acquisition command satisfies the operation acquisition end condition ( S205 ), and if the operation acquisition end condition is not satisfied (NO), the process returns to the step 203 ( S203 ), the current operation acquisition command is continued to the storage unit 113 . When the motion acquisition termination condition is satisfied (Yes), the optimum determination unit 112 determines whether or not the operation has been terminated normally in step 206 (S206).

For example, when it is determined that one cycle of operation is to be performed, the optimal determination unit 112 acquires the operation state from the control unit 111, and causes the storage unit 113 to acquire the current operation at the time of starting the operation, and at the time of stopping the operation. It is judged to be over. In addition, when the user wants to determine the setting of the rated value based on the actions of the day, the action setting is performed by the display operation unit 115, and the optimum determination unit 112 uses the acquired start signal as a trigger, and performs 24 hours from the input of the start signal. The judgment ends after the count.

The optimum judgment unit 112 detects the normal end (Yes) based on the judgment of the normal end in step 206 (S206), acquires the current operation in step 207 (S207), and then obtains the current operation in step 208 (S208) according to the current Action judges the optimum value of the rated value. Here, the acquired current behavior may be, for example, current waveform data in the detection state, or may be stored in the allowable level of the current setting determined in advance by the power conversion device, and how often and how long to exceed it. data for this tolerance level. Then, the optimum determination unit 112 notifies the display operation unit 115 of the optimum value of the rated value in step 209 (S209).

On the other hand, when the optimal determination unit 112 detects an abnormal end in step 206 (S206) (NO), the optimal determination unit 112 acquires the current operation in step 210 (S210), and determines that there is an error due to the current operation. If there is a possibility that the rated capacity of the currently operating power conversion device is insufficient, if the error is caused by other reasons, it is determined that there is a system abnormality, and the determination result is notified to the display operation unit 115 in step 211 (S211) (S211).

FIG. 3 is a diagram showing an example of a current operation detected based on an acquisition command of automatic setting in Embodiment 1. FIG.

In FIG. 4 , (1) shows an example of a plurality of power conversion devices with different rated capacities determined according to the applicable AC motor capacity, and (2) shows the relationship between a plurality of rated currents and a plurality of protective currents. In addition, the apparatus used in the test run in Example 1 is the apparatus 1. FIG. In addition, the rated capacity is expressed by the product of the rated voltage and the rated current. When the voltage is constant, the rated capacity and the rated current are in an equivalent relationship.

FIG. 3 shows the state of the start and end of automatic setting (current operation detection section) determined by the output state. Here, the optimum determination unit 112 operates on the basis of the detected current, and detects for how many periods currents of various current reference values or more at the rated capacity determined in advance for each power conversion device flow. Then, the respective settings of the rated capacity and the rated current are comprehensively determined by the optimum determination unit 112 based on, for example, the temperature characteristics of the hardware of the AC conversion unit 104 and the like. Among the plurality of power conversion devices having a capacity series, the power conversion device with a higher rated current is generally more expensive. For example, in Figure 4, device 1 has the highest price and device 3 has the lowest price. The characteristics of a single power conversion device are that the higher the rated current, the more rapid protection is required when the rated current is exceeded, and the lower the limit value such as the operating temperature, the lower the level of error occurrence relative to the rated current. For the setting of the protection current, for example, as shown in the relationship between (1) and (2) in Fig. 4 , it can withstand 110% of the rated current for 60 seconds at the rated value of 6-1, and at the rated value of 6-2. 60 seconds at 120% of rated current, 60 seconds at 150% of rated current at 6-3 and 60 seconds at 180% of rated current at 6-4 until protection occurs component error. These currents can be set with leeway relative to the damage level of the element.

The optimum determination unit 112 measures the time based on the current operation acquired by the storage unit 113 . The optimal determination unit 112 may acquire the current operation from the storage unit 113 in real time (in FIG. 2 , in step 204 ( S204 )), or may acquire it together after the current acquisition command is completed (in FIG. 2 , in step 207 ). (obtained in S207). In the current operation shown in FIG. 3 , for example, 38A is continuously operated for 60 seconds (a-1), 28A is continuously operated for 100 seconds (b-1), and 28A is continuously operated for 400 seconds (c-1). situation. The optimum determination unit 112 may measure the excess time of the current based on, for example, the current value determined in advance by the characteristics of the power conversion device shown in FIG.

Here, the optimum determination unit 112 can determine, based on various current reference values, that the rated current value needs to exceed 28 A in order to operate at 30 A or less for 60 seconds or longer, for example. That is, in the table concerning the rated current of FIG. 4( 1 ), the combination of the device and the rated value exceeding the rated current value of 28 A becomes a candidate. That is, as candidates from the rated current value, in device 1 are rated values 6-1, 6-2 and 6-3, in device 2 are rated values 6-1 and 6-2, in device 3 is rated value 6- 1.

In addition, the optimum determination unit 112 can determine that in order to operate at 38A for 60 seconds in the current operation shown in FIG. 3 , it is necessary to select a protection current value exceeding 38A. That is, in the table concerning the protection current of FIG. 4(2), the combination of the device and the rated value which exceeds the protection current value of 38A becomes a candidate. That is, as candidates from the protection current value, the rated values 6-1, 6-2, and 6-3 in the device 1, and the rated value 6-1 in the device 2.

Then, the optimum determination unit 112 selects the device and the rated value from candidates satisfying both the rated current value and the protection current value. For example, in Example 1, the rated value 6-1 of the device 2 can be selected which is lower in price than the device 1, so it is determined that the rated value 6-1 of the device 2 is optimal.

In addition, the optimum determination unit 112 may determine the optimum value of the rated value for each power conversion device. In the case of using the device 1, since the operating temperature limit is high and there is room for errors to occur, it can determine the candidate device 1. A rating of 6-3 is optimal, allowing the user to select the best setting from multiple candidates.

Furthermore, in the first embodiment, the optimum determination unit 112 can automatically set the optimum rated value setting of the device 1 itself as the optimum setting value for the determination of the automatic setting. Change the settings of device 1.

FIG. 5 is a diagram showing a state in which the display operation unit 115 receives a notification of the optimum value from the optimum determination unit 112 and displays the state thereof. When the user selects the optimum value to be displayed, the display operation unit 115 may automatically change the setting of the power conversion device without displaying it, if it is the setting of the device 1 itself, or may output “whether to apply or not”. Setting?" and other messages are displayed as content, and settings are automatically made in the power conversion device with the user's consent. In addition, the display operation unit 115 may output “replacement to be replaced by the device 2 when the user designates the device 2 even though the test operation was performed with the device 1 in the first embodiment, for example, when the optimum device is different from that during the test operation. Device 2." and other messages are displayed as the content to indicate the necessity of changing the device.

As described above, the optimum power conversion device and its rated value setting can be determined.

Example 2

This embodiment is a modification of the first embodiment, and since the configuration of the second embodiment has the same function as the configuration shown in FIG. 1 to which the same reference numerals have already been added, the description thereof will be omitted.

In the second embodiment, it is assumed that the user system connected to the AC motor 105 has a heavier load than that in the first embodiment.

6 is a diagram showing an example of a current operation detected based on an acquisition command of automatic setting in the second embodiment.

FIG. 6 shows a situation where the operating current increases (increases) to a current level that the power conversion device considers to be abnormal. The optimum determination unit 112 starts the determination operation with the output state as a trigger in the same manner as in the first embodiment, according to the flow shown in FIG. 2 . For example, when the current error level of the current conversion device is 80A, an error occurs when the operating current reaches 80A, and the status is updated (step 204 ( S204 ) in FIG. 2 ). When an error is detected, the optimum determination unit 112 determines that it has ended abnormally (step 206 ( S206 ) in FIG. 2 ), and acquires a current operation (step 210 ( S210 ) in FIG. 2 ).

In the second embodiment, since it is determined as abnormal based on the error of the detected current operation, the optimal determination unit 112 determines that there is a possibility that the rated capacity and rated current of the power conversion device are low, and notifies the display operation unit 115 of the abnormality. And the notification capacity is insufficient. The display operation unit 115 displays a state of abnormal end and insufficient capacity of the power conversion device. As a result, if there is no abnormality in the system operation, the user can determine that a higher capacity is required.

As described above, it is possible to determine whether or not the rated value setting is permitted even when the power conversion device of the capacity required by the system is not installed.

Example 3

The present embodiment is also a modification of the first embodiment, and the configuration of the third embodiment has the same function as the configuration shown in FIG. 1 to which the same reference numerals have already been added, so the description thereof will be omitted.

In the third embodiment, the current operation detection command received by the display operation unit 115 and the determination content of the optimum determination unit 112 are different from those in the first embodiment. In Example 3, in order to judge based on the daily operation of the user system, regardless of the output of the power conversion device, for example, 24 hours are measured from the time specified by the user, and the detection is automatically terminated after the current operation is detected.

FIG. 7 is a diagram showing an example of the current operation detected based on the acquisition command of the automatic setting in the third embodiment.

FIG. 8 is a table showing a reference example of the rated current value and the power cycle of the power conversion device. The power cycle is, for example, the number of cycles in the life determined by the thermal stress of the IGBT module, and can be calculated from the power cycle tolerance provided by the IGBT device manufacturer or the like based on the rise and fall of the temperature of the module. In Example 3, the temperature rises due to the flow of electric current through the module, and the temperature drops due to interruption of the electric current. Therefore, FIG. 7 schematically shows an example of the number of power cycles per day as a life based on the current operation.

The detected current operation in FIG. 7 shows, for example, a state of being connected to a system that performs stable operation with a current value of 25 A or less for 20 cycles in one day's operation. The optimum determination unit 112 may measure based on, for example, the rated current value and the power cycle previously determined by the characteristics of the power conversion device shown in FIG. 8 , and does not necessarily need to obtain all continuous current values for determination.

The optimum determination unit 112 determines, based on the detected current operation in FIG. 7 , a device that can perform an operation with a current value of 25 A and 20 cycles or more. That is, in the table of FIG. 8 , the combination of the rated current value and the power cycle exceeding 25 A and 20 cycles is a candidate.

As candidates for which both the rated current value and the cycle are satisfied, the rated values 8-2 and 8-3 in device 1 and the rated value 8-2 in device 2. In Example 3, the rated value 8-2 of the device 2 can be selected which is lower in price than the device 1, so it is determined that the rated value 8-2 of the device 2 is the best.

In addition, the optimum determination unit 112 may determine the optimum value of the rated value for each power conversion device. In the case of using the device 1 in FIG. 8 , since the operating temperature limit is high and there is room for errors to occur, it is determined that the rated value 8-3 of the device 1 among the candidates is optimal. Alternatively, the user may be asked to select an optimal setting from a plurality of candidates.

As described above, the optimum power conversion device and its rated value setting can be determined.

Example 4

The present embodiment is a modification of the first embodiment, and the configuration of the fourth embodiment has the same function as the configuration shown in FIG. 1 to which the same reference numerals have already been added, so the description thereof will be omitted.

In the fourth embodiment, the content of determination by the optimum determination unit 112 is different from that in the first embodiment. Embodiment 4 is suitable, for example, when the user wants to select a power conversion device with leeway. Specifically, it is assumed that the user wants to set the rated current with a margin of 10 A compared to the standard selected reference value.

When 10 A is set as the margin value in the power conversion device by the display operation unit 115, in the determination of the rated current value performed in the first embodiment, the optimum determination unit 112 determines the reference value of FIG. 4(1) Judgment is performed by subtracting all 10A as shown in FIG. 9(1). That is, in the current operation shown in FIG. 3 , the optimal determination unit 112 shows, for example, that the operation continued at 38A for 60 seconds (a-1), the operation continued at 28A for 100 seconds (b-1), and the operation continued at 28A. 400 seconds (c-1) condition.

The optimum determination unit 112 can determine that, for example, in order to operate at 30 A or less for 60 seconds or longer, the rated current value needs to exceed 28 A. That is, in the table concerning the rated current of FIG. 9( 1 ), the combination of the device and the rated value exceeding the rated current value of 28 A is a candidate. As candidates from the rated current values, in device 1 are rated values 9-1 and 9-2, in device 2 is rated value 9-1.

In addition, the optimum determination unit 112 can determine that in order to operate at 38A for 60 seconds, it is necessary to select a protection current value exceeding 38A. That is, in the table concerning the protection current of FIG. 9(2), the combination of the device and the rated value exceeding the protection current value of 38A becomes a candidate. Here, as in the first embodiment, the protection current value is calculated based on the ratio to the rated current value. As a candidate from the protection current value, the device 1 has only the rated value 9-1, so the optimum determination unit 112 determines that the rated value 9-1 of the device 1 as a candidate satisfying both the rated current value and the protection current value is the best good.

As described above, it is possible to determine an optimal power conversion device with margin and its rated value setting.

Example 5

The present embodiment is a modification of the first embodiment, and the configuration of the fifth embodiment has the same function as the configuration shown in FIG. 1 to which the same reference numerals have already been added, so the description thereof will be omitted.

10 is a diagram showing an example of the configuration of the power conversion device of the fifth embodiment and an AC motor used in a user system connected to the power conversion device.

The first embodiment focuses on the current operation, whereas the fifth embodiment focuses on the temperature operation. Compared with the first embodiment, the temperature detector 1001 and the temperature detection unit 1014 are provided, and the determination content of the optimum determination unit 112 is different. .

The temperature detector 1001 is, for example, a thermistor or the like, detects the temperature of the six IGBTs arranged in the AC conversion unit 104 , and outputs detected temperature data to the temperature detection unit 1014 .

The temperature detection unit 1014 converts the detected temperature data input from the temperature detector 1001 into temperature operation data for calculation, and outputs the data to the control unit 111 and the storage unit 113 .

In addition, the detection value data stored in the storage unit 113 is temperature operation data from the temperature detection unit 1014 . The storage unit 113 outputs the temperature operation data to the optimum determination unit 112 .

FIG. 11 is a flowchart showing the flow of automatic setting performed by the optimum determination unit 112 . The steps that perform the same operations as in FIG. 2 are given the same symbols.

Hereinafter, only steps different from the operations of the flowchart shown in FIG. 2 will be described.

In step 202 ( S202 ), when the optimum determination unit 112 determines that a trigger to start determination has occurred (Yes), in step 1103 ( S1103 ), a temperature action acquisition command is issued to the storage unit 113 .

In step 206 ( S206 ), the optimum determination unit 112 determines whether the temperature operation acquisition has been completed normally or abnormally. For example, when determining in one cycle of operation, the optimal determination unit 112 acquires the operation state from the control unit 111, acquires the temperature action from the storage unit 113 at the time of starting the operation, and determines at the time when the operation is stopped. Finish. In addition, for example, when the user wants to determine the setting of the rated value based on the actions of one day, the action setting is performed by the display operation unit 115, and the optimum determination unit 112 uses the acquired start signal as a trigger, and performs 24 hours from the input of the start signal. It is judged to be finished after the count of .

In step 206 (S206), when the optimum determination unit 112 detects that the acquisition of the temperature operation has been completed normally (Yes), the temperature operation is acquired in step 1107 (S1107), and then in step 208 (S208), the operation is performed according to the temperature Determine the optimum value of the rated value. Here, the acquired temperature action may be, for example, the temperature waveform data in the detection state, or may be stored in the allowable level of the temperature setting determined in advance by the power conversion device, and how often it is stored. Time exceeds this tolerance level for data.

On the other hand, in step 206 (S206), when the optimum determination unit 112 detects that the acquisition of the temperature operation has ended abnormally (No), the temperature operation is acquired in step 1110 (S1110), and if it is an error based on the temperature operation, Then it is determined that there is a possibility that the rated capacity of the currently operating power conversion device is insufficient. If the error is caused by other reasons, it is determined that there is a system abnormality, and the display operation unit 115 is notified of the determination result in step 211 (S211). .

FIG. 12 is a diagram showing an example of the temperature operation detected based on the acquisition command of the automatic setting in the fifth embodiment. In addition, FIG. 13 is a table showing a reference example of the operating temperature and the power cycle of the power conversion device.

The detected temperature operation in FIG. 12 shows, for example, a state of being connected to a system that performs 20 cycles of stable operation at 80° C. or lower in one day’s operation. The optimum determination unit 112 may measure based on, for example, the temperature and power cycle previously determined by the characteristics of the power conversion device shown in FIG. 13 , and does not necessarily need to acquire all continuous temperatures for determination.

The optimum determination unit 112 operates based on the temperature detected in FIG. 12 , and determines an apparatus that can operate at 80° C. and 20 cycles or more. That is, in the table of FIG. 13 , a combination of temperature and power cycle at 80° C. and 20 cycles or more is a candidate. As candidates for which both temperature and power cycling are satisfied, device 1 is rated 12-1 and 12-2, device 2 is rated 12-1, and device 3 is rated 12-1. In Example 5, since the rated value 12-1 of the device 3 which is lower in price than the device 1 and the device 2 can be selected, it is determined that the rated value 12-1 of the device 3 is optimal.

In addition, the optimum determination unit 112 may determine the optimum rated value for each power conversion device. In the case of device 1, since the operating temperature limit is high and there is room for errors to occur, it determines the rated value of device 1 among candidates. 12-2 is optimal. Alternatively, the user may be asked to select the optimum setting from among a plurality of candidates.

As described above, even in the case of focusing on the temperature operation, it is possible to determine the optimum power conversion device and its rated value setting.

In addition, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-mentioned embodiments are described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to all the configurations described. In addition, a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can also be added to the configuration of a certain embodiment. In addition, other structures can be added, deleted, or replaced with respect to a part of the structures of the respective embodiments.

In addition, with regard to the processing (function) and the like executed by the above-mentioned optimum determination unit, a part or all of it may be realized by hardware, for example, by designing in an integrated circuit or the like, or it may be realized by interpretation and execution by a processor not shown. A program of processing (function) is implemented in software. Information such as programs, tables, and files used for it can be stored in a memory, a recording device such as a hard disk, and an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, and a DVD.

Description of reference numerals

101...Three-phase AC power supply, 102...DC conversion unit, 103...Smoothing capacitor, 104...AC conversion unit, 105...AC motor, 106...Current detector, 111...Control unit, 112...Optimal judgment unit, 113...Storage part, 114...current detection part, 115...display operation part, 1001...temperature detector, 1014...temperature detection part.

Claims (9)

1. A power conversion apparatus, characterized by comprising:

an AC conversion unit for outputting AC power;

a current detection unit that detects a current flowing through the ac conversion unit;

a storage unit for storing the current operation detected by the current detection unit;

a judging section for judging an optimum value of the rated current value; and

a display operation section for instructing operation and outputting display,

the determination unit receives a rated value determination command from the display operation unit, determines an optimum value of a rated current value by comparing the current operation input from the storage unit with various current reference values at a predetermined rated capacity, and displays a setting output of the optimum value of the rated current value on the display operation unit.

2. The power conversion apparatus according to claim 1, characterized in that:

the storage unit stores the current operation only during an effective period of the rated value determination command,

the current operation input from the storage unit is the current operation stored in the storage unit only in the active period.

3. The power conversion apparatus according to claim 1 or 2, characterized in that:

the current operation input from the storage unit is a frequency and a time when the detected current exceeds a current allowable level determined by the power conversion device.

4. The power conversion apparatus according to claim 1 or 2, characterized in that:

the determination unit selects a rated current value closest to an optimum value of the rated current values from among a plurality of rated current values provided to the power conversion device or a plurality of rated current values provided to other power conversion devices having rated current values different from the power conversion device, based on the applicable load.

5. The power conversion apparatus according to claim 4, characterized in that:

the determination unit receives the setting of the margin current value from the display operation unit, and selects the rated current value closest to a value lower than the optimum value of the rated current value by the margin current value from the plurality of rated current values provided in the power conversion device or the other power conversion devices.

6. A power conversion apparatus, characterized by comprising:

an AC conversion unit for outputting AC power;

a current detection unit that detects a current flowing through the ac conversion unit;

a storage unit for storing the current operation detected by the current detection unit;

a judging section for judging an optimum value of the rated current value; and

a display operation section for instructing operation and outputting display,

the determination unit receives a rated value determination command from the display operation unit, determines a combination of an optimum value of a rated current value and a power cycle by comparing the current operation for a predetermined period input from the storage unit with a characteristic of the power cycle indicating a lifetime of a semiconductor element module constituting the ac conversion unit, and displays a setting output of the combination on the display operation unit.

7. A power conversion apparatus, characterized by comprising:

an AC conversion unit for outputting AC power;

a temperature detection unit that detects a temperature generated in the ac conversion unit;

a storage unit for storing the temperature operation detected by the temperature detection unit;

a judging section for judging an optimum value of the rated current value; and

a display operation section for instructing operation and outputting display,

the determination unit receives a rated value determination command from the display operation unit, determines a combination of an optimum value of a rated current value and a power cycle by comparing the temperature operation for a predetermined period input from the storage unit with a characteristic of the power cycle indicating a lifetime of a semiconductor element module constituting the ac conversion unit, and displays a setting output of the combination on the display operation unit.

8. The power conversion apparatus according to claim 1 or 6, characterized in that:

the determination unit determines that there is a possibility that the rated capacity of the power conversion device is insufficient if the error is due to the current operation input from the storage unit when the error information of the power conversion device is detected, determines that there is a system abnormality if the error is due to a factor other than the current operation, and outputs and displays the determination result to the display operation unit.

9. The power conversion apparatus according to claim 7, characterized in that:

the determination unit determines that there is a possibility that the rated capacity of the power conversion device is insufficient if the error is due to the temperature operation input from the storage unit when the error information of the power conversion device is detected, determines that there is a system abnormality if the error is due to a factor other than the temperature operation, and outputs and displays the determination result to the display operation unit.

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