CN116418240A - Bidirectional alternating current power conversion device - Google Patents
Bidirectional alternating current power conversion device Download PDFInfo
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- CN116418240A CN116418240A CN202111652459.6A CN202111652459A CN116418240A CN 116418240 A CN116418240 A CN 116418240A CN 202111652459 A CN202111652459 A CN 202111652459A CN 116418240 A CN116418240 A CN 116418240A
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- 238000006243 chemical reaction Methods 0.000 title claims abstract description 99
- 230000002457 bidirectional effect Effects 0.000 title abstract description 19
- 230000002159 abnormal effect Effects 0.000 claims abstract description 10
- 238000012360 testing method Methods 0.000 claims description 5
- 230000007246 mechanism Effects 0.000 description 12
- 239000003990 capacitor Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000004146 energy storage Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 230000005856 abnormality Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- 230000008859 change Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
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Abstract
The application provides a bidirectional alternating current power conversion device, which comprises a power conversion module and a digital control module. The power conversion module sets the input or output first alternating current energy according to the control signal. The digital control module comprises a phase-locked loop and a control unit. The phase-locked loop detects the input or output first alternating current energy and generates a real-time voltage signal, wherein the real-time voltage signal is defined with an amplitude component and an angular velocity component. The control unit sets the control signal according to the amplitude component and at least one amplitude variation obtained in different switching periods. The control unit calculates at least one amplitude variation according to the amplitude components obtained in different switching periods, and when the amplitude components or the at least one amplitude variation are abnormal, the control signal instructs the power conversion module to stop inputting or outputting the first alternating current energy.
Description
Technical Field
The present invention relates to a bidirectional ac power conversion device, and more particularly, to a bidirectional ac power conversion device capable of cutting off a component to be tested at any time.
Background
Conventionally, when an ac power conversion device is used to pump current to a component to be tested, if the component to be tested needs to be disconnected (electrical connection is interrupted) from the ac power conversion device, the pump current of the ac power conversion device needs to be reset first, so that the component to be tested can be disconnected from the ac power conversion device safely. If the component to be tested is not separated from the alternating current power conversion device in an early warning way, the alternating current power conversion device is often enabled to trigger a protection mechanism, and the work cannot be quickly recovered. In one example, if the component to be tested has no early warning to disconnect the output end of the ac power conversion device, the ac power conversion device still continuously draws current to the output end that has already formed an open circuit because the ac power conversion device cannot immediately determine that the component to be tested has disconnected the output end. In this case, the output end of the ac power conversion device may bear an abnormally high voltage, so that the conventional ac power conversion device may directly trigger the protection mechanism in order to avoid the ac power conversion device from being damaged. Once the protection mechanism is triggered, the conventional ac power conversion device may need to be checked in a certain step to release the protection mechanism even if the component to be tested is connected again, so that the current pumping operation of the component to be tested cannot be quickly recovered.
Accordingly, there is a need for a new ac power conversion device that does not enter into the protection mechanism when the device under test is disconnected and can effectively protect the internal components. And when the component to be tested is connected again, the work of pumping current of the component to be tested can be quickly recovered, and the elasticity of the component to be tested can be adjusted at any time.
Disclosure of Invention
The technical problem to be solved in the application is to provide a bidirectional alternating current power conversion device which can judge whether a component to be tested is cut off from an output end or not more sensitively. When the component to be tested has no early warning cut-off output end, the bidirectional alternating current power conversion device can immediately detect and stop inputting or outputting alternating current power, and the component to be tested can not enter a protection mechanism and can effectively protect internal components.
The application provides a bidirectional alternating current power conversion device which is used for inputting or outputting first alternating current electric energy and comprises a power conversion module and a digital control module. The power conversion module sets the input or output first alternating current energy according to the control signal. The digital control module comprises a phase-locked loop and a control unit. The phase-locked loop is electrically connected with the power conversion module and is used for detecting the input or output first alternating current electric energy and generating a real-time voltage signal, wherein the real-time voltage signal is defined with an amplitude component and an angular velocity component. The control unit is electrically connected with the power conversion module and the phase-locked loop, and sets a control signal according to the amplitude component and at least one amplitude variation obtained in different switching periods. The control unit calculates at least one amplitude variation according to the amplitude components obtained in different switching periods, and when the control unit judges that the amplitude components or the at least one amplitude variation are abnormal, the control signal instructs the power conversion module to stop inputting or outputting the first alternating current energy.
In some embodiments, the control unit may determine the amplitude variation of each of the plurality of consecutive switching periods, and determine that the amplitude variation is abnormal when the amplitude variation of each of the plurality of consecutive switching periods is greater than the first threshold. In addition, the control unit may determine an amplitude component of each of the plurality of consecutive switching periods, and when the amplitude component of each of the plurality of consecutive switching periods is not greater than the second threshold, the control unit may determine that the amplitude component is abnormal. In addition, the control signal may be used to instruct the duty ratio of the power conversion module, and when the control unit determines that the duty ratio is greater than the third threshold, the control unit may set the control signal to instruct the power conversion module to stop inputting or outputting the first ac power.
In some embodiments, the phase detector may perform park conversion on the real-time voltage signal to obtain an amplitude component and an angular velocity component. In addition, the power conversion module may pull the first ac power to the component to be tested via the output terminal, or supply the first ac power to the component to be tested.
In summary, the bidirectional ac power conversion device provided in the present application uses the phase-locked loop to lock the input or output first ac power, and determines whether the component to be tested is separated from the output terminal according to the amplitude component of the real-time voltage signal. When the component to be tested has no early warning cut-off output end, the bidirectional alternating current power conversion device can immediately detect and stop inputting or outputting alternating current power, and the component to be tested can not enter a protection mechanism and can effectively protect internal components.
Other details of the other functions and embodiments of the present application are described below with reference to the drawings.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a functional block diagram of a bi-directional AC power conversion apparatus according to an embodiment of the present application;
fig. 2 is a schematic diagram of an ac voltage.
Symbol description
1 bidirectional ac power conversion device 10 power conversion module
100 output 12 digital control module
120 phase-locked loop 122 control unit
2 external Power DUT component to be tested
Detailed Description
The positional relationship described in the following embodiments includes: the upper, lower, left and right, unless otherwise indicated, are relative to the orientation of the elements shown in the drawings.
Referring to fig. 1, fig. 1 is a functional block diagram of a bi-directional ac power conversion device according to an embodiment of the present application. As shown in fig. 1, the bi-directional ac power conversion apparatus 1 is electrically connected between an external power source 2 and a DUT, and is used for transmitting ac power (first ac power) to the DUT. In practice, the external power source 2 may be a mains or other voltage source, while the component DUT to which the bi-directional ac power conversion device 1 may be applied is not limited to a load or voltage source. In one example, the bi-directional ac power conversion apparatus 1 may provide power to drive the DUT when the DUT is a load. When the component DUT is a voltage source, the bi-directional ac power conversion apparatus 1 may draw power from the component DUT so that the power provided by the component DUT can be fed to the external power source 2. That is, the bidirectional ac power conversion device 1 does not limit the transmission direction of the ac power that can be input to or output from the bidirectional ac power conversion device 1.
The bi-directional ac power conversion device 1 comprises a power conversion module 10 and a digital control module 12, wherein the digital control module 12 comprises a phase-locked loop 120 and a control unit 122. The power conversion module 10 has an output terminal 100, and the output terminal 100 is used for electrically connecting to a DUT. In one example, the connection between the output 100 and the DUT may be via a bus. In addition, the control unit 122 is electrically connected to the phase-locked loop 120 and the power conversion module 10, and is capable of generating a control signal to set the first ac power to be input or output by the power conversion module 10. The control signal may be a Pulse Width Modulation (PWM) signal, and the control unit 122 may set various parameters of the ac voltage or the ac current output by the power conversion module 10 by determining a duty ratio (duty ratio) of the PWM signal in one duty cycle (duty cycle).
In practice, the phase-locked loop 120 has a phase detector (phase detector) that locks the ac voltage or the ac current transmitted between the power conversion module 10 and the DUT after the output terminal 100 and the DUT are connected. For example, assuming that the power conversion module 10 is set to pull the DUT, the PLL 120 can generate a real-time voltage signal according to the locked AC voltage after the phase detector locks the AC voltage. In one example, the PLL 120 generates a real-time voltage signal that can be used as a means for determining whether the DUT is operating properly. That is, when the phase detector successfully locks the ac voltage (generates the real-time voltage signal), the control unit 122 can determine that the DUT has been put into the system. In addition, the phase-locked loop 120 may perform park conversion (park transformation) on the real-time voltage signal to obtain an amplitude component and an angular velocity component of the real-time voltage signal. One skilled in the art should understand the working principle of the pll 120, and the disclosure of this embodiment is omitted here. In one example, the pll 120 may obtain a corresponding real-time voltage signal in each switching cycle, so that the control unit 122 may calculate a difference between two amplitude components, i.e. an amplitude variation, according to the real-time voltage signals of two adjacent switching cycles. In practice, the control unit 122 may record corresponding N-1 amplitude variation amounts according to the real-time voltage signals of N consecutive switching periods, and may set the control signal according to the N-1 amplitude variation amounts.
As a practical example, assume that the power conversion module 10 is set to pull the DUT, and the connection line between the output terminal 100 and the DUT is suddenly interrupted, so that the DUT is disconnected from the output terminal 100 without warning. Since the ac power is originally transmitted between the bidirectional ac power conversion device 1 and the DUT, the ac voltage at this point may be near the peak voltage or near the zero voltage when the DUT is disconnected from the output terminal 100 without warning. The processing manner of the bidirectional ac power conversion device 1 of the present embodiment will be exemplified below in these two cases. Referring to fig. 1 and fig. 2 together, fig. 2 is a schematic diagram of an ac voltage. As shown, the ac voltage is at a value near the peak, assuming the DUT is disconnected from the output 100 at time T1. At this time, the control unit 122 may learn that the amplitude variation suddenly and abnormally increases from the real-time voltage signal (the previous switching period and the current switching period), for example, the voltage rapidly fades from the peak value so that the amplitude variation is greater than the preset first threshold value. In practice, after the control unit 122 determines that the amplitude variation is abnormal, the control signal is quickly adjusted to instruct the power conversion module 10 to stop inputting or outputting the first ac power. For example, the control unit 122 may adjust the control signal to zero the duty cycle, so that the output terminal 100 of the power conversion module 10 maintains zero voltage without inputting or outputting the first ac power.
The actual value of the first threshold is not limited in this embodiment, and it will be understood by those skilled in the art that the first threshold may be determined according to the transmitted ac voltage. On the other hand, the control unit 122 does not necessarily need to adjust the control signal immediately only when an abnormality occurs in accordance with a single amplitude variation amount. For example, the control unit 122 may determine whether the amplitude variation is abnormal from the real-time voltage signal of a plurality of consecutive adjacent switching periods. For example, when the control unit 122 knows that at least 6 consecutive amplitude variations are larger than the preset first threshold, it can determine that the DUT has been cut off the output terminal 100.
In one example, assuming that the DUT is off the output terminal 100 at time T2, the current input or output by the output terminal 100 is originally approaching zero because the AC voltage at time T2 is approaching zero. If the conventional ac power conversion device is used, the conventional ac power conversion device cannot immediately determine whether the component to be tested is disconnected, which is easy to cause erroneous determination. In particular, in the conventional ac power conversion device, errors such as noise and interference exist in a digital current measurement manner, so that it is difficult to determine whether the minute value detected around the current zero point is the current zero point. In other words, when the DUT is cut off around the current zero, the conventional ac power conversion device cannot grasp the timing point of the fast trigger protection mechanism. In contrast, the amplitude component of the present embodiment is a value that has undergone park conversion to separate the angular velocity component (phase), so that the control unit 122 can more quickly see whether there is a change in the voltage amplitude. Accordingly, when the DUT is disconnected from the output terminal 100 at time T2, the control unit 122 of the present embodiment can also determine whether an abnormality occurs according to the amplitude variation and rapidly adjust the control signal, so that the control signal instructs the power conversion module 10 to stop inputting or outputting the first ac power.
The above determination means using the amplitude variation is suitable for the case where the variation of the input or output ac voltage of the power conversion module 10 is large, and if the variation of the input or output ac voltage of the power conversion module 10 is small, the control unit 122 can determine whether the DUT is disconnected by using the amplitude component. In one example, since the voltage peak value of the input or output ac voltage of the power conversion module 10 is known, the present embodiment may set the threshold value (the second threshold value) with reference to the voltage peak value. In practice, the second threshold is not necessarily equal to the voltage peak but may be slightly smaller than the voltage peak, which is not limited by the present embodiment. As a practical example, assume that the power conversion module 10 is set to pull the DUT to be tested, and that the phase detector of the pll 120 has locked the real-time voltage signal to take the amplitude component and the angular velocity component. At this time, the control unit 122 may determine whether the component DUT under test is cut from whether one or more amplitude components are below the second threshold. For example, the control unit 122 may record the amplitude components of the continuous switching periods, and when the amplitude components of the continuous switching periods are continuously smaller than the second threshold, the control unit 122 can determine that the DUT is cut off. As described above, the amplitude component of the present embodiment is a value that has undergone park conversion to separate the angular velocity component (phase), so that the control unit 122 can quickly determine whether the DUT is cut off even if the ac voltage variation is small. Likewise, when the control unit 122 determines that the DUT has been disconnected, the control unit 122 may adjust the control signal to zero the duty cycle, so that the output terminal 100 of the power conversion module 10 maintains zero voltage without inputting or outputting the first ac power.
It should be noted that, since the output terminal 100 is generally connected across the energy storage capacitor (e.g. between two terminals), the energy storage capacitor may also cause a surge and further boost the voltage value after the DUT is cut off, and the present embodiment further designs a mechanism for avoiding the surge and discharging the energy of the energy storage capacitor. For example, assuming that the power conversion module 10 is pulling the DUT, the power conversion module 10 of the present embodiment may preset the duty cycle to be limited to a third threshold, for example, the duty cycle is 0.95, in order to avoid the sudden wave caused by the DUT being separated. That is, when the control unit 122 determines that the duty cycle of the power conversion module 10 is greater than the third threshold, it can be presumed that a possible reason for the duty cycle being greater than the third threshold is that the component under test DUT is cut off when the ac voltage is near the peak value. The control unit 122 can directly adjust the control signal to zero the duty cycle at this time, so that the output terminal 100 of the power conversion module 10 maintains zero voltage without inputting or outputting the first ac power. In addition, the digital control module 12 can monitor the voltage and the current value of the output terminal 100, and the power conversion module 10 maintains the zero voltage for a period of time after stopping inputting or outputting the first ac power until the digital control module 12 determines that the energy storage capacitor has released the power according to the voltage and the current value of the output terminal 100.
On the other hand, although the above has been described taking the power conversion module 10 as an example of pulling the component DUT to be tested, the above embodiment can be applied to the power conversion module 10 to supply power to the component DUT to be tested. That is, the control unit 122 determines that the abnormal condition such as the amplitude variation amount being greater than the first threshold, the amplitude component being smaller than the second threshold, the duty ratio of the power conversion module 10 being greater than the third threshold is irrelevant to the power transmission direction. Even though the power conversion module 10 is used to supply power to the DUT, the control unit 122 can determine whether the DUT is cut off according to the above embodiment.
As can be seen from the above, when the DUT is not detected to be disconnected from the output terminal 100 with early warning, the bidirectional ac power conversion device 1 of the present embodiment determines based on the real-time voltage signal generated by the ac voltage locked by the phase-locked loop 120, so that erroneous determination caused by the voltage phase effect can be reduced, and the duty ratio of the control signal can be quickly adjusted to be zero before the DUT is disconnected to cause the voltage value to be pushed up, so that the bidirectional ac power conversion device 1 will not trigger the protection mechanism due to the abnormally high voltage of the output terminal 100. Since the bi-directional ac power conversion apparatus 1 does not trigger the protection mechanism due to the disconnection of the DUT, the bi-directional ac power conversion apparatus 1 can quickly resume operation after the DUT is connected to the output terminal 100 again.
In summary, the bidirectional ac power conversion device provided in the present application uses the phase-locked loop to lock the input or output first ac power, and determines whether the component to be tested is separated from the output terminal according to the amplitude component of the real-time voltage signal. When the component to be tested has no early warning cut-off output end, the bidirectional alternating current power conversion device can immediately detect and stop inputting or outputting alternating current power, and the component to be tested can not enter a protection mechanism and can effectively protect internal components.
The above examples and/or embodiments are merely for illustrating the preferred examples and/or embodiments for implementing the technology of the present application, and are not limited in any way to the embodiments of the technology of the present application, and any person skilled in the art should be able to make some changes or modifications to other equivalent examples without departing from the scope of the technical means disclosed in the present application, but should still consider the technology or examples substantially identical to the present application.
Claims (6)
1. A bi-directional ac power conversion apparatus for inputting or outputting a first ac power, the bi-directional ac power conversion apparatus comprising:
the power conversion module is used for setting the input or output first alternating current electric energy according to a control signal; and
a digital control module, comprising:
the phase-locked loop is electrically connected with the power conversion module and is used for detecting the input or output first alternating current energy and generating a real-time voltage signal, wherein the real-time voltage signal is defined with an amplitude component and an angular velocity component; and
the control unit is electrically connected with the power conversion module and the phase-locked loop and is used for setting the control signal according to the amplitude component and at least one amplitude variation obtained in different switching periods;
the control unit calculates the at least one amplitude variation according to the amplitude component obtained in different switching periods, and when the control unit judges that the amplitude component or the at least one amplitude variation is abnormal, the control signal instructs the power conversion module to stop inputting or outputting the first alternating current energy.
2. The bi-directional ac power converting apparatus according to claim 1, wherein the control unit determines the amplitude variation of each of the consecutive switching periods, and determines that the amplitude variation is abnormal when the amplitude variation of each of the consecutive switching periods is greater than a first threshold.
3. The bi-directional ac power converting apparatus according to claim 1, wherein the control unit determines the amplitude component of each of the consecutive switching periods, and determines the amplitude component as abnormal when the amplitude component of each of the consecutive switching periods is not greater than a second threshold.
4. The bi-directional ac power conversion apparatus according to claim 1, wherein the control signal is configured to instruct the power conversion module to stop inputting or outputting the first ac power when the control unit determines that the duty ratio is greater than a third threshold.
5. The bi-directional ac power conversion apparatus according to claim 1, wherein said phase detector performs park conversion on said real-time voltage signal to obtain said amplitude component and said angular velocity component.
6. The bi-directional ac power conversion apparatus according to claim 1, wherein the power conversion module pulls the first ac power to a device under test via an output terminal or supplies the first ac power to the device under test.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111652459.6A CN116418240A (en) | 2021-12-30 | 2021-12-30 | Bidirectional alternating current power conversion device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111652459.6A CN116418240A (en) | 2021-12-30 | 2021-12-30 | Bidirectional alternating current power conversion device |
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| Publication Number | Publication Date |
|---|---|
| CN116418240A true CN116418240A (en) | 2023-07-11 |
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| CN202111652459.6A Pending CN116418240A (en) | 2021-12-30 | 2021-12-30 | Bidirectional alternating current power conversion device |
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| CN (1) | CN116418240A (en) |
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- 2021-12-30 CN CN202111652459.6A patent/CN116418240A/en active Pending
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