A device and a regulating method for improving the rapid change characteristic of a power supply output

Abstract

The application discloses a device and a regulating method for improving the quick change characteristic of power output, wherein the voltage switching device is connected between a high-power direct current source and a measured object; the bypass relay K1 is connected in series with the voltage reduction branch, and one end of the bypass relay K1 is connected with the positive pole of the high-power direct current source, the other end of the bypass relay K1 is connected with one end of the series-connected resistor R4 and the relay K6, the other end of the series-connected resistor R4 and the relay K6 is connected with the high-power direct current source; the total relay K2 is connected in parallel with the two ends of the series-connected bypass relay K1 and the voltage reduction branch; the two ends of the series-connected resistor R4 and the relay K6 are connected with the positive and negative poles of the measured object; when the bypass relay K1 is closed, the high-power direct current source is connected with the measured object; when the bypass relay K1 is disconnected and the total relay K2 is closed, the high-power direct current source is connected with the measured object through the voltage reduction branch. The application realizes that the conventional high-power direct current source can also meet the quick change of the input voltage of the measured object by arranging the voltage switching device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of voltage fast conversion, in particular to a device and a regulating method for improving the output fast change characteristic of a power supply. BACKGROUND

[0002] With the development of technology, higher requirements are put forward for the testing of new energy controllers at present. In the testing process, the sudden cutout of the load of the controller needs to be simulated. Under normal power electronic conversion technology conditions, the sudden cutout of the load will cause the voltage of the source end to rise rapidly. According to the standard, when the controller cuts out the load instantaneously, the voltage rising speed of the input end should reach 250V / ms or more. The controller input end is designed with a capacitance of 400uF or more, and in the case of voltage mutation, hundreds of kilowatts of power need to be generated instantaneously as support. When testing in the laboratory, a DC test power supply with a voltage conversion rate of 250V / ms needs to be provided to simulate the controller load cutout experiment. However, the current conventional test power supply cannot meet this requirement.

[0003] DC test power supplies are divided into high-power power supplies and low-power power supplies. According to the power level, it is generally believed in the industry that a single machine of 40kW or more is a high-power test power supply, and a single machine of less than 40kW is a low-power test power supply. Different types of test power supplies also have great differences in topology architecture. High-power DC test power supplies mainly adopt a two-stage architecture to realize the conversion of main power through the selection of different types of IGBT modules. Because of the characteristics of switching devices, the main current is large, and the switching frequency is mainly below 10kHz, which makes the switching frequency of high-power test power supplies generally 5-10kHz.

[0004] The bidirectional DC chopper circuit is an important variable unit of the high-power DC test power supply. The commonly used topological forms include single-channel BUCK circuit, multi-channel interleaved BUCK circuit and three-level BUCK circuit. For the multi-channel interleaved BUCK circuit, the interleaved control method is used to achieve the purpose of reducing the ripple and improving the output response speed, but the actual switching frequency is limited to below 10kHz. At present, the voltage conversion rate of 50V / ms is already a very high level. Moreover, due to the cost and control complexity, the number of interleaved channels cannot be increased unlimitedly.

[0005] Because the high-power test power supply is difficult to meet the testing requirements of such controllers in the conventional design, and the special design does not meet the cost requirements, it is more meaningful and valuable to develop a switching device independent of the power supply, which can use a low-cost design scheme to realize the fast conversion of the input voltage of the controller and solve the testing problem of the controller load cutout experiment.

[0006] The patent application with the publication number CN112234624A discloses a method for active voltage quality controller main bypass fast switching. The application realizes that the device can provide stable power supply for the user in the rear stage during the switching process of the main path and the bypass path, and realizes uninterrupted switching, by setting the main bypass, and by the reverse parallel thyristor as a bridge during the switching process of the main path and the bypass path. However, the application still does not solve the above problems. SUMMARY

[0007] The technical problem to be solved by the present application is to solve the problem that the output voltage change rate of the high-power test power supply cannot meet the test requirements of the controller.

[0008] To solve the above technical problems, the present application provides the following technical solutions:

[0009] A device for improving the output fast change characteristic of a power supply includes a voltage switching device connected between a high-power DC source and a measured object.

[0010] The voltage switching device includes a voltage reduction branch, a resistor R4, a bypass relay K1, a total relay K2, and a relay K6.

[0011] The bypass relay K1 is connected in series with the voltage reduction branch, with one end connected to the positive pole of the high-power DC source, and the other end connected to one end of the series-connected resistor R4 and relay K6. The other end of the series-connected resistor R4 and relay K6 is connected to the high-power DC source.

[0012] The total relay K2 is connected in parallel with both ends of the series-connected bypass relay K1 and voltage reduction branch. The two ends of the series-connected resistor R4 and relay K6 are connected to the positive and negative poles of the measured object.

[0013] When the bypass relay K1 is closed, the high-power DC source is connected to the measured object.

[0014] When the bypass relay K1 is disconnected and the total relay K2 is closed, the high-power DC source is connected to the measured object through the voltage reduction branch.

[0015] Advantages: The present application sets up a voltage switching device, and the voltage reduction branch is set up to form a voltage drop at the voltage reduction branch of the high-power DC source, so that the voltage at the input end of the measured power supply is low, and the bypass relay K1 is closed and disconnected quickly to reduce the voltage reduction branch, so that the voltage of the measured object is equal to the voltage of the high-power DC source, and the input end voltage of the measured object is quickly changed.

[0016] Preferably, the voltage reduction branch is provided with a plurality of voltage reduction branches, and the plurality of voltage reduction branches are connected in parallel.

[0017] Preferably, the voltage reduction branch is provided with three, namely the first voltage reduction branch, the second voltage reduction branch and the third voltage reduction branch; the first voltage reduction branch, the second voltage reduction branch and the third voltage reduction branch are all connected in parallel.

[0018] The first voltage reduction branch comprises a resistor R1 and a relay K3 connected in series; the second voltage reduction branch comprises a resistor R2 and a relay K4 connected in series; and the third voltage reduction branch comprises a resistor R3 and a relay K5 connected in series.

[0019] Preferably, the voltage switching device further comprises an electric reactor L1 connected in series with the total relay K2; after being connected in series, the electric reactor L1 and the total relay K2 are connected in parallel across the bypass relay K1 and the voltage reduction branch connected in series.

[0020] Preferably, the on-off of the total relay K2, the bypass relay K1, the relay K3, the relay K4, the relay K5 and the relay K6 are all controlled by the cooperation of a power resistor and a switching switch.

[0021] Preferably, the measured object further comprises a capacitor C1 connected to the positive and negative poles of the input end of the measured object.

[0022] A regulating method of the device for improving the rapid change characteristic of the output of the power supply comprises the following steps:

[0023] S1, installing the voltage switching device between the high-power direct current source and the measured object;

[0024] S2, confirming the resistance value of the voltage reduction branch of the voltage switching device according to the measured object, and turning on the resistor on the corresponding voltage reduction branch;

[0025] S3, turning on the high-power direct current source, outputting the voltage U1 of the high-power direct current source, closing the bypass relay K1 and the relay K6, opening the total relay K2, and turning on the voltage switching device; when the instruction voltage U1 is stable, starting the measured object, at this time, the voltage at the input end of the measured object is the voltage U2; there is a stable current I1 in the circuit;

[0026] S4, after the measured object is stably operated, the output current of the high-power direct current source reaches the set current, the relay K6 is opened, and the resistor R4 is opened;

[0027] S5, when the output current of the high-power direct current source falls back to I1, timing is performed, after the time T, the total relay K2 is closed, the voltage reduction branch is cut off, and the voltage of the measured object is switched from U2 to the voltage U1; the voltage at the input end of the measured object is rapidly switched once.

[0028] Preferably, the set current is 2*I1.

[0029] Compared with the prior art, the present application has the following beneficial effects:

[0030] (1) The application sets the voltage switching device, the setting of the voltage reduction branch makes the voltage drop of the high-power DC source at the voltage reduction branch, the voltage of the input end of the measured power supply is low, and the closing and rapid opening of the bypass relay K1 breaks the voltage reduction branch, so that the voltage of the measured object is equal to the voltage of the high-power DC source, and the rapid transformation of the input end voltage of the measured object is realized.

[0031] (2) The voltage switching device of the application adopts resistive load for voltage regulation, and the relay is used for switching, and the overall design cost is low.

[0032] (3) The voltage variation range of the application can be freely adjusted by the opening and closing of each voltage reduction branch and the replacement of the corresponding resistance, thereby ensuring the universality of the voltage switching device, and the conventional high-power DC power supply can be adapted. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is the connection schematic diagram of the first embodiment of the application;

[0034] Figure 2 is the working flowchart of the second embodiment of the application. DETAILED DESCRIPTION

[0035] In order to facilitate those skilled in the art to understand the technical scheme of the application, the technical scheme of the application will be further described in conjunction with the drawings of the specification.

[0036] The terms "first", "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0037] Embodiment one

[0038] Referring to Figure 1 , the embodiment discloses a device for improving the rapid change characteristic of power supply output, which comprises a voltage switching device 2; the voltage switching device 2 is connected between a high-power DC source 1 and a measured object 3; the voltage switching device 2 comprises a voltage reduction branch, a resistor R4, a bypass relay K1, a total relay K2 and a relay K6;

[0039] The bypass relay K1 is connected in series with the voltage reduction branch, and one end of the bypass relay K1 is connected to the positive pole of the high-power DC source 1, and the other end of the bypass relay K1 is connected to one end of the series connection of the resistor R4 and the relay K6, and the other end of the series connection of the resistor R4 and the relay K6 is connected to the high-power DC source 1; the total relay K2 is connected in parallel with the two ends of the series connection of the bypass relay K1 and the voltage reduction branch; and the two ends of the series connection of the resistor R4 and the relay K6 are connected to the positive and negative poles of the measured object 3.

[0040] When the bypass relay K1 is closed, the measured object 3 is connected to the high-power DC source 1; when the bypass relay K1 is disconnected and the total relay K2 is closed, the high-power DC source 1 is connected to the measured object 3 through the voltage reduction branch.

[0041] The voltage reduction branch is provided in multiple, and the multiple voltage reduction branches are connected in parallel. In the specific implementation of the embodiment, the voltage reduction branch is provided in three, which are a first voltage reduction branch 21, a second voltage reduction branch 22, and a third voltage reduction branch 23; the first voltage reduction branch 21, the second voltage reduction branch 22, and the third voltage reduction branch 23 are connected in parallel; the first voltage reduction branch 21 includes the series connection of the resistor R1 and the relay K3; the second voltage reduction branch 22 includes the series connection of the resistor R2 and the relay K4; and the third voltage reduction branch 23 includes the series connection of the resistor R3 and the relay K5. In the actual use process, the control of the voltage change of the measured object 3 can be realized by replacing the resistors on the respective voltage reduction branches and turning on and off the related voltage reduction branches.

[0042] In some embodiments, the voltage switching device 2 further includes an electric reactor L1, and the electric reactor L1 is connected in series with the total relay K2; and the series connection of the electric reactor L1 and the total relay K2 is connected in parallel at the two ends of the series connection of the bypass relay K1 and the voltage reduction branch. When the bypass relay K1 is switched, the electric reactor L1 has a certain resistance to the current, but after the current is stable, the impedance of the electric reactor L1 is small, and the input voltage of the measured object 3 can be considered to be equal to the output voltage of the high-power DC source 1. Thus, the switching of the voltage of the measured object 3 from U2 to U1 is realized, and the switching time depends on the charging speed of the input capacitor C1 of the controller and has a certain relationship with the bypass impedance and the capacitor resistance. When the current rising speed is slow in the test, the DC voltage switching rate is affected, and the electric reactor L1 can be removed to suppress the current through the self inductance of the output lead.

[0043] In some embodiments, the on-off of the total relay K2, the bypass relay K1, the relay K3, the relay K4, the relay K5, and the relay K6 is controlled by the cooperation of the power resistor and the switching switch.

[0044] In some embodiments, the measured object 3 further includes a capacitor C1, and the capacitor C1 is connected to the positive and negative poles of the input end of the measured object 3. By arranging the capacitor C1, the voltage change of the measured object 3 is relatively smooth, and the inductance parameter of the measured object 3 is reduced, and the peak voltage of the bus of the measured object 3 is weakened.

[0045] The embodiment also discloses a regulating method of the voltage switching device 2, comprising the following steps:

[0046] S1, installing the voltage switching device 2 between the high-power direct current source 1 and the measured object 3;

[0047] S2, confirming the resistance value of the voltage reduction branch of the voltage switching device 2 according to the measured object 3, and turning on the resistance on the corresponding voltage reduction branch;

[0048] S3, turning on the high-power direct current source 1, outputting the instruction voltage U1, closing the bypass relay K1 and the relay K6, opening the total relay K2, and turning on the voltage switching device 2, when the instruction voltage U1 is stable, starting the measured object 3, at this time, the voltage of the measured object 3 is the voltage U2, and there is a stable current I1 in the circuit;

[0049] S4, after the measured object 3 is stably operated, the output current of the high-power direct current source 1 reaches the set current, the relay K6 is opened, and the resistance R4 is opened;

[0050] S5, when the output current of the high-power direct current source 1 falls to I1, timing is performed, after the time T, the total relay K2 is closed, the voltage reduction branch is cut off, and the voltage of the measured object 3 is switched from U2 to U1; the input voltage of the measured object 3 is rapidly switched once.

[0051] In some embodiments, the set current is 2*I1. In the embodiment, the resistance R4 is used as a load first, and the current formed is I1, then the current equal to I1 is formed on the measured object 3, and the two currents are combined to be 2*I1. The purpose is that when the K6 is opened, the R4 load is cut off in the whole circuit, so that the current in the circuit returns to I1, and the voltage difference formed in the circuit is unchanged, and the voltage between the measured object 3 is still the voltage U2. That is, the resistance R4 is a transitional resistance load, and the target is to regulate the voltage difference in the circuit and transfer to the final measured object 3. Therefore, the set current is twice I1.

[0052] In the specific implementation process of the embodiment, the voltage variation of the measured object 3 is controlled through the resistance value of the voltage reduction branch of the voltage switching device 2, and the resistance value of the whole voltage reduction branch can be freely adjusted through the opening and closing of each voltage reduction branch and the replacement of the corresponding resistance value, so that the universality of the voltage switching device 2 is ensured, and the voltage switching device 2 is suitable for conventional high-power direct current sources 1.

[0053] Meanwhile, the voltage switching device 2 adopts a resistive load for voltage regulation and a relay for switching, and the overall design cost is low.

[0054] The voltage switching device 2 of the embodiment can realize the fast transformation of the input voltage of the measured object 3, meet the test standard, and the whole control process is simple.

[0055] Embodiment two

[0056] Referring to Figure 2 The embodiment takes the voltage switching from 450V to 500V at the input end of the measured object 3 as an example for testing, and the test requirement is that the voltage at the input end of the measured object 3 is switched from 450V to 500V, and the voltage switching rate is above 200V / ms. The test power reaches 5kW under the condition of 500V.

[0057] First, set the output instruction of the high-power DC source 1 to 500V, adjust the resistance of the whole voltage reduction branch to 5Ω, select the resistance R4=45Ω, and close the total relay K2. After starting the high-power DC source 1 to output according to the instruction 500V, the voltage U1=500V, and passing through the resistance R1, the resistance R2, the resistance R3 and the resistance R4 to form a loop, the current is 10A. This current forms a 50V voltage drop after passing through the voltage reduction resistance, that is, ΔU=50V, and the voltage U2 at the input end of the measured object 3 is U1-ΔU=500-50V=450V. After the voltage is stable, start the measured object 3, the output current of the DC source increases, and when the current reaches 20A and is stable, the K6 relay is disconnected, and the resistance R4 is removed, at this time the output current of the DC source decreases to 10A, and the voltage U2 at the input end of the measured object 3 is 450V.

[0058] Start the switching countdown time T, set to 10 seconds, when T=0, the DC source control bypass relay K1 is closed, and K2 is disconnected. The reactor L1=50uH is selected, which has a certain inhibitory effect on the current rise, but will not produce obvious voltage drop in the loop. If the current rise speed is slow in the test, which affects the DC voltage switching rate, the reactor L1 can be removed, and the current is inhibited by the inductance of the output wire itself.

[0059] The bypass relay K1 controls the bypass to remove the voltage reduction loop, and the output voltage of the measured object 3 is quickly switched from U2 to U1.

[0060] The voltage rises from 454V to 500V, the switching time is 0.205ms, and the voltage switching rate is calculated to be about 224V / ms>200V / ms. The voltage switching amplitude and switching rate in the test process can be realized by adjusting the voltage reduction resistance and the inhibitory reactor L1.

[0061] It is apparent for a person skilled in the art that the present application is not limited to the details of the above-described exemplary embodiments, but can be implemented in other concrete forms without departing from the spirit or essential characteristics of the application. Consequently, the embodiments should be considered in all respects as illustrative and not restrictive, the scope of the application being defined by the appended claims rather than the above description, and it is therefore intended that all changes and modifications that fall within the meaning and range of equivalency of the claims be embraced therein, any reference signs in the claims not being considered as limiting the claims concerned.

[0062] The above-described embodiments are merely exemplary and are not intended to limit the scope of the present application, and it is apparent for a person skilled in the art that various modifications and improvements can be made thereto without departing from the spirit of the present application, and such modifications and improvements are intended to fall within the scope of the present application.

Claims

1. An apparatus for improving the rapid change characteristic of a power supply output, characterized by: It comprises a voltage switching device (2) connected between a high-power DC source (1) and an object to be measured (3); The voltage switching device (2) comprises a voltage reduction branch, a resistor R4, a bypass relay K1, a total relay K2 and a relay K6; The total relay K2 is connected in series with the voltage reduction branch, with one end connected to the positive pole of the high-power DC source (1) and the other end connected to one end of the resistor R4 and the relay K6 connected in series, and the other end of the resistor R4 and the relay K6 connected in series is connected to the negative pole of the high-power DC source (1). The bypass relay K1 is connected in parallel across the total relay K2 and the voltage reduction branch connected in series; the two ends of the resistor R4 and the relay K6 connected in series are connected to the positive and negative poles of the object to be measured (3). The resistance value of the voltage reduction branch of the voltage switching device (2) is confirmed according to the object to be measured (3), and the resistance on the corresponding voltage reduction branch is turned on. When the bypass relay K1 is open and the total relay K2 is closed, the high-power DC source (1) is connected to the object to be measured (3) through the voltage reduction branch. When the high-power DC source (1) is turned on, the high-power DC source (1) outputs a voltage U1, and the total relay K2 and the relay K6 are closed, the voltage switching device (2) is turned on, and when the command voltage U1 is stable, the object to be measured (3) is started, at this time the voltage at the end of the object to be measured (3) is voltage U2. After the object to be measured (3) runs stably, the output current of the high-power DC source (1) reaches the set current, the relay K6 is opened, and the resistor R4 is disconnected. When the bypass relay K1 is closed, the high-power DC source (1) is connected to the object to be measured (3); when the output current of the high-power DC source (1) falls to I1, timing is performed, after a time T, the bypass relay K1 is closed, the total relay K2 is opened, and the voltage reduction branch is cut off, the voltage of the object to be measured (3) is switched from U2 to voltage U1.

2. The apparatus of claim 1, wherein: The voltage reduction branch is provided with a plurality of voltage reduction branches, and the plurality of voltage reduction branches are connected in parallel.

3. The apparatus of claim 2, wherein: The voltage reduction branch is provided with three voltage reduction branches, which are a first voltage reduction branch (21), a second voltage reduction branch (22) and a third voltage reduction branch (23); the first voltage reduction branch (21), the second voltage reduction branch (22) and the third voltage reduction branch (23) are connected in parallel. The first voltage reduction branch (21) comprises a resistor R1 and a relay K3 connected in series; the second voltage reduction branch (22) comprises a resistor R2 and a relay K4 connected in series; the third voltage reduction branch (23) comprises a resistor R3 and a relay K5 connected in series.

4. The apparatus of claim 1, wherein: The voltage switching device (2) further comprises an electric reactor L1, and the electric reactor L1 is connected in series with the bypass relay K1; the electric reactor L1 and the bypass relay K1 connected in series are connected in parallel across the total relay K2 and the voltage reduction branch connected in series.

5. The apparatus of claim 1, wherein: The on-off of the total relay K2, the bypass relay K1, the relay K3, the relay K4, the relay K5 and the relay K6 is controlled by the cooperation of the power resistor and the switching switch.

6. The apparatus of claim 1, wherein: The object to be measured (3) further comprises a capacitor C1 connected between the positive and negative poles of the input end of the object to be measured (3).

7. A regulating method of applying the device of any one of claims 1-6 to improve the rapid change characteristic of the output of the power supply, characterized in that: The method comprises the following steps: S1, installing the voltage switching device (2) between the high-power DC source (1) and the object to be measured (3); S2, according to the measured object (3) confirm voltage switching device (2) voltage reduction branch resistance, and the corresponding resistance on the voltage reduction branch conduction; S3, open high-power DC source (1), high-power DC source (1) output voltage U1, and close the total relay K2 and relay K6, voltage switching device (2) conduction, when the command voltage U1 stable, start the measured object (3), the voltage at the measured object (3) end is voltage U2; there is a stable current I1 in the circuit; S4, after the measured object (3) stable operation, detect the output current of high-power DC source (1) reaches the set current, open the relay K6, and the resistance R4 is disconnected; S5, when the output current of high-power DC source (1) falls to I1, timing is performed, after time T, close the bypass relay K1, open the total relay K2, and the voltage reduction branch is cut off, the voltage of the measured object (3) is switched from U2 to voltage U1; The input voltage of the measured object (3) is switched once.

8. The regulating method of claim 7, wherein the regulating method is characterized by: The set current is 2*I1.

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