Testing method and device of direct-current transformer and storage medium

Abstract

The invention discloses a DC transformer test method and device and a storage medium, and relates to the field of DC power distribution, a boost converter is cascaded between a first to-be-tested DC transformer and a second to-be-tested DC transformer, and the current and power in the two to-be-tested DC transformers can be synchronously controlled by changing the output transformation of the boost converter. In the testing process, the duty ratio of the boost converter is adjusted to control the current and power of the direct-current transformer, and then the operation characteristics of the direct-current transformer under the power are tested. Based on the method, the test process of the direct current transformer can be realized without controlling the direct current transformer, the condition that part of the direct current transformers cannot control the output voltage is avoided, and the normal realization of the test process in different application scenes is ensured.

Description

Technical Field

[0001] The present invention relates to the field of direct current power distribution, and in particular to a testing method, a testing device and a storage medium for a direct current transformer. Background Art

[0002] Compared with AC grid, DC grid has more advantages in efficiency and power supply capacity when organizing new energy, energy storage devices and DC loads in DC form. DC transformer is one of the core equipment of DC grid, which is the interconnection and isolation of DC networks of different levels. In order to fully verify the performance of DC transformer, it is necessary to perform power test on DC transformer.

[0003] At present, there are generally two methods for power testing of DC transformers, direct testing method and back-to-back drag testing method. The direct testing method is to directly connect the power supply and load at both ends of the DC transformer. The power during the test is provided by the power supply and directly dissipated on the load. However, this method requires a large-capacity power supply and load, and has high requirements on the power supply and load equipment capacity of the laboratory, which is difficult to achieve under laboratory environmental conditions; therefore, the back-to-back drag testing method is commonly used for testing.

[0004] The prior art pair-drag test method is implemented using a two-phase identical DC transformer. A specific implementation method in the prior art is: the low-voltage side and the high-voltage side of the two-phase DC transformer are connected in parallel, and the low-voltage side output of the forward-phase DC transformer is connected to the low-voltage side input of the reverse-phase DC transformer, and the high-voltage side output of the reverse-phase DC transformer is connected in parallel back to the high-voltage side input of the forward-phase DC transformer to form a power loop. The DC power supply is connected in parallel on the high-voltage side to provide power to compensate for the losses in the power cycle of the DC transformer. However, this test method requires changing the working mode of one of the DC transformers. Specifically, this method requires that one of the DC transformers can actively control the voltage or current of its port. However, some DC transformers do not have the ability to actively control voltage or current, which makes the test process difficult to implement. Summary of the invention

[0005] The purpose of the present invention is to provide a testing method, device and storage medium for a DC transformer, by adding a boost converter, and by controlling the voltage of the boost transformer to adjust the current and power in the DC transformer. The DC transformer can be tested under different working conditions without adjusting the DC transformer.

[0006] To solve the above technical problems, the present invention provides a method for testing a DC transformer, which is applied to a control module in a test device for a DC transformer. The test device for the DC transformer also includes a boost converter, wherein an input end of the boost converter is connected to a second end of a first DC transformer to be tested, and an output end of the boost converter is connected to a second end of a second DC transformer to be tested. The first end of the first DC transformer to be tested and the first end of the second DC transformer to be tested are both connected in parallel to a DC power supply. The method for testing the DC transformer includes:

[0007] Get the reference cycle power that needs to be tested currently;

[0008] determining a reference operating current of the boost converter based on the reference cycle power;

[0009] The control parameters of the boost converter are adjusted so that the operating current of the boost converter is maintained at the reference operating current.

[0010] Optionally, determining a reference operating current of the boost converter based on the reference cycle power includes:

[0011] Acquiring a current input voltage of the boost converter;

[0012] A ratio of the reference cycle power to the current input voltage is calculated, and the ratio is determined as the reference operating current.

[0013] Optionally, the control parameter is a duty cycle of a drive signal of each power switch tube in the boost converter, and the step of adjusting the control parameter of the boost converter so that the operating current of the boost converter is maintained at the reference operating current includes:

[0014] Acquire a preset duty cycle of a drive signal of each power switch tube in the boost converter corresponding to the reference operating current;

[0015] Generate a drive signal for each power switch tube in the boost converter according to the preset duty cycle;

[0016] The driving signals are respectively output to the control ends of the corresponding power switch tubes.

[0017] Optionally, adjusting the control parameter of the boost converter so that the operating current of the boost converter is maintained at the reference operating current includes:

[0018] Obtaining a current operating current of the boost converter;

[0019] Subtracting the reference operating current from the current operating current;

[0020] determining an adjustment value of a control parameter of the boost converter based on a difference between the reference operating current and the current operating current;

[0021] The control signal output to the boost converter is adjusted according to the adjustment value to control the operating current of the boost converter to reach the reference operating current.

[0022] Optionally, the control parameter is a duty cycle of a drive signal of each power switch tube in the boost converter, and the step of determining an adjustment value of the control parameter of the boost converter based on a difference between the reference operating current and the current operating current includes:

[0023] Inputting the difference between the reference working current and the current working current into a PI compensator to obtain a duty cycle adjustment amount of a driving signal of each power switch tube in the boost converter;

[0024] The step of adjusting the control signal output to the DC converter according to the adjustment value comprises:

[0025] Determining a target duty cycle of each power switch tube in the DC converter according to the duty cycle adjustment amount, and generating a drive signal for each power switch tube in the DC converter;

[0026] The driving signals are respectively output to the control ends of the corresponding power switch tubes.

[0027] In order to solve the above technical problems, the present invention also provides a test device for a DC transformer, comprising:

[0028] A boost converter, wherein the input end is connected to the second end of the first DC transformer to be tested, the output end is connected to the second end of the second DC transformer to be tested, and the first end of the first DC transformer to be tested and the first end of the second DC transformer to be tested are both connected in parallel to a DC power supply;

[0029] A control module, whose output end is connected to the control end of the boost converter, is used to implement the steps of the DC transformer testing method as described above.

[0030] Optionally, the second end of the first DC transformer to be tested includes a first sub-port and a second sub-port, the second end of the second DC transformer to be tested includes a third sub-port and a fourth sub-port, and the boost converter includes:

[0031] A first inductor, a first end of which is connected to a first sub-port of the first DC transformer to be tested;

[0032] A second capacitor;

[0033] A first power switch tube, a first end of which is respectively connected to the first end of the second power switch tube and the second end of the first inductor, and a second end of which is respectively connected to the third sub-port of the second DC transformer to be tested and the first end of the second capacitor;

[0034] The second end of the second power switch tube is respectively connected to the second sub-port of the first DC transformer to be tested, the second end of the second capacitor and the fourth sub-port of the second DC transformer to be tested.

[0035] Optionally, the boost converter further includes:

[0036] A first capacitor, wherein a first end is respectively connected to the first end of the first inductor and the first sub-port of the first DC transformer to be tested, and a second end is respectively connected to the second end of the second power switch tube, the second end of the second capacitor, the second sub-port of the first DC transformer to be tested, and the fourth sub-port of the second DC transformer to be tested.

[0037] In order to solve the above technical problem, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the DC transformer testing method as described above are implemented.

[0038] The present invention provides a method for testing a DC transformer. An additional boost converter is added to the circuit topology of the test device. Since the boost converter is cascaded between the first DC transformer to be tested and the second DC transformer to be tested, changing its output voltage will synchronously control the current and power in the two DC transformers to be tested. During the test, the duty cycle of the boost converter is adjusted to control the current and power of the DC transformer, and then the operating characteristics of the DC transformer under the power are tested. Based on this method, the test process of the DC transformer can be realized without controlling the DC transformer, avoiding the situation that some DC transformers cannot control the output voltage, and ensuring the normal implementation of the test process in different application scenarios.

[0039] The present invention also provides a testing device for a DC transformer and a computer-readable storage medium, which have the same beneficial effects as the above-mentioned testing method for the DC transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1A schematic flow chart of a method for testing a DC transformer provided by the present invention;

[0042] Figure 2 A schematic structural diagram of a DC transformer testing device provided by the present invention;

[0043] Figure 3 A schematic structural diagram of another DC transformer testing device provided by the present invention;

[0044] Figure 4 A schematic diagram of power flow in a DC transformer testing device provided by the present invention;

[0045] Figure 5 A control block diagram of a method for testing a DC transformer in an open-loop control mode provided by the present invention;

[0046] Figure 6 A control block diagram of a method for testing a DC transformer in a closed-loop control mode provided by the present invention;

[0047] Figure 7 A schematic diagram of a signal waveform during a test process provided by the present invention. DETAILED DESCRIPTION

[0048] The core of the present invention is to provide a testing method, device and storage medium for a DC transformer, add a boost converter, and adjust the current and power in the DC transformer by controlling the voltage of the boost transformer. The DC transformer can be tested under different working conditions without adjusting the DC transformer.

[0049] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] Please refer to Figure 1 , Figure 1 A flow chart of a DC transformer testing method provided by the present invention; please refer to Figure 2 , Figure 2 This is a structural diagram of a DC transformer testing device provided by the present invention; please refer to Figure 3 , Figure 3 A structural schematic diagram of another DC transformer testing device provided by the present invention; Figure 3As shown, port 21 and port 22 are the first end of the first DC transformer 3 to be tested, port 23 and port 24 are the second end of the first DC transformer 3 to be tested, port 31 and port 32 are the first end of the second DC transformer 3 to be tested, port 33 and port 34 are the second end of the second DC transformer 3 to be tested, wherein V HV Represents the high voltage side voltage of the DC transformer, V LV Indicates the low voltage side voltage of the DC transformer, i back In order to solve the above technical problems, the present invention provides a method for testing a DC transformer, which is applied to a control module 1 in a test device for a DC transformer. The test device for the DC transformer also includes a boost converter 2. The input end of the boost converter 2 is connected to the second end of a first DC transformer 3 to be tested, and the output end is connected to the second end of a second DC transformer 4 to be tested. The first end of the first DC transformer 3 to be tested and the first end of the second DC transformer 4 to be tested are both connected in parallel to the DC power supply. The method for testing a DC transformer includes:

[0051] S11: Obtain the reference cycle power currently required to be tested;

[0052] It is understandable that the main purpose of testing the DC transformer is to test whether the DC transformer can operate normally under a specific power. Considering that the test is implemented through a power loop composed of a DC power supply, two DC transformers to be tested, and a boost converter 2, the reference cycle power of the DC transformer currently to be tested can be determined according to the test requirements of the DC transformer to be tested. The specific value and determination method of the reference cycle power are not particularly limited in this application. The reference cycle power is used as a control target, and the power in the power loop needs to be maintained at this control target during the test.

[0053] S12: Determine a reference operating current of the boost converter 2 based on the reference cycle power;

[0054] It is not difficult to understand that in the present application, the first DC transformer to be tested 3, the boost converter 2 and the second DC transformer to be tested 4 are sequentially cascaded. Taking the first end of the first DC transformer to be tested 3 as the high-voltage side as an example, the output of the DC power supply passes through the first DC transformer to be tested 3, and the voltage is changed from high voltage to low voltage. After the low voltage passes through the boost converter 2, it is reversely passed through the second DC transformer to be tested 4, and it is changed from low voltage to high voltage again, and then connected back to the DC power supply, thereby constructing a power circulation loop. At this time, the current and power in the entire power loop can be adjusted by adjusting the control parameters of the boost converter 2, so as to achieve power control. Therefore, the reference working current that needs to be controlled to be finally reached by the boost converter 2 can be determined according to the reference circulation power obtained.

[0055] S13: adjusting the control parameters of the boost converter 2 so that the operating current of the boost converter 2 is maintained at the reference operating current.

[0056] It is understandable that, ultimately, by adjusting the control parameters of the boost converter 2, the operating current at its input / output end is maintained at the reference operating current, and the operating current of the boost converter 2 is controlled by feedback, and its operating current is adjusted and controlled to the target value, thereby achieving control of the circulating power. Since the power control of the entire power loop is undertaken by the boost converter 2, the DC transformer device under test does not need to actively control the voltage or current of its port during the whole process of the towing test. The control parameters of the boost converter 2 can specifically be the duty cycle of the drive signal of the power switch tube, etc., and only the parameters that can adjust the operating current of the boost converter 2 are required.

[0057] It is not difficult to understand that this solution adds an additional boost converter 2 to the circuit topology of the DC transformer test device. At the same time, the DC transformer to be tested no longer needs to be actively controlled in terms of control strategy, and the boost converter 2 is instead responsible for controlling the circulating power. As a result, the two DC transformers to be tested in the towing test do not need to actively control the voltage or current of their own ports, avoiding the problem that some DC transformers do not have the ability to actively control voltage or current, and ensuring that the circulating power in the power loop can be effectively controlled during the test.

[0058] It should be noted that the present application does not specifically limit the specific type and implementation of the boost converter 2 set in the test device and the DC transformer to be tested. The specific capacity of the DC power supply can also be selected and set according to the specific voltage level of the DC transformer to be tested, and the present application does not specifically limit it. The topology specifically implemented by the boost converter 2 can be a boost-type Boost circuit, or a buck-boost type Buck-Boost circuit, Cuk circuit, Zeta circuit or Sepic circuit. As a key component in a medium-voltage DC distribution network, a DC transformer generally uses a transformer with high-frequency isolation, and its high-voltage side and low-voltage side can both use circuit topologies including active switching actions, such as DAB converters (dual active bridge converters), series resonant converters, LLC resonant converters and other circuit topologies. These circuit topologies generally work in a fixed voltage ratio or voltage feedback control mode. The test device and test method of the present application can achieve power testing while ensuring its original fixed voltage ratio or voltage feedback control mode. Among them, resonant converters specifically include series resonant converters and LLC resonant converters. These circuit topologies can effectively reduce the volume of high-frequency transformers and passive components by increasing the switching frequency, thereby achieving higher power density. In DC distribution networks, DC transformers are not only used to achieve power conversion between medium-voltage DC (such as ±10kV) and low-voltage DC (such as ±375V), but also provide the necessary electrical isolation. Figure 3 As shown, both DC transformers can be used as the device under test and adopt a constant voltage / ratio working mode. Only the boost / buck-boost converter needs to adopt a constant current / power control working mode to realize the feedback control of the circulating power.

[0059] It is understandable that a DC transformer generally allows bidirectional power flow, that is, the DC transformer can work in both directions. The specific implementation of the first end and the second end needs to be determined according to the actual power flow direction during operation. The high voltage side can be the first end, or the low voltage side can be the first end. Taking the DC transformer connecting the medium voltage and low voltage DC power grids as an example, it can transmit electric energy from medium voltage to low voltage DC, and from low voltage to medium voltage DC. It should be pointed out that when designing the test device, there are no special requirements for the setting positions of the DC power supply and the boost converter 2. The DC power supply can be connected in parallel to the high voltage side bus or the low voltage side bus of the DC transformer, and the boost converter 2 can be connected in parallel to the other side of the DC transformer, and the corresponding cascade is on the low voltage side bus or the high voltage side bus. It is only necessary to adjust the specific voltage and current parameter requirements of the DC power supply and the boost converter 2 according to the specific voltage size of the high voltage side or the low voltage side of the DC transformer, which has no effect on the circuit working principle of the test device. Such as Figure 3As shown, taking the LLC resonant converter working in open loop with fixed duty cycle as an example, the two-phase LLC switching frequency can be kept equal to the resonant frequency under different voltage and power conditions, and the working conditions at the forward and reverse resonant points can also be verified.

[0060] It should be noted that the boost converter 2 is cascaded to the low-voltage side or high-voltage side DC bus of the DC transformer to be tested, so the boost converter 2 needs to transmit all the circulating power, so the power of the boost converter 2 needs to be the same as that of a single DC transformer to ensure that the full power output by the DC transformer to be tested can be transmitted. In the test device, in addition to controlling the circulating power of the entire towing system through current feedback control of the boost converter 2, the boost converter 2 can also provide a voltage gain greater than 1 to offset the voltage drop of the power device in the DC transformer under the circulating power.

[0061] As a specific embodiment, the circuit connection method in the test device is as follows: Figure 3 As shown, the first end of the first DC transformer 3 to be tested is its high-voltage side DC bus, and the second end is its low-voltage side DC bus. The input end of the boost converter 2 is cascaded with the low-voltage side DC bus of the first DC transformer 3 to be tested, and the output end is cascaded with the low-voltage side DC bus of the second DC transformer 4 to be tested. The second end of the second DC transformer 4 to be tested is the low-voltage side DC bus, and the first end is the high-voltage side DC bus. The DC power supply is connected in parallel with the high-voltage side buses of the first DC transformer 3 to be tested and the second DC transformer 4 to be tested, respectively.

[0062] As an optional embodiment, considering that the working modes of the two-phase DC transformers to be tested are different during the test in the prior art, when it is necessary to analyze the performance of the DC transformer under specific operating parameters, only the parameters of one of the DC transformers can be controlled as the parameters to be tested, that is, in one test process, only one of the DC transformers can be used as the DC transformer to be tested, and the other DC transformer can only be used as a companion test device, and the test process cannot be realized. Therefore, the prior art cannot simultaneously analyze the performance of the DC transformers under the same working conditions when they are running forward and reverse. In the present application, the control of the circulating power is achieved by adjusting the control parameters of the boost converter 2. Therefore, the two DC transformers in the circuit topology can be used as the DC transformers to be tested at the same time. By setting the structure and working mode of the first DC transformer 3 to be tested and the second DC transformer 4 to be tested to be consistent, the forward and reverse tests of the DC transformers can be performed simultaneously. Figure 3 For example, when the current direction of the first DC transformer 3 to be tested changes from high voltage to low voltage, it is working in the forward direction, and when the current direction of the second DC transformer 4 to be tested changes from low voltage to high voltage, it is working in the reverse direction.

[0063] Please note that, please refer to Figure 4 , Figure 4A schematic diagram of power flow in a DC transformer test device provided by the present invention; considering that the efficiency of a general DC transformer can reach 98%-99%, the input power of the first DC transformer 3 to be tested and the input power of the second DC transformer 4 to be tested generally differ by only 1%-2%. Within the allowable range, it can be considered that the two-phase DC transformers are operating under the same power conditions. The input power of the DC power supply is only the power loss of each device in the test system, which is about 2%-4% of the circulating power. The schematic diagram of the power flow is as follows Figure 4 As shown. Therefore, when the modulation and control modes of the two-phase DC transformer in the test device are consistent, the input power of the two-phase DC transformer under the same control mode is slightly different, which can be directly regarded as the forward and reverse working states of the same DC transformer under the same control and the same input, thereby providing a basis for simultaneously measuring and evaluating the forward and reverse DC transformer work, so as to simultaneously complete the forward working test and reverse working test of the same DC transformer, which is convenient for the test work.

[0064] It is not difficult to understand that the present invention provides a pair-drag test method and device for power testing of a DC transformer, simplifies the complexity of building and controlling the pair-drag test platform, and can simultaneously test the forward and reverse working states of the same DC transformer when in use. By adding a boost converter 2 to control the circulating power of the DC transformer, the two-phase DC transformer to be tested can remain unchanged in its original control mode, thereby avoiding the problem that some DC transformers are not convenient to change the control mode, and allowing the two-phase DC transformer to be tested to work under approximately the same working conditions, so as to simultaneously measure and evaluate the forward and reverse working characteristics of the DC transformer.

[0065] The present invention provides a method for testing a DC transformer, wherein changing its output voltage will synchronously control the current and power in two DC transformers to be tested. During the test, the duty cycle of the boost converter is adjusted to control the current and power of the DC transformer, and then the operating characteristics of the DC transformer under the power are tested. Based on this method, the test process of the DC transformer can be implemented without controlling the DC transformer, avoiding the situation where some DC transformers cannot control the output voltage, and ensuring the normal implementation of the test process in different application scenarios.

[0066] Based on the above embodiments:

[0067] As an optional embodiment, determining the reference operating current of the boost converter 2 based on the reference cycle power includes:

[0068] Obtaining the current input voltage of boost converter 2;

[0069] The ratio of the reference cycle power to the current input voltage is calculated, and the ratio is determined as the reference operating current.

[0070] It is understandable that the boost converter 2 will achieve power control by adjusting the operating current. Therefore, it is necessary to first determine the reference operating current of the boost converter 2 corresponding to the reference cycle power based on the input voltage of the boost converter 2, and adjust the control parameters of the boost converter 2 with the reference operating current as the control target.

[0071] Specifically, considering that the boost converter 2 realizes power control by adjusting the working current, it is necessary to convert the reference cycle power, which is a power control target, into a corresponding current control target, and directly use the relationship between power, current and voltage to calculate the reference working current, so that the boost converter 2 can be subsequently regulated and controlled according to the reference working current.

[0072] Please refer to Figure 5 , Figure 5 A control block diagram of a method for testing a DC transformer in an open-loop control mode provided by the present invention; source Refers to the initial current output by the DC power supply to the test circuit, i boost Refers to the current flowing into the boost converter, that is, the working current of the boost converter, i back Refers to the return current that eventually flows back to the DC power supply. As an optional embodiment, the control parameter is the duty cycle of the drive signal of each power switch tube in the boost converter. Adjusting the control parameter of the boost converter so that the operating current of the boost converter is maintained at the reference operating current includes:

[0073] Obtaining a preset duty cycle of a drive signal of each power switch tube in the boost converter corresponding to a predetermined reference operating current;

[0074] Generate a drive signal for each power switch tube in the boost converter according to a preset duty cycle;

[0075] The driving signals are output to the control ends of the corresponding power switch tubes respectively.

[0076] It is understandable that the adjustment of the control parameters of the boost converter can be achieved by open-loop control, that is, the control parameters of the boost converter corresponding to the test process to be performed by the boost converter are estimated or selected empirically in advance, a fixed control parameter is determined by estimation or empirical selection, and then the control parameters of the boost converter, such as the duty cycle of the drive signal of each power switch tube in the boost converter, are directly set to a predetermined fixed value. Before the test, two DC transformers and one boost converter can be started to start switching action, and then the DC power supply is started to gradually increase the bus voltage and circulating power. During the test, the duty cycle of the boost converter is set to a pre-estimated fixed value. Later, the duty cycle setting can be fine-tuned according to the power results in the circuit or the current results of the boost converter during the actual test process, so that the circulating power approaches the value to be measured. In the Boost converter embodiment, assuming that the line loss is ignored, the transformer and converter losses are concentrated in the voltage drop, and the lower tube duty cycle can be estimated as D=1-η1*η1*η2, where η1 is the efficiency of the DC transformer and η2 is the efficiency of the boost converter.

[0077] Specifically, the test process of the DC transformer can be realized by open-loop control. The open-loop test can maintain stable operation and is relatively safe in high-power testing. The approximate value of the duty cycle of the boost converter can be directly estimated in advance, and the implementation method is simple.

[0078] Please refer to Figure 6 , Figure 6 A control block diagram of a method for testing a DC transformer in a closed-loop control mode provided by the present invention; G iboost_d (s) is the transfer function of the boost circuit. As an optional embodiment, adjusting the control parameters of the boost converter 2 so that the operating current of the boost converter 2 is maintained at the reference operating current includes:

[0079] Obtaining the current operating current of the boost converter 2;

[0080] Subtract the reference working current from the current working current;

[0081] Determining an adjustment value of a control parameter of the boost converter 2 based on a difference between a reference operating current and a current operating current;

[0082] The control signal output to the boost converter 2 is adjusted according to the adjustment value, so as to control the operating current of the boost converter 2 to reach the reference operating current.

[0083] It is not difficult to understand that the current source mode mainly ensures that the working current can reach the target value by current feedback control. Therefore, it is necessary to obtain the current working current of the boost converter 2 in real time, and adjust the control parameters of the boost converter 2 according to the difference between the current working current and the target reference working current, so that the working current of the boost converter 2 can reach and maintain the reference working current, and maintain the constant current working state. The corresponding relationship between the specific difference and the adjustment value of the control parameter is not specifically limited in this application, and can be adjusted and set according to the specific circuit topology of the boost converter 2 in actual application. The specific type and implementation method of the control signal need to be set according to the specific type of the adjusted control parameter, and the application does not make special restrictions here. For example, when the control parameter is the duty cycle of the drive signal of the power switch tube, the corresponding control signal is the drive signal output to each power switch tube in the boost converter 2.

[0084] Specifically, the current adjustment and power control of the boost converter 2 need to be implemented using a current feedback control loop, and the current is controlled by feedback, and the current is adjusted and limited to a required value, thereby achieving control of the circulating power. As an optional embodiment, the control parameter is the duty cycle of the drive signal of each power switch tube in the boost converter, and the adjustment value of the control parameter of the boost converter is determined based on the difference between the reference working current and the current working current, including:

[0085] The difference between the reference working current and the current working current is input into the PI compensator to obtain the duty cycle adjustment of the driving signal of each power switch tube in the boost converter 2. d;

[0086] The control signal output to the DC converter is adjusted according to the adjustment value, including:

[0087] Determine the target duty cycle of each power switch tube in the DC converter according to the duty cycle adjustment amount, and generate a drive signal for each power switch tube in the DC converter;

[0088] The driving signals are output to the control ends of the corresponding power switch tubes respectively.

[0089] It is not difficult to understand that the duty cycle adjustment of the driving signal of the power switch tube can be determined based on the difference between the reference working current and the current working current by proportional integral control. The difference between the reference working current and the current working current is input into the PI compensator as the current error. The PI compensator has a preset corresponding relationship between the current error and the control target, which can directly generate the target switch duty cycle adjustment of a power switch tube in the boost converter 2. d, the final duty cycle d = D + d, thereby determining the target duty cycle of the driving signal of the power switch tube, and then determining the target duty cycles of the driving signals of other power switch tubes according to the conduction relationship between the power switch tubes.

[0090] As a specific embodiment, the boost converter 2 is provided as follows: Figure 5 The current loop control strategy shown in FIG. 1 includes obtaining the cycle power Pref set by the user and comparing it with the input voltage V of the boost circuit obtained by measurement. LV By comparing, we can get the reference working current Iref as the ratio. The reference working current Iref is then subtracted from the measured real-time current of the boost circuit, and the difference is sent to the PI compensator to obtain the switch duty cycle adjustment of the preset power switch tube. d. By adjusting the switching duty cycle of the power switch tube, the current is controlled, thereby achieving closed-loop control of the circulating power.

[0091] It is understandable that the magnitude of the operating current of the boost converter 2 mainly depends on the conduction duty cycle of the power switch tube therein, so the operating current of the boost converter 2 can be adjusted by adjusting the duty cycle of the drive signal of the power switch tube output to the boost converter 2. In actual applications, the power switch tube in the boost converter 2 will be implemented by alternating conduction, so the corresponding relationship between the operating current of the boost converter 2 and the conduction duty cycle of a power switch tube in the boost converter 2 can be established in advance, and then the conduction duty cycle and the corresponding drive signal of the power switch tube in the boost converter 2 are determined according to the difference between the reference operating current and the current operating current, and then the corresponding drive signals of other power switch tubes are determined according to the conduction relationship between other power switch tubes and this power switch tube. Figure 3 As shown, the boost converter 2 is implemented by a boost circuit (boost circuit), wherein the power switch tube includes a first power switch tube Q1 and a second power switch tube Q2, and the first power switch tube Q1 and the second power switch tube Q2 are alternately turned on. During the control process, the switch duty ratio of the second power switch tube Q2 can be determined according to the difference between the reference working current and the current working current of the boost converter 2, and then the switch duty ratio of the first power switch tube Q1 can be determined according to the alternating conduction characteristics, thereby generating corresponding drive signals for the first power switch tube Q1 and the second power switch tube Q2. The specific type and implementation method of the drive signal are not particularly limited in this application,

[0092] Specifically, the PI compensator can be used to generate the control signal. The PI compensator can form a control deviation based on the given value and the actual output value, and form a control quantity by linearly combining the proportion and integral of the deviation to control the controlled object, thereby effectively realizing the current feedback control of the boost converter 2 and realizing closed-loop control to adjust the control parameters of the boost converter; at the same time, the working current can be effectively controlled by adjusting the switch duty cycle of the power switch tube in the boost converter 2. The control of the switch duty cycle can be realized by adjusting the drive signal of the power switch tube output to the boost converter 2, which is easy to realize. The closed-loop test can be realized on the basis of the open-loop test. When the actual circulating power is close to the power to be measured, the controller closed-loop control takes over the duty cycle adjustment. That is, the boost converter obtains its own input voltage, calculates the ratio of the reference circulating power to the input voltage as the current reference value and inputs it into the PI compensator, and negatively feedbacks the lower tube switch duty cycle to make the circulating power close-loop track the reference circulating power.

[0093] In order to solve the above technical problems, the present invention also provides a test device for a DC transformer, comprising:

[0094] A boost converter 2, wherein the input end is connected to the second end of the first DC transformer 3 to be tested, the output end is connected to the second end of the second DC transformer 4 to be tested, and the first end of the first DC transformer 3 to be tested and the first end of the second DC transformer 4 to be tested are both connected in parallel to a DC power supply;

[0095] The control module 1 has an output end connected to the control end of the boost converter 2, and is used to implement the steps of the aforementioned DC transformer testing method.

[0096] It is understandable that the control module 1 needs to be set in the test device of the DC transformer to execute the above test method to realize the control of the boost converter 2. The specific type and implementation of the control module 1 are not particularly limited in this application, and other devices such as memory can be further set in the test device. The first DC transformer 3 to be tested and the second DC transformer 4 to be tested can be adopted as follows Figure 3 The DC transformer shown includes capacitor C11, capacitor C12, capacitor C13, capacitor C14, capacitor C15, power switch tube Q11, power switch tube Q12, power switch tube Q13, power switch tube Q14, power switch tube Q15, power switch tube Q16, inductor L1, inductor L2 and transformer T0.

[0097] Among them, the control module 1 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The control module 1 can be implemented in at least one hardware form of DSP (Digital Signal Processor), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). The control module 1 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a central processing unit; the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the control module 1 may integrate a GPU (graphics processing unit), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the control module 1 may also include an AI (Artificial Intelligence) processor, which is used to process computing operations related to machine learning.

[0098] The memory may include one or more computer-readable storage media, which may be non-transitory. The memory may also include high-speed random access memory, and non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In this embodiment, the memory is at least used to store the following computer program, wherein, after the computer program is loaded and executed by the control module 1, the relevant steps of the test method of the DC transformer disclosed in any of the aforementioned embodiments can be implemented. In addition, the resources stored in the memory may also include an operating system and data, etc., and the storage method may be temporary storage or permanent storage. Among them, the operating system may include Windows, Unix, Linux, etc. The data may include, but is not limited to, data of the test method of the DC transformer, etc.

[0099] In some embodiments, the DC transformer testing device may further include a display screen, an input / output interface, a communication interface, a power supply, and a communication bus.

[0100] Those skilled in the art will appreciate that the above description does not constitute a limitation on the testing device for the DC transformer, and the testing device may include more or fewer components than those described above.

[0101] For an introduction to a testing device for a DC transformer provided by the present invention, please refer to the embodiment of the testing method for a DC transformer described above, and the present invention will not be described in detail herein.

[0102] As an optional embodiment, the second end of the first DC transformer to be tested includes a first sub-port and a second sub-port, the second end of the second DC transformer to be tested includes a third sub-port and a fourth sub-port, and the boost converter 2 includes:

[0103] A first inductor L0, a first end of which is connected to a first sub-port 23 of a first DC transformer to be tested;

[0104] A second capacitor C2;

[0105] A first power switch tube Q1, a first end of which is respectively connected to a first end of a second power switch tube Q2 and a second end of a first inductor L0, and a second end of which is respectively connected to a third sub-port 33 of a second DC transformer to be tested and a first end of a second capacitor C2;

[0106] The second power switch tube Q2 has a second end connected to the second sub-port 24 of the first DC transformer 3 to be tested, the second end of the second capacitor C2 and the fourth sub-port 34 of the second DC transformer 4 to be tested.

[0107] It is understandable that the boost converter 2 can be implemented by using a Boost circuit, such as Figure 3 As shown, the Boost circuit specifically includes a first power switch tube Q1 and a second power switch tube Q2 that are alternately turned on by a first inductor L0 and a second capacitor C2. The specific types and implementation methods of the first power switch tube Q1 and the second power switch tube Q2 are not particularly limited in this application. The first inductor L0 can maintain the stability of the output voltage, filter out high-frequency noise, perform power conversion and reduce voltage, and ensure the normal operation of the boost converter 2. Subsequently, the current in the boost converter 2 can be detected in real time by the inductor current flowing through the first inductor L0; the second capacitor C2 can play a role in filtering and stabilizing voltage, ensuring the stability and reliability of the voltage output by the boost converter 2 to the second DC transformer to be tested. A capacitor connected in parallel on the input side can be further set in the Boost circuit. The first capacitor C1 can play a role in filtering and stabilizing voltage, ensuring the stability of the voltage input to the boost converter 2.

[0108] As an optional embodiment, the boost converter 2 further includes:

[0109] The first capacitor C1 has a first end respectively connected to the first end of the first inductor L0 and the first sub-port 23 of the first DC transformer to be tested, and a second end respectively connected to the second end of the second power switch tube Q2, the second end of the second capacitor C2, the second sub-port 24 of the first DC transformer to be tested, and the fourth sub-port 34 of the second DC transformer to be tested.

[0110] Specifically, the boost converter 2 can be implemented by a Boost circuit. The entire circuit structure is simple and easy to implement, which is conducive to the simple implementation of the entire test device.

[0111] As a specific embodiment, please refer to Figure 7 , Figure 7 A schematic diagram of a signal waveform during a test process provided by the present invention. Figure 7 The first waveform in is the duty cycle of the driving signal of the second power switch tube Q2 in the Boost circuit, the lower tube refers to the second power switch tube Q2, the second waveform is the comparison waveform between the inductor current of the first inductor L0 on the input side of the Boost circuit and the reference working current, and the third waveform is the comparison waveform between the resonant current of the first DC transformer to be tested passing through the circulating power of the boost circuit and the reference circulating power Pref. It is not difficult to find that when the DC power supply outputs a certain voltage to establish the bus voltage, by changing the reference circulating power Pref and the corresponding reference working current Iref, the current of the boost circuit and the circulating power of the DC transformer can be controlled to change accordingly, thereby testing the operating characteristics of the DC transformer under this power.

[0112] In order to solve the above technical problems, the present invention further provides a test system for a DC transformer, which is applied to a control module in a test device for a DC transformer, wherein the test device for the DC transformer further includes a boost converter, wherein an input end of the boost converter is connected to a second end of a first DC transformer to be tested, and an output end of the boost converter is connected to a second end of a second DC transformer to be tested, and a first end of the first DC transformer to be tested and a first end of the second DC transformer to be tested are both connected in parallel to a DC power supply; the test system for the DC transformer includes:

[0113] A reference power acquisition unit, used to acquire the reference cycle power currently required to be tested;

[0114] a reference current acquisition unit, configured to determine a reference operating current of the boost converter based on the reference cycle power;

[0115] The control unit is used to adjust the control parameters of the boost converter so that the operating current of the boost converter is maintained at the reference operating current.

[0116] For an introduction to a DC transformer testing system provided by the present invention, please refer to the embodiment of the DC transformer testing method described above, and the present invention will not be described in detail here.

[0117] In order to solve the above technical problems, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the DC transformer testing method as described above are implemented.

[0118] It is understandable that if the method in the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium to execute all or part of the steps of the method described in each embodiment of the present application. Specifically, the computer-readable storage medium may include but is not limited to any type of disk, including a floppy disk, an optical disk, and a mobile hard disk, or any type of medium or device suitable for storing instructions, data, etc., and the present application does not make any special restrictions here.

[0119] For an introduction to a computer-readable storage medium provided by the present invention, please refer to the embodiment of the above-mentioned DC transformer testing method, and the present invention will not be repeated here.

[0120] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0121] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0122] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0123] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for testing a DC transformer, characterized in that: A control module applied to a test device for a DC transformer, wherein the test device for the DC transformer further comprises a boost converter, wherein an input end of the boost converter is connected to a second end of a first DC transformer to be tested, and an output end of the boost converter is connected to a second end of a second DC transformer to be tested, and a first end of the first DC transformer to be tested and a first end of the second DC transformer to be tested are both connected in parallel to a DC power supply; The testing method of the DC transformer includes: Get the reference cycle power that needs to be tested currently; determining a reference operating current of the boost converter based on the reference cycle power; The control parameters of the boost converter are adjusted so that the operating current of the boost converter is maintained at the reference operating current.

2. The DC transformer testing method according to claim 1, characterized in that: The step of determining a reference operating current of the boost converter based on the reference cycle power comprises: Acquiring a current input voltage of the boost converter; A ratio of the reference cycle power to the current input voltage is calculated, and the ratio is determined as the reference operating current.

3. The DC transformer testing method according to claim 1 or 2, characterized in that: The control parameter is a duty cycle of a drive signal of each power switch tube in the boost converter, and the step of adjusting the control parameter of the boost converter so that the operating current of the boost converter is maintained at the reference operating current includes: Acquire a preset duty cycle of a drive signal of each power switch tube in the boost converter corresponding to the reference operating current; Generate a drive signal for each power switch tube in the boost converter according to the preset duty cycle; The driving signals are respectively output to the control ends of the corresponding power switch tubes.

4. The method for testing a DC transformer according to claim 1 or 2, characterized in that: The step of adjusting the control parameter of the boost converter so that the operating current of the boost converter is maintained at the reference operating current includes: Obtaining a current operating current of the boost converter; Subtracting the reference operating current from the current operating current; determining an adjustment value of a control parameter of the boost converter based on a difference between the reference operating current and the current operating current; The control signal output to the boost converter is adjusted according to the adjustment value to control the operating current of the boost converter to reach the reference operating current.

5. The method for testing a DC transformer as claimed in claim 4, characterized in that: The control parameter is a duty cycle of a drive signal of each power switch tube in the boost converter, and the step of determining an adjustment value of the control parameter of the boost converter based on a difference between the reference working current and the current working current includes: Inputting the difference between the reference working current and the current working current into a PI compensator to obtain a duty cycle adjustment amount of a driving signal of each power switch tube in the boost converter; The step of adjusting the control signal output to the DC converter according to the adjustment value comprises: Determining a target duty cycle of each power switch tube in the DC converter according to the duty cycle adjustment amount, and generating a drive signal for each power switch tube in the DC converter; The driving signals are respectively output to the control ends of the corresponding power switch tubes.

6. A test device for a DC transformer, characterized in that: include: A boost converter, wherein the input end is connected to the second end of the first DC transformer to be tested, the output end is connected to the second end of the second DC transformer to be tested, and the first end of the first DC transformer to be tested and the first end of the second DC transformer to be tested are both connected in parallel to a DC power supply; A control module, whose output end is connected to the control end of the boost converter, is used to implement the steps of the DC transformer testing method according to any one of claims 1 to 5.

7. The DC transformer testing device according to claim 6, characterized in that: The second end of the first DC transformer to be tested includes a first sub-port and a second sub-port, the second end of the second DC transformer to be tested includes a third sub-port and a fourth sub-port, and the boost converter includes: A first inductor, a first end of which is connected to a first sub-port of the first DC transformer to be tested; A second capacitor; A first power switch tube, a first end of which is respectively connected to the first end of the second power switch tube and the second end of the first inductor, and a second end of which is respectively connected to the third sub-port of the second DC transformer to be tested and the first end of the second capacitor; The second end of the second power switch tube is respectively connected to the second sub-port of the first DC transformer to be tested, the second end of the second capacitor and the fourth sub-port of the second DC transformer to be tested.

8. The DC transformer testing device according to claim 7, characterized in that: The boost converter further comprises: A first capacitor, wherein a first end is respectively connected to the first end of the first inductor and the first sub-port of the first DC transformer to be tested, and a second end is respectively connected to the second end of the second power switch tube, the second end of the second capacitor, the second sub-port of the first DC transformer to be tested, and the fourth sub-port of the second DC transformer to be tested.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the DC transformer testing method according to any one of claims 1 to 5 are implemented.

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