Bidirectional DC-DC converter test platform and test method

Abstract

The bidirectional DC-DC converter test platform and test method provided by the embodiment of the present invention include a first bidirectional DC-DC converter cabinet, a second bidirectional DC-DC converter cabinet, a first PWM rectifier cabinet, a second PWM rectifier cabinet, a control console and an input power supply. The control console collects the first test parameter of the second bidirectional DC-DC converter cabinet and obtains the first test result, and collects the second test parameter of the first bidirectional DC-DC converter cabinet and obtains the second test result. The electric energy obtained by the second PWM rectifier cabinet from the input power supply passes through the second bidirectional DC-DC converter cabinet and the first bidirectional DC-DC converter cabinet, and then is fed back to the input power supply through the first PWM rectifier cabinet. The obtained electric energy and the fed-back electric energy offset each other, reducing the requirements for the power grid capacity, thereby realizing the assessment test of the large-capacity bidirectional DC-DC converter when boosting or bucking under limited power supply and load capacity.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of electrical technology, and in particular to a bidirectional direct current-direct current (DC-DC) converter test platform and test method. Background Art

[0002] In recent years, bidirectional DC-DC converters have been widely used in new energy, aerospace, transportation, communications, and industrial control.

[0003] Before putting a bidirectional DC-DC converter into use, it is necessary to conduct a comprehensive assessment test on the bidirectional DC-DC converter. Only after passing the comprehensive assessment test can the bidirectional DC-DC converter be actually deployed to ensure that the bidirectional DC-DC converter can operate safely and reliably. For small-power bidirectional DC-DC converters, the power supply and load capacity are easy to meet the requirements, so the assessment test is relatively easy. However, for medium and large-capacity bidirectional DC-DC converters (especially those above the million watts (MW) level), it is difficult to achieve a comprehensive assessment test of the bidirectional DC-DC converter due to the limitations of the power supply and load capacity.

[0004] Under limited power and load capacity, achieving assessment and testing of large-capacity bidirectional DC-DC converters when stepping up or down is a problem that currently needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] The embodiments of the present invention provide a bidirectional DC-DC converter test platform and a test method to overcome the problem that the prior art cannot implement the assessment test of a large-capacity bidirectional DC-DC converter when boosting or bucking the voltage under limited power supply and load capacity.

[0006] On the one hand, an embodiment of the present invention provides a bidirectional DC-DC converter test platform, including a first bidirectional DC-DC converter cabinet, a second bidirectional DC-DC converter cabinet, a first pulse width modulation (PWM) rectifier cabinet, a second PWM rectifier cabinet, a control console and an input power supply;

[0007] The input power supply is connected to the first end of the first PWM rectifier cabinet and the first end of the second PWM rectifier cabinet respectively;

[0008] The second end of the second PWM rectifier cabinet is connected to the first end of the second bidirectional DC-DC converter cabinet, the second end of the second bidirectional DC-DC converter cabinet is connected to the first end of the first bidirectional DC-DC converter cabinet, and the second end of the first bidirectional DC-DC converter cabinet is connected to the second end of the first PWM rectifier cabinet;

[0009] The console is connected to the first bidirectional DC-DC converter cabinet, the second bidirectional DC-DC converter cabinet, the first PWM rectifier cabinet and the second PWM rectifier cabinet respectively, and the console is used to control the second bidirectional DC-DC converter cabinet to operate in a boost mode, control the first bidirectional DC-DC converter cabinet to operate in a buck mode, control the second PWM rectifier cabinet to operate in a rectifier mode, and control the first PWM rectifier cabinet to operate in an inverter mode;

[0010] The console is also used to collect a first test parameter of the second bidirectional DC-DC converter cabinet when operating in a boost mode, and a second test parameter of the first bidirectional DC-DC converter cabinet when operating in a buck mode, and obtain a first test result of the second bidirectional DC-DC converter cabinet according to the first test parameter, and obtain a second test result of the first bidirectional DC-DC converter cabinet according to the second test parameter.

[0011] Optionally, the input power source includes a low-voltage power grid, a low-voltage power distribution cabinet and an isolation transformer, and the input power source is used to provide power to the first PWM rectifier cabinet and the second PWM rectifier cabinet.

[0012] Optionally, the isolation transformer is a three-winding transformer;

[0013] The input power supply is connected to the first end of the first PWM rectifier cabinet and the first end of the second PWM rectifier cabinet respectively, including:

[0014] The first end of the first PWM rectifier cabinet and the first end of the second PWM rectifier cabinet are respectively connected to the two windings on the secondary side of the isolation transformer.

[0015] Optionally, the first test parameters include a first input instantaneous current, a first input instantaneous voltage, a first output instantaneous current, a first output instantaneous voltage, and a first ambient temperature, and obtaining a first test result of the second bidirectional DC-DC converter cabinet according to the first test parameters includes:

[0016] A first test result of the second bidirectional DC-DC converter cabinet is obtained according to the first input instantaneous current, the first input instantaneous voltage, the first output instantaneous current, the first output instantaneous voltage and the first ambient temperature, wherein the first test result includes a first power assessment result, a first energy efficiency assessment result, a first current and voltage ripple rate assessment result, a first current and voltage error assessment result and a first ambient temperature assessment result.

[0017] Optionally, the second test parameter includes a second input instantaneous current, a second input instantaneous voltage, a second output instantaneous current, a second output instantaneous voltage, and a second ambient temperature, and obtaining a second test result of the first bidirectional DC-DC converter cabinet according to the second test parameter includes:

[0018] A second test result of the first bidirectional DC-DC converter cabinet is obtained according to the second input instantaneous current, the second input instantaneous voltage, the second output instantaneous current, the second output instantaneous voltage and the second ambient temperature, and the second test result includes a second power assessment result, a second energy efficiency assessment result, a second current and voltage ripple rate assessment result, a second current and voltage error assessment result and a second ambient temperature assessment result.

[0019] Optionally, the second PWM rectifier cabinet is used to maintain the voltage value of the second end of the second PWM rectifier cabinet at a first constant voltage through a voltage and current dual closed-loop control method.

[0020] Optionally, the second bidirectional DC-DC converter cabinet is used to maintain the voltage value of the second end of the second bidirectional DC-DC converter cabinet at a second constant voltage through a voltage and current dual closed-loop control method.

[0021] Optionally, the first bidirectional DC-DC converter cabinet is used to maintain the current value of the second end of the first bidirectional DC-DC converter cabinet at a first constant current through a current closed-loop control method.

[0022] Optionally, the first PWM rectifier cabinet is used to maintain the voltage value of the second end of the first PWM rectifier cabinet at a third constant voltage through a voltage and current dual closed-loop control method.

[0023] Optionally, it also includes:

[0024] The control console is further used to control the first bidirectional DC-DC converter cabinet to operate in a boost mode, control the second bidirectional DC-DC converter cabinet to operate in a buck mode, control the first PWM rectifier cabinet to operate in a rectifier mode, and control the second PWM rectifier cabinet to operate in an inverter mode;

[0025] The console is also used to collect a third test parameter of the first bidirectional DC-DC converter cabinet when operating in a boost mode, and a fourth test parameter of the second bidirectional DC-DC converter cabinet when operating in a buck mode, and obtain a third test result of the first bidirectional DC-DC converter cabinet according to the third test parameter, and obtain a fourth test result of the second bidirectional DC-DC converter cabinet according to the fourth test parameter.

[0026] On the other hand, an embodiment of the present invention further provides a bidirectional DC-DC converter test method, the method is applied to a bidirectional DC-DC converter test platform, the platform includes a first bidirectional DC-DC converter cabinet, a second bidirectional DC-DC converter cabinet, a first PWM rectifier cabinet, a second PWM rectifier cabinet, a console and an input power supply, the method includes:

[0027] The console sends a first configuration instruction to the second PWM rectifier cabinet, where the first configuration instruction is used to configure the second PWM rectifier cabinet to operate in a rectifier mode;

[0028] The console sends a second configuration instruction to the second bidirectional DC-DC converter cabinet, where the second configuration instruction is used to configure the second bidirectional DC-DC converter cabinet to operate in a boost mode;

[0029] The console sends a third configuration instruction to the first bidirectional DC-DC converter cabinet, where the third configuration instruction is used to configure the first bidirectional DC-DC converter cabinet to operate in a buck mode;

[0030] The console sends a fourth configuration instruction to the first PWM rectifier cabinet, where the fourth configuration instruction is used to configure the first PWM rectifier cabinet to operate in an inverter mode;

[0031] The control console sends a first control instruction to the second bidirectional DC-DC converter cabinet, where the first control instruction is used to instruct the second bidirectional DC-DC converter cabinet to start operation;

[0032] The control console sends a second control instruction to the first bidirectional DC-DC converter cabinet, where the second control instruction is used to instruct the first bidirectional DC-DC converter cabinet to start operation;

[0033] The control console sends a third control instruction to the first PWM rectifier cabinet, where the third control instruction is used to instruct the first PWM rectifier cabinet to start operation;

[0034] The control console sends a fourth control instruction to the second PWM rectifier cabinet, where the fourth control instruction is used to instruct the second PWM rectifier cabinet to start operation;

[0035] The console collects a first test parameter of the second bidirectional DC-DC converter cabinet when operating in a boost mode and a second test parameter of the first bidirectional DC-DC converter cabinet when operating in a buck mode, and obtains a first test result of the second bidirectional DC-DC converter cabinet according to the first test parameter, and obtains a second test result of the first bidirectional DC-DC converter cabinet according to the second test parameter.

[0036] Optionally, the first test parameters include a first input instantaneous current, a first input instantaneous voltage, a first output instantaneous current, a first output instantaneous voltage, and a first ambient temperature, and obtaining a first test result of the second bidirectional DC-DC converter cabinet according to the first test parameters includes:

[0037] A first test result of the second bidirectional DC-DC converter cabinet is obtained according to the first input instantaneous current, the first input instantaneous voltage, the first output instantaneous current, the first output instantaneous voltage and the first ambient temperature, wherein the first test result includes a first power assessment result, a first energy efficiency assessment result, a first current and voltage ripple rate assessment result, a first current and voltage error assessment result and a first ambient temperature assessment result.

[0038] Optionally, the second test parameter includes a second input instantaneous current, a second input instantaneous voltage, a second output instantaneous current, a second output instantaneous voltage, and a second ambient temperature, and obtaining a second test result of the first bidirectional DC-DC converter cabinet according to the second test parameter includes:

[0039] A second test result of the first bidirectional DC-DC converter cabinet is obtained based on the second input instantaneous current, the second input instantaneous voltage, the second output instantaneous current, the second output instantaneous voltage and the second ambient temperature, and the second test result includes a second power assessment result, a second energy efficiency assessment result, a second current and voltage ripple rate assessment result, a second current and voltage error assessment result and a second ambient temperature assessment result.

[0040] Optionally, the first configuration instruction is further used to configure the second PWM rectifier cabinet to maintain the voltage value of the second end of the second PWM rectifier cabinet at a first constant voltage through a voltage and current dual closed-loop control method.

[0041] Optionally, the second configuration instruction is further used to configure the second bidirectional DC-DC converter cabinet to maintain the voltage value of the second end of the second bidirectional DC-DC converter cabinet at a second constant voltage through a voltage and current dual closed-loop control method.

[0042] Optionally, the third configuration instruction is further used to configure the first bidirectional DC-DC converter cabinet to maintain the current value of the second end of the first bidirectional DC-DC converter cabinet at a first constant current through a current closed-loop control method.

[0043] Optionally, the fourth configuration instruction is further used to configure the first PWM rectifier cabinet to maintain the voltage value of the second end of the first PWM rectifier cabinet at a third constant voltage through a voltage and current dual closed-loop control method.

[0044] Optionally, it also includes:

[0045] The console sends a fifth configuration instruction to the first PWM rectifier cabinet, where the fifth configuration instruction is used to configure the first PWM rectifier cabinet to operate in a rectifier mode;

[0046] The console sends a sixth configuration instruction to the first bidirectional DC-DC converter cabinet, where the sixth configuration instruction is used to configure the first bidirectional DC-DC converter cabinet to operate in a boost mode;

[0047] The console sends a seventh configuration instruction to the second bidirectional DC-DC converter cabinet, where the seventh configuration instruction is used to configure the second bidirectional DC-DC converter cabinet to operate in a buck mode;

[0048] The control console sends an eighth configuration instruction to the second PWM rectifier cabinet, where the eighth configuration instruction is used to configure the second PWM rectifier cabinet to operate in an inverter mode;

[0049] The console sends a fifth control instruction to the first bidirectional DC-DC converter cabinet, where the fifth control instruction is used to instruct the first bidirectional DC-DC converter cabinet to start operation;

[0050] The console sends a sixth control instruction to the second bidirectional DC-DC converter cabinet, where the sixth control instruction is used to instruct the second bidirectional DC-DC converter cabinet to start operation;

[0051] The control console sends a seventh control instruction to the second PWM rectifier cabinet, where the seventh control instruction is used to instruct the second PWM rectifier cabinet to start operation;

[0052] The control console sends an eighth control instruction to the first PWM rectifier cabinet, where the eighth control instruction is used to instruct the first PWM rectifier cabinet to start operation;

[0053] The console collects a third test parameter of the first bidirectional DC-DC converter cabinet when operating in a boost mode, and a fourth test parameter of the second bidirectional DC-DC converter cabinet when operating in a buck mode, and obtains a third test result of the first bidirectional DC-DC converter cabinet according to the third test parameter, and obtains a fourth test result of the second bidirectional DC-DC converter cabinet according to the fourth test parameter.

[0054] The bidirectional DC-DC converter test platform and test method provided by the embodiment of the present invention include a first bidirectional DC-DC converter cabinet, a second bidirectional DC-DC converter cabinet, a first PWM rectifier cabinet, a second PWM rectifier cabinet, a console and an input power supply. The console controls the bidirectional DC-DC converter cabinet and the PWM rectifier cabinet to operate in different modes, and at the same time collects the first test parameter of the second bidirectional DC-DC converter cabinet when it operates in the boost mode, and obtains the first test result based on the first test parameter. And collects the second test parameter of the first bidirectional DC-DC converter cabinet when it operates in the buck mode, and obtains the second test result based on the second test parameter. The electric energy obtained from the input power supply by the second PWM rectifier cabinet passes through the second bidirectional DC-DC converter cabinet and the first bidirectional DC-DC converter cabinet, and then passes through the first PWM rectifier cabinet to feed back to the input power supply, and the obtained electric energy and the fed-back electric energy offset each other, reducing the requirements for the power grid capacity, thereby realizing the assessment test of the large-capacity bidirectional DC-DC converter when boosting or bucking under limited power supply and load capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 A bidirectional DC-DC converter test platform provided by an embodiment of the present invention;

[0056] Figure 2 Another bidirectional DC-DC converter test platform provided by an embodiment of the present invention;

[0057] Figure 3 It is a circuit diagram of a voltage and current dual closed-loop control method provided by an embodiment of the present invention;

[0058] Figure 4 is a circuit diagram of a current closed-loop control method provided by an embodiment of the present invention;

[0059] Figure 5 A bidirectional DC-DC converter testing method is provided in an embodiment of the present invention;

[0060] Figure 6 Another bidirectional DC-DC converter testing method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0061] The test of the bidirectional DC-DC converter is mainly to collect the operating parameters of the bidirectional DC-DC converter during the step-up and step-down process, including but not limited to current, voltage and ambient temperature, etc. Based on the above operating parameters, the various test results during step-up and step-down are obtained through formula conversion. These test results together constitute a comprehensive test of the bidirectional DC-DC converter. The test results include but are not limited to: power assessment results, energy efficiency assessment results, current and voltage ripple rate assessment results, current and voltage error assessment results and ambient temperature assessment results.

[0062] The technical solution of the embodiment of the present invention will be described below in conjunction with several specific embodiments.

[0063] Figure 1 A bidirectional DC-DC converter test platform is provided in an embodiment of the present invention, such as Figure 1 As shown, the platform includes a first bidirectional DC-DC converter cabinet 1 , a second bidirectional DC-DC converter cabinet 2 , a first PWM rectifier cabinet 3 , a second PWM rectifier cabinet 4 , a control console 5 and an input power supply 6 .

[0064] The input power source 6 is connected 41 to the first end 31 of the first PWM rectifier cabinet 3 and the first end of the second PWM rectifier cabinet 4 respectively.

[0065] The second end 42 of the second PWM rectifier cabinet 4 is connected 21 to the first end of the second bidirectional DC-DC converter cabinet 2, the second end 22 of the second bidirectional DC-DC converter cabinet 2 is connected 11 to the first end of the first bidirectional DC-DC converter cabinet 1, and the second end 12 of the first bidirectional DC-DC converter cabinet 1 is connected to the second end 32 of the first PWM rectifier cabinet 3.

[0066] The control console 5 is respectively connected to the first bidirectional DC-DC converter cabinet 1, the second bidirectional DC-DC converter cabinet 2, the first PWM rectifier cabinet 3 and the second PWM rectifier cabinet 4. The control console 5 is used to control the second bidirectional DC-DC converter cabinet 2 to operate in the boost mode, control the first bidirectional DC-DC converter cabinet 1 to operate in the buck mode, control the second PWM rectifier cabinet 4 to operate in the rectification mode, and control the first PWM rectifier cabinet 3 to operate in the inverter mode.

[0067] The console 5 is also used to collect a first test parameter of the second bidirectional DC-DC converter cabinet 2 when operating in a boost mode, and a second test parameter of the first bidirectional DC-DC converter cabinet 1 when operating in a buck mode, and obtain a first test result of the second bidirectional DC-DC converter cabinet 2 based on the first test parameter, and obtain a second test result of the first bidirectional DC-DC converter cabinet 1 based on the second test parameter.

[0068] In this embodiment, the input power source refers to an AC power source, and illustratively, it may be an AC power source with a voltage of 380V and a frequency of 50Hz input from a low-voltage power grid.

[0069] Among them, the control console controls the second bidirectional DC-DC converter cabinet, the first bidirectional DC-DC converter cabinet, the second PWM rectifier cabinet and the first PWM rectifier cabinet to operate in boost mode, buck mode, rectification mode and inverter mode respectively. Boost mode refers to a mode of converting a lower DC voltage to a required higher DC voltage; buck mode refers to a mode of converting a higher DC voltage to a required lower DC voltage. Rectification mode refers to a process of converting AC to DC as rectification mode; inverter mode corresponds to rectification mode, which means that a process of converting DC to AC is inverter mode.

[0070] The current flow process is as follows: first, the second PWM rectifier cabinet operates in the rectifier mode, converting the AC power of the input power supply into DC power, DC voltage V1; second, the second bidirectional DC-DC converter cabinet operates in the boost mode, increasing the DC voltage V1 to the DC voltage V2, wherein V2 is greater than V1; third, the first bidirectional DC-DC converter cabinet operates in the buck mode, converting the DC voltage V2 into the DC voltage V3, wherein V3 is less than V2, and V3 and V1 can be the same or different; finally, the first PWM rectifier cabinet operates in the inverter mode, converting the DC power into AC power and feeding it back to the AC power grid. The console further obtains the first test result of the second bidirectional DC-DC converter cabinet when boosting and the second test result of the first bidirectional DC-DC converter cabinet when bucking by collecting the test parameters of the first bidirectional DC-DC converter cabinet and the second bidirectional DC-DC converter cabinet.

[0071] In this embodiment, the test result of the bidirectional DC-DC converter cabinet when boosting or reducing the voltage can be obtained through only one test process. In addition, the electric energy obtained by the second PWM rectifier cabinet from the input power supply passes through the second bidirectional DC-DC converter cabinet and the first bidirectional DC-DC converter cabinet, and then is fed back to the input power supply through the first PWM rectifier cabinet. The obtained electric energy and the fed-back electric energy offset each other, reducing the requirements for the grid capacity, thereby realizing the assessment test of the large-capacity bidirectional DC-DC converter when boosting or reducing the voltage under limited power supply and load capacity.

[0072] Figure 2 Another bidirectional DC-DC converter test platform provided by the embodiment of the present invention is Figure 1 On the basis of Figure 2 As shown, further comprising:

[0073] The input power supply includes a low-voltage power grid 61 , a low-voltage power distribution cabinet 62 and an isolation transformer 63 . The input power supply 6 is used to provide power to the first PWM rectifier cabinet 3 and the second PWM rectifier cabinet 4 .

[0074] The low-voltage power grid provides AC power with a rated voltage of 380V and a frequency of 50Hz. The low-voltage distribution cabinet can protect the circuit and prevent damage to personnel and equipment. For example, the rated voltage of the low-voltage distribution cabinet is 380V and the frequency is 50Hz; the functions of the isolation transformer are mainly voltage transformation and isolation. For example, the capacity of the isolation transformer is 500kVA.

[0075] Optionally, the isolation transformer 63 is a three-winding transformer.

[0076] The input power source 6 is connected to the first end 31 of the first PWM rectifier cabinet 3 and the first end 41 of the second PWM rectifier cabinet 4 respectively, including:

[0077] The first end 31 of the first PWM rectifier cabinet 3 and the first end 41 of the second PWM rectifier cabinet 4 are respectively connected to two windings on the secondary side of the isolation transformer 63 .

[0078] Each phase of the three-winding transformer has three windings. When one winding is connected to the AC power supply, the other two windings induce different potentials. In this embodiment, one winding of the three-winding transformer is connected to the AC power supply output by the low-voltage distribution cabinet, and the other two windings on the secondary side are respectively connected to the first end 31 of the first PWM rectifier cabinet 3 and the first end 41 of the second PWM rectifier cabinet 4.

[0079] Optionally, the first bidirectional DC-DC converter cabinet includes a first bidirectional DC-DC converter and a first bidirectional DC-DC controller, the second bidirectional DC-DC converter cabinet includes a second bidirectional DC-DC converter and a second bidirectional DC-DC controller, the first PWM rectifier cabinet includes a first PWM rectifier and a first PWM controller, the second PWM rectifier cabinet includes a second PWM rectifier and a second PWM controller, and the control console is respectively connected to the first bidirectional DC-DC converter cabinet, the second bidirectional DC-DC converter cabinet, the first PWM rectifier cabinet, and the second PWM rectifier cabinet, including:

[0080] The control console is respectively connected to the first bidirectional DC-DC controller, the second bidirectional DC-DC controller, the first PWM controller and the second PWM controller.

[0081] Optionally, the control console is a personal computer (PC), and the PC is respectively connected to the first bidirectional DC-DC converter cabinet, the second bidirectional DC-DC converter cabinet, the first PWM rectifier cabinet, and the second PWM rectifier cabinet.

[0082] Optionally, the first test parameter includes a first input instantaneous current, a first input instantaneous voltage, a first output instantaneous current, a first output instantaneous voltage and a first ambient temperature, and obtaining a first test result of the second bidirectional DC-DC converter cabinet 2 according to the first test parameter includes:

[0083] A first test result of the second bidirectional DC-DC converter cabinet 2 is obtained according to the first input instantaneous current, the first input instantaneous voltage, the first output instantaneous current, the first output instantaneous voltage and the first ambient temperature. The first test result includes but is not limited to a first power assessment result, a first energy efficiency assessment result, a first current and voltage ripple rate assessment result, a first current and voltage error assessment result and a first ambient temperature assessment result.

[0084] In the above embodiment, the first power assessment result in the first test result is calculated by the first output instantaneous voltage and the first output instantaneous current, and the calculation formula is as follows:

[0085] P(t)=u(t)×i(t) (1)

[0086] Wherein, during boost, P(t) is the power at time t, u(t) is the first output instantaneous voltage at time t, and i(t) is the first output instantaneous current at time t;

[0087] The first energy efficiency assessment result in the first test result is calculated by the first input instantaneous voltage, the first input instantaneous current, the first output instantaneous voltage and the first output instantaneous current, and the calculation formula is as follows:

[0088]

[0089] Among them, E in Inputting electric energy to the second bidirectional DC-DC converter cabinet; E out is the output electric energy; i1 and u1 are the first input instantaneous current and the first input instantaneous voltage respectively; i2 and u2 are the first output instantaneous current and the first output instantaneous voltage respectively; t1 and t2 are the start and end time of the test respectively.

[0090] The first current and voltage ripple rate assessment result in the first test result is obtained by calculating the first output instantaneous current and the first output instantaneous voltage, and the calculation formula is as follows:

[0091]

[0092] Among them, ΔI% and ΔU% are the current ripple rate and the voltage ripple rate respectively; ΔI and ΔU are the current ripple peak-to-peak value and the voltage ripple peak-to-peak value respectively; I0 and U0 are the current average value and the voltage average value respectively. ΔI, ΔU, I0 and U0 can all be calculated through the first output instantaneous current and the first output instantaneous voltage.

[0093] The first current and voltage error assessment result in the first test result is obtained by calculating the first output instantaneous current, the first output instantaneous voltage, the first constant current and the second constant voltage. The calculation formula is as follows:

[0094]

[0095] Among them, I1 and I2 are the first output instantaneous current and the first constant current respectively, and U1 and U2 are the first output instantaneous voltage and the second constant voltage respectively.

[0096] The first ambient temperature assessment result in the first test result is obtained in the following way:

[0097] The ambient temperature assessment result during the pressure increase is obtained according to the first ambient temperature.

[0098] Through the above calculation method, a first test result of the second bidirectional DC-DC converter cabinet during voltage boosting can be obtained.

[0099] Optionally, the second test parameters include a second input instantaneous current, a second input instantaneous voltage, a second output instantaneous current, a second output instantaneous voltage, and a second ambient temperature, and obtaining a second test result of the first bidirectional DC-DC converter cabinet 1 according to the second test parameters includes:

[0100] A second test result of the first bidirectional DC-DC converter cabinet 1 is obtained according to the second input instantaneous current, the second input instantaneous voltage, the second output instantaneous current, the second output instantaneous voltage and the second ambient temperature. The second test result includes but is not limited to a second power assessment result, a second energy efficiency assessment result, a second current and voltage ripple rate assessment result, a second current and voltage error assessment result and a second ambient temperature assessment result.

[0101] The second test parameters include the second input instantaneous current, the second input instantaneous voltage, the second output instantaneous current, the second output instantaneous voltage and the second ambient temperature. The difference from the first test parameters is that the first test parameters are the parameters collected when the second bidirectional DC-DC converter cabinet is running in boost mode, while the second test parameters are the parameters collected when the first bidirectional DC-DC converter cabinet is running in buck mode. Therefore, in the second test result, the second power assessment result, the second energy efficiency assessment result, the second current and voltage ripple rate assessment result, the second current and voltage error assessment result and the second ambient temperature assessment result are calculated from the second input instantaneous current, the second input instantaneous voltage, the second output instantaneous current, the second output instantaneous voltage and the second ambient temperature. The calculation formula replaces the second test parameter with the first test parameter in the calculation formula of the first test result, which will not be repeated here.

[0102] The second test result of the first bidirectional DC-DC converter cabinet during voltage reduction can be obtained by the same calculation method as the first test result.

[0103] Optionally, the second PWM rectifier cabinet 4 is used to maintain the voltage value of the second end 42 of the second PWM rectifier cabinet 4 at a first constant voltage through a voltage and current dual closed-loop control method.

[0104] The voltage-current dual closed-loop control method is used to control the voltage at the second end 42 of the second PWM rectifier cabinet 4 to be constant. Figure 3 is a circuit diagram of a voltage and current dual closed-loop control method provided by an embodiment of the present invention, such as Figure 3 As shown, the control circuit includes a current inner loop and a voltage outer loop. In the voltage outer loop, U dc_ref is the preset first constant pressure, U dc The measured output voltage feedback value is used. The difference between the two is adjusted by proportional integral (PI) to obtain the charge and discharge current command i of the current inner loop. sc_ref , in the inner current loop, i sc The current deviation value is obtained by subtracting the measured current feedback value, and the modulation wave for PWM modulation is obtained through PI adjustment. Then the PWM modulation module compares the modulation wave with the carrier triangle wave to obtain the control pulse of the switching tube. The actual voltage value is adjusted by the control pulse to stabilize near the preset first constant voltage.

[0105] Optionally, the second bidirectional DC-DC converter cabinet 2 is used to maintain the voltage value of the second end 22 of the second bidirectional DC-DC converter cabinet 2 at a second constant voltage through a voltage and current dual closed-loop control method.

[0106] The voltage and current double closed-loop control mode is used to control the voltage of the second end 22 of the second bidirectional DC-DC converter cabinet 2 to be constant. The voltage and current double closed-loop control mode is the same as that of the second PWM rectifier cabinet, and will not be described in detail.

[0107] Optionally, the first bidirectional DC-DC converter cabinet 1 is used to maintain the current value of the second end 12 of the first bidirectional DC-DC converter cabinet 1 at a first constant current through a current closed-loop control method.

[0108] The current closed-loop control method is used to control the current at the second end 12 of the first bidirectional DC-DC converter cabinet 1 to be constant. Figure 4 is a circuit diagram of a current closed-loop control method provided by an embodiment of the present invention, such as Figure 4 As shown, it includes: the control circuit is a current inner loop, i sc_ref is the preset first constant current, i sc The current deviation value is obtained by subtracting the measured current feedback value, and the modulation wave for PWM modulation is obtained through PI adjustment. Then the PWM modulation module compares the modulation wave with the carrier triangle wave to obtain the control pulse of the switching tube. The actual current value is adjusted by the control pulse to stabilize it near the preset first current.

[0109] Optionally, the first PWM rectifier cabinet 3 is used to maintain the voltage value of the second end 32 of the first PWM rectifier cabinet 3 at a third constant voltage through a voltage and current dual closed-loop control method.

[0110] The voltage-current dual closed-loop control mode is used to control the voltage of the second end 32 of the first PWM rectifier cabinet 3 to be constant. The voltage-current dual closed-loop control mode is the same as that of the second PWM rectifier cabinet, and will not be described in detail.

[0111] Previous Figure 1 The second bidirectional DC-DC converter cabinet 2 operates in the boost mode, the first bidirectional DC-DC converter cabinet 1 operates in the buck mode, the second PWM rectifier cabinet 4 operates in the rectifier mode, and the first PWM rectifier cabinet 3 operates in the inverter mode. In an optional implementation, it also includes:

[0112] The control console 5 is also used to control the first bidirectional DC-DC converter cabinet 1 to operate in a boost mode, control the second bidirectional DC-DC converter cabinet 2 to operate in a buck mode, control the first PWM rectifier cabinet 3 to operate in a rectifier mode, and control the second PWM rectifier cabinet 4 to operate in an inverter mode;

[0113] The console 5 is also used to collect a third test parameter of the first bidirectional DC-DC converter cabinet 1 when operating in a boost mode, and a fourth test parameter of the second bidirectional DC-DC converter cabinet 2 when operating in a buck mode, and obtain a third test result of the first bidirectional DC-DC converter cabinet 1 according to the third test parameter, and obtain a fourth test result of the second bidirectional DC-DC converter cabinet 2 according to the fourth test parameter.

[0114] The current flow process is as follows: first, the first PWM rectifier cabinet operates in the rectifier mode, converting the AC power of the input power supply into DC power, DC voltage V4; second, the first bidirectional DC-DC converter cabinet operates in the boost mode, increasing the DC voltage V4 to DC voltage V5, where V5 is greater than V4; third, the second bidirectional DC-DC converter cabinet operates in the buck mode, converting the DC voltage V5 into DC voltage V6, where V6 is less than V5, and V6 and V4 can be the same or different; finally, the second PWM rectifier cabinet operates in the inverter mode, converting DC power into AC power and feeding it back to the AC power grid. The console further obtains the third test result of the first bidirectional DC-DC converter cabinet when boosting and the fourth test result of the second bidirectional DC-DC converter cabinet when bucking by collecting the test parameters of the first bidirectional DC-DC converter cabinet and the second bidirectional DC-DC converter cabinet. In this embodiment, by combining the first test result and the fourth test result, comprehensive test results of the second bidirectional DC-DC converter cabinet during boosting and bucking can be obtained, and by combining the second test result and the third test result, comprehensive test results of the first bidirectional DC-DC converter cabinet during boosting and bucking can be obtained.

[0115] This embodiment can obtain comprehensive test results of two sets of bidirectional DC-DC converter cabinets during voltage step-up and voltage step-down through only one test process, thereby improving test efficiency.

[0116] Optionally, the third test parameter includes a third input instantaneous current, a third input instantaneous voltage, a third output instantaneous current, a third output instantaneous voltage and a third ambient temperature, and a third test result of the first bidirectional DC-DC converter cabinet 1 is obtained according to the third test parameter, including:

[0117] A third test result of the first bidirectional DC-DC converter cabinet 1 is obtained according to the third input instantaneous current, the third input instantaneous voltage, the third output instantaneous current, the third output instantaneous voltage and the third ambient temperature. The third test result includes but is not limited to a third power assessment result, a third energy efficiency assessment result, a third current and voltage ripple rate assessment result, a third current and voltage error assessment result and a third ambient temperature assessment result.

[0118] The third test parameter includes a third input instantaneous current, a third input instantaneous voltage, a third output instantaneous current, a third output instantaneous voltage and a third ambient temperature. The difference from the first test parameter is that the first test parameter is a parameter collected when the second bidirectional DC-DC converter cabinet is running in boost mode, while the third test parameter is a parameter collected when the first bidirectional DC-DC converter cabinet is running in boost mode. Therefore, in the third test result, the third power assessment result, the third energy efficiency assessment result, the third current and voltage ripple rate assessment result, the third current and voltage error assessment result and the third ambient temperature assessment result are calculated from the third input instantaneous current, the third input instantaneous voltage, the third output instantaneous current, the third output instantaneous voltage and the third ambient temperature. The calculation formula replaces the third test parameter with the first test parameter in the calculation formula of the first test result, and will not be repeated here.

[0119] The third test result of the first bidirectional DC-DC converter cabinet during voltage boosting can be obtained by the same calculation method as the first test result.

[0120] Optionally, the fourth test parameter includes a fourth input instantaneous current, a fourth input instantaneous voltage, a fourth output instantaneous current, a fourth output instantaneous voltage and a fourth ambient temperature, and a fourth test result of the second bidirectional DC-DC converter cabinet 2 is obtained according to the fourth test parameter, including:

[0121] A fourth test result of the second bidirectional DC-DC converter cabinet 2 is obtained according to the fourth input instantaneous current, the fourth input instantaneous voltage, the fourth output instantaneous current, the fourth output instantaneous voltage and the fourth ambient temperature. The fourth test result includes but is not limited to a fourth power assessment result, a fourth energy efficiency assessment result, a fourth current and voltage ripple rate assessment result, a fourth current and voltage error assessment result and a fourth ambient temperature assessment result.

[0122] The fourth test parameter includes the fourth input instantaneous current, the fourth input instantaneous voltage, the fourth output instantaneous current, the fourth output instantaneous voltage and the fourth ambient temperature, and the difference from the first test parameter is that the first test parameter is a parameter collected when the second bidirectional DC-DC converter cabinet is running in boost mode, while the fourth test parameter is a parameter collected when the second bidirectional DC-DC converter cabinet is running in buck mode. Therefore, in the fourth test result, the fourth power assessment result, the fourth energy efficiency assessment result, the fourth current and voltage ripple rate assessment result, the fourth current and voltage error assessment result and the fourth ambient temperature assessment result are calculated from the fourth input instantaneous current, the fourth input instantaneous voltage, the fourth output instantaneous current, the fourth output instantaneous voltage and the fourth ambient temperature. The calculation formula replaces the fourth test parameter with the first test parameter in the calculation formula of the first test result, and will not be repeated here.

[0123] By using the same calculation method as the first test result, a fourth test result of the second bidirectional DC-DC converter cabinet during voltage reduction can be obtained.

[0124] Optionally, the second PWM rectifier cabinet 4 is used to maintain the voltage value of the second end 42 of the second PWM rectifier cabinet 4 at a fourth constant voltage through a voltage and current dual closed-loop control method.

[0125] The fourth constant voltage may be the same as or different from the first constant voltage.

[0126] Optionally, the second bidirectional DC-DC converter cabinet 2 is used to maintain the voltage value of the second end 22 of the second bidirectional DC-DC converter cabinet 2 at a fifth constant voltage through a voltage and current dual closed-loop control method.

[0127] The fifth constant voltage may be the same as or different from the second constant voltage.

[0128] Optionally, the first bidirectional DC-DC converter cabinet 1 is used to maintain the current value of the second end 12 of the first bidirectional DC-DC converter cabinet 1 at a second constant current through a current closed-loop control method.

[0129] The second constant current may be the same as or different from the first constant current.

[0130] Optionally, the first PWM rectifier cabinet 3 is used to maintain the voltage value of the second end 32 of the first PWM rectifier cabinet 3 at a sixth constant voltage through a voltage and current dual closed-loop control method.

[0131] The sixth constant voltage may be the same as or different from the third constant voltage.

[0132] Figure 5 FIG. 1 is a flow chart of a bidirectional DC-DC converter testing method provided by an embodiment of the present invention, such as Figure 5 As shown, the method is applied to a bidirectional DC-DC converter test platform, the test platform includes a first bidirectional DC-DC converter cabinet, a second bidirectional DC-DC converter cabinet, a first PWM rectifier cabinet, a second PWM rectifier cabinet, a console and an input power supply, the method includes:

[0133] S101, the control console sends a first configuration instruction to the second PWM rectifier cabinet, where the first configuration instruction is used to configure the second PWM rectifier cabinet to operate in a rectifier mode.

[0134] S102: The control console sends a second configuration instruction to the second bidirectional DC-DC converter cabinet, where the second configuration instruction is used to configure the second bidirectional DC-DC converter cabinet to operate in a boost mode.

[0135] S103: The console sends a third configuration instruction to the first bidirectional DC-DC converter cabinet, where the third configuration instruction is used to configure the first bidirectional DC-DC converter cabinet to operate in a buck mode.

[0136] S104: The control console sends a fourth configuration instruction to the first PWM rectifier cabinet, where the fourth configuration instruction is used to configure the first PWM rectifier cabinet to operate in an inverter mode.

[0137] S105: The control console sends a first control instruction to the second bidirectional DC-DC converter cabinet, where the first control instruction is used to instruct the second bidirectional DC-DC converter cabinet to start operation.

[0138] S106: The control console sends a second control instruction to the first bidirectional DC-DC converter cabinet, where the second control instruction is used to instruct the first bidirectional DC-DC converter cabinet to start operation.

[0139] S107: The control console sends a third control instruction to the first PWM rectifier cabinet, where the third control instruction is used to instruct the first PWM rectifier cabinet to start operation.

[0140] S108: The control console sends a fourth control instruction to the second PWM rectifier cabinet, where the fourth control instruction is used to instruct the second PWM rectifier cabinet to start operation.

[0141] S109, the console collects a first test parameter of the second bidirectional DC-DC converter cabinet when it operates in boost mode, and a second test parameter of the first bidirectional DC-DC converter cabinet when it operates in buck mode, and obtains a first test result of the second bidirectional DC-DC converter cabinet according to the first test parameter, and obtains a second test result of the first bidirectional DC-DC converter cabinet according to the second test parameter.

[0142] In step S101, the first configuration command instructs the second PWM rectifier cabinet to adopt a voltage-current dual closed-loop control method, inputs a preset output voltage V1 into the voltage-current dual closed-loop control circuit, and after adjustment, the second end of the second PWM rectifier cabinet outputs a DC voltage with a voltage value of V1.

[0143] In step S102, the second configuration command instructs the second bidirectional DC-DC converter cabinet to adopt a voltage-current dual closed-loop control method, and inputs a preset output voltage V2 into the voltage-current dual closed-loop control circuit. After adjustment, the second end of the second bidirectional DC-DC converter cabinet outputs a DC voltage with a voltage value of V2. V2 is greater than V1, that is, it operates in boost mode.

[0144] The output voltage of the second end of the first bidirectional DC-DC converter cabinet is determined by the first PWM rectifier cabinet. In step 104, the fourth configuration command instructs the first PWM rectifier cabinet to adopt a voltage-current dual closed-loop control method, and inputs a preset output voltage V3 into the voltage-current dual closed-loop control circuit. After adjustment, the second end of the first PWM rectifier cabinet outputs a DC voltage with a voltage value of V3. Since the second end of the first PWM rectifier cabinet is connected to the second end of the first bidirectional DC-DC converter, the voltage of the second end of the first bidirectional DC-DC converter is also V3, which is less than V2, that is, it operates in buck mode.

[0145] At the same time, in step S103, the third configuration command instructs the first bidirectional DC-DC converter cabinet to adopt a current closed-loop control method, and inputs a preset output current into the current dual closed-loop control circuit. After adjustment, the first bidirectional DC-DC converter cabinet outputs a constant current. Through the constant current and voltage V3, the system power is controlled to be constant.

[0146] The execution order of steps S101-S104 can be interchanged arbitrarily or can be executed simultaneously.

[0147] Steps S105 to S107 may be executed in any order or simultaneously.

[0148] The current flow process is as follows: first, the second PWM rectifier cabinet operates in the rectifier mode, converting the AC power of the input power supply into DC power, DC voltage V1; second, the second bidirectional DC-DC converter cabinet operates in the boost mode, increasing the DC voltage V1 to the DC voltage V2, wherein V2 is greater than V1; third, the first bidirectional DC-DC converter cabinet operates in the buck mode, converting the DC voltage V2 into the DC voltage V3, wherein V3 is less than V2, and V3 and V1 can be the same or different; finally, the first PWM rectifier cabinet operates in the inverter mode, converting the DC power into AC power and feeding it back to the AC power grid. The console further obtains the first test result of the second bidirectional DC-DC converter cabinet when boosting and the second test result of the first bidirectional DC-DC converter cabinet when bucking by collecting the test parameters of the first bidirectional DC-DC converter cabinet and the second bidirectional DC-DC converter cabinet.

[0149] In this embodiment, the test result of the bidirectional DC-DC converter cabinet when boosting or reducing the voltage can be obtained through only one test process. In addition, the electric energy obtained by the second PWM rectifier cabinet from the input power supply passes through the second bidirectional DC-DC converter cabinet and the first bidirectional DC-DC converter cabinet, and then is fed back to the input power supply through the first PWM rectifier cabinet. The obtained electric energy and the fed-back electric energy offset each other, reducing the requirements for the grid capacity, thereby realizing the assessment test of the large-capacity bidirectional DC-DC converter when boosting or reducing the voltage under limited power supply and load capacity.

[0150] Optionally, the first test parameter includes a first input instantaneous current, a first input instantaneous voltage, a first output instantaneous current, a first output instantaneous voltage and a first ambient temperature, and obtaining a first test result of the second bidirectional DC-DC converter cabinet according to the first test parameter includes:

[0151] A first test result of the second bidirectional DC-DC converter cabinet is obtained according to the first input instantaneous current, the first input instantaneous voltage, the first output instantaneous current, the first output instantaneous voltage and the first ambient temperature. The first test result includes a first power assessment result, a first energy efficiency assessment result, a first current and voltage ripple rate assessment result, a first current and voltage error assessment result and a first ambient temperature assessment result.

[0152] The calculation method of the first power assessment result, the first energy efficiency assessment result, the first current and voltage ripple rate assessment result, the first current and voltage error assessment result and the first ambient temperature assessment result in the first test result is the same as that recorded in the above-mentioned first test result and will not be repeated here.

[0153] By using the above-mentioned calculation method of the first test result, the first test result of the second bidirectional DC-DC converter cabinet during voltage boosting can be obtained.

[0154] Optionally, the second test parameter includes a second input instantaneous current, a second input instantaneous voltage, a second output instantaneous current, a second output instantaneous voltage, and a second ambient temperature, and obtaining a second test result of the first bidirectional DC-DC converter cabinet according to the second test parameter includes:

[0155] A second test result of the first bidirectional DC-DC converter cabinet is obtained according to the second input instantaneous current, the second input instantaneous voltage, the second output instantaneous current, the second output instantaneous voltage and the second ambient temperature. The second test result includes a second power assessment result, a second energy efficiency assessment result, a second current and voltage ripple rate assessment result, a second current and voltage error assessment result and a second ambient temperature assessment result.

[0156] The second test parameters include the second input instantaneous current, the second input instantaneous voltage, the second output instantaneous current, the second output instantaneous voltage and the second ambient temperature. The difference from the first test parameters is that the first test parameters are the parameters collected when the second bidirectional DC-DC converter cabinet is running in boost mode, while the second test parameters are the parameters collected when the first bidirectional DC-DC converter cabinet is running in buck mode. Therefore, in the second test result, the second power assessment result, the second energy efficiency assessment result, the second current and voltage ripple rate assessment result, the second current and voltage error assessment result and the second ambient temperature assessment result are calculated from the second input instantaneous current, the second input instantaneous voltage, the second output instantaneous current, the second output instantaneous voltage and the second ambient temperature. The calculation formula can be calculated by replacing the second test parameter with the first test parameter in the calculation formula of the first test result, which will not be repeated here.

[0157] The second test result of the first bidirectional DC-DC converter cabinet during voltage reduction can be obtained by the same calculation method as the first test result.

[0158] Optionally, the first configuration instruction is further used to configure the second PWM rectifier cabinet to maintain the voltage value of the second end of the second PWM rectifier cabinet at a first constant voltage through a voltage and current dual closed-loop control method.

[0159] The voltage-current dual closed-loop control method is used to control the voltage of the second end 42 of the second PWM rectifier cabinet 4 to be constant. The voltage-current dual closed-loop control method is the same as that of the aforementioned second PWM rectifier cabinet, and will not be described in detail.

[0160] Optionally, the second configuration instruction is further used to configure the second bidirectional DC-DC converter cabinet to maintain the voltage value of the second end of the second bidirectional DC-DC converter cabinet at a second constant voltage through a voltage-current dual closed-loop control method.

[0161] The voltage and current double closed-loop control mode is used to control the voltage of the second end 22 of the second bidirectional DC-DC converter cabinet 2 to be constant. The voltage and current double closed-loop control mode is the same as that of the second PWM rectifier cabinet, and will not be described in detail.

[0162] Optionally, the third configuration instruction is further used to configure the first bidirectional DC-DC converter cabinet to maintain the current value of the second end of the first bidirectional DC-DC converter cabinet at a first constant current through a current closed-loop control method.

[0163] The current closed-loop control method is used to control the current of the second end 12 of the first bidirectional DC-DC converter cabinet 1 to be constant. The current closed-loop control method is the same as that of the first bidirectional DC-DC converter cabinet, and will not be described in detail.

[0164] Optionally, the fourth configuration instruction is further used to configure the first PWM rectifier cabinet to maintain the voltage value of the second end of the first PWM rectifier cabinet at a third constant voltage through a voltage and current dual closed-loop control method.

[0165] The voltage-current dual closed-loop control mode is used to control the voltage of the second end 32 of the first PWM rectifier cabinet 3 to be constant. The voltage-current dual closed-loop control mode is the same as that of the second PWM rectifier cabinet described above, and will not be described in detail.

[0166] Figure 6 Another bidirectional DC-DC converter testing method provided by an embodiment of the present invention is Figure 5 On the basis of Figure 6 As shown, it also includes:

[0167] S201: The control console sends a fifth configuration instruction to the first PWM rectifier cabinet, where the fifth configuration instruction is used to configure the first PWM rectifier cabinet to operate in a rectifier mode.

[0168] S202: The console sends a sixth configuration instruction to the first bidirectional DC-DC converter cabinet, where the sixth configuration instruction is used to configure the first bidirectional DC-DC converter cabinet to operate in a boost mode.

[0169] S203: The console sends a seventh configuration instruction to the second bidirectional DC-DC converter cabinet, where the seventh configuration instruction is used to configure the second bidirectional DC-DC converter cabinet to operate in a buck mode.

[0170] S204: The console sends an eighth configuration instruction to the second PWM rectifier cabinet, where the eighth configuration instruction is used to configure the second PWM rectifier cabinet to operate in an inverter mode.

[0171] S205: The control console sends a fifth control instruction to the first bidirectional DC-DC converter cabinet, where the fifth control instruction is used to instruct the first bidirectional DC-DC converter cabinet to start operation.

[0172] S206: The control console sends a sixth control instruction to the second bidirectional DC-DC converter cabinet, where the sixth control instruction is used to instruct the second bidirectional DC-DC converter cabinet to start running.

[0173] S207: The control console sends a seventh control instruction to the second PWM rectifier cabinet, where the seventh control instruction is used to instruct the second PWM rectifier cabinet to start operation.

[0174] S208: The control console sends an eighth control instruction to the first PWM rectifier cabinet, where the eighth control instruction is used to instruct the first PWM rectifier cabinet to start operation.

[0175] S209, the console collects a third test parameter of the first bidirectional DC-DC converter cabinet when operating in boost mode, and a fourth test parameter of the second bidirectional DC-DC converter cabinet when operating in buck mode, and obtains a third test result of the first bidirectional DC-DC converter cabinet according to the third test parameter, and obtains a fourth test result of the second bidirectional DC-DC converter cabinet according to the fourth test parameter.

[0176] In step S201, the fifth configuration command instructs the first PWM rectifier cabinet to adopt a voltage-current dual closed-loop control method, inputs a preset output voltage V4 into the voltage-current dual closed-loop control circuit, and after adjustment, the second end of the first PWM rectifier cabinet outputs a DC voltage with a voltage value of V4.

[0177] In step S202, the sixth configuration command instructs the first bidirectional DC-DC converter cabinet to adopt a voltage-current dual closed-loop control method, and inputs a preset output voltage V5 into the voltage-current dual closed-loop control circuit. After adjustment, the second end of the first bidirectional DC-DC converter cabinet outputs a DC voltage with a voltage value of V5. V5 is greater than V4, that is, it operates in boost mode.

[0178] The output voltage of the second end of the second bidirectional DC-DC converter cabinet is determined by the second PWM rectifier cabinet. In step S204, the eighth configuration command instructs the second PWM rectifier cabinet to adopt a voltage-current dual closed-loop control method, and inputs a preset output voltage V6 into the voltage-current dual closed-loop control circuit. After adjustment, the second end of the second PWM rectifier cabinet outputs a DC voltage with a voltage value of V6. Since the second end of the second PWM rectifier cabinet is connected to the second end of the second bidirectional DC-DC converter, the voltage of the second end of the second bidirectional DC-DC converter is also V6, which is less than V5, that is, it operates in buck mode.

[0179] At the same time, in step S203, the seventh configuration command instructs the second bidirectional DC-DC converter cabinet to adopt a current closed-loop control method, and inputs the preset output current into the current dual closed-loop control circuit. After adjustment, the second bidirectional DC-DC converter cabinet outputs a constant current. Through the constant current and voltage V6, the system power is controlled to be constant.

[0180] The execution order of steps S201-S204 can be interchanged arbitrarily or can be executed simultaneously.

[0181] Steps S205 - S207 may be executed in any order or simultaneously.

[0182] The current flow process is as follows: first, the first PWM rectifier cabinet operates in the rectifier mode, converting the AC power of the input power supply into DC power, DC voltage V4; second, the first bidirectional DC-DC converter cabinet operates in the boost mode, increasing the DC voltage V4 to DC voltage V5, wherein V5 is greater than V4 by 2; third, the second bidirectional DC-DC converter cabinet operates in the buck mode, converting the DC voltage V5 into DC voltage V6, wherein V6 is less than V5, and V6 and V4 can be the same or different; finally, the second PWM rectifier cabinet operates in the inverter mode, converting DC power into AC power and feeding it back to the AC power grid. The console further obtains the third test result of the first bidirectional DC-DC converter cabinet when boosting and the fourth test result of the second bidirectional DC-DC converter cabinet when bucking by collecting the test parameters of the first bidirectional DC-DC converter cabinet and the second bidirectional DC-DC converter cabinet. In this embodiment, by combining the first test result and the fourth test result, comprehensive test results of the second bidirectional DC-DC converter cabinet during boosting and bucking can be obtained, and by combining the second test result and the third test result, comprehensive test results of the first bidirectional DC-DC converter cabinet during boosting and bucking can be obtained.

[0183] This embodiment can obtain comprehensive test results of two sets of bidirectional DC-DC converter cabinets during voltage step-up and voltage step-down through only one test process, thereby improving test efficiency.

[0184] Optionally, the third test parameter includes a third input instantaneous current, a third input instantaneous voltage, a third output instantaneous current, a third output instantaneous voltage and a third ambient temperature, and a third test result of the first bidirectional DC-DC converter cabinet 1 is obtained according to the third test parameter, including:

[0185] A third test result of the first bidirectional DC-DC converter cabinet 1 is obtained according to the third input instantaneous current, the third input instantaneous voltage, the third output instantaneous current, the third output instantaneous voltage and the third ambient temperature. The third test result includes but is not limited to a third power assessment result, a third energy efficiency assessment result, a third current and voltage ripple rate assessment result, a third current and voltage error assessment result and a third ambient temperature assessment result.

[0186] The third test parameter includes a third input instantaneous current, a third input instantaneous voltage, a third output instantaneous current, a third output instantaneous voltage and a third ambient temperature. The difference from the first test parameter is that the first test parameter is a parameter collected when the second bidirectional DC-DC converter cabinet is running in boost mode, while the third test parameter is a parameter collected when the first bidirectional DC-DC converter cabinet is running in boost mode. Therefore, in the third test result, the third power assessment result, the third energy efficiency assessment result, the third current and voltage ripple rate assessment result, the third current and voltage error assessment result and the third ambient temperature assessment result are calculated from the third input instantaneous current, the third input instantaneous voltage, the third output instantaneous current, the third output instantaneous voltage and the third ambient temperature. The calculation formula replaces the third test parameter with the first test parameter in the calculation formula of the first test result, and will not be repeated here.

[0187] The third test result of the first bidirectional DC-DC converter cabinet during voltage boosting can be obtained by the same calculation method as the first test result.

[0188] Optionally, the fourth test parameter includes a fourth input instantaneous current, a fourth input instantaneous voltage, a fourth output instantaneous current, a fourth output instantaneous voltage and a fourth ambient temperature, and a fourth test result of the second bidirectional DC-DC converter cabinet 2 is obtained according to the fourth test parameter, including:

[0189] A fourth test result of the second bidirectional DC-DC converter cabinet 2 is obtained according to the fourth input instantaneous current, the fourth input instantaneous voltage, the fourth output instantaneous current, the fourth output instantaneous voltage and the fourth ambient temperature. The fourth test result includes but is not limited to a fourth power assessment result, a fourth energy efficiency assessment result, a fourth current and voltage ripple rate assessment result, a fourth current and voltage error assessment result and a fourth ambient temperature assessment result.

[0190] The fourth test parameter includes the fourth input instantaneous current, the fourth input instantaneous voltage, the fourth output instantaneous current, the fourth output instantaneous voltage and the fourth ambient temperature, and the difference from the first test parameter is that the first test parameter is a parameter collected when the second bidirectional DC-DC converter cabinet is running in boost mode, while the fourth test parameter is a parameter collected when the second bidirectional DC-DC converter cabinet is running in buck mode. Therefore, in the fourth test result, the fourth power assessment result, the fourth energy efficiency assessment result, the fourth current and voltage ripple rate assessment result, the fourth current and voltage error assessment result and the fourth ambient temperature assessment result are calculated from the fourth input instantaneous current, the fourth input instantaneous voltage, the fourth output instantaneous current, the fourth output instantaneous voltage and the fourth ambient temperature. The calculation formula replaces the fourth test parameter with the first test parameter in the calculation formula of the first test result, and will not be repeated here.

[0191] By using the same calculation method as the first test result, a fourth test result of the second bidirectional DC-DC converter cabinet during voltage reduction can be obtained.

[0192] Optionally, the second PWM rectifier cabinet 4 is used to maintain the voltage value of the second end 42 of the second PWM rectifier cabinet 4 at a fourth constant voltage through a voltage and current dual closed-loop control method.

[0193] The fourth constant voltage may be the same as or different from the first constant voltage.

[0194] Optionally, the second bidirectional DC-DC converter cabinet 2 is used to maintain the voltage value of the second end 22 of the second bidirectional DC-DC converter cabinet 2 at a fifth constant voltage through a voltage and current dual closed-loop control method.

[0195] The fifth constant voltage may be the same as or different from the second constant voltage.

[0196] Optionally, the first bidirectional DC-DC converter cabinet 1 is used to maintain the current value of the second end 12 of the first bidirectional DC-DC converter cabinet 1 at a second constant current through a current closed-loop control method.

[0197] The second constant current may be the same as or different from the first constant current.

[0198] Optionally, the first PWM rectifier cabinet 3 is used to maintain the voltage value of the second end 32 of the first PWM rectifier cabinet 3 at a sixth constant voltage through a voltage and current dual closed-loop control method.

[0199] The sixth constant voltage may be the same as or different from the third constant voltage.

[0200] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0201] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bidirectional DC-DC converter test platform, characterized in that: It includes a first bidirectional DC-DC converter cabinet, a second bidirectional DC-DC converter cabinet, a first PWM rectifier cabinet, a second PWM rectifier cabinet, a control console and an input power supply; The input power supply is connected to the first end of the first PWM rectifier cabinet and the first end of the second PWM rectifier cabinet respectively; The second end of the second PWM rectifier cabinet is connected to the first end of the second bidirectional DC-DC converter cabinet, the second end of the second bidirectional DC-DC converter cabinet is connected to the first end of the first bidirectional DC-DC converter cabinet, and the second end of the first bidirectional DC-DC converter cabinet is connected to the second end of the first PWM rectifier cabinet; The console is connected to the first bidirectional DC-DC converter cabinet, the second bidirectional DC-DC converter cabinet, the first PWM rectifier cabinet and the second PWM rectifier cabinet respectively, and the console is used to control the second bidirectional DC-DC converter cabinet to operate in a boost mode, control the first bidirectional DC-DC converter cabinet to operate in a buck mode, control the second PWM rectifier cabinet to operate in a rectifier mode, and control the first PWM rectifier cabinet to operate in an inverter mode; The console is also used to collect a first test parameter of the second bidirectional DC-DC converter cabinet when it operates in a boost mode, and a second test parameter of the first bidirectional DC-DC converter cabinet when it operates in a buck mode, and obtain a first test result of the second bidirectional DC-DC converter cabinet according to the first test parameter, and obtain a second test result of the first bidirectional DC-DC converter cabinet according to the second test parameter; The second PWM rectifier cabinet is used to maintain the voltage value of the second end of the second PWM rectifier cabinet at a first constant voltage through a voltage and current dual closed-loop control method; The second bidirectional DC-DC converter cabinet is used to maintain the voltage value of the second end of the second bidirectional DC-DC converter cabinet at a second constant voltage through a voltage and current dual closed-loop control method.

2. The test platform according to claim 1, characterized in that: The input power source includes a low-voltage power grid, a low-voltage power distribution cabinet and an isolation transformer, and the input power source is used to provide power to the first PWM rectifier cabinet and the second PWM rectifier cabinet.

3. The test platform according to claim 2, characterized in that: The isolation transformer is a three-winding transformer; The input power supply is connected to the first end of the first PWM rectifier cabinet and the first end of the second PWM rectifier cabinet respectively, comprising: The first end of the first PWM rectifier cabinet and the first end of the second PWM rectifier cabinet are respectively connected to the two windings on the secondary side of the isolation transformer.

4. The test platform according to claim 1, characterized in that: The first test parameters include a first input instantaneous current, a first input instantaneous voltage, a first output instantaneous current, a first output instantaneous voltage and a first ambient temperature, and obtaining a first test result of the second bidirectional DC-DC converter cabinet according to the first test parameters includes: A first test result of the second bidirectional DC-DC converter cabinet is obtained according to the first input instantaneous current, the first input instantaneous voltage, the first output instantaneous current, the first output instantaneous voltage and the first ambient temperature, wherein the first test result includes a first power assessment result, a first energy efficiency assessment result, a first current and voltage ripple rate assessment result, a first current and voltage error assessment result and a first ambient temperature assessment result.

5. The test platform according to claim 1, characterized in that: The second test parameters include a second input instantaneous current, a second input instantaneous voltage, a second output instantaneous current, a second output instantaneous voltage, and a second ambient temperature. The second test result of the first bidirectional DC-DC converter cabinet obtained according to the second test parameters includes: A second test result of the first bidirectional DC-DC converter cabinet is obtained according to the second input instantaneous current, the second input instantaneous voltage, the second output instantaneous current, the second output instantaneous voltage and the second ambient temperature, and the second test result includes a second power assessment result, a second energy efficiency assessment result, a second current and voltage ripple rate assessment result, a second current and voltage error assessment result and a second ambient temperature assessment result.

6. The test platform according to claim 1, characterized in that: The first bidirectional DC-DC converter cabinet is used to maintain the current value at the second end of the first bidirectional DC-DC converter cabinet at a first constant current through a current closed-loop control method.

7. The test platform according to claim 1, characterized in that: The first PWM rectifier cabinet is used to maintain the voltage value of the second end of the first PWM rectifier cabinet at a third constant voltage through a voltage and current dual closed-loop control method.

8. The test platform according to any one of claims 1 to 7, characterized in that: Also includes: The control console is further used to control the first bidirectional DC-DC converter cabinet to operate in a boost mode, control the second bidirectional DC-DC converter cabinet to operate in a buck mode, control the first PWM rectifier cabinet to operate in a rectifier mode, and control the second PWM rectifier cabinet to operate in an inverter mode; The console is also used to collect a third test parameter of the first bidirectional DC-DC converter cabinet when operating in a boost mode, and a fourth test parameter of the second bidirectional DC-DC converter cabinet when operating in a buck mode, and obtain a third test result of the first bidirectional DC-DC converter cabinet according to the third test parameter, and obtain a fourth test result of the second bidirectional DC-DC converter cabinet according to the fourth test parameter.

9. A bidirectional DC-DC converter testing method, characterized in that: The method is applied to a bidirectional DC-DC converter test platform, the platform comprising a first bidirectional DC-DC converter cabinet, a second bidirectional DC-DC converter cabinet, a first PWM rectifier cabinet, a second PWM rectifier cabinet, a console and an input power supply, and the method comprises: The console sends a first configuration instruction to the second PWM rectifier cabinet, where the first configuration instruction is used to configure the second PWM rectifier cabinet to operate in a rectifier mode; The console sends a second configuration instruction to the second bidirectional DC-DC converter cabinet, where the second configuration instruction is used to configure the second bidirectional DC-DC converter cabinet to operate in a boost mode; The console sends a third configuration instruction to the first bidirectional DC-DC converter cabinet, where the third configuration instruction is used to configure the first bidirectional DC-DC converter cabinet to operate in a buck mode; The console sends a fourth configuration instruction to the first PWM rectifier cabinet, where the fourth configuration instruction is used to configure the first PWM rectifier cabinet to operate in an inverter mode; The control console sends a first control instruction to the second bidirectional DC-DC converter cabinet, where the first control instruction is used to instruct the second bidirectional DC-DC converter cabinet to start operation; The control console sends a second control instruction to the first bidirectional DC-DC converter cabinet, where the second control instruction is used to instruct the first bidirectional DC-DC converter cabinet to start operation; The control console sends a third control instruction to the first PWM rectifier cabinet, where the third control instruction is used to instruct the first PWM rectifier cabinet to start operation; The control console sends a fourth control instruction to the second PWM rectifier cabinet, where the fourth control instruction is used to instruct the second PWM rectifier cabinet to start operation; The console collects a first test parameter of the second bidirectional DC-DC converter cabinet when operating in a boost mode, and a second test parameter of the first bidirectional DC-DC converter cabinet when operating in a buck mode, and obtains a first test result of the second bidirectional DC-DC converter cabinet according to the first test parameter, and obtains a second test result of the first bidirectional DC-DC converter cabinet according to the second test parameter; The first configuration instruction is further used to configure the second PWM rectifier cabinet to maintain the voltage value of the second end of the second PWM rectifier cabinet at a first constant voltage through a voltage and current dual closed-loop control method; The second configuration instruction is also used to configure the second bidirectional DC-DC converter cabinet to maintain the voltage value of the second end of the second bidirectional DC-DC converter cabinet at a second constant voltage through a voltage and current dual closed-loop control method.

10. The testing method according to claim 9, characterized in that: The first test parameters include a first input instantaneous current, a first input instantaneous voltage, a first output instantaneous current, a first output instantaneous voltage and a first ambient temperature, and obtaining a first test result of the second bidirectional DC-DC converter cabinet according to the first test parameters includes: A first test result of the second bidirectional DC-DC converter cabinet is obtained according to the first input instantaneous current, the first input instantaneous voltage, the first output instantaneous current, the first output instantaneous voltage and the first ambient temperature, wherein the first test result includes a first power assessment result, a first energy efficiency assessment result, a first current and voltage ripple rate assessment result, a first current and voltage error assessment result and a first ambient temperature assessment result.

11. The testing method according to claim 9, characterized in that: The second test parameters include a second input instantaneous current, a second input instantaneous voltage, a second output instantaneous current, a second output instantaneous voltage, and a second ambient temperature. The second test result of the first bidirectional DC-DC converter cabinet obtained according to the second test parameters includes: A second test result of the first bidirectional DC-DC converter cabinet is obtained based on the second input instantaneous current, the second input instantaneous voltage, the second output instantaneous current, the second output instantaneous voltage and the second ambient temperature, and the second test result includes a second power assessment result, a second energy efficiency assessment result, a second current and voltage ripple rate assessment result, a second current and voltage error assessment result and a second ambient temperature assessment result.

12. The testing method according to claim 9, characterized in that: The third configuration instruction is further used to configure the first bidirectional DC-DC converter cabinet to maintain the current value of the second end of the first bidirectional DC-DC converter cabinet at a first constant current through a current closed-loop control method.

13. The testing method according to claim 9, characterized in that: The fourth configuration instruction is further used to configure the first PWM rectifier cabinet to maintain the voltage value of the second end of the first PWM rectifier cabinet at a third constant voltage through a voltage and current dual closed-loop control method.

14. The testing method according to any one of claims 9 to 13, characterized in that: Also includes: The console sends a fifth configuration instruction to the first PWM rectifier cabinet, where the fifth configuration instruction is used to configure the first PWM rectifier cabinet to operate in a rectifier mode; The console sends a sixth configuration instruction to the first bidirectional DC-DC converter cabinet, where the sixth configuration instruction is used to configure the first bidirectional DC-DC converter cabinet to operate in a boost mode; The console sends a seventh configuration instruction to the second bidirectional DC-DC converter cabinet, where the seventh configuration instruction is used to configure the second bidirectional DC-DC converter cabinet to operate in a buck mode; The control console sends an eighth configuration instruction to the second PWM rectifier cabinet, where the eighth configuration instruction is used to configure the second PWM rectifier cabinet to operate in an inverter mode; The console sends a fifth control instruction to the first bidirectional DC-DC converter cabinet, where the fifth control instruction is used to instruct the first bidirectional DC-DC converter cabinet to start operation; The console sends a sixth control instruction to the second bidirectional DC-DC converter cabinet, where the sixth control instruction is used to instruct the second bidirectional DC-DC converter cabinet to start operation; The control console sends a seventh control instruction to the second PWM rectifier cabinet, where the seventh control instruction is used to instruct the second PWM rectifier cabinet to start operation; The control console sends an eighth control instruction to the first PWM rectifier cabinet, where the eighth control instruction is used to instruct the first PWM rectifier cabinet to start operation; The console collects a third test parameter of the first bidirectional DC-DC converter cabinet when operating in a boost mode, and a fourth test parameter of the second bidirectional DC-DC converter cabinet when operating in a buck mode, and obtains a third test result of the first bidirectional DC-DC converter cabinet according to the third test parameter, and obtains a fourth test result of the second bidirectional DC-DC converter cabinet according to the fourth test parameter.

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